Oxidative stress, an imbalance between the production of free radicals and the ability of the body to counteract their harmful effects, has been implicated as a key mechanism in dementia. Consequently, antioxidants have been of interest as a potential treatment for the condition.
A study, published in JAMA Neurology
(online, 20 March 2017), observed 7,540 older men for an average of 5.4 years and a subset of 3,786 men for up to 6.0 additional years. The men received either vitamin E or selenium alone, a combination of both, or a placebo.
The researchers found that the incidence of dementia (325 of 7,338 men; 4.4%) did not differ between the four study groups. They conclude that neither vitamin E nor selenium should be recommended as a preventive agent but identified the inclusion of only men and the relatively short supplement exposure time as key limitations of the study.