Diet full of antioxidants helps cut stroke risk

By David Liu, Ph.D. and editing by Stacey Sexton

Eating a diet full of antioxidants may help reduce the risk of stroke in women, a study published in the Dec 1, 2011 issue of the journal Stroke suggests.

The study, led by S. Rautiainen of Karolinska Institute in Stockholm, Sweden and colleagues, found that healthy women who ate a diet with the highest total antioxidant capacity (TAC) were 17 percent less likely to suffer a stroke compared to those who ate a diet with lowest TAC.

For the study, the researchers followed 31,035 cardiovascular disease (CVD) free women and 5,680 women with a history of cardiovascular disease from Sept. 1997 through Dec. 2009.  During the follow-up, 1,322 cases of stroke were identified among CVD-free women, including 988 cerebral infarctions, 226 hemorrhagic strokes and 108 unspecified strokes. Among women with a history of CVD, 1,007 cases of stroke were identified, including 796 cerebral infarctions, 100 hemorrhagic strokes and 111 unspecified strokes.

In addition to the association found in healthy women who were free of cardiovascular disease at baseline, the researchers found similar associations in women with a history of cardiovascular disease.

Among women with a history of CVD, those who had an intake of antioxidants in the highest quartile were 10 percent less likely to suffer total stroke and 45 percent less likely to experience hemorrhagic stroke compared with those whose intake of antioxidants was in the lowest quartile.

The study is not a trial and it does not prove that eating a diet rich in antioxidants helps prevent stroke. But it is possible that antioxidants help reduce risk. Antioxidants can inhibit oxidative stress and inflammation, which scientists believe lead to strokes.

Stroke occurs when a clot blocks the blood flow to the brain or when a blood vessel in the brain bursts.  It is the third leading cause of death in the U.S. An estimated 137,000 men and women in the country die of stroke each year, according to the U.S. Centers for Disease Control and Prevention.

People with medical conditions such as high blood pressure, high blood cholesterol, heart disease, diabetes or sickle cell disease are at high risk for a stroke.  Those who are overweight or obese or have had a previous stroke or transient ischemic attack are also at high risk.  Smoking, drinking alcohol and physical inactivity boost the risk of stroke.

Eating a healthy diet has been associated with reduced risk of strokes.  Antioxidants are mostly found in fruits and vegetables.   Foods that have highest total antioxidant capacity include, in descending order, small red beans, wild blueberries, red kidney beans, pinto beans, cranberries, artichoke hearts, blackberries, prunes, raspberries, strawberries, red delicious apples, granny smith apples, pecans, sweet cherries, black plums, Russet potatoes, black beans, plums and gala apples.

Common antioxidants are vitamin A or retinol, vitamin C and vitamin E.    Other antioxidants in foods include carotenoid terpenoids such as alpha carotene, astaxanthin, beta-carotene, canthaxanthin,  lutein, lycopene,  zeaxanthin;  flavonoid polyphenolics; phenolic acids; nonflavonoid phenolics such as curcimin, flavonolignans, xanthones, and eugenol; and some organic antioxidants such as citric acid, capsaicin, and uric acid.