Posted on: Saturday, October 16, 2004
PRESCRIPTIONS
B vitamins, exercise may help prevent Alzheimer's
By Amy Tousman
Q. Can B vitamins prevent Alzheimer's disease?
A. The B vitamins niacin, folate, B6, and B12 show promise in the fight against Alzheimer's disease and age-related declines in memory and reasoning. Exercise also may help keep us sharp as we age. Researchers at the Chicago Health and Aging Project studied the diets and intellectual abilities of folks who were at least 65. The more niacin participants consumed, especially from food, the less likely they were to develop Alzheimer's disease over the next four years. Those with the highest niacin intake from food (22.4 milligrams a day) had 80 percent less risk than those with the lowest intake (12.6 milligrams). Higher niacin intakes from food also were associated with fewer symptoms of dementia.
Severe niacin deficiency is a known cause of dementia. This study shows that even slight deficiencies can affect brain functioning. Niacin's importance in DNA synthesis and nerve conduction may be part of the reason. It may also act as an antioxidant in brain cells.
The B vitamins folate, B6 and B12 play a role in both heart health and brain function. These vitamins lower the amount of a substance called homocysteine in the blood. Excess homocysteine damages the blood vessels leading to the heart and brain, along with nerve cells. This can lead to declines in memory and reasoning. High concentrations of homocysteine have been found in the blood of people with Alzheimer's and vascular dementia.
Food sources of brain-friendly B vitamins include cereals, rice, breads, starchy beans, fish and meats. In addition to consuming food sources of B vitamins, I would recommend people older than 65 take a multivitamin that contains approximately 100 percent of the daily value for niacin, folate, B6 and B12.
Exercise also offers protection against age-related declines in thinking ability and Alzheimer's. A Harvard study showed that physically active older women, including those who walked at a leisurely pace two to three hours a week, performed better on tests of memory and thinking than inactive women. Those who exercised more did even better.
University of Virginia researchers found that older men who walked less than a quarter-mile daily had nearly twice the risk of developing dementia as men who walked more than two miles daily.
Exercise triggers the release of substances that protect the brain cells and keep them performing at top speed. It also keeps oxygen and nutrients circulating, which may increase mental alertness.
Amy Tousman is a registered dietitian with the Health Education Center of Straub Clinic and Hospital. Send your questions to Prescriptions, Island Life, The Advertiser, P.O. Box 3110, Honolulu, HI 96802; fax 535-8170 or to islandlife@honoluluadvertiser.com. This column is not intended to provide medical advice.
