People in their 40s with larger stomachs have a higher risk for dementia when they reach their 70s, according to a study published in the March 26, 2008, online issue of Neurology®, the medical journal of the American Academy of Neurology.
Previous studies have looked at central obesity (as determined by waist circumference) and body mass index in the elderly and its link to dementia risk. In addition, previous studies have shown that a large abdomen -- in midlife -- increases the risk of diabetes, stroke, and coronary heart disease. This is the first time researchers have demonstrated a longitudinal association between midlife belly fat and the risk of dementia.
Capturing abdominal obesity in midlife may be a much better indicator of the long term metabolic dysregulation that leads to dementia risk, said study author Rachel Whitmer, PhD, a research scientist at the Kaiser Permanente Division of Research in Oakland, CA. Measuring abdomen size in older age people may not be as good an indicator because as people age they tend to naturally lose muscle and bone mass and gain belly size, she explained.
“Considering that 50 percent of adults in this country have abdominal obesity, this is a disturbing finding. It is well known that being overweight in midlife and beyond increases risk factors for disease. However, where one carries the weight –especially in midlife -- appears to be an important predictor for dementia risk,” she said.
“Autopsies have shown that changes in the brain associated with Alzheimer's disease may start in young to middle adulthood, and another study showed that high abdominal fat in elderly adults was tied to greater brain atrophy. These findings imply that the dangerous effects of abdominal obesity on the brain may start long before the signs of dementia appear.” She explained that additional research needs to be completed to determine the underlying mechanisms that link abdominal obesity in midlife to dementia risk.