Antioxidants and the Brain

As we age, our brains experience the loss of cells, particularly in the cerebral cortex. That loss is often experienced as cognitive decline — and can be slowed through things like exercise and continual mental engagement — but can become severe enough to interfere with daily life, a condition known as dementia.

Much of this loss is due to oxidative stress (OS) — the presence of reactive oxygen species, commonly known as “free radicals” — in the brain. Many scientists hypothesize that both Alzheimer’s disease and vascular dementia have their roots in OS. One promising approach to battling OS might be to increase in antioxidant intake, since those chemicals (most commonly vitamin C, vitamin E, vitamin A, and beta carotene) help eliminate that reactive oxygen.

Some early studies were encouraging — for instance, showing a protective effect for vascular dementia from supplementation of vitamins C and E (Masaki, 2000), and for Alzheimer’s disease with supplements of vitamins C and E, beta carotene, and flavonoids (Engelhart, 2002). Another showed that vitamin E from food rather than supplements was associated with a reduced risk of Alzheimer’s disease, though only in individuals with a particular genetic variant (Morris, 2002).

However, many studies proved inconclusive. More recent analysis of the available literature shows no benefit from vitamin E supplementations, inconsistent results from combinations of vitamins E and C. One survey of current research (Devi, 2009) did show a positive effect with the use of vitamin E, but only when combined with exercise, where this synergistic combination slowed the loss of synaptic connections and helped maintain vital communications in the brain.

Though more research is needed to clarify the role of antioxidants in brain function, filling your diet with natural sources of antioxidants will also help you ingest other brain-friendly nutrients such as B vitamins, folate, and polyunsaturated fatty acids. And remember, when it comes to boosting brain power, there’s no magic pill, so stay sharp by keeping up with those other Brain Commandments.


Devi, A. (2009). Aging brain: prevention of oxidative stress by vitamin E and exercise. The Scientific World Journal, 9, 366–372.

Department of Psychiatry, University of California, San Francisco, and San Francisco VA Medical Center, CA, USA. (2004).  Impact of antioxidants, zinc, and copper on cognition in the elderly. Neurology, 63, (9), 1705–1707.

Engelhart, M.J., Geerlings, M.I., Ruitenberg, A., van Swieten, J.C., Hofman, A., Witteman, J.C. & Breteler, M.M. (2002). Dietary intake of antioxidants and risk of Alzheimer disease.” JAMA, 287, 924), 3223-9.
Masaki, K.H., Masaki, K.H., Losonczy, K.G., Izmirlian, G., Foley, D.J., Ross, G.W., Petrovitch, H., Havlik, R., & White, L.R. (2000). Association of vitamin E and C supplement use with cognitive function and dementia in elderly men. Neurology, 54, (6), 1265-72.
Bjelakovic, G., Nikolova, D., Gluud, L.L., Simonetti, R.G., & Gluud, C. (2007). Mortality in randomized trials of antioxidant supplements for primary and secondary prevention: systematic review and meta-analysis. JAMA, 297, (8), 842-57.