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 has found.

The study, led by Dr Jose Luchsinger of Columbia University Medical Centre 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.

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