Want to prevent Alzheimer’s disease? Eat less!

Want to prevent brain diseases like Alzheimer’s disease or simply slow age-related mental decline? Forget about taking B vitamins like B6, B12 and folate, according to one study. Instead reduce your intake of calories, according to another study.

B vitamins have been known to be beneficial to the brain. But if you have already got a brain disease like Alzheimer’s, then taking B vitamin supplements does not seem to help you, according to a study in the Oct. 15 issue of The Journal of the American Medical Association.

The study found people who had had Alzheimer’s disease and then took high doses of B vitamins simply did not experience beneficial effect on the primary cognitive measure. Paul S. Aisen coauthor of the study at the University of California in San Diego, California warned that people should not count on taking high doses of B vitamins to slow mental decline.

A review published in the Nov 2008 issue of Current Opinion in Clinical Nutrition and Metabolic Care suggests, however, that by restricting your intake of calories, a practice known as caloric restriction, you may not have to contract Alzheimer’s disease in the first place.

The review led by Gillette-Guyonnet S and Vellas B. from aGérontopôle Toulouse, France bInserm, U558, Toulouse, France says caloric restriction does not just extend lifespan, but may benefit brain functioning as well.

The authors say in their report that “it has been proven that caloric restriction prevents age-related neuronal damage.” The only thing that remians uncertain is how caloric restriction affects brain functions.

They predict there might be a possibility in the future that this dietary practice will be proposed to prevent or even to treat neurodegenerative disorders such as Alzheimer’s disease.

The idea is not too far-fetching. Caloric restriction could help cognitive capability through “anti-inflammatory mechanisms, reduction of neural oxidative stress, promotion of synaptic plasticity, induction of various stress and neurotrophic/neuroprotective factors,” according to the authors.

It is known for a fact at least that caloric restriction may prevent beta-amyloid neuropathology in Alzheimer transgenic models.

Reading the reports of these two studies, what are we going to do with the risk of brain diseases like Alzheimer’s or Parkinson’s disease?

We now know that next time we go to some China Buffet, we’d better not eat too much because caloric restriction is known to extend out lifespan, probably by protecting against Alzheimer’s and many other chronic diseases.

But we should not forget taking B vitamins regardless of the Aisen study because these vitamins are beneficial to the brain.

The Aisen study was not meant to explain why B vitamins folic acid, B6 and B12 do not work for Alzheimer’s patients. It’s possible that patients did not take the vitamin supplements properly or simply they could not absorb these nutrients.

Early studies have found that deficiency of these vitamins were linked to high risk of Alzheimer’s, suggesting that these patients were likely unable to absorb these vitamins properly.

Alzheimer’s disease affects an estimated 4.5 million Americans, according to the U.S. National Institutes of Health. About 5 percent of people ages 65 to 74 and almost half of those ages 85 suffer the disease.

There is no cure for Alzheimer’s. People with the disease may experience memory loss, difficulty to trouble remembering recent events, activities, or the names of familiar people or things. This disease does not result from normal aging.