Experiments in mice genetically engineered to develop a form of Alzheimer’s disease show that a diet high in saturated fats and low in carbohydrates reduces levels of the protein amyloid-beta in the brain, which is thought to be one of the key factors in the diseases

Previous studies have suggested that diets rich in saturated fats increase the deposition of amyloid-beta and increase the risk of developing Alzheimer’s, Dr. Samuel T. Henderson and colleagues note in their report in the journal Nutrition and Metabolism. However, those studies did not investigate the effect of a high-fat diet that’s also low in carbohydrates.

In their own experiments, Henderson from Accera, Inc., in Broomfield, Colorado, and colleagues in Belgium used mice that produce high levels of amyloid-beta in the brain and extensive plaque deposition.

Eight of the animals were fed a standard high-carbohydrate low-fat diet. Another eight mice were fed a diet very low in carbohydrates and high in fat for 43 days beginning at three months of age.

Levels of amyloid-beta were significantly reduced - by about 25 percent - during the high-fat low-carb diet, though levels were not related to weight change or brain protein content.

“The data presented here,” Henderson’s group concludes, “suggested that it may not be fats in the diet that increase amyloid-beta levels, but perhaps levels of total calories, carbohydrates, or the metabolic state of the animal.”

SOURCE: Nutrition & Metabolism, October 17, 2005.