High Protein Diet and AD

Contributed by: Michael Rafii, M.D., Ph.D - Director of the Memory Disorders Clinic at the University of California, San Diego. ______________________________________

A research team from the US, Canada, and the UK have concluded a study comparing the relationship between four different diets and Alzheimer's pathology in mice.

For 14 weeks the mice were fed one of four diets: (1) a regular (reference) diet; (2) a high fat/low carbohydrate diet; (3) a high protein/low carbohydrate diet; or (4) a high carbohydrate/low fat diet. After this, the researchers did post mortem analyses on the brains of the mice and measured their weight, plaque build up and structural differences in those regions known to be involved in the memory defects of Alzheimer's disease.

Amyloid Precurser Protein's role in the brain is not fully understood; however it is of great interest to AD researchers because the body uses it to generate the amyloid plaques typical of Alzheimer's. For each diet group, the researchers looked at the brain and body weight of the mice, as well as plaque build up and differences in the structure of several brain regions that are involved in the memory defect underlying AD. Unexpectedly, mice fed a high protein/low carbohydrate diet had brains five percent lighter that all the others, and regions of their hippocampus were less developed.

However, until researchers test for this effect in non-genetically engineered mice, it remains unclear whether the loss of brain mass is linked to the amyloid plaque found in Alzheimer's disease. The only way to verify this in humans would be to do prospective randomized double blind diet trials.