TUESDAY, Jan. 9, 2007 (HealthDay News) -- People with higher levels of the nutrient folate from both diet and supplements may have a lower risk of Alzheimer's disease, a new study says.
The study by researchers at Columbia University Medical Center in New York City included 965 people, average age 75.8, who were followed for an average of 6.1 years. None of them had dementia at the start of the study.
During the follow-up period, 192 of the study participants developed Alzheimer's disease. Those with a higher intake of folate from both diet and supplements had a lower risk of Alzheimer's than other people in the study. However, neither dietary intake of folate nor supplements alone had an effect; only the two in combination appeared to produce a benefit, the researchers said.
The researchers found that higher folate intake was modestly associated with lower levels of the amino acid homocysteine in the blood. Elevated levels of homocysteine in the blood are associated with increased risk for cardiovascular disease and stroke and may also boost the risk for Alzheimer's disease.
The finding that higher folate intake is linked with lower homocysteine levels indirectly suggests "that a lower homocysteine level is a potential mechanism for the association between higher folate intake and a lower Alzheimer's disease risk," the study authors wrote.
The researchers noted that more study is needed to determine whether increasing folate intake can help prevent Alzheimer's disease.
The study was published in the January issue of the journal Archives of Neurology.
According to the National Institutes of Health, folate -- also known as folic acid -- works with vitamin B-12 and vitamin C to help the body digest and utilize proteins and to synthesize new proteins when they are needed. It's necessary for the production of red blood cells and the synthesis of DNA.
Folic acid also helps with tissue growth and cell function. In addition, it helps to increase appetite when needed and 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 NIH.
More information
The U.S. National Institute on Aging has more about Alzheimer's disease.
