NORTHWESTERN (US)—The key to the relationship between a woman’s weight and memory? Location, location, location.

A new study shows that the more an older woman weighs, the worse her memory, especially if the woman is pear-shaped and carries excess weight on the hips, instead of apple-shaped with extra pounds around the waist.

The study of 8,745 cognitively normal, post-menopausal women ages 65 to 79 from the Women’s Health Initiative hormone trials is the first in the United States to link obesity to poorer memory and brain function in women and to identify the body-shape connection.

“The message is obesity and a higher body mass index (BMI) are not good for your cognition and your memory,” says Diana Kerwin, assistant professor of medicine at Northwestern University.

“While the women’s scores were still in the normal range, the added weight definitely had a detrimental effect.”

For every one-point increase in a woman’s BMI, her memory score dropped by one point. The women were scored on a 100-point memory test, called the Modified Mini-Mental Status Examination. The study controlled for such variables as diabetes, heart disease, and stroke.

The study appears in the July 14 issue of the Journal of the American Geriatric Society.

The reason pear-shaped women experienced more memory and brain function deterioration than apple-shaped women is likely related to the type of fat deposited around the hips versus the waist.

“Obesity is bad, but its effects are worse depending on where the fat is located,” Kerwin says.

Cytokines, hormones released by the predominant kind of fat in the body that can cause inflammation, likely affect cognition, Kerwin explains.

Scientists already know different kinds of fat release different cytokines and have different effects on insulin resistance, lipids, and blood pressure.

“We need to find out if one kind of fat is more detrimental than the other, and how it affects brain function,” she says. “The fat may contribute to the formation of plaques associated with Alzheimer’s disease or a restricted blood flow to the brain.”

In the meantime, the new findings provide guidance to physicians with overweight, older female patients.

“The study tells us if we have a woman in our office, and we know from her waist-to-hip ratio that she’s carrying excess fat on her hips, we might be more aggressive with weight loss,” Kerwin says. “We can’t change where your fat is located, but having less of it is better.”

Kerwin’s research is funded by the T. Franklin Williams Award from Atlantic Philanthropies and Association of Specialty Professors and the Wisconsin Women’s Health Foundation Faculty Scholar Award.

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