Consuming at least 400 mcg of folate (folic acid) daily could reduce your risk of developing Alzheimer's disease by 55 percent, according to a recent study in the journal Alzheimer's & Dementia (2005, vol. 1, no. 1). Folate, one of the B-vitamins, is abundant in fruits (especially oranges and melons), green leafy vegetables, liver, eggs, many beans and peas, and enriched breads and cereals. Unfortunately, processing or cooking often destroys the nutrient.

Researchers from the University of California, Irvine, compared daily diet and supplement diaries provided by 579 volunteers older than 60; of those, 57 eventually developed Alzheimer's disease. Results showed that participants who reached or surpassed the 400 mcg recommended daily allowance of folate by taking supplements reduced their risk of developing the disease.

Coauthor Claudia Kawas, MD, says that factors other than increased folate consumption may also have contributed to the risk reduction. People who get the RDA of folate through their diet and/or supplements, she says, may also get the RDA of other nutrients and, in general, lead healthier lifestyles. She and lead author Maria Corrada, ScD, say more studies are needed to substantiate the causes for the risk reduction.