Excess Weight in Older Women Linked to Diminished Memory

Middle-aged women who are overweight may have yet another motivation to take off those excess pounds: The more a postmenopausal woman weighs, the worse her memory, researchers have found.

What's more, the negative impact on memory was more pronounced in "pear-shaped" women who carry excess weight around their hips, and less of a factor in "apple-shaped" women who carry it around their waists, the study authors noted.

In the new study, researchers found that for every one point increase in a woman's body mass index (BMI), her score on a standard memory test—though still in the normal range—dropped by one point.

The study, which was based on data from nearly 9,000 women who were enrolled in the Women's Health Initiative, a large government-sponsored study of postmenopausal women, was released online in the Journal of the American Geriatrics Society.

"This study really underscores the importance of maintaining an ideal body weight," says lead researcher Diana Kerwin, MD, an assistant professor of medicine in the division of geriatrics at Northwestern University's Feinberg School of Medicine in Chicago. "Even if a woman feels that she's generally healthy because her blood pressure and cholesterol levels are good, what these findings suggest is that she also needs to pay attention to her weight, because it's not only good for her heart, it's also good for her brain."

For the study, Kerwin and her colleagues examined data on 8,745 women aged 65 to 79 who had no signs of dementia or other brain abnormalities. In addition to looking at BMI and waist and hip measurements (to determine body fat distribution), they also reviewed the women's scores on the Modified Mini-Mental Status Examination. Roughly 70% of the women were overweight or obese.

After controlling for age, level of education and vascular diseases that have been shown to raise the risk of dementia, such as stroke, the researchers found that the association between obesity and poorer memory and brain function persisted. Kerwin, who conducted the study while a geriatrics researcher at the Medical College of Wisconsin, adds that although the women's scores were still in the normal range, the added weight clearly had a detrimental effect.

Kerwin says more studies are needed to confirm and explain the apparent disparity between pear- and apple-shaped women. But one possibility is that the type of fat that's deposited on the hips is more likely to release hormones that are detrimental to brain function, she says. A follow-up study now in the planning stages will involve conducting MRIs of women's bodies, "so we can look at how much abdominal fat they have vs. hip fat, and see if there's any difference in their brain functioning," Kerwin explains.

Source: Brigham and Women's Hospital