Adiposity and Alzheimer's disease

Purpose of review: Alzheimer's disease is the most common form of dementia. There are no known preventive or curative measures. There is increasing evidence for the role of total adiposity, usually measured clinically as BMI, and central adiposity, in Alzheimer's disease. This topic is of enormous public health importance given the global epidemic of high adiposity and its consequences. Recent findings: Salient publications in 2007 and 2008 showed that (a) central adiposity in middle age predicts dementia in old age; (b) the relation between high adiposity and dementia is attenuated with older age; (c) waist circumference in old age, a measure of central adiposity, may be a better predictor of dementia than BMI; (d) lower BMI predicts dementia in elderly people; and (e) weight loss may precede dementia diagnosis by decades, which may explain seemingly paradoxical findings. Summary: The possibility that high adiposity increases Alzheimer's disease risk is alarming given global trends of overweight and obesity in the general population. However, prevention and manipulation of adiposity may also provide a means to prevent Alzheimer's disease. Treatment of weight loss in Alzheimer's disease may also be important but is beyond the score of this review.