Antioxidants may not reduce risk of stroke, dementia

February 26, 2013

A study published in Neurology shows that the total level of antioxidants in people’s diets may not protect against stroke or dementia. Antioxidants such as lycopene, beta-carotene, and vitamins C and E are found in many foods.

The study involved 5,395 people, ages 55+, who had no signs of dementia at the start of the study. Participants completed questionnaires about how often they ate 170 foods over the past year at the start of the study. Then the participants were followed for an average of nearly 14 years. Participants were divided into three groups: low, moderate, and high levels of antioxidants in the diet.

About 600 people developed dementia during the study and about 600 people had a stroke. However, researchers found that people with high levels of antioxidants were no more or less likely to develop brain disease than people with low levels of antioxidants. They noted that about 90% of the difference in antioxidant levels in the study was due to the amount of coffee and tea people drank. Coffee and tea contain high levels of nontraditional antioxidants such as flavonoids.

“This differed from an Italian study that found the higher total antioxidant levels were associated with a lower risk of stroke, where the variation from coffee and tea was lower, and the contribution from alcoholic beverages, fruits, and vegetables was higher,” said Elizabeth E. Devore, Harvard Medical School in Boston and Erasmus Medical Center in Rotterdam, Netherlands.