New research suggests that eating a high-fat diet may increase the risk of developing Alzheimer's disease.

Frédéric Calon and colleagues from Université Laval in Quebec found that mice fed a diet containing high levels of animal fat and low levels of omega-3 fatty acids had elevated levels of tau protein and amyloid-beta – both of which are hallmarks of Alzheimer's disease - in their brains.

Study results showed that the brains of mice fed a high-fat diet for nine months had 1.5-times more tau protein, the protein found in neurofibrillary tangles, and 8.7-times more amyloid-beta, the main constituent of amyloid plaques, than control mice fed a normal diet containing 7-times less fat. Furthermore, the mice fed the high-fat diet also had decreased cortical levels of the postsynaptic marker drebrin, another feature of Alzheimer's disease.

The researchers conclude that their findings suggest that eating a high-fat diet that contains little omega-3 “promote Alzheimer's disease-like neuropathology.”

Julien C, Tremblay C, Phivilay A, Berthiaume L, Émond V, Julie P, Calon F. High-fat diet aggravates amyloid-beta and tau pathologies in the 3xTg-AD mouse model. Neurobiology of Aging. DOI: 10.1016/j.neurobiolaging.2008.08.022