17 October 2005 Alzheimer's Lessened With High Fat, Low Carb Diet
The equivalent of Alzheimer's disease in mice was lessened when treated with a high-fat, low-carbohydrate diet, says a report in the journal Nutrition and Metabolism. The high-fat, low-carb intake, known as a ketogenic diet, reduced levels of the amyloid-beta brain protein, which is an indicator of Alzheimer's disease. Interestingly, the new research seems to contradict earlier studies which suggested fat had a negative effect on Alzheimer's.
"This work supports the premise that key aspects of Alzheimer's disease can be altered by changes in metabolism. It also highlights the interaction of dietary components and how such components influence the metabolic state", said the researchers. They believe that insulin and the related hormone, insulin-related growth factor-1 (IGF-1), are the key players. "Insulin is often considered a storage hormone, since it promotes deposition of fat but insulin may also work to encourage amyloid-beta production."
The editor of Nutrition and Metabolism, Richard Feinman, explained how the relationship between fat and carbs works: "You might say that fat is the bomb, and insulin (from carbohydrate) is the fuse. Most studies of the deleterious effects of fat have been done in the presence of high carbohydrate. If carbs are high, dietary fat is not oxidized and is instead stored as body fat."
But when carbohydrates are very low and fat is high, compounds called ketone bodies are generated and these compounds could play a role in the reduction of amyloid-beta. The researchers had previously shown cognitive improvement in patients with mild Alzheimer's disease who were given a diet that raises ketone bodies.
Feinman said it was too early to tell how the results will fit into the treatment of Alzheimer's disease but the researcher's "effort is one of several recent studies that point the way to understanding metabolism beyond the issues surrounding simple fat reduction."