Antioxidants and risk of stroke

Stroke remains one of the main causes of death and morbidity worldwide. Epidemiological studies indicate that environmental factors, such as diet, play a role in the risk of stroke. Fruits and vegetables are our main dietary suppliers of antioxidants, and some contain high levels of popular antioxidants ascorbic acid, beta-carotene and vitamin E. Randomized controlled studies investigating the effect of the intake of these three antioxidants as supplements have failed to find a reduction in stroke. But fruits and vegetables are also rich sources of a broad range of phytochemicals, most of which have strong antioxidant capacities. Antioxidants may reduce the process of atherosclerosis by neutralizing free radicals, but also by improving the endothelial function, lowering blood pressure and reducing inflammation.

Study results

Lead author Daniele Del Rio from the University of Parma, Italy, reported in the Journal of Nutrition that antioxidants may play a role in reducing the risk of cerebral infarction [1]. This study investigated the relation between dietary total antioxidant capacity and risk of ischemic and hemorrhagic stroke in 41,620 men and women. They also found that a high intake of vitamin E could be positively associated to the risk of brain hemorrhagic events.

A more recent study found that the more antioxidants a women eats the less chance that she will suffer from stroke [2]. For this study, Wolk and co-workers used the results of the large Swedish Mammography Cohort that included 36,715 women who were followed during a period of about 11 years. In the group of women who had no cardiovascular disease at baseline, those with the highest intake of antioxidants had a 17% lower risk of total stroke when compared with those with the lowest intake. The study concluded that total antioxidant capacity of the diet may be of importance for the prevention of stroke among women free from cardiovascular disease and for the prevention of hemorrhagic stroke among women with a history of cardiovascular disease.

Resources

[1] Total antioxidant capacity of the diet is associated with lower risk of ischemic stroke in a large Italian cohort. J Nutr. 2011 Jan;141(1):118-23.
[2] Total Antioxidant Capacity of Diet and Risk of Stroke: A Population-Based Prospective Cohort of Women. Stroke. 2011 Dec 1.