Antioxidants in coffee and tea may not reduce risk of stroke or dementia

According to a new study, increased intakes of antioxidants found in coffee and tea, such as flavonoids, do not seem to decrease the risk of developing stroke or dementia for elderly people. Other studies observed potential preventive effects of higher consumptions of fruits and vegetables containing antioxidant beta-carotene and vitamins C and E.

The observational study involved 5,395 people aged 55 and older with no signs of dementia or stroke at the beginning (1). Participants were asked to complete questionnaires about how often they ate 170 foods over the past year at the start of the study, and the food-specific total antioxidant activity of their diet was calcu-lated. Afterwards, cases of dementia and stroke were documented for an average of nearly 14 years. The study results showed that participants consuming diets with high levels of antioxidants were no more or less likely to develop dementia or stroke than people with low levels of antioxidants in their diet.

The researchers commented that these results are interesting because other studies have suggested that higher total antioxidant levels of diets may help protect against stroke and dementia. However, they noted, about 90 percent of the difference in the diets’ antioxidant levels observed in their study was due to the amount of coffee and tea – containing high levels of antioxidants such as flavonoids – people consumed. In studies showing potential preventive effects of antioxidants, participants consumed less coffee and tea and more fruits and vegetables which contain antioxidants such as beta-carotene and the vitamins C and E. Thus, a person’s overall intake of antioxidants appears to be less important than the fact that they eat certain antioxidant-rich foods, especially fruits and vegetables.

1. Devore E. E. et al. Total antioxidant capacity of the diet and major neurologic outcomes in older adults. Neurology. Published online February 2013.