By Will Dunham WASHINGTON, Jan 8 (Reuters) - Higher intake of the nutrient folate may reduce the risk of developing Alzheimer's disease, but vitamin B12 and vitamin B6 did not yield the same benefit, a study published on Monday found. The study, led by Dr. Jose Luchsinger of Columbia University Medical Center in New York, looked at 965 people age 65 and older in Manhattan. Those with higher levels of folate through diet and supplements were less likely to get the devastating brain ailment, the study found. Alzheimer's disease is the leading cause of dementia among the elderly. This was the latest study to indicate folate may protect against Alzheimer's disease, perhaps by breaking down an amino acid in the blood called homocysteine, but Luchsinger said it was premature to recommend increasing folate intake. "I can't emphasize enough that there has to be great caution. This is one more study that supports the notion that folate is beneficial. However, there have been cases in the past where what these studies show does not pan out in clinical trials," Luchsinger said in an interview. The study was published in the journal Archives of Neurology. Folate is a B vitamin the body needs to make healthy new cells. It is found in foods such as leafy green vegetables like spinach, citrus fruits and beans. Folic acid is its form found in dietary supplements and in fortified foods. Elevated homocysteine levels also are linked to a higher risk for cardiovascular disease and stroke. The vitamins that affect homocysteine levels are folate, vitamin B12 and vitamin B6. "We studied whether the dietary intake of the vitamins that are related to homocysteine was also related to the risk of Alzheimer's disease," Luchsinger said. "And what we found was that with folate, but not vitamin B12 and not vitamin B6, the higher intake was related to lower risk of Alzheimer's disease over time." Between 1992 and 1994, the researchers examined, interviewed and reviewed the diets of 965 people, with an average age near 76, who did not have dementia, then tracked them for an average of about six years. Of these, 192 people developed Alzheimer's disease. Higher folate intake was weakly associated with lower homocysteine levels, the study found. There is no known cure for Alzheimer's disease, which gradually destroys a person's memory and ability to learn, reason, make judgments, communicate and carry out daily activities.
