Belly Fat in Midlife, Dementia Later?
Study Shows Getting a Big Belly in Midlife Ups Risk of Dementia Later in Life
Belly Fat and Health: How Much Is Too Much?
How to tell if your belly fat is a health risk? Men who have a waist circumference over 40 inches and women with a waist circumference over 35 inches are at greater risk, says Whitmer, citing National Institutes of Health guidelines.
While Whitmer's study didn't look at why belly fat increases dementia risk, she can speculate. "We are hypothesizing that the mechanism must have something to do with some of the substances the belly fat secretes," she says, "and those may have an effect on the brain."
The study results make sense to two other experts not involved in the research. "It fits quite nicely with all the other data that suggest vascular risk factors are also risk factors for dementia and Alzheimer's disease," says William H. Thies, PhD, vice president of medical and scientific relations for the Alzheimer's Association in Chicago.
While the study didn't investigate whether reducing belly fat reduces risk, Thies says, it's still a good idea for those with big bellies to work on reducing them through diet and exercise. "Ultimately there is enough data in other places to say changing your central obesity [belly fat] is good for your health."
"It's another piece of information that midlife cardiovascular risk factors are not just bad for your heart, they are bad for your brain," says David Bennett, MD, director of the Rush Alzheimer's Disease Center at Rush University Medical Center in Chicago.
Where you carry your weight is somewhat genetically determined, Whitmer says. Some people are ''apple" shaped, carrying excess belly fat, while others are more "pear" shaped, carrying excess weight in their hips and thighs.
"If you are apple shaped and do carry fat around your middle," she says, "be really aware you are at greater risk. One message is, if you can't lose the weight, lose the belly."