In the News: Berries & Vitamin D

Think Purple and Red. Think Health.

Can putting more purple and red produce on the menu really help maintain good health? Mounting evidence says that it can.

Certain red and purple fruits and vegetables owe their color to a type of naturally occurring bioflavonoid called anthocyanins. Bilberries, blueberries, and blackberries are loaded with this flavonoid. Other good contributors include grapes, cherries, raspberries, strawberries, plums, cranberries, and blood oranges. Choosing red cabbage, red onions, and red wines will boost your intake too.

Consuming more anthocyanins, according to two newly published studies, may reduce the risk of developing Parkinson’s as well as support healthier blood pressure.

An Anthocyanin-Rich Diet and Parkinson’s

Experimental studies suggest that anthocyanins may help protect nerve cells and enhance the connections between these cells. Now, Harvard School of Public Health investigators say that if their findings are confirmed, anthocyanins may be one way to reduce the risk of Parkinson’s (1).

A degenerative disease affecting movement and balance, Parkinson’s involves nerve cells in several parts of the brain and nervous system – particularly those that use the chemical messenger dopamine.

After more than 20 years of tracing nearly 50,000 men from the Health Professional Follow-up Study and over 80,000 women from the Nurses’ Health Study, the Harvard team reports that men eating the most flavonoids lowered their risk by 35%. Risk reduction was observed in both women and men who regularly consumed anthocyanin-rich foods specifically.

Anthocyanins Linked to Reduced Blood Pressure

Also led by Harvard researchers, a second study found that the highest intake of anthocyanins – mainly from blueberries and strawberries – reduced the risk of high blood pressure by 12% among people over 60 (2).

The information about blood pressure and diet came from about 150,000 U.S. health professionals. After crunching the numbers, the researchers found that the highest average intakes of anthocyanins ranged from 16 to 21 mg per day – a rather modest amount since a normal serving of blueberries provides in excess of 500 mg. What’s needed now, says this team, are studies that test whether optimal doses of anthocyanin-rich foods can prevent hypertension.

Anthocyanins seem to help regulate blood pressure by influencing the flow of blood through vessels, and the vessels’ ability to expand and contract as needed.

A Role for Vitamin D in Urinary Tract Health?

Adequate vitamin D may increase the body’s immune response, and in doing so, help protect against urinary tract infections (UTIs), according to preliminary but intriguing research from Sweden (3). After menopause, women are more prone to UTIs. And they often have low blood levels of vitamin D as well.

The Swedish scientists measured amounts of a protective, anti-microbial substance made by bladder cells in postmenopausal women before and after they were given vitamin D supplements for 3 months.

Levels of the protective substance went up when the vitamin D enriched bladder tissue was exposed to E. coli bacteria, suggesting that vitamin D prepares the bladder to mount a stronger and faster immune response when bacteria enter the bladder.

In light of the emerging resistance to antibiotics that are used to treat UTIs, we need to fully explore whether improving vitamin D in older women really helps fight off these infections.

References

1. Gao X, et al. Habitual intake of dietary flavonoids and risk of Parkinson disease. Am Acad of Neurology Meeting Abstract, 2011.
2. Cassidy A, et al. Habitual intake of flavonoid subclasses and incident hypertension in adults. Am J Clin Nutr 93:338-47, 2011.
3. Hertting O, et al. Vitamin D Induction of the human antimicrobial peptide cathelicidin in the urinary bladder. PLoS ONE 5:e15580, 2011.