In the News: Med Diet & Mood, AMD, & Fish Tips

Can the Med-Style Diet Influence Mood?

Are you eating a diet packed with fruits and veggies, beans, cereals, nuts, olive oil and fish? Including a little red wine? Avoiding junk food and limiting meat and dairy?

If so, you’re following the Mediterranean style diet – a diet that’s good for the heart, the waistline, and for reducing the risk of diabetes and some cancers. Research now suggests that this way of eating might support a positive outlook as well.

Med-Style Diet May Help Battle Depression

Investigators from Spain examined the diets of over 10,000 participants, and each person was assigned a score that reflected how closely their eating habits adhered to a Med-style diet. All the volunteers were free of depression when the study began, and were followed for an average of nearly 4 ½ years. Individuals who followed the Med-style dietary pattern most closely were 30% less likely to suffer from depression than those with the lowest scores (1).

Since these findings simply represent an association between diet and mental outcome, clinical trials will be necessary to confirm them. However, many scientists are convinced that some of the damaging inflammatory and metabolic processes involved in cardiovascular disease also play a role in mental health. In addition, the kinds of fatty acids present in the Med-style diet support good nerve cell function, and the vitamin and minerals this diet provides are needed for the body’s manufacture of neurotransmitters.

Omega-3 Intake and Age-related Vision Loss

Age-related macular degeneration (AMD) is a degenerative disease of the retina that causes loss of central vision. One form, ‘wet’ AMD, occurs when blood vessels grow abnormally beneath the macula and leak, eventually scarring the macula. The other form, ‘dry’ AMD happens when normal tissue in the macular slowly disappears, resulting in a pale area called central geographic atrophy.

It’s known that the omega-3 fatty acids, EPA and DHA, play an important role in the inner layer of nerve cells in the retina, and some studies have already linked better intake of these fatty acids to AMD risk reduction. A new study, involving a sub-group of participants in the AREDS trial, supports these earlier findings.

All of the participants in the study were considered to be at moderate-to-high risk of advanced AMD. Over 12 years of study, the researchers found that intake of omega-3 fats were related to risk for both wet and dry AMD. Those who consumed the most EPA and DHA had a 30% lower risk of developing both types of AMD compared to those who ate the least (2).

How Fish Is Cooked Is Important

Seafood safely is an important consideration. It’s best to eat some of the larger species infrequently, as they may contain more heavy metals and other marine contaminants (see Staying Healthy “Be Savvy about Seafood Safety”, Nov 2009).

Also, be aware that how fish is prepared can influence the heart and eye health benefits of the omega-3 fats they contain. The high heat of frying, for example, can cause deterioration of EPA and DHA, and frying oil also leaches out these fatty acids. Steaming is a good method, and a recent study presented at the 2009 American Heart Association meeting in Orlando, Florida, suggests that baking delivers the heart health benefits of fish better than frying.

References

1. Sanchez-Villegas A, et al. Association of the Mediterranean dietary pattern with the incidence of depression. Arch of Gen Psych 66:1090-98, 2009.
2. SanGiovanni JP, et al. Omega-3 long-chain polyunsaturated fatty acid intake and 12-y incidence of neovascular age-related macular degeneration and central geographic atrophy: a prospective cohort study from the Age-Related Eye Disease Study. Am J of Clin Nutr 90:1601-1607, 2009.