FRIDAY, Jan. 19, 2007 (HealthDay News) -- Dutch researchers have added another chapter to the continuing debate over whether folic acid supplements can sharpen the aging mind. Their conclusion: The nutrient does improve cognitive function in older adults.
Previous studies on the subject have been split, although most have suggested that folic acid supplementation in people with high levels of the amino acid homocysteine in the blood helps with cognitive function. Higher homocysteine levels are associated with an increased risk for cardiovascular disease and stroke and possibly also Alzheimer's disease.
The new study, published in the Jan. 20 issue of The Lancet, adds to the growing impression that adding folic acid can help brain functioning, at least in certain groups of people.
"We can certainly take away that folate is going to be beneficial for cognitive improvement when you have high homocysteine levels," said Maria Carrillo, director of medical and scientific relations at the Alzheimer's Association.
"This underscores the importance of B vitamins," added Richard Finnell, Regents Professor in the Center for Environmental and Genetic Medicine at Texas A&M's Health Science Center Institute of Biosciences and Technology at Houston. "They do more than protect babies against birth defects."
Folic acid, or folate, is a B vitamin probably best known for its role in helping to prevent neural-tube defects in newborns.
But folic acid also has several other functions: It helps the body digest and utilize proteins and to synthesize new proteins when they are needed; it's essential for the production of red blood cells and the synthesis of DNA; it helps with tissue growth and cell function; it helps to increase appetite when needed; and it stimulates the formation of digestive acids.
Food sources of folate include beans and legumes; citrus fruits and juices; wheat bran and other whole grains; dark, green leafy vegetables; poultry; pork; shellfish and liver, according to the National Institutes of Health.
Cognitive function, especially areas such as information processing speed and memory, decline with age. These cognitive changes have been linked to a risk of dementia.
For this study, first reported at the Alzheimer's Association's 2005 prevention conference, researchers randomly assigned 818 older adults in Holland, aged 50 to 70 years old, to receive 800 micrograms of folic acid supplementation daily or a placebo for three years.
All participants had low folate levels, as evidenced by elevated homocysteine concentrations.
Adults who received the folic acid supplementation had improved cognitive functioning, especially in the areas of memory and information processing speed. What's more, folate concentration increased 576 percent in those getting the supplements, and homocysteine levels fell 26 percent.
"Folate can help people with high homocysteine levels," Carrillo confirmed. "This is in line with what we have been thinking."
The same Dutch researchers, reporting in the Jan. 2 issue of the Annals of Internal Medicine, found that people who took a folic acid supplement had less decline in hearing low-frequency sounds over time, compared with people who didn't take the supplement.
More information
The National Institute on Aging has more on aging and dietary supplements, including vitamins and minerals.
