Results from a small study of postmenopausal women suggest that obesity might relate to a reduced volume of gray matter in the brain. However, whether the results have relevance in a woman’s day-to-day life is unclear.

“A subset of women from the Pittsburgh Healthy Women Study (HWS) who had been followed for an average of 15 years was invited to participate in brain imaging studies,” said lead author Isabella Soreca, M.D., an assistant professor at the University of Pittsburgh. “We found that those who had gained the most weight had lower gray matter volume.”

The study appears online in the journal Psychosomatic Medicine: Journal of Biobehavioral Medicine.

Forty-eight women participants underwent MRIs to determine the volume of both white and gray matter in their brains. Researchers excluded participants from the study if their white matter showed specific signs of possible decreases in blood supply to the brain. They also excluded participants if they had high blood pressure, diabetes or other health concerns.

“Women who gain weight tend to have high blood pressure, impaired glucose tolerance and other health concerns that are known to affect the brain,” Soreca said. “The group we used were overweight, but were otherwise completely healthy. It was surprising that these healthy women still showed reductions in gray matter volume, and this indicates that weight gain by itself may impact the brain.”

Charles D. Smith, M.D., a professor of neurology at the University of Kentucky in Lexington, said that although the study results are interesting for researchers, for now they are only likely to add confusion for a public concerned about weight and nutrition.

“There was no evidence presented that decreased gray matter in these healthy subjects represented atrophy, or that decreased gray matter was associated with diminished memory, judgment or daily function or with any impairment at all,” Smith said. “Some heavier folks had had decreased gray matter — so what? There are plenty of good health reasons to maintain an appropriate weight, but this isn’t one of them.”

Psychosomatic Medicine: Journal of Biobehavioral Medicine is the official bimonthly peer-reviewed journal of the American Psychosomatic Society. For information, contact Victoria White at (352) 476-9552 or .(JavaScript must be enabled to view this email address), or visit http://www.psychosomaticmedicine.org.

Soreca I, et al. Gain in adiposity across 15 years is associated with reduced gray matter volume in healthy women. Psychosom Med online, 2009.

Source: Health Behavior News Service