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Nutrient Glossary

Nutrient Glossary

Nutrient Glossary

ScienceBased Health nutritional formulations are manufactured according to the highest quality standards and are made from the finest quality, most bioavailable ingredients, including pharmaceutical grade components wherever available. To view information on a particular nutrient, click on a link below. To view an animated tour of ScienceBased Health products and to learn how they work, view our interactive guide


Vitamin A

Vitamin A occurs in several forms. Pre-formed vitamin A is the simple form of vitamin A. Beta-carotene can also be a source of vitamin A, but is converted into vitamin A only as required by the body. Vitamin A protects night vision and is vital for the health of the eye's cornea. It also interacts with zinc and the amino acid taurine within the photoreceptors of the retina. Vitamin A is required for the manufacture of mucin, an important component of the innermost layer of the eye's tear film.


Amount of vitamin A (per day) in selected ScienceBased Health products:

Dry Eye Relief

HydroEye provides 2,080 IU (from retinyl palmitate)

Multinutrient Protection for Eyes & Body

OcularProtect provides 5,000 IU (from retinyl palmitate, beta-carotene & mixed carotenoids)


Alpha Lipoic Acid

Alpha lipoic acid is a versatile fat and water-soluble antioxidant that can scavenge free radicals and help recharge other antioxidants, such as glutathione and vitamin C. It is an important antioxidant in nerve tissue, and experimental evidence suggests that it may help protect the retina against oxidative stress.


Amount of alpha lipoic (per day) in selected ScienceBased Health products:

Multinutrient Protection for Eyes & Body

OcularProtect provides 20 mg

Protection for Macular Health

MacularProtect Complete AREDS2 provides 20 mg


B-Vitamins

Folic acid, B6 and B12 have been shown to reduce artery-damaging levels of homocysteine in the body, thus helping to retain normal cardiovascular function (elevated levels of homocysteine have also been implicated in other chronic diseases such as Alzheimer's and diabetes). Additionally, folic acid has been found to play an important role in colon health.


Amounts of B-vitamins (per day) in selected ScienceBased Health products:

Dry Eye Relief

HydroEye provides:

  • 12.6 mg of vitamin B6

Multinutrient Protection for Eyes & Body

OcularProtect provides:

  • 400 mcg of folic acid
  • 20 mg of vitamin B6
  • 50 mcg of vitamin B12

Protection for Macular Health

MacularProtect Complete AREDS2 provides:

  • 400 mcg of folic acid
  • 10 mg of vitamin B6
  • 30 mcg of vitamin B12


Beta-Carotene

Beta-carotene functions primarily as a fat-soluble antioxidant. It can also be converted to vitamin A as needed by the body.


Amount of beta-carotene (per day) in selected ScienceBased Health products:

Multinutrient Protection for Eyes & Body

OcularProtect provides 2,250 IU

Protection for Macular Health

MacularProtect Complete AREDS2 provides 25,000 IU


Vitamin C

Vitamin C is the major water-soluble antioxidant concentrated in the ocular tissues, especially the lens. Found to play an important role in protecting macular health, research also shows that long-term intake of supplemental vitamin C, at levels of 240-360 mg per day, can significantly decrease the odds of developing age-related clouding of the central portion of the eye's lens. In addition, vitamin C is the most abundant water-soluble antioxidant in tear fluid, where it acts to neutralize free radicals and helps recharge the antioxidant vitamin E.


Amount of vitamin C (per day) in selected ScienceBased Health products:

Dry Eye Relief

HydroEye provides 180 mg

Multinutrient Protection for Eyes & Body

OcularProtect provides 400 mg

Protection for Macular Health

MacularProtect Complete AREDS2 provides 1,000 mg


Copper

Copper is a mineral that is necessary for the function of an antioxidant enzyme. It is also needed to produce connective tissue, nerve sheaths, skin pigment, and for the proper utilization of iron.

Amount of copper (per day) in selected ScienceBased Health products:

Multinutrient Protection for Eyes & Body

OcularProtect provides 2.5 mg

Protection for Macular Health

MacularProtect Complete AREDS2 provides 2 mg


Vitamin D

Generated in the body from sunlight, Vitamin D helps calcium absorption, has important effects on the immune system, and may provide cardiovascular benefits. Research shows that vitamin D may be even more critical than calcium for maintaining bone health in older people. Other research shows a potential link between vitamin D and decreased risk of breast, prostate and colon cancers.

There is growing scientific consensus that increasing vitamin D intake well beyond the RDI of 400 IU, may have significant health benefits. ScienceBased Health products that include a multinutrient now feature 800-900 IU of vitamin D - a safe level that brings most people into what many experts now consider to be the optimal intake range, when combined with a typical calcium supplement. Read more


Amount of vitamin D (per day) in selected ScienceBased Health products:

Multinutrient Protection for Eyes & Body

  • OcularProtect provides 900 IU
  • OcularEssentials provides 800 IU

Protection for Macular Health

  • MacularProtect Complete AREDS2 and MacularProtect Complete-S each provide 900 IU


Vitamin E

Vitamin E, a fat-soluble vitamin, protects cell membranes against free radical attack. Several studies have consistently found that higher vitamin E intakes or blood levels may improve one's chance of prolonging lens and macular health with advancing age. Vitamin E has also been shown to boost immune function in older individuals. ScienceBased Health formulations utilize natural source vitamin E, which research has found to be better absorbed and retained in the tissues.


Amount of vitamin E (per day) in selected ScienceBased Health products:

Multinutrient Protection for Eyes & Body

OcularProtect provides 200 IU

Protection for Macular Health

MacularProtect Complete AREDS2 provides 400 IU


Flavonoids

Flavonoids (Lemon, Quercetin, Ginkgo biloba, Bilberry, Grape Seed, Green Tea, OptiBerry® Mixed Berry Blend, Trans-Resveratrol, Pine Bark Extract)

Functioning as antioxidants, flavonoids support healthy circulation by protecting vessel walls in the body and the eyes from free radical damage. Evidence continues to build in support of the role of flavonoids in the prevention of age-related conditions associated with oxidative stress. Flavonoids are believed to contribute to the health benefits of eating 5 or more fruit and vegetable servings daily.


Amount of flavonoids (per day) in selected ScienceBased Health products:

Multinutrient Protection for Eyes & Body

OcularProtect provides:

  • Lemon Bioflavonoids: 175 mg
  • Quercetin: 50 mg
  • Ginkgo Leaf Extract: 40 mg
  • Bilberry Fruit Extract: 15 mg
  • Grape seed Extract: 30 mg
  • Green Tea Extract: 50 mg
  • OptiBerry® Mixed Berry Blend: 20 mg
  • Trans-Resveratrol: 2.5 mg

OcularEssentials provides:

  • Quercetin: 50 mg
  • Bilberry Fruit Extract: 30 mg
  • Trans-Resveratrol: 1.25 mg

MacularProtect Complete AREDS2 and MacularProtect Complete-S provide:

  • Lemon Bioflavonoids: 50 mg
  • Quercetin: 20 mg
  • Ginkgo Leaf Extract: 20 mg
  • Bilberry Fruit Extract: 15 mg
  • Grape seed Extract: 15 mg
  • OptiBerry® Mixed Berry Blend: 20 mg
  • Trans-Resveratrol: 1.25 mg


FloraGLO® Lutein and Zeaxanthin

Lutein and zeaxanthin are two similarly structured carotenoids that make up the macular pigment in the retina and help protect against damaging blue (visible) light. Research has linked lutein intake levels of 6-10 mg per day with a better chance of maintaining macular health. ScienceBased Health formulations utilize FloraGLO® lutein, a premium source with proven bioavailability.

Read more about Lutein & Zeaxanthin

Read or listen to an interview with ScienceBased Health Science Advisory Board Member, Paul S. Bernstein, MD, PhD on the role of lutein in macular health.


Amount of lutein & zeaxanthin (per day) in selected ScienceBased Health products:

Multinutrient Protection for Eyes & Body

OcularProtect provides:

  • Lutein: 7 mg
  • Zeaxanthin: 1 mg

Protection for Macular Health

MacularProtect Complete AREDS2 provides:

  • Lutein: 10 mg
  • Zeaxanthin: 1 mg


GLA (Gamma Linolenic Acid)

GLA, a unique and specialized omega-6 fatty acid, is found only in ultra trace amounts in the diet. GLA can be converted to the anti-inflammatory prostaglandin, PGE1, which supports normal tear secretion. Clinical studies report that GLA reduces symptoms and calms inflammation in people with dry eye and improves symptoms and increases tear production in people undergoing corrective laser procedures . It also reduces symptoms and increases anti-inflammatory prostaglandin levels in those with Sjögren’s syndrome.

  • Featured interview: John D. Sheppard, MD and Stephen C. Pflugfelder, MD on new developments in dry eye treatment and diagnosis
  • GLA: A Safe & Effective Anti-Inflammatory Omega-6 Fatty Acid
  • Inflammation: Friend and Foe

    The acute inflammatory response defends against invading microorganisms and damaged cells, and is essential for wound healing & tissue repair. Chronic inflammation, however, damages tissues and can lead to or worsen chronic diseases such as arthritis, heart disease & dry eye syndrome.

    GLA as an Anti-Inflammatory Nutrient

    A recent review underscores the role of the fatty acid gamma linolenic acid (GLA) in modulating the inflammatory response (1). GLA has gained recognition over the last few decades for its anti-inflammatory and anti-cancer actions. Some key findings from controlled clinical trials include:

    • In arthritics, several trials report that GLA reduced inflammation, symptoms, and the requirement for NSAIDs
    • In inflammatory dry eye, GLA improved symptoms and reduced inflammation; in PRK patients, GLA relieved symptoms, and increased tear production and clearance; in Sjögren's patients, GLA eased ocular discomfort by reducing inflammation and increasing tear content of PGE1
    • In diabetics, GLA improved nerve conduction velocity leading to improved blood flow and reduced tingling of extremities
    • In patients with acute lung injury, GLA along with EPA improved gaseous exchange
    • In breast cancer patients, GLA improved the effectiveness of tamoxifen, reduced side-effects, and hastened therapeutic response
    • In uremic pruiritis, a common problem in hemodialysis patients, topically applied GLA relieved symptoms

    Sources & Rationale for Supplementation

    Dietary intake of GLA is typically negligible as GLA is present only in trace amounts in some green leafy vegetables and nuts. Supplemental sources include the oils of: borage (Borage officinalis), 20-26% GLA; black currant (Ribes nigrum), 15-18%; and evening primrose (Oenoethera biennis), 8-12%. According to Tufts researchers, black currant seed oil is a preferred source because it contains 13-16% of the omega-3 fatty acid alpha-linolenic as well as GLA. Examining the effects of black currant seed oil (vs. placebo) in healthy elderly subjects, researchers from Tufts found that GLA reduced levels of PGE2 and improved immune function (2).

    GLA is produced in the body as an intermediate in the metabolism of linoleic acid (LA). However this reaction is very slow and further restricted by alcohol use, stress, smoking, saturated and trans-fatty acid intake, and deficiencies of magnesium, vitamin B6 and zinc. These factors - as well as hypertension, arthritis, psoriasis and diabetes - impair the activity of delta-6-desaturase, the enzyme that converts linoleic acid to GLA. Administering oral GLA is a means to bypass this often inefficient and rate-limiting step in the metabolism of LA to GLA.

    Anti-Inflammatory Mechanism of Action

    GLA is rapidly converted to dihomo GLA (DGLA) which is incorporated into cell membrane phospholipids. When released by the action of the enzyme phospholipase A2, DGLA competes with arachidonic acid for the enzymes COX and LOX. Arachidonic acid is the omega-6 found abundantly in meat and dairy, and the precursor to pro-inflammatory eicosinoids like PGE2.

    The COX products of DGLA include prostaglandins of series 1 (PGE1) and thromboxane A1. These products exert anti-inflammatory, anti-aggregation and vaso-dilatory actions.

    A key LOX product of DGLA, 15-HETrE, inhibits production of leukotriene B4 from inflammatory cells including neutrophils. Some research suggests that DGLA may act directly on T-cells to modulate immune response in diseases such as rheumatoid arthritis.

    Anti-Cancer Mechanisms of Action

    Pre-clinical research indicates that the anti-cancer properties of GLA include: direct cytotoxic action on cancer cells, anti-angiogenic action in tumor cells, stimulation of apoptosis, gene activation, and the effects of DGLA eicosinoids. Preliminary clinical studies suggest that GLA may have benefit in some cancers. GLA injected directly into tumor cells of patients with advanced glioma significantly reduced tumor mass.

    Safety of Supplemental GLA

    Supplemental GLA has been safely administered in clinical trials at oral doses of 2.8 grams per day or less, for up to a year (3-5). GLA-rich oils have also been commonly used in the U.S. for over 20 years, with no reports of serious adverse events or effects (6).

    Americans, who generally obtain an excess of omega-6 fats through over-consumption of meat, dairy, vegetable cooking oils and shortenings, are advised to consume more omega-3s from fatty fish and nuts. The amount of omega-6 fatty acids present in common doses of GLA-rich oil do not make a significant contribution to overall fat intake - typically about 67 grams daily for a 2000 kcal diet with 30% of calories from fats. Further, black currant seed oil contains a recommended ratio of omega-6 to omega-3 fats.

    GLA & EPA: Complementary Actions

    One concern related to DGLA, is that it could be further metabolized to arachidonic acid with subsequent pro-inflammatory effects. This is not relevant in inflammatory cells such as neutrophils, since these cells lack enzyme (delta-5-desaturase) activity needed to convert DGLA to arachidonic acid (7). Importantly, inflammatory cells from subjects supplemented with GLA produce significantly less pro-inflammatory leukotriene B4 (8,9) .

    In contrast to inflammatory cells, high levels of supplemental GLA have been shown in some but not other studies to elevate serum arachidonic acid levels. Human studies, however, have demonstrated that the addition of fish-derived omega-3 EPA in a balanced ratio to GLA, blocks the activity of delta-5-desaturase and prevents elevations in serum arachidonic acid (10,11).

    Co-ingesting similar levels of EPA and GLA increases cellular membrane content of both DGLA and EPA (precursor to anti-inflammatory eicosinoids). In short, this supplementation strategy successfully maintains the anti-inflammatory capacity of GLA and increases serum EPA, without causing accumulation of arachidonic acid.

    Flaxseed oil is a concentrated source of omega-3 alpha linolenic acid. However, conversion of this fatty acid to EPA is limited, and further metabolism to DHA is very low or negligible (12). Typically, only 15-40% of alpha linoleic is converted to EPA This may, in part, explain why omega-3 fatty acids from fish or fish-oil supplements, but not alpha-linolenic acid, have been found to benefit cardiovascular disease outcomes in primary- and secondary-prevention studies (13). Thus GLA-enriched oils are more effectively paired with fish oil rather than flaxseed oil to promote the complementary actions of GLA and EPA.

    References

    1. Kapoor R, et al. Gamma Linolenic Acid: An anti-inflammatory omega-6 fatty acid (Review) Curr Pharm Biotech 7:531-34, 2006.
    2. Wu D, et al. Effect of dietary supplementation with black currant seed oil on the immune response of healthy elderly subjects. Am J Clin Nutr 70: 536-543, 1999.
    3. van der Merwe, et al. The effect of gamma-linolenic acid, an in vitro cytostatic substance contained in evening primrose oil, on primary liver cancer. A double- blind placebo controlled trial. Prostaglandins Leukot Essent Fatty Acids 40:199-202, 1992.
    4. Zurier RB, et al. Gamma-linolenic acid treatment of rheumatoid arthritis. A randomized, placebo-controlled trial. Arthritis Rheum39:1808-17, 1996.
    5. Keen H, et al. Treatment of diabetic neuropathy with gamma-linolenic acid. The gamma-Linolenic Acid Multicenter Trial Group. Diabetes Care 16:8-15, 1993.
    6. Physicians' Desk Reference for Nutritional Supplements, 1st Edition, ISBN 1-56363-364-7, p. 173.
    7. Chilton-Lopez T, et al. Metabolism of GLA in human neutrophils. J Immunol 156:2941-47, 1996.
    8. Johnson M, et al. Dietary supplementation with GLA alters fatty acid content and eicosanoid production in healthy humans. J Nutr 127:1435-44, 1997.
    9. Ziboh VA, et al. Dose-response effects of dietary GLA-enriched oils on human polymorphonuclear-neutrophil biosynthesis of leukotriene B4. Am J Clin Nutr 55:39-45, 1992.
    10. Barham JB, et al. Addition of eicosapentaenoic acid to gamma-linolenic acid-supplemented diets prevents serum arachidonic acid accumulation in humans. J Nutr 130:1925-31, 2000.
    11. Laidlaw M, et al. Effects of supplementation with fish oil-derived n-3 fatty acids and gamma-linolenic acid on circulating plasma lipid profiles in women. Am J Clin Nutr 77:37-42, 2003.
    12. Burdge G, et al. Alpha linolenic metabolism in adult humans. Eur J Lipid Sci Tech 107:426-39, 205, 2005.
    13. Wang C, et al. n-3 Fatty acids from fish or fish-oil supplements, but not alpha-linolenic acid, benefit cardiovascular disease outcomes in primary- and secondary-prevention studies: a systematic review. Am J of Clin Nutr 84:5-17, 2006.

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  • Contact Lens Wear, Dry Eye & Fatty Acids
  • Contact Lens Wear Can Lead to Dry Eye

    Most people are aware that dry eye is a pervasive problem. Estimated to affect up to 1 in 5 adults, it is the most common condition seen in ophthalmology practices. Lesser known, however, is that dry eye is also the most common complaint among those who wear contact lenses.

    In some cases, people who already have existing, marginal dry eye can experience worsening of the condition when they begin to wear contact lenses. For others, the lenses themselves may lead to dry eye symptoms over time.

    Disturbing the Tear Film

    The tear film that hydrates and lubricates the optical surface of the eye is composed of several layers. There is an oily outer layer which helps prevent the tear fluid from evaporating, and an inner layer of fluid that also contains a mucous-like gel which allows the fluid to spread evenly over the surface. A normal and stable tear film is necessary in order to be a successful contact lens wearer who does not suffer from symptoms of dryness or sensation of grittiness.

    When a contact lens is placed in the eye, the lens can alter the normal structure of the tear film and affect its rate of evaporation. Greater evaporation leads to increased osmolarity (saltiness or lower volume of tear fluid) - a good predictor of dry eye (1). Tear osmolarity is often elevated in contact lens wearers, and even more so in those who can't tolerate them.

    Microvilli Losses

    For those who have been wearing their lenses for many years, there may be another contributing factor. The continual rubbing of the lens across the surface of the cornea may result in some loss of the microscopic hair-like structures called microvilli that exist on the outermost layer of the cornea. The microvilli bind to the mucous-like gel in the tear fluid so that the tear film adheres well to the cornea and maintains a stable, uniform layer on the cornea.

    It's believed that the constant movement of the contact lens across the surface of the cornea over years of wear may reduce the microvilli. In turn, this can destabilize the tear film and result in contact lens-induced dry eye. It is also thought that discontinuing lens use temporarily will help restore microvilli.

    Strategies for More Successful Lens Wear

    Contact lenses are often a good alternative for people who are bothered by the cosmetic appearance of eyeglasses or the limitation to activities that they pose. To have a comfortable experience with contact lenses, it's important to be under the care of an eye care practitioner to ensure that the lens fit and lens materials you currently have are the best possible choice for you.

    The type of lens chosen may make a difference in reducing the chance for dry eye. While some research has not shown a difference in tear osmolarity between soft, water-containing lens and the rigid, gas-permeable type of lens, in some cases soft, high-water content lenses may not be the best choice (2). In general, the more water a soft contact lens contains, the more prone it is to become dehydrated. As water evaporates from the front of the water-containing lens during wear, the lens draws moisture from the tear film. In addition to choosing appropriate lens materials, your eye doctor may also recommend lubricating drops or other aids, and suggest ways to modify environmental factors that can exacerbate dry eye such as overheated rooms, use of hairdryers or uninterrupted time at the computer.

    Important Fatty Acids Can Be Helpful

    An additional strategy is to try supplemental GLA and EPA, fatty acids that can bolster one's own natural, inflammation-fighting ability. Whatever the cause of dry eye - insufficient tear production, evaporation, chronic allergy or other - the result is an inflammatory reaction, and the contact lens wearer with symptoms of dryness is no exception (3). Research suggests that fatty acid supplementation can help calm inflammation and improve dry eye symptoms (4). Balanced amounts of GLA and EPA work together to reduce production of pro-inflammatory compounds while increasing the manufacture of compounds that are anti-inflammatory.

    References

    1. Tomlinson A, et al. Tear film osmolarity: determination of a referent for dry eye diagnosis. Invest Ophthalmol Vis Sci 47:4309-15, 2006.
    2. Iskelei G, et al. Comparison of tear-film osmolarity in different types of contact lenses. CLAO J 28:184-6, 2002.
    3. Kallinikos P, et al. Assessment of stromal keratocytes and tear film inflammatory mediators during extended wear of contact lenses. Cornea 25:1-10, 2006.
    4. Barabino S, et al. Systemic linoleic and gamma-linolenic acid therapy in dry eye syndrome with an inflammatory component. Cornea 22:97-102, 2003.

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  • GLA and Vision-Corrective Laser Surgery
  • Know someone who's scheduled for vision-corrective laser surgery? GLA may help!

    LASIK or PRK Can Cause Temporary Dry Eye
    Some people, who are appropriate candidates, opt for laser surgery to help correct their vision. The two most common types of procedures are LASIK (Laser In Situ Keratomileusis) and PRK (Photorefractive Keratectomy). These popular procedures use a laser or a combination of microsurgery and laser to reshape the eye's cornea. Reshaping the cornea alters the focusing power of the eye, allowing one to become less dependent upon glasses or contact lenses.

    Having Dry Eye Before Surgery May Prolong or Worsen Symptoms Afterward
    One common side-effect of the surgery is dry eye. It can make the cornea less sensitive, resulting in lower tear production and inflammation. The good news is that dry eye is temporary, typically lasting no more than a month. But symptoms may last longer and be more severe in people who already have dry eye before they undergo the surgery (1).

    What Is Dry Eye Syndrome?
    A common condition, dry eye has many causes. One of the most common reasons is the normal aging process. It's also associated with certain conditions such as rosacea and Parkinson's. Women frequently experience dry eye, especially as they enter menopause. Symptoms include itching, burning, or a gritty sensation - even tearing when the eye is irritated. Visual efforts like reading or computer time can aggravate symptoms, and other factors such as hot, dry, or windy climates; high altitudes; air-conditioning; and cigarette smoke are also contributors. Ironically, contact lens wear can also contribute to or worsen dry eye, which often leads people to laser surgery.

    Special Fatty Acids May help
    Italian researchers recently investigated the effects of fatty acids on dry eye in people undergoing PRK. Thirty patients were given supplements of linoleic acid and gamma-linolenic acid or GLA. Another group underwent PRK without the supplement. Compared to the untreated control patients, the group getting fatty acids were found to have significantly fewer symptoms of dry as measured by questionnaire. They also scored better in the Schirmer test-a method for measuring tear production-and their eyes were able to more readily clear a staining dye from their tears, reflecting better ocular surface sensitivity and tear clearance.

    GLA is a specialized fatty acid with the ability to modify inflammation and support tear production (2-4). These researchers concluded that GLA as a precursor to anti-inflammatory compounds, could be helpful in increasing tear production and clearance after PRK (5).

    HydroEye is a unique, oral formulation for dry eye relief. It provides GLA and nutrient cofactors that help dampen inflammation and support a healthy tear film.

    References

    1. Toda I et al. Laser-assisted in situ keratomileusis for patients with dry eye. Arch Opthalmol 120:1024-28, 2002.
    2. Aragona P et al. Tear PGE1 levels in dry eye patients after treatment with essential fatty acids. Invest Ophthalmol Vis Sci 42:5259, 2001.
    3. Bababino S et al. Efficacy of systemic linoleic and gamma-linolenic acid therapy in dry-eye syndrome with inflammatory component. ARVO Annual Meeting, Fl, May 2002, abstract 2105.
    4. Horobin DF et al. Treatment of the sicca syndrome and Sjögren's syndrome with EFA, pyridoxine, and vitamin C. Prog Lipid Res 20:253-4, 1981.
    5. Macri A et al. Effect of linoleic acid and gamma-linolenic acid on tear production, tear clearance and on the ocular surface after photorefractive keratectomy. Graefes Arch Clin Exp Ophthalmol (published online, May 27, 2003)

    - Close

  • Oral Omega Fats, GLA & LA, Increase Tear Production After PRK
  • Introduction:

    PRK is known to cause a temporary reduction in corneal sensitivity, leading to tear film changes, lowered reflex tearing, and production of inflammatory cytokines and free radicals. Transitory dry eye is a common complication after PRK and LASIK, lasting longer in patients with preoperative dry eye (1).

    The anti-inflammatory properties of the fatty acid GLA have long been known. Recent studies report that oral administration of GLA and LA leads to a significant increase in tear concentrations of anti-inflammatory prostaglandin E1 (2,3), and reduces the symptoms of dry eye (2). The aim of this study was to evaluate the effects of GLA and LA on tear production, tear fluorescein clearance, dry eye symptoms, and the ocular surface after PRK (4).

    Methods:

    In this randomized, controlled trial, 31 patients received modest amounts of oral GLA and LA 3 days prior to 30 days after undergoing PRK. Another 29 patients underwent PRK without the supplement, serving as controls. The following measurements were made at baseline and at the end of the study period: symptom questionnaire, Schirmer 1 test, fluorescein clearance test using standardized visual scale and corneal fluorescein staining.

    Results:

    All 60 patients completed the study. Statistical analysis showed a significant mean difference between the groups for dry eye symptoms, fluorscein clearance, and Schirmer's results. Compared to controls, the treated group had lower symptom scores, greater Schirmer test values, and more favorable fluorescein clearance scores [See Figures 1-3]. Both groups showed no signs of corneal staining at baseline. While more areas stained in controls than treated patients at 1 month post-surgery (0.09 ± 0.10 vs. 0.25 ± 0.21 respectively), the difference was not significant. The researchers concluded that oral precursors of prostaglandin E1, GLA and LA, could be helpful in increasing tear production and clearance after PRK.

    Figure 1. Results of symptoms questionnaire (mean score) before starting study (T0) and 1 month after PRK (T1). (*P<0.05)

    Figure 2. Results of Schirmer 1 test (mm/5 min) before starting study (T0) and 1 month after PRK (T1). (*P<0.0001)

    Figure 3. Results of fluorescein clearance test by means of visual scale (mean score) before starting study (T0) and 1 month after PRK (T1). (*P<0.0001)

    References

      • Toda I et al. Laser-assisted in situ keratomileusis for patients with dry eye. Arch Opthalmol 120:1024-28, 2002.
      • Aragona P et al. Tear PGE1 levels in dry eye patients after treatment with essential fatty acids. Invvest Ophthalmol Vis Sci 42:5259, 2001.
      • Barabino S et al. Systemic linoleic and gamma-linolenic acid therapy in dry-eye syndrome with inflammatory component. Cornea 22(2): 97–101, 2003.
      • Macri A et al. Effect of linoleic acid and gamma-linolenic acid on tear production, tear clearance and on the ocular surface after photorefractive keratectomy. Graefes Arch Clin Exp Ophthalmol (published first online, May 27, 2003) Full paper available upon request.

    - Close

  • Supplemental GLA Improves Dry Eye in Sjögren's Syndrome
  • Inflammation and Sjögren's Syndrome

    Affecting more than 1.4 million Americans, Sjögren's syndrome is an autoimmune disorder in which immune cells attack and destroy the glands that produce tears and saliva. The hallmark symptoms of the disorder are dry mouth and dry eyes. Sjögren's syndrome is also frequently associated with rheumatic disorders such as rheumatoid arthritis.

    T-cell infiltration and markers of immune activation have been noted in both the conjunctiva and lacrimal glands of these patients. Topical anti-inflammatory treatment of patients with dry eye reportedly produces a significant reduction of activated lymphocyte in the conjunctiva, thus demonstrating the potential for anti-inflammatory treatment of dry eyes.

    Anti-inflammatory Activity of GLA

    Gamma-linolenic acid (GLA) and its precursor linoleic acid (LA) are essential fatty acids found in certain plant seed oils such as black currant seed oil. Oral administration of GLA and LA has been shown to have beneficial effects in the treatment of chronic inflammatory disorders such as rheumatoid arthritis, and several pilot studies conducted in the 1980's suggest that these fatty acids may also benefit the ocular status of patients with Sjögren's.

    GLA is metabolized to dihomo-linolenic acid (DGLA), the immediate precursor of PGE1, an eicosanoid with known anti-inflammatory action. In addition, both GLA and DGLA modulate the immune responses by acting directly on T lymphocytes. Researchers from the University of Messina in Italy now report that modest amounts of supplemental GLA and LA raise PGE1 tear content in Sjögren's, and improve signs and symptoms of ocular discomfort in these patients.

    Design and Methods

    This randomized, double-blind, controlled trial involved 40 patients with primary Sjögren's Syndrome divided into 2 groups. One group received GLA (15 mg) and LA (112 mg) twice daily for 1 month (GLA group), while the other group received placebos. Subjects underwent 3 examinations: baseline (T0), after 1 month (T1), and 15 days after treatment was suspended (T2). At each exam, the following tests were performed: tear sampling from the inferior meniscus, TBUT, fluorescein stain of the ocular surface, and tear basal secretion. A symptom score was also obtained each time. PGE1 was evaluated by enzyme immunoassay, and PGE1 content of tears was the primary endpoint.

    Results

    Tear PGE1 levels were significantly increased in the GLA group after 1 month of treatment. Fifteen days after treatment was halted, a significant reduction of the PGE1 levels toward baseline was observed. The symptom score was significantly lower in the GLA group after 1 month, with several symptoms (burning, foreign body sensation and dryness) remaining improved after treatment was stopped. The corneal fluorescein stain in this group also showed a significant improvement after the first month, which was sustained 15 days after treatment cessation.

    No statistically significant differences were found for the other tests. In contrast to the GLA group, no statistically significant changes were noted in the placebo group at all examination time points. These results are summarized in the table below (group 1 = supplemented; group 2 = placebo).

    Conclusions

    According to the authors, these results indicate that supplemental GLA and LA effectively increases PGE1, an indicator of anti-inflammatory activity, improves ocular surface status and reduces dry eye symptoms.

    Reference
    Aragona P, et al. Systemic omega-6 essential fatty acid treatment and PGE1 tear content in Sjogren's syndrome patients. Invest Ophthalmol Vis Sci 46:4474-9, 2005.

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  • Black Currant Seed Oil and EFAs in Dry Eye and Immunity
  • Studies have shown that dry eye patients experience a chronic inflammatory cycle, causing symptoms and impacting tear production. A Phase III FDA study of cyclosporine, an immunomodulatory drug, demonstrated that in moderate and severe cases of Sjögren's syndrome and keratoconjunctivitis sicca (KCS), markers of inflammation were significantly reduced from baseline following treatment with this drug. However, this potent immunomodulatory drug is not a first-line defense.

    A more effective and preventive approach may be to address the biochemical basis of a healthy and intact tear film. Studies have shown that nutritional supplementation with omega-3 and omega-6 fatty acids and nutrient cofactors involved in the biosynthesis of the prostaglandin PGE1 result in reduced symptoms in dry-eye and KCS patients (1,2). PGE1 is necessary for tear secretion and also regulates inflammation. Essentially, in the event of reduction of PGE1 synthesis (due to a deficiency of omega-3 and omega-6 fatty acids), there is overproduction of series 2 prostaglandins (PGE2). Increased PGE1 production is anti-inflammatory because it down-regulates PGE2 production, and thus reduces over-reactive B-cell activity and may be a regulator of the arachidonic acid cascade. Wu and colleagues carried out a placebo-controlled study of the effect of dietary supplementation with black current seed oil (BCSO) on immune response in healthy subjects 65 years or older (3).

    Methods:

    This was a randomized double-blind study. Forty patients were randomized to receive either 750 mg BCSO or 750 mg soybean oil. BCSO contains linoleic acid and 15% gamma-linolenic acid (GLA) - both omega-6 fatty acids, as well as the omega-3 fatty acids alpha-linolenic acid and stearidonic acid. The ratio of omega-3 to omega-6 fatty acids in BCSO is about 1 to 4. The level of vitamin E intake in both groups was controlled equally. Supplementation continued for 2 months.

    Results:

    BSCO supplementation, significantly increased plasma concentrations of gamma-linolenic acid (omega-6), alpha-linolenic acid (omega-3), and dihomo-gamma-linolenic acid compared with baseline. These increases were not evident in the control group. The BCSO group exhibited enhanced response to tetanus toxoid. In the BCSO group, stimulated PGE2 production was significantly reduced from baseline (488 ng/L to 258 ng/L). This was significantly (p<0.05) different from the control (soybean oil) group, which did not exhibit this reduction (Figure). The authors concluded that BCSO has a moderate immune enhancing effect attributable to reduction of PGE2 production.



    Comment:

    This study and previous research suggests that the combination of omega-3 and omega-6 fatty acids in black current seed oil both results in increased PGE1, which both stimulates aqueous tear secretion and reduces the production of PGE2.

    ScienceBased Health's HydroEye® is a proprietary blend of BCSO (rich in both omega-3 and 6 fatty acids), Cod Liver Oil (additional omega-3 fatty acids, Vitamin A, and eicosanoids), Vitamins B6 and C and Magnesium. This optimal ratio of omega-3 and omega-6 fatty acids along with the essential cofactors for the PGE-1 pathway, results in increased PGE1 production. PGE1 both stimulates aqueous tear secretion and reduces inflammation by down-regulating production of PGE2 (enhancing T-cell production and inhibiting over-reactive B-cells).

    References

      • Horrobin DF, Campbell A, McEwen CG: Treatment of the Sicca Syndrome and the Sjögren's Syndrome with E.F.A., Pyridoxine and Vitamin C. Prog Lipid Res 8(4): 253-4, 1981
      • Oxholm P, Manthorpe R, Prause JU, Horrobin D: Patients with Primary Sjögren's Syndrome Treated for 2 Months With Evening Primrose Oil. Scand J Rheumatology 1986; 15:103-108.
      • Wu D, Meydani M, Leka L, et. al.: Effect of dietary supplementation with black current seed oil on the immune response of healthy elderly subjects. Am J Clin Nutr 1999;70:536-543.

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  • Dry Eye: A Clinical Trial of Essential Fatty Acids
  • In the previous EduFacts we summarized preliminary work by Horrobin and colleagues (1) which indicated that an effective approach to the treatment of dry eye disorders may be to address the biochemical basis of an intact tear film. In this preliminary study the authors had evaluated the use of supplemental intake of the essential fatty acids (EFA); linoleic and gamma linolenic acids; vitamin B6 ; and vitamin C to treat dry eye. These nutrients are necessary components of the pathway for biosynthesis of prostaglandin E1 (PGE1), which is necessary for aqueous tear secretion by the lacrimal glands. The rationale for their study was based on earlier research showing that gamma linolenic acid (GLA), an upstream metabolite of the EFA linoleic acid, was lower among patients with Sjögren's Syndrome. This suggested a breakdown in the biochemical pathway which might be remedied by supplying both GLA, linoleic acid and the vitamin cofactors involved.

    Another controlled study of treatment with precursor EFAs was performed by Oxholm and colleagues on patients with primary Sjögren's Syndrome (2).

    Methods:

    28 patients with primary Sjögren's Syndrome were studied in a "cross-over" clinical study. Each patient received either Efamol (73% cis-linoleic acid, 9% gamma linolenic acid) or placebo for 8 weeks. Dosing was 6 3g capsules daily. Then each patient was "crossed-over" and received the opposite treatment for 8 more weeks. The initial treatment assignment was randomly chosen for each patient and the study was double masked - neither patients nor clinicians knew the treatment given to the patient. Clinical tests for keratoconjunctivitis sicca (KCS) included Schirmer test, tear-break-up-time, and Bijstervald score. These tests were evaluated before and after treatment. A combined ocular score was also computed. In addition the levels of DGLA (a metabolite of linoleic acid produced during biosynthesis of PGE1) were measured in serum and in erythrocytes before and after treatment.

    Results:

    Statistically significant baseline-to-post-treatment improvement in the overall ocular score was found in the Efamol group (p<0.05). Fewer patients in the control group experienced improvement (baseline-to-post-treatment) in ocular score. Furthermore, levels of the metabolite Di-hommo-gamma linolenic acid (DGLA) were increased significantly in both plasma (25% increase, p<0.001), and erythrocytes (10% increase, p<0.05) during Efamol treatment but not placebo treatment.

    References

      • Horrobin DF, Campbell A, McEwen CG: Treatment of the Sicca Syndrome and the Sjögren's Syndrome with E.F.A., Pyroxidine and vitamin C. Prog Lipid Res 8(4): 253-4, 1981.
      • 2. Oxholm P, Manthorpe R, Prause JU, Horrobin D: Patients with Primary Sjögren's Syndrome Treated for 2 Months With Evening Primrose Oil. Scand J Rheumatology 1986; 15:103-108.

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Amount of GLA (per day) in selected ScienceBased Health products:

Dry Eye Relief

    HydroEye provides:

  • GLA: 235 mg


Lycopene

Lycopene is a red-yellow carotenoid that not only gives tomatoes, pink grapefruit and watermelon their color, but also contributes to the health benefits of eating fruit & vegetable rich diets. A Harvard Medical School study has linked frequent consumption of tomato products with a greater likelihood of retaining prostate health, and a relationship between higher blood levels of lycopene and cardiovascular health has also been reported.


Amount of lycopene (per day) in selected ScienceBased Health products:

Multinutrient Protection for Eyes & Body

OcularProtect provides 2 mg

Protection for Macular Health

MacularProtect Complete AREDS2 provides 2 mg


Omega-3 Fatty Acids (EPA and DHA)

Coldwater, fatty fish are a concentrated source of the omega-3 fats docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Numerous studies have shown that intake of these omega-3s provides significant benefits for cardiovascular health, leading to the American Heart Association's 2002 recommendation that the general public consume fish at least twice per week and that individuals with coronary heart disease (CHD) consume EPA and DHA from fatty fish or supplements. In addition, recent studies have found that DHA and EPA may also support macular health. Current research is also investigating whether EPA and DHA may help support healthy mental function.

  • Read about studies linking EPA and DHA to cardiovascular health
  • Read about research on EPA and DHA for retinopathy as well as colon and prostate health
  • Read about research into EPA and DHA for macular health
  • Read about studies on EPA and DHA for healthy mental function
  • Read about studies investigating EPA and DHA for healthy lungs
  • Read about the benefits of EPA and DHA as part of a healthy diet
Amount of EPA & DHA (per day) in selected ScienceBased Health products:

Omega-3 Support for Macular and Heart Health

    OmegaAdvance provides:

  • EPA: 300 mg
  • DHA: 200 mg

Dry Eye Relief

    HydroEye provides:

  • EPA: 100 mg
  • DHA: 70 mg

    EPA and DHA for cardiovascular health
  • From Inuit to Implementation: Omega-3s Have Come of Age
  • Omega-3s: From Inuit to Implementation

    While the relationship between the omega-3 fatty acids and age related cognition and retinal function have only recently begun to emerge, the cardio-vascular effects of EPA and DHA have been studied for nearly three decades. Interest in these fatty acids from cold water fish began in the late 1970's when studies revealed that Greenland's indigenous Inuits had a significantly lower rate of heart attack compared with Western control subjects. These observations generated an estimated 5000 studies to explore this and other effects of omega-3 fats, and ultimately led to the American Heart Association's recommendations for regular omega-3 consumption in 2002. Research continues to support the cardio-protective role of these fatty acids as evidenced by the findings of several newly published studies.

    Fish Fatty Acids More Effective Than Defibrillators

    Omega-3 fatty acids may prevent more sudden deaths than automated external defibrillators (AED) in homes and public places or implanted defibrillators according to results of a study supported by the Centers for Disease Control (1). Researchers compared these preventive strategies in a computer-simulated community of 100,000 people that resembled the population of Olmsted County, Minnesota.

    Raising the omega-3 fatty acid levels among the cyber-Olmsted citizens resulted in lowering overall mortality rates by 6.4%. In contrast, AEDs reduced death rates by 0.8% and implanted defibrillators (ICDs) lowered the rates by 3.3%. Three-quarters of the reduction in deaths from increased omega-3 levels would come from raising them among the healthy portion of the population.

    Raising blood levels of the omega-3 in people after a heart attack could save 58 lives yearly according to the simulation's predictions, while only 7 lives were saved by AEDs and implanted defibrillators prevented 30 deaths yearly. While heart attack survivors are routinely given omega-3 supplements in some European countries, this is generally not the case in the U.S., though the evidence supports it. According to a study published in the September issue of the Journal of the American Board of Family Medicine, only 17% of family doctors were likely to advise patients - including those who had suffered a heart attack - to take omega-3 supplements (2). There is a great need, the authors concluded, to "improve awareness of this important advice."

    Heart Benefits Confirmed In Systematic Review

    A recently published systematic review of randomized controlled trials, prospective cohort and case-control studies, concludes that the evidence suggests that fish or fish oil supplements reduces the rates of all cause mortality, cardiac and sudden death, and possibly stroke(3). The evidence was stronger for secondary than primary prevention.

    Commissioned by the NIH, the review found that increased consumption of EPA and DHA - but not the omega-3 fatty acid alpha linolenic (ALA) - reduces the rates of these CVD outcomes. Data on the effects of ALA, found in flaxseed and other vegetable oils, were reportedly limited and typically of poor quality.

    Future Directions: An Omega-3 Index

    A second review published online in August ahead of print in the journal Cardiovascular Research, also concludes that the majority of the evidence supports the benefits of omega-3 intake for heart health. The authors, from Saint Luke's Hospital, University of Missouri-Kansas City School of Medicine, have proposed an omega-3 index as a modifiable risk factor for CVD. The Index measures the sum of EPA+DHA in the membrane of erythrocytes as the percent of all fatty acids in the red blood cell membrane. The authors also determined that membrane EPA+DHA index equal to or exceeding 8% is associated with the greatest cardio-protection. In the future, this measure of EPA/DHA status could help physicians tailor advice to their patients to help them achieve levels of omega-3 scientifically reported to provide CVD benefits.

    References

    1. Kottke TE, et al. Preventing sudden death with n-3 (omega-3) fatty acids and defibrillators. Am J Prev Med 31:316-23, 2006.
    2. Oh RC, et al. The fish in secondary prevention of heart disease (FISH) survey-primary care physicians and omega-3 fatty acid prescribing behaviors. J Am Board Fam Med 19:459-67, 2006.
    3. Wang C, et al. n-3 Fatty acids from fish or fish-oil supplements, but not alpha-linolenic acid, benefit cardiovascular disease outcomes in primary- and secondary-prevention studies: a systematic review. Am J Clin Nutr 84:5-17, 2006.

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  • AREDS Analysis: Antioxidants, Omega-3 and the AMD-CVD Connection
  • CVD & AMD Share Common Risks, Processes

    A Harvard research team led by Dr. Johanna Seddon notes that age-related macular degeneration (AMD) and cardiovascular disease (CVD) share common risk factors, such as smoking and higher body mass index (BMI). They propose that mechanisms involved in developing AMD could be better understood by evaluating biomarkers of CVD. A number of analyses, in fact, have shown that systemic biomarkers for inflammation and artery damage, including C-reactive protein (CRP) and homocysteine (HCY), are related to AMD. Basic research also demonstrates that inflammatory, immune and atherosclerotic processes are related to AMD development.

    To further explore mechanisms related to AMD pathogenesis, these researchers evaluated the relationships between CRP, HCY and other known risk or protective factors for AMD in subjects from the original AREDS trial (1). According to Dr. Seddon, the findings indicate that "sick eyes may occur in sick bodies related to smoking, overweight, inadequate nutrient intake, and other unhealthy behaviors".

    Study Design

    After randomization for AREDS, 934 subjects from two clinical sites underwent blood draws, measurements, photographs of the macula and answered questionnaires. Dietary, behavioral and medical risk, and protective factors for AMD were evaluated for their associations with blood values of CRP and HCY. This original data provided information on intake of fish as well as antioxidants such as vitamins C and E, alpha- and beta-carotene and lutein/zeaxanthin. In addition, serum nutrient values obtained from participants at one of the sites were also evaluated for their association with CRP and HCY. Multivariable regression analyses were performed after adjusting for age, gender and AREDS treatment.

    Results

    Higher levels of serum antioxidants vitamin C and lutein/zeaxanthin and higher fish intake (a source of omega-3 fats) were associated with lower serum CRP levels. CRP levels decreased 2 milligrams per litre for every 1000 microgram per decilitre increase in blood levels of lutein/zeaxanthin. A 0.2 milligram per litre decrease in CRP was also associated with more than 2 servings of fish weekly.

    Increased BMI and smoking were associated with increased CRP, while serum alpha-carotene, dietary intake of antioxidants and vitamin B6 were associated with lower levels of plasma HCY. Levels of HCY were observed to be higher in those with hypertension. While serum vitamin E was linked to lower concentrations of HCY, it was unexpectedly linked to higher levels of CRP.

    Comments

    Factors reported to be related to AMD, namely antioxidants, smoking, BMI, HCY (2) and fish intake, are also associated with inflammatory, immune, or other CVD mechanisms. These results are consistent with previous findings associating smoking, BMI, and the biomarkers CRP and interleukin-6 with AMD in a different study cohort of AMD patients (3).

    The relationship between fish intake, BMI, and levels of inflammatory markers have been previously reported in other "non-ocular" study populations. These data support and expand on these associations. The positive link between higher vitamin E and CRP deserves further study, according to the authors. This finding disagrees with the recent Rotterdam study, which found that vitamin E significantly lowered AMD risk [EduFacts Vol.6 No.1].

    Overall, the Harvard study adds to a growing body of data showing a protective effect of antioxidants such as lutein/zeaxanthin, and omega-3 fats against AMD.

    References

    1. Seddon JM et al. C-reactive protein and homocysteine are associated with dietary and behavioral risk factors for age-related macular degeneration. Nutrition 22:441-43, 2006.
    2. Seddon JM et al. Evaluation of homocysteine and risk of age-related macular degeneration. Am J Ophthalmol 141:201-3, 2006.
    3. Seddon JM et al. Progression of age-related macular
      degeneration: prospective assessment of C-reactive protein, interleukin-6, and other cardiovascular biomarkers. Arch Ophthalmol 123:774-82, 2005.

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    EPA and DHA for preventing retinopathy, improved colon & prostate health
  • Fish Oil Omega-3s: New Research Findings
  • EPA & DHA: Beyond Heart & Brain Benefits

    The long chain fats in fish oil, EPA and DHA, are best known for their cardiovascular benefits. They help guard arteries by quelling chronic inflammation, keeping levels of triglycerides in check, and making vessels more elastic. Factor in their ability to improve electrical communication between heart cells and prevent arrhythmia, and it's easy to understand why omega-3s are a standard part of cardiac care in European countries.

    The evidence for an Omega-3 role in fending off mental aging is also increasing [see the February 2007 and December 2006 newsletter issues]. Several new areas of potential benefit for these fatty acids are also emerging: visual, prostate and colon health.

    Preventing Retinopathy?

    In addition to being studied in the AREDS-2 trial for AMD, the omega-3s may help protect against retinopathy, a deterioration of the retina that affects about 4 million diabetics and 40,000 premature infants. This disease is a 2-part process that starts with a loss of blood vessels. With the vessel loss, the retina becomes oxygen deprived and reacts by spurring new vessel growth. However, the low-oxygen triggered vessels grow abnormally and are malformed, leaky and over-abundant.

    Collaborating researchers from the NEI, Harvard, the University of Göteborg in Sweden and other institutions, recently examined the effects of omega-3 and omega-6 in an animal model of retinopathy (1). Animals were fed EPA and DHA from fish oil, or arachidonic acid - an omega-6 typically found in meats and dairy, and made in the body from other fats present in many vegetable oils. The investigators found that mice on the omega-3 diet initially lost 40-50% less retinal vessels compared to the omega-6 group. As a result, the omega-3 fed group had a 40-50% reduction in abnormal vessel growth.

    One of the study's authors said: "If clinical trials find that supplementing with omega-3 s is as effective in protecting humans against retinal disease as demonstrated by the findings of this study, this cost effective intervention could benefit millions of people".

    Better Colon Health?

    Findings from a new study published in the American Journal of Epidemiology, add to a growing body of science linking omega-3 and fatty fish consumption to a reduced risk of colorectal cancer (2). Scottish researchers examined the type and amounts of fats in the diets of 1,455 subjects with colorectal cancer and the same number of matched healthy individuals.

    Increased intake of EPA was associated with a 41% reduction in risk, while a 37% lower risk was linked to DHA intake, comparing highest against lowest average intakes. The omega-3s have been shown to reduce the body's inflammatory response (3). This is very important, because chronic inflammation is believed to be the culprit in about 20% of all cancers.

    Healthier Prostates?

    In addition to colorectal cancer, prostate cancer is also believed to be influenced by chronic inflammation. The incidence of prostate cancer has been increasing over the past 15 years, with over a half million new cases diagnosed every year worldwide.

    Higher intake of the omega-3s DHA and EPA could cut the risk of developing this cancer by 40% according to a new study from Harvard (4). The investigators compared blood levels of fatty acids in 476 men with prostate cancer and the same number of healthy controls. The results tally with other studies reporting that regular intake of fatty fish like salmon is associated with a prostate-protective effect.

    References

    1. Connor KM, et al. Increased dietary intake of 3-poly-unstaturated acids reduces pathological retinal angiogenesis. Nature Medicine 13:868-874, 2007.
    2. Theodoratou E, et al. Dietary fatty acids and colorectal cancer: a case-control study. American Journal of Epidemiology 166:181-195, 2007.
    3. Wada M, et al. Enzymes and receptors of prostaglandin pathways with arachidonic acid-derived versus eicosapentaenoic acid-derived substrates and products. Journal of Biological Chemistry 282: 22254-66. 2007.
    4. Chavarro JE, et al. A prospective study of polyunsaturated fatty acid levels in blood and prostate cancer risk. Cancer Epidemiology, Biomarkers and Prevention. 16:1364-70 ,2007.

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    EPA and DHA for macular health
  • AREDS Analyses: Higher Omega-3 & Lutein Lower AMD Likelihood
  • AREDS Reports Numbers 20 and 22

    Dietary data was collected from participants when they enrolled in the AREDS trial so that investigators could later examine the relationship of AMD case groups with intake levels of individual nutrients.

    To explore these relationships, AREDS subjects were divided into four groups based on increasing severity of drusen or type of AMD. The dietary information from those four groups was then compared with that from AREDS participants categorized as being 'free' of AMD. AMD-free was defined as having no drusen or less than 15 small drusen. Nutrient intake values were adjusted for energy intake then stratified into quintiles.

    Results of the analyses were published in the May and September issues of the journal Archives of Ophthalmology. The first of these case-control studies reports on the relationship of dietary lipids and AMD (1), while the second study assessed whether nutrients such as carotenoids, vitamins A, C and E and others, were related to AMD risk (2).

    Omega-3 and Fish Intake Lower AMD Risk

    The researchers found that only higher intake of total long chain omega-3 and fish (the primary dietary source of EPA and DHA), were linked to a decreased likelihood of having neovascular AMD. Benefit was not seen for the other AMD groups.

    Arachidonic acid was the only dietary lipid directly associated with neovascular AMD prevalence. Participants getting the most arachidonic acid in their diets were 54% more likely to have late AMD. Arachidonic acid, an omega-6 fat abundant in meat and dairy, is a precursor for inflammatory eicosinoids.

    No statistically significant relationships were seen for other dietary lipids such as the monounsaturates, found in olive oil for example, or saturated fats.

    It's interesting to note that the omega-3 fat alpha-linolenic acid, found in flaxseed oil for example, was associated with decreased AMD risk only when it was included along with EPA and DHA as part of the total intake of long chain polyunsaturated fats. Assessed alone, alpha-linolenic was not related to AMD. Alpha-linolenic acid must first be metabolized to EPA to provide anti-inflammatory activity, and this conversion is only 10-20% effective.

    Comparing the highest to lowest quintiles, those consuming the most total omega-3 fats were about 39% less likely to have neovascular AMD. Risk reduction for greater fish intake was the same. A 46% lower chance of having late AMD was linked with the highest consumption of DHA.

    EPA, DHA and arachidonic acid are major fatty acids in the diet. Both arachidonic acid and DHA (which can be formed from EPA), are key components of retinal photoreceptor outer segments and vascular tissue. While all three of these lipids are essential, a better balance of EPA and DHA to arachidonic acid is recommended for cardiovascular health. This study strongly suggests that improving that balance can favorably influence retinal health as well.

    Only Lutein / Zeaxanthin Independently Linked to AMD

    Higher dietary intake of lutein and zeaxanthin was independently associated with a reduced likelihood of having neovascular AMD, geographic atrophy, and large or extensive intermediate drusen. No other nutrients were independently related to AMD.

    After adjusting for total energy intake and other non-nutritional risk factors, subjects consuming the highest amount of lutein and zeaxanthin were 35% less likely to have neovascular AMD and 55% less likely to have geographic atrophy than those eating the least. Those whose diets provided the most of these two carotenoids also had a 26% reduced likelihood of having large or extensive drusen.

    The findings from both of these AREDS case-control studies are, in part, the basis for testing 10 mg of lutein, 2 mg of zeaxanthin, 650 mg EPA and 350 mg of DHA in the AREDS 2 trial currently underway.

    References

    1. AREDS Report No. 20: The relationship of dietary lipid intake and age-related macular degeneration in a case-control study. Arch Ophthalmol 125:671-9, 2007.
    2. AREDS Report No. 22: The relationship of dietary carotenoids with age-related macular degeneration in a case-control study. Arch Ophthalmol 125:1225-32, 2007.

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  • The Second Age-Related Eye Disease Study (AREDS 2)
  • AREDS 2 Slated to Get Underway

    One of the most influential studies of the past decade is about to have a sequel. The Age-Related Eye Disease Study (AREDS), published in late 2001, was the first large-scale trial to demonstrate that supplementation with antioxidant nutrients can help slow the progression of age-related macular degeneration (AMD) and it's associated vision loss.

    AREDS found that a combination of vitamins C, E, beta-carotene, zinc and copper lowered the risk of advanced AMD by 25% in high-risk patients. No effects of this antioxidant combination were observed in people without signs of the disease or with early AMD. Subjects without AMD didn't receive zinc - a mineral that also lowered the risk of AMD progressing when given alone to higher risk patients.

    Lutein, Zeaxanthin and Omega-3 Fatty Acids

    Now, researchers at the National Eye Institute (NEI) are gearing up to assess the impact of other nutrients that have emerged as potentially beneficial since the first AREDS study began: lutein, zeaxanthin and the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Lutein and zeaxanthin are thought to shield the macula and retina from oxidative stress generated by exposure to light.

    EPA and DHA, fatty acids that are present in cold-water fish, also play important roles in the eye. According to a review by the NEI, these fatty acids lessen the effects of exposure to light, stress, inflammation and other factors. DHA is also a major component of photoreceptors (rods and cones).

    AREDS Analysis

    When researchers analyzed the dietary intake of participants in the original AREDS trial, they found that those with the highest intake of DHA had a 50% lower risk of advanced AMD, and those consuming the most EPA had nearly the same 50% decrease in their risk of developing advanced geographic atrophy (a severe form of "dry" AMD). The investigators also studied patients' intake of lutein and zeaxanthin, finding that those with the highest intake had a 50% lower risk of developing new AMD during the trial compared to the control group. For people with high intakes and elevated blood levels of lutein and zeaxanthin, a decreased risk of both neovascular (wet AMD) and dry AMD was observed.

    Wet AMD, characterized by leaky blood vessels behind the retina, is considered advanced-stage AMD, while the dry AMD develops slowly over time as light sensitive macular cells degenerate. There are several stages of dry AMD, including early, intermediate and advanced. Dry AMD is more common than the wet form, though wet AMD is usually more severe.

    The Next Phase: AREDS 2

    The new trial will be a multi-center, randomized study of 4000 participants aged 55 to 80 who have large drusen (yellow-white "spots under the retina) or advanced AMD in one eye. Participants will receive one of four supplements: either placebo, 10 mg of lutein along with 2 mg of zeaxanthin, 1 g of DHA and EPA, or a combination of the lutein, zeaxanthin, DHA and EPA.

    AREDS 2 will start recruiting patients in 2006, with a 24-month recruiting period and 5 years of following participants. In addition, the investigators will evaluate a new version of the original AREDS supplements with a reduced level of zinc and without beta-carotene. While the main focus of AREDS II will be on AMD and cataract, the researchers also hope to learn more about the effects of EPA and DHA on mental function.

    We won't know the results of AREDS 2 for a number of years. But in the meantime, it makes good sense to keep eating a diet rich in fruits and vegetables for antioxidant nutrients, especially dark green leafy veggies which are good sources of lutein, and to eat fish at least 2-3 times weekly for their heart-healthy omega-3 fats. And if your eye care practitioner has recommended that you take supplements of the original AREDS nutrients, be sure to follow that advice.

    References

    1. Chew, EY. AREDS links higher intake of DHA, EPA, lutein and zeaxanthin with decreased risk of AMD. Presented at ARVO Minisymposium, Bethesda, Maryland, May, 2005.
    2. SanGiovanni JP and Chew EY. The role of omega-3 long-chain polyunsaturated fatty acids in health and disease of the retina. Prog in Retinal Eye Res 24:87-138, 2005.

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  • Oily Fish Consumption Found to Lower Early & Late AMD Risk
  • Support for Macular Benefits of Omega-3

    Reviewers from the National Eye Institute recently summarized the functions of the omega-3 fatty acids eicosapentenoic acid (EPA) and docosapentaenoic acids (DHA) in retinal tissues. [See EduFacts, Vol. 5 No 7]. According to the reviewers, studies looking at the relationship of the omega-3 fats to the prevalence of advanced AMD have generally observed a protective effect. A new study by Australian researchers adds to this growing body of evidence, and suggests that regularly consuming omega-3 fat, especially from fish, protects against early and late AMD in older individuals (1).

    Design and Methods

    To assess longitudinal associations between dietary fat and incident AMD, dietary intakes were measured by food frequency questionnaires at baseline in 2895 participants of the Blue Mountains Eye Study (BMES). Since the questionnaires can under- or over-report food consumption, dietary data were verified in a sub- group of participants who completed 4-day weighed food records 3 times over the course of a year. The results were generally in good agreement with the questionnaire data. Seventy five percent of the BMSE cohort (2335 persons) was re-examined after 5 years. Presence of AMD was graded from retinal photographs (Wisconsin ARM Grading System). Logistic regression adjusted for age, sex, vitamin C intake and smoking.

    Results

    The researchers examined the risk of incident AMD participants in the lowest and highest quintiles of dietary fat intakes with respect to the 60% of the population who represent a moderate, normal intake, or those in the middle 3 quintiles. Participants in the highest vs. the lowest quintiles of omega-3 fat intake had a lower risk of incident early AMD (odds ratio 0.41 [0.22-0.75])

    A 40% reduction of incident early ARM was associated with fish consumption at least once a week (odds ratio 0.58 [0.37-0.90]). Consuming fish at least 3 times weekly resulted in about a 70% reduction in the incidence of late AMD (odds ratio 0.25 [0.06-1.00]). (See Table)

    When the intake of specific types of fats was calculated, a trend toward increased risk of developing early AMD was noted for people with the lowest intake of monounsaturated fats and omega-3 including alpha-linolenic acid.

    Comments

    Though several population health studies have linked high dietary fat intake from any source to increased AMD risk, this study found no evidence that dietary fat of any kind raised that risk. The findings are largely in agreement with other studies showing that diets high in omega-3 fatty acids, particularly DHA derived largely from fish, may protect against retinal oxidation and degeneration, according to the authors. They propose that insufficient omega-3 intake could cause abnormal metabolism in the retina and affect cell renewal.

    ORs and CIs of Early and Late ARM with Increasing Frequency of Certain Food Types in BMES Participants*



     

    5-y Incidence, OR (95% CI)

       
       
    Early ARM
    (n = 130)
    Late ARM
    (n = 22)

    Margarine

       
     

    <1/wk

    1.00 (Reference)

    1.00 (Reference)

     

    1-6/wk

    .89 (0.57-1.38)

    1.55 (0.44-5.40)

     

    Daily

    0.87 (0.58-1.29

    0.85 (0.33-2.22)

    Butter

     

    <1/wk

    1.00 (Reference)

    1.00 (Reference)

     

    1-6/wk

    0.48 (0.22-1.02)

    0.82 (0.18-3.76)

     

    Daily

    0.77 (0.48-1.24)

    0.85 (0.27-2.66)

    Total Fish †

     

    < 1/mo

    1.00 (Reference)

    1.00 (Reference)

     

    ≥1/wk

    0.48 (0.37-0.90)

    0.44 (0.16-1.21)

     

    ≥3/wk

    0.62 (0.38-1.03)

    0.25 (0.06-1.00)

    Nuts

      Never

    1.00 (Reference)

    1.00 (Reference)

     

    ≥ 1/wk

    0.80 (0.52-1.25)

    0.82 (0.29-2.34)

     

    ≥ 1/wk

    0.79 (0.46-1.34)

    0.55 (0.14-2.16)


    Abbreviations: ARM, age-related maculopathy; BMES, Blue Mountains Eye Study; CI, confidence interval; OR, odds ratio. *Food types are categorized by frequency of servings. † Includes sardines, tuna, and other fish.

    References

    1. Chua B, et al. Dietary fatty acids and the 5-year incidence of age-related maculopathy. Archives Ophthalmol 124:981-6, 2006.

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  • Discoveries Shed Light on How DHA Helps Protect Against AMD
  • DHA and Cell Survival

    A paper E-published in March, 2006 reports on the role that the omega-3 fatty acid docosahexaenoic acid (DHA) in fish oil plays in protecting cells in the retina from degenerative diseases like age-related macular degeneration and retinitis pigmentosa (1).

    In both of these blinding eye diseases, photoreceptors (rods and cones) degenerate and die. Although this process can be triggered by many different things, one of the most significant protective factors may be the close association of retinal pigment epithelial cells (RPE) and the amount of DHA they contain.

    The main role of RPE cells is photoreceptor maintenance. RPE cells conduct the daily shedding, internalization and degradation of the tips of photo-receptor outer segments. Now it appears that RPE cells are also crucial to the survival of photoreceptor cells.

    Closer to Solving a Complex Riddle

    Both RPE and photoreceptor cells are exposed to potentially damaging factors such as sunlight and high oxygen tension on a daily basis. It's known that antioxidants such as lutein afford some protection, but exactly how these cells avoid harm from these and other factors, has been somewhat of a mystery up to now. However, Nicolas Bazan, MD, PhD, Director of the Neuroscience Center of Excellence at LSU Health Sciences Center in New Orleans, working in col-
    laboration with Harvard researchers, has made several important discoveries that are beginning to provide answers to this complex question.

    One of the answers is the importance of DHA. RPE cells cope with UV and oxidative stress, as well as trauma, by using antioxidants like vitamin E present in cellular membranes. Part of the RPE cells' response to these insults is to activate the synthesis of a major neuroprotective compound called neuroprotectin D1 or NPD1. Oxidative stress and other triggers turn on genes that lead to inflammation and cell death. NPD1 inhibits these genes. RPE cells contain DHA, which has been found to be the precursor to NPD1.

    The DHA - NPD1 Connection

    RPE cells regulate the uptake, conservation and delivery of DHA to photoreceptor cells. In addition to stimulating the production of NDP1, DHA promotes protective cell signaling by facilitating the expression of helpful rather than destructive proteins. DHA and NPD1 also decrease the production of damaging free radicals.

    DHA is known to be in short supply in patients with retinitis pigmentosa and Usher's syndromes, and an oral supply of DHA has been shown to improve the condition of retinitis pigmentosa patients with chronic progressive neurodegeneration (2). Additionally, studies have found that higher dietary intake of DHA is associated with AMD risk reduction. DHA has been shown to promote the survival and inhibit cell death not only of photoreceptor cells, but also of neurons in an experimental model of Alzheimer's disease.

    Other important questions remain, including the identification of another receptor believed to be an important pathway for NPD1, and more information is needed about the signals that control NPD1 formation. It's important to define these initial events, notes Dr. Bazan, since early clinical manifestations of retinal degeneration precedes massive photoreceptor cell death.

    Physiological and pathological features of DHA in photoreceptors

    • Photoreceptor outer segments have the highest DHA content of any cell and have unusual DHA-retention ability.
    • Prolonged dietary deprivation of omega-3 fatty acids is required to reduce DHA content. Only then do function impairments occur.
    • During outer-segment renewal, the retinal pigment epithelium (RPE) recycles DHA back to the inner segments.
    • DHA-supplemented infant formulas enhance:

      • Maturation of retinal function
      • Visual acuity
      • Overall neurological performance in pre-term and term infants
    • Blood DHA levels are decreased in various forms of retinitis pigmentosa, in Usher's syndrome, and in animal models of inherited retinal degeneration.
    • Rodents with rhodopsin mutations that are homologous to mutations in human retinitis pigmentosa display decreased levels of DHA in photoreceptors.
    • In age-related macular degeneration, there is an inverse relationship between diets high in DHA and risk for the disease

    References

    1. Bazan NG. Review. Cell survival matters: docosahexaenoic acid signaling neuroprotection and photoreceptors. Trends in Nueroscience. [Epub ahead of print], March 30, 2006.
    2. Berson EI, et al. Further evaluation of DHA in patients with retinitis pigmentosa receiving vitamin A treatment subgroup analyses. Arch Ophthalmol 122:457-64, 2004.

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  • AREDS Analysis: Antioxidants, Omega-3 and the AMD-CVD Connection
  • CVD & AMD Share Common Risks, Processes

    A Harvard research team led by Dr. Johanna Seddon notes that age-related macular degeneration (AMD) and cardiovascular disease (CVD) share common risk factors, such as smoking and higher body mass index (BMI). They propose that mechanisms involved in developing AMD could be better understood by evaluating biomarkers of CVD. A number of analyses, in fact, have shown that systemic biomarkers for inflammation and artery damage, including C-reactive protein (CRP) and homocysteine (HCY), are related to AMD. Basic research also demonstrates that inflammatory, immune and atherosclerotic processes are related to AMD development.

    To further explore mechanisms related to AMD pathogenesis, these researchers evaluated the relationships between CRP, HCY and other known risk or protective factors for AMD in subjects from the original AREDS trial (1). According to Dr. Seddon, the findings indicate that "sick eyes may occur in sick bodies related to smoking, overweight, inadequate nutrient intake, and other unhealthy behaviors".

    Study Design

    After randomization for AREDS, 934 subjects from two clinical sites underwent blood draws, measurements, photographs of the macula and answered questionnaires. Dietary, behavioral and medical risk, and protective factors for AMD were evaluated for their associations with blood values of CRP and HCY. This original data provided information on intake of fish as well as antioxidants such as vitamins C and E, alpha- and beta-carotene and lutein/zeaxanthin. In addition, serum nutrient values obtained from participants at one of the sites were also evaluated for their association with CRP and HCY. Multivariable regression analyses were performed after adjusting for age, gender and AREDS treatment.

    Results

    Higher levels of serum antioxidants vitamin C and lutein/zeaxanthin and higher fish intake (a source of omega-3 fats) were associated with lower serum CRP levels. CRP levels decreased 2 milligrams per litre for every 1000 microgram per decilitre increase in blood levels of lutein/zeaxanthin. A 0.2 milligram per litre decrease in CRP was also associated with more than 2 servings of fish weekly.

    Increased BMI and smoking were associated with increased CRP, while serum alpha-carotene, dietary intake of antioxidants and vitamin B6 were associated with lower levels of plasma HCY. Levels of HCY were observed to be higher in those with hypertension. While serum vitamin E was linked to lower concentrations of HCY, it was unexpectedly linked to higher levels of CRP.

    Comments

    Factors reported to be related to AMD, namely antioxidants, smoking, BMI, HCY (2) and fish intake, are also associated with inflammatory, immune, or other CVD mechanisms. These results are consistent with previous findings associating smoking, BMI, and the biomarkers CRP and interleukin-6 with AMD in a different study cohort of AMD patients (3).

    The relationship between fish intake, BMI, and levels of inflammatory markers have been previously reported in other "non-ocular" study populations. These data support and expand on these associations. The positive link between higher vitamin E and CRP deserves further study, according to the authors. This finding disagrees with the recent Rotterdam study, which found that vitamin E significantly lowered AMD risk [EduFacts Vol.6 No.1].

    Overall, the Harvard study adds to a growing body of data showing a protective effect of antioxidants such as lutein/zeaxanthin, and omega-3 fats against AMD.

    References

    1. Seddon JM et al. C-reactive protein and homocysteine are associated with dietary and behavioral risk factors for age-related macular degeneration. Nutrition 22:441-43, 2006.
    2. Seddon JM et al. Evaluation of homocysteine and risk of age-related macular degeneration. Am J Ophthalmol 141:201-3, 2006.
    3. Seddon JM et al. Progression of age-related macular
      degeneration: prospective assessment of C-reactive protein, interleukin-6, and other cardiovascular biomarkers. Arch Ophthalmol 123:774-82, 2005.

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  • Fending Off Mental Aging
  • A flurry of recent research suggests that there may be ways to improve our odds of preventing Alzheimer's or age-related mental decline through diet and life-style. Here's a look at some of the promising findings.

    Mental Exercises for Brain Gain

    Lead researchers from Pennsylvania State University report that mental exercise may play a key role in staving off age-related loss of mental agility (1). The research team divided the 2,800+ subjects aged 65 and older into four groups of roughly 700 to receive training in either memory, reasoning or speed of processing, and a control group that received no instruction. Memory training consisted of strategies to remember word lists or texts, such as associating various words, visualizing them or organizing them in specific ways. Reasoning training taught subjects how to spot the pattern in a series of letters or numbers. Processing speed was enhanced by repeated practice in identifying an object on a screen after increasingly shorter visual exposures.

    Training Yields Long Term Improvements

    Participants were asked to appraise their own skills, and indicate whether the training helped with every-day tasks. Practical skills like finding items in a medicine cabinet were also independently evaluated by the scientists. After training, 87% of the speed trainees, 74% of the reason trainees and 26% of the memory trainees showed immediate improvement.

    That advantage over their untrained peers persisted over the next 5 years. Compared to controls, the memory group, for example, was able to remember about 3-4 more words from a list of 12-15. Some who got refresher training 1and 3 years after the initial instruction performed best of all, especially those in the speed-processing group. Tasks like making change for a purchase or reading medication labels were performed more quickly and efficiently.

    Most impressively, the training seemed to largely offset the cognitive decline experienced by nearly of the control subjects. By the end of 5 years, a significant gap had opened between those in the instruction groups and controls. According to one of the study's authors, "to drive this effect, you have to practice things you don't necessary like or things you don't regularly practice". In other words, it may not be quite as simple as doing crossword or sudoku puzzles. In the future, the authors hope to make these training programs more widely available. It's not hard to envision mental exercise programs in senior centers nationwide to help prevent mind decline as we age.

    Dietary Strategies for Brain Fitness

    Research shows that brain levels of DHA decrease with age, and that getting more DHA later in life increases brain content. The December, 2006 issue of Staying Healthy describes a Tufts study which links higher blood levels or intake of DHA (from fish) to a significantly lower risk of Alzheimer's and dementia. A second double-blind study from Sweden found that omega-3 supplements slowed mental decline in people with very mild Alzheimer's, though the group with mild disease was small and no effect was seen in people with more advanced forms (2). In addition, a small study from Japan reports improvements in immediate memory and attention in patients with mild cognitive impairment after taking DHA and arachidonic acid supplements (vs. placebo) for 3 months (3).

    Since the Mediterranean diet is abundant in seafood, it's no surprise that it would also show promise in protecting mental function. But that diet's potential benefits may extend beyond its fish content. Scientists report that subjects most closely following a "Med" style diet consisting mostly of vegetables, legumes, fruits, cereals and some fish were almost 40% less likely to develop Alzheimer's than those with the poorest adherence (see the August, 2006 issue).

    Lastly, a series of studies conducted at Tufts have shown that diets enriched with antioxidant-rich blueberries, strawberries, cranberries or grape juice can reduce or reverse declines in brain function in laboratory animals.

    References

    1. Willis SL, et al. Long-term effects of cognitive training on everyday function outcomes in older adults. JAMA 296:2805-14, 2006.
    2. Freund-Levi Y, et al. Omega-3 fatty acid treatment in 174 patients with mild to moderate Alzheimer disease: OmegAD Study. Arch Neurol 63:1402-8, 2006.
    3. Kotani S, et al. Dietary supplementation of arachidonic and docosahexaenoic acids improves cognitive dysfunction. Neurosci Res 56:159-64, 2006.

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    EPA and DHA for healthy mental function
  • News Bites: Fish as Food for the Brain & Exercise for Eye Health
  • DHA, Fish Lower Risk for Alzheimer's

    Coldwater, fatty fish are a concentrated source of the omega-3 fats docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Population health studies have consistently shown positive health effects from fish consumption and, now, a study published in the November issue of The Archives of Neurology, links greater fish intake to a lower risk of developing Alzheimer's and other dementias (1). And in this study, DHA was most important for cutting risk.

    Using data from the Framingham Heart study, researchers followed about 900 healthy participants for an average of more than 9 years. During that time, 99 people developed dementia including 71 cases of Alzheimer's. Researchers quantified the amount of DHA and fish the participants typically consumed by dietary questionnaires, and measured the level of fatty acids in their blood.

    DHA Cuts Risk of Dementia by Nearly 50%

    The top 25% of study volunteers with the highest blood levels of DHA reduced their risk of developing dementia by 47%. They were about half as likely to develop dementia as the 75% of participants with lower levels of DHA in their blood. The risk reduction was seen even after controlling for other known or suspected risk factors for dementia such as smoking, overweight, high blood pressure and diabetes.

    Participants who ate two or more servings of fish weekly reduced their dementia risk by 39%, while those who ate less had no risk reduction.

    According to the study's authors, the observation that DHA seems to be key in lowering dementia risk is consistent with earlier data showing high levels of DHA in healthy brain tissue and low levels in the brains of people with Alzheimer's. The next step will be to conduct placebo controlled trials of DHA in people who don't yet have Alzheimer's to see whether DHA can help protect against this disease.

    Active Lifestyle Could Protect Against AMD

    Exercise may help protect against age-related macular degeneration (AMD) according to the results of a large study supported by the NIH and published in the British Journal of Ophthalmology (2). The authors examined the relationship between physical activity and AMD because heart disease and AMD appear to share common risk factors. And regular exercise, as we all know, is good for the heart and arteries.

    Participants in the Beaver Dam Eye Study were followed for 15 years. During that time they were given eye exams periodically, and they filled out questionnaires at the beginning of the study to assess their level of activity. They were asked how many flights of stairs they climbed daily, how many city blocks they walked each day, and how often each week they engaged in physical activity that involved working up a sweat.

    Compared with sedentary people, those who participated in regular activity 3 times weekly were less likely to develop wet AMD. Those with an active lifestyle - defined as engaging in an activity that resulted in sweating 3 or more times each week - reduced their risk of wet AMD by 70%. Walking 12 or more blocks daily lowered that risk by 30%.

    Walk Daily, Put More Fish on Menu

    Can't get to the gym or participate in vigorous exercise? Try walking at least a mile daily. Though each city and each block vary in length, walking 8-12 city blocks is roughly equivalent to a mile. It's certainly good for heart and may help your eyesight as well.

    For better mental function as we age, remember that fatty fish is best, and frying fish can cause some deterioration of its DHA content. You can also consider augmenting your intake of DHA and EPA with supplemental fish oil.

    References

    1. Schaefer EJ, et al. Plasma phosphatidylcholine docosahexaenoic Acid content and risk of dementia and Alzheimer disease: the Framingham Heart study. Arch Neurol. 63:1545-50, 2006.
    2. Knudtson MD, et al. Physical Activity and the 15-year Cumulative Incidence of Age-related Macular Degeneration: The Beaver Dam Eye Study. British J of Ophthalmology, published online Oct. 31, 2006.

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    EPA and DHA for healthy lungs
  • Healthful Eating for Better Lung Function
  • Diet May Keep Chronic Lung Disorders at Bay

    You don't smoke, and you avoid second hand smoke and air pollution as much as possible. Are there other steps you can take to help maintain healthy airways and lung function? Well, research suggests that your diet can influence the risk of chronic bronchitis and asthma, and may lessen symptoms for those who already suffer from such conditions.

    Mediterranean-Style Diet Fends Off COPD

    Consuming a "Med"-style diet rich in fruits, veggies and fish may halve the risk of chronic obstructive pulmonary disease (COPD), the umbrella term for chronic bronchitis and emphysema (1).

    Harvard researchers tracked more than 42,000 male health professionals for 12 years, ranking them by how closely they followed a Med style diet or how much they stuck to a Western dietary pattern. After adjusting for age, smoking and other factors, greater adherence to the Med diet was associated with a 50% decrease in COPD risk compared to men with the lowest adherence. At the same time, men who followed a Western style diet most closely were about four and a half times more likely to suffer from newly diagnosed COPD as those who ate the least from that menu.

    The Western diet was defined as one high in processed foods, refined grains, cured and red meats, French fries and deserts. The researchers noted that this diet contains nitrites used to preserve or color foods such as bacon, corned beef, luncheon meats, sausage and ham. Nitrites generate free radical compounds that could contribute to progressive deterioration of pulmonary function. A high-glycemic diet like the Western eating pattern has also been linked to impaired lung function.

    In contrast, a Med-style diet is rich in beta-carotene, vitamins C and E, polyphenols (bioflavonoids), omega-3s, and essential minerals. It is these antioxidants and polyphenols that appear to offer protection. According to the study authors, their findings are consistent with previous study results suggesting a beneficial effect for antioxidants on COPD - particularly vitamin C and, to a lesser extent, vitamin E.

    Fish & Whole-Grains Guard Against Asthma

    A study published late last year also supports components of the Med-style diet as helpful for young asthmatics (2). With the assistance of their parents, Dutch public health researchers assessed the diets of nearly 600 children 8-13 years old.

    The investigators found that whole grains and fish intake were most closely linked with asthma risk. High intakes of whole grains and fish were associated with a 54% and 66% reduction in the odds of having asthma, respectively. Kids who consumed a high intake of both foods experienced significantly less wheezing. Only 4.2% of children who ate the most grains and fish suffered wheezing, while 20% of those eating the least exhibited this symptom.

    It's also worth noting that a diet rich in antioxidants found in fruits and veggies is important for expectant moms. A study conducted by Harvard researchers found that higher maternal intakes of antioxidants during pregnancy decrease the risk for wheezing illnesses in early childhood (3).

    Fish Oil Helps Exercisers with Asthma

    Exercise is a powerful trigger of asthma symptoms in about 80% of asthmatics. Vigorous exercise can cause airways to narrow, resulting in shortness of breath, wheezing and chest tightness. Recently, researchers from Indiana University tested the ability of fish oil to reduce the severity of these symptoms (4). They found that when asthmatics were given high dose fish oil supplements instead of placebos, they had better pulmonary function and needed to use a bronchodilator less frequently after a bout of exercise.

    References

    1. Varraso R, et al. Prospective study of dietary patterns and chronic obstructive pulmonary disease among US men. Thorax (Br Med J) E pub online, May 15, 2007.
    2. Tabak C, et al. Diet and asthma in Dutch school children (ISAAC-2). Thorax (Br Med J) 61:1048-53, 2006.
    3. Litonjua AA, et al. Maternal antioxidant intake in pregnancy and wheezing illnesses in children at 2 y of age. Am J Clin Nutr 84:903-11, 2006.
    4. Mickleborough TD, et al. Protective effect of fish oil supplementation on exercise-induced bronco-constriction in asthma. Chest 129:39-49, 2006.

    - Close


    EPA and DHA as part of a healthy diet
  • Embracing the Mediterranean-Style Diet
  • Chances are that we all know someone who has been diagnosed with coronary heart disease (CHD). It is, after all, one of the most common chronic diseases. Diet is a first line defense for preventing and treating this condition, yet evidence suggests that the benefits of following the Mediterranean diet may outweigh those of low-fat diets often prescribed for people with CHD. In the Lyon Diet Heart Study, for example, the Mediterranean style dietary approach was found to be better than the older American Heart Association's low-fat diet in preventing heart attacks in people with heart disease. It was also more protective against certain cancers.

    What is The Mediterranean Diet?

    This eating pattern is based on the traditional diets of Greece, Crete and southern Italy. The pattern is similar but varies a bit in the 16 countries that border the Mediterranean Sea due to cultural differences. But here's what the overall pattern looks like: lots of vegetables and fruit, whole grain breads, unrefined cereals and dairy daily, with olive oil as the main source of added fat. It calls for fish, poultry and nuts weekly, with very moderate intake of sweets, eggs and potatoes. Red meat is eaten sparingly, about once a week, but moderate red wine is consumed daily.


    Why is This Diet Heart-Healthy?

    The fats you get from the Mediterranean diet are important. At least some of the diet's cardio-protective effects are due to the omega-3 fats found in fish. Fish oils have been shown to reduce the rate of heart attack and stroke over the long term. The diet contains a moderate amount of fat, with more coming from fish and less from red meat. It also relies on fats from heart-healthy nuts and olive (or canola) oil as the primary added fat. This type of fat has a more favorable effect on triglycerides and the "good" HDL cholesterol compared to the more typical low-fat diet. Another important benefit comes from whole grains and unrefined cereals. They offer lots of fiber and essential nutrients, as do vegetables and fruits.

    Embracing the Mediterranean style diet doesn't mean you have to follow it exactly. For one thing, the number of servings will vary depending on body size, level of activity and overall calorie needs. Including foods from your own culinary heritage can be important too. Certain Asian patterns of eating are actually similar to the Mediterranean diet in that they focus on eating less red meat and more plant-based sources of fat and protein. If you use the pyramid as a general guide, here are a few things to keep in mind:

    • Daily physical activity is the foundation of any healthful pyramid. Start by doing what activities you can do, since every little bit helps;
    • Most people, especially non-dairy consumers, may need to take supplemental calcium and vitamin D. A healthy diet pyramid designed by Harvard experts also suggests taking a daily multi-supplement;
    • While moderate alcohol intake is cardio-protective, daily consumption may not be right for everyone. Red wine can be a trigger for some migraine suffers, for example, and older women at risk for breast cancer are advised to limit alcohol consumption.
    • Lastly, if you have an existing disease it's best to follow your health professional/s dietary advice.

    References

    1. Curtis BM et al. Understanding the Mediterranean diet. Postgrad Med 112:online, 2002
    2. Bautista MC et al. The Mediterranean Diet: Is it cardioprotective? Prog Cardiovasc Nurs 20:70-76, 2005.
    3. Kinney JM. Challenges to rebuilding the US Food Pyramid. Cur Opin Clin Nutr Metab Care 8:1-7, 2005.

    - Close


Selenium

Selenium is an essential mineral required for the proper function of glutathione peroxidase, an antioxidant enzyme found in the eye's lens and localized in the photoreceptor and retinal pigment epithelial cells.


Amount of vitamin E (per day) in selected ScienceBased Health products:

Multinutrient Protection for Eyes & Body

OcularProtect provides 100 mcg

Protection for Macular Health

MacularProtect Complete AREDS2 provides 70 mcg


Zinc

Since over 300 metabolic processes depend on this essential mineral, its role in the body is wide-ranging, from helping to keep the skin healthy and the immune system working properly, to supporting sensory functions such as smell, taste and vision. Zinc is particularly concentrated in the eye, where it helps regulate the light-rhodopsin reaction, influences nerve transmission and serves as an antioxidant.


Amount of zinc (per day) in selected ScienceBased Health products:

Multinutrient Protection for Eyes & Body

OcularProtect provides 40 mg

Protection for Macular Health

MacularProtect Complete AREDS2 provides 80 mg

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