Fat At 40? Dementia May Follow

Study: Obesity In Middle Age Might Be Linked To Later Dementia

(AP) 
The effect was more profound for women than men. Obese women were twice as likely as women of normal weight to develop Alzheimer's disease or other types of dementia, while for men the risk increased by 30 percent.

However, when the researchers used skin-fold thickness, instead of the body-mass index, to measure obesity, there was no difference between the men and women; both were up to 70 percent more likely to develop dementia if they had a thick fold between the tweezers than if they had a thin fold of skin on the test. And the thicker the skin fold, the higher the chance of later dementia, the study found.

Perhaps the most impressive aspect of the study, according to James, is that the researchers eliminated the influence of heart disease, diabetes and other conditions that might be the real culprits in dementia.

"We really adjusted for everything under the sun that is related to dementia. We brought in stroke, high cholesterol, hypertension, diabetes, heart disease - everything that has been implicated - and yet we still found this effect," said the study's leader, Dr. Rachel Whitmer, gerontological epidemiologist at the Kaiser Permanente Medical Foundation. "That suggests that there's another pathway - it's not just that being overweight raises the risk of heart disease and diabetes and that's why these people get dementia."

The study was not able to explain how obesity might increase the risk of dementia, but does propose several theories.

One is that fat cells are known to produce harmful, inflammatory chemicals, and there is evidence that these may cross into the brain.

James suggested a dietary lack of the right kinds of fatty acids, such as those found in fish, might also be a factor.

"It's been shown that the Western societies are short of fatty acids of this type," he said, adding that obese people "will be very deficient in these long-chain essential fats, which are known to be fundamental for brain development."

Scientists are studying whether fish oil supplements can prevent dementia.