Antioxidant-rich diet may reduce risk of stroke in women

Women who have a diet rich in vegetables and fruits may have fewer strokes regardless of a previous history of cardiovascular disease, a new Swedish study suggests.

In the prospective cohort study, the dietary data of 31,035 women from 49 to 83 years of age without a history of heart disease and 5,680 women with a history of heart disease were analyzed using a food-frequency questionnaire (1). To examine the potential link between antioxidant intake and the risk of stroke, the researchers determined the participants' total antioxidant capacity (TAC), which measures the free radical reducing capacity of all antioxidants in the diet and considers synergistic effects between substances. They then measured the amount of time until the first stroke or death during an average study duration of 10 years. The results showed that higher TAC was related to lower stroke rates in women without cardiovascular disease. Women without cardiovascular disease and the highest levels of dietary TAC had a statistically significant 17% lower risk of total stroke compared to those with the lowest levels. Women with a history of cardiovascular disease and the highest levels of dietary TAC had a statistically significant 46% to 57% lower risk of hemorrhagic stroke compared to those with the lowest levels. The observed association between dietary TAC and stroke persisted even after adjustments for potential confounders related to healthy behavior such as smoking, physical activity and education. For women with no history of cardiovascular disease and the highest TAC, fruits and vegetables contributed to about 50% of the TAC.

The researchers concluded that eating antioxidant-rich foods may reduce the risk of stroke by inhibiting oxidative stress and inflammation. People should eat more foods such as fruits and vegetables that contribute to total antioxidant capacity. Antioxidants such as vitamins C and E and carotenoids can inhibit oxidative stress and inflammation by scavenging the free radicals. Antioxidants may also help improve endothelial function and reduce blood clotting and blood pressure. Further studies would be needed to assess the link between dietary TAC and the risk of stroke in men.

1. Rautiainen S. et al. Total antioxidant capacity of diet and risk of stroke: A population-based prospective cohort of women. Stroke. Published online in December 2011.