B vitamins. In 20 trials that randomly assigned people to take high doses of three B vitamins (folic acid, B-6, and B-12) or a placebo, not much happened.
In the Women’s Antioxidant and Folic Acid Cardiovascular Study on 5,442 people at high risk of heart attack or stroke, for example, the B vitamins had no effect on memory. They did seem to help women who got low levels of the vitamins from their food, though the study wasn’t designed to answer that question.
“It’s critically important for brain health to ensure that one is not deficient in folate, B-12, and B-6,” says Jae Hee Kang, assistant professor of medicine at Harvard Medical School and the Brigham and Women’s Hospital in Boston. “However, for most people, who have adequate intakes, B vitamin supplements are unlikely to help.”
Antioxidant vitamins. Taking high doses of vitamin E (600 IU every other day), beta-carotene (83,333 IU every other day), and vitamin C (500 mg a day) for nine years had no impact on memory or cognition in 2,824 women at high risk of cardiovascular disease.
“In one of our trials, men who took beta-carotene for about 18 years did have a benefit,” notes Kang. But in other trials, high doses raised the risk of lung cancer in smokers or former smokers. So it’s not worth the risk even if you’ve never smoked.
Other supplements. In nearly 6,000 men participating in the Physicians’ Health Study, those who took an ordinary multivitamin for seniors (Centrum Silver) for 12 years did no better on cognitive tests than those who took a placebo.
And studies have largely come up empty on phosphatidyl serine, vinpocetine, huperzine-A, and ginkgo, which are often added to “memory” supplements.
Sources: Am. J. Clin. Nutr. 88: 1602, 2008; Circulation 119: 2772, 2009; Arch. Intern. Med. 167: 2184, 2007; Ann. Intern. Med., in press.