Here's an article by Erin Allday about this on from the SF Gate:
Middle-aged people with excess visceral fat - usually apparent in the thick waist or pot belly of an apple-shaped body - are nearly three times more likely to suffer from dementia in their 70s and 80s than people with little to no belly fat, according to a study of Kaiser Permanente patients.
Researchers have long connected obesity, diabetes and heart disease to dementia. The new study - published today in Neurology, the journal of the American Academy of Neurology - suggests that the effect of fat on the body is more complicated than just a number on a scale.
"People need to think not just about weight, but where they carry their weight," said Rachel Whitmer, a research scientist at Kaiser's Division of Research in Oakland and lead author of the study. "They need to know if they're apples or pears."
People with pear-shaped bodies tend to carry most of their weight below the waist, in the hips, buttocks and thighs. People with apple-shaped bodies are at greater risk of having too much visceral fat surrounding internal organs deep in the abdominal cavity. Visceral fat is more common in people who are overweight, but even a very lean person with a small pot belly could have hidden visceral fat.
Researchers don't yet understand why visceral fat is particularly dangerous, but the fat is metabolically active and doctors think it may release toxins associated with atherosclerosis or plaque build-up in the brain that is apparent in people with Alzheimer's disease, Whitmer said.
In the Kaiser study, researchers looked at records from patients in their 40s and 50s who had their abdominal fat measured in the 1960s and '70s. Of the 6,583 patients studied, 15.9 percent had been diagnosed with dementia by 2006.
Among patients with the most visceral fat in middle age, the rate of dementia was 324.3 cases per 10,000; patients with the least belly fat had a rate of dementia of 214.6 cases per 10,000.
When the data was adjusted for factors that can affect dementia - including age, education, sex, and medical conditions such as stroke or heart disease - people with the most belly fat were 2.72 times more likely to develop dementia than those with the least fat.
Even thin people could be at risk if they have a large pot belly. In the study, patients who were of average weight but in the category with the most visceral fat were 89 percent more likely to develop dementia than people of average weight with little or no belly fat.
I just have to add a couple of comments on there about the article. Too funny!
1. Relatedness does not mean causality. Just because people with pot bellies have more dementia does not mean pot bellies cause it. For example, bad breath doesn't cause cancer, but rather a third factor - smoking - causes both. Similarly, it could be lack of exercise causing both pot bellies and dementia. Better research would rule such things out.
2. So then what's Bush's excuse?
3. Could this study be carried further to determine if there is a link between pot-bellies and Republicanism? ;-)