Posted on Jul 29, 2010, 6 a.m.
Among older women, excess weight is associated with poorer brain function, with differing effects based on where fat is stored.
In that overweight/obesity has previously been linked to increased risks of cognitive decline and dementia in older people, Diana R. Kerwin, from Northwestern University Feinberg School of Medicine (Illinois, USA), and colleagues studied 8,745 postmenopausal women, ages 65 to 79 years, who were enrolled in the Women’s Health Initiative. All subjects were free of dementia, as assessed by the 100-point standardized Modified Mini-Mental Status Examination, at the study’s start. After adjusting for confounding factors , the team found that for every one-point increase in a woman's BMI, her memory score dropped by one point. In addition, women who carried weight around the hips (“pear-shaped”) experienced more memory and brain function deterioration than women storing fat around the chest and abdomen (“apple-shaped”). The team posits the difference may be due to cytokines, hormones released by the predominant kind of fat in the body that can cause inflammation and likely affect cognition, that release differently based on the type of fat and location of deposits on the body. The team concludes that: “Higher [body mass index] was associated with poorer cognitive function in women with smaller [waist-to-hip ratio]. Higher [waist-to-hip ratio], estimating central fat mass, was associated with higher cognitive function in this cross-sectional study."
Diana R. Kerwin, Yinghua Zhang, Jane Morley Kotchen, Mark A. Espeland, Linda Van Horn, Kathleen M. McTigue, Jennifer G. Robinson, Lynda Powell, Charles Kooperberg, Laura H. Coker, Raymond Hoffmann. “The Cross-Sectional Relationship Between Body Mass Index, Waist–Hip Ratio, and Cognitive Performance in Postmenopausal Women Enrolled in the Women's Health Initiative.” Journal of the American Geriatrics Society, July 2010.