Antioxidants on the Brain
Study suggests antioxidants may not reduce the risk of developing dementia or stroke
Antioxidants have long been thought to reduce the possibility of developing dementia. However, a recent study that was published in the February 20, 2013 online issue of Neurology, the medical journal of the American Academy of Neurology, suggests otherwise.
According to this study, diets that consist of various antioxidants containing foods such as vegetables, fruits, spices and cocoa powder may not affect the risk of dementia or stroke.
The study, which was supported by the Netherlands Organization for Scientific Research and the U.S National Institutes of Health, had 5,395 participants ages 55 and above. Participants showed no prior symptoms of having dementia. At the beginning of the study, participants were asked to fill out questionnaires concerning their food intake of 170 different foods over the past year. They were then followed for an average of 14 years.
Researchers divided participants 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. But 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.
“It is possible that individual antioxidants, or the main foods that contribute those antioxidants – rather than the total antioxidant level in the diet – contribute to the lower risk of dementia and stroke found in earlier studies,” said Elizabeth E. Devore, the study’s co-author from Harvard Medical School in Boston and Erasmus Medical Center in Rotterdam, Netherlands, who examined the study of aging.
Antioxidants are substances that help protect the body from the effects of free radicals. Free radicals are molecules that can possibly increase the risk of developing heart disease, cancer and cell damage. Devore says that caffeine and tea, which consist of high levels of antioxidants such as flavonoids, contributed to 90 percent of the difference in antioxidant level in the recent study.
According to Devore, this study is interesting as it contradicts other studies that suggest antioxidants such as lycopene, beta-carotene, and vitamins C and E protect individuals from developing stroke or dementia. The Italian study that most closely contradicts Devore’s study discovered higher total antioxidants levels did relate to a lower risk of stroke.
“One issue could be that the Italian study had higher relative contributions of antioxidants in fruits and vegetables than coffee and tea. And to me, it was essentially important to explore this study looking into specific antioxidants in comparison to overall antioxidant rich foods,” Devore says.
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