Here's another good reason to lose weight: It may improve your memory and concentration, new research suggests.
Scientists know that overweight and obese people are at a greater risk for memory problems and other cognitive disabilities, but the latest study is one of the first to indicate that substantial weight loss improves brain health.
John Gunstad, an associate professor of psychology at Kent State University, and a team of scientists from several research centers analyzed memory tests taken by 150 people who weighed an average of 300 pounds. Many had several health problems, such as high blood pressure, type 2 diabetes and sleep apnea.
Of that group, 109 of them then had bariatric surgery -- mostly gastric bypass surgery, which creates a smaller stomach and bypasses part of the small intestine. The other 41 obese patients did not have surgery.
After 12 weeks, all participants took the same set of memory tests a second time. Findings:
The surgery patients, who had lost an average 50 pounds, showed improvement in multiple cognitive abilities, including memory and executive functioning, which includes organization skills.
The morbidly obese patients, whose weight stayed the same, showed a mild decline in memory.
The improved memory for the surgery patients likely is not solely due to improved blood pressure because only a small number went from being classified as having hypertension to no longer having it, Gunstad says.
It appears that there is another physiological process that is causing these improvements in memory, he says. "We've known for a while that diet and exercise may also improve cognition, so it's possible there are several factors that are causing these changes."
He says it's a logical conclusion that as the body becomes healthier, the brain would become healthier also.
Michael Devlin, another author on the study and a professor of clinical psychiatry at Columbia University, agrees it's important to emphasize not just losing weight but also adopting a healthy lifestyle -- healthy eating and healthy activity.
Duke University Medical Center professor Murali Doraiswamy, an Alzheimer's expert who wasn't involved in this research, says, this is "a pioneering study" because it shows treating obesity might improve memory.
More research is needed to see whether mildly overweight people experience similar improvements with weight loss through exercise or diet, he says. Gunstad and colleagues will continue to follow the participants for two years. The study, published online this week in the journal Surgery for Obesity and Related Diseases, was funded by a grant from the National Institutes of Health.
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