High-Fat Diet Increases Levels of Beta Amyloid

A diet high in fat, cholesterol, and sugar has been implicated in Alzheimer's. But how might it contribute? By increasing the level of beta-amyloid—a hallmark of Alzheimer's—in the brain and cerebrospinal fluid, a new pilot study suggests. It was headed by Suzanne Craft, Ph.D., of Wake Forest University and reported in JAMA Neurology.

The study included 20 older adults with normal cognition and 27 with mild cognitive impairment, which is often a precursor to Alzheimer's. Levels of beta amyloid in subjects' cerebrospinal fluid were compared. The subjects with mild cognitive impairment had more beta amyloid in their cerebrospinal fluid than did the cognitively normal subjects. The subjects were then randomized to a high-fat or low-fat diet for four weeks. The researchers assessed whether the diets affected the levels of beta amyloid in cerebrospinal fluid. The high-fat diet increased such levels; the low-fat diet lowered them. The results not only suggest how an unhealthy diet may contribute to Alzheimer's, but imply that changing one's diet might be one way to lower Alzheimer's risk.

Among potentially effective factors that might reduce Alzheimer's risk are increased physical activity and memory training, but more and larger controlled trials are needed to confirm preliminary findings on these factors. See Psychiatric News here. More information about Alzheimer's drugs in clinical trials can be found in Psychiatric News here.

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