There is a growing body of scientific evidence to suggest that obesity and overweight in middle life significantly increases the risk of dementia in later life. The exact mechanisms involved are not well understood, but may be related to abnormalities in the metabolism of blood sugar related hormones. Weight loss surgery, on the other hand, has been shown to improve mental functioning 12-weeks post-operatively, though the longer term effects on cognitive function are not clear. In a recent study, researchers recruited 63 patients undergoing weight-loss surgery, together with 23 obese controls. All subjects completed a variety of questionnaires prior to surgery and then again at 12-weeks and 24 months post-operatively.
Results showed that, relative to controls, surgical patients had improvements in memory both at 12-weeks and at 24-months after surgery. This suggests that improvements in mental function are durable and extend well beyond the immediate post-operative period.
Why this should be the case is not entirely clear. One simple explanation might be that weight loss among the surgery patients improves the quality and duration of sleep and that this alone might improve memory test results. Other factors, such as increased physical activity may also contribute. Whatever the mechanisms involved, the benefits in terms of mental functioning appear to be significant. So will surgical weight loss reduce the risk of dementia in later life? The answer to that is that we simply don’t know and it will take large prospective studies – probably lasting decades – to find out. But this study certainly points in that direction.
Alosco ML, Spitznagel MB et al. Improved memory function two years after bariatric surgery, Obesity 2013, April 27th [Epub ahead of print]
Dr David Ashton MD PhD
16th July 2013