Could Excess Weight Cause Memory Impairment?

In a recent study, obese people where shown to function below average when it came to memory, and twelve weeks after undergoing weight loss surgery, those same obese people were functioning within normal memory range. It was also noted that those who did not undergo surgery actually suffered decline in those twelve weeks, but researchers are not sure why that happened. It is the first study of its kind to look at the changes in mental abilities after bariatric surgery. The surgery results in a large amount of weight loss in a short amount of time, and this study shows that obesity related cognitive issues may at least be partially reversible. This very well may provide some extra motivation for those considering trying to lose weight.

Some contend, however, that more research is needed in order to understand exactly what it is that causes the increase in cognitive function. This study is next in a growing list studying the connections between obesity and memory deficits, including increased risk for Alzheimer’s disease, as well as other types of dementia. Though the study’s result is positive, bariatric and other weight loss surgery is not without risk, with many patients experiencing complications over time. Still, the benefits may outweigh the costs depending on the situation.
For the study, 150 people with an average weight of 300 pounds were observed, with 109 of the participants going through the weight loss surgery. Most of them had gastric bypass surgery, but some opted instead to have the gastric band. The bypass surgery involves stapling a part of the stomach and rerouting the intestine, while the gastric band involves using a band around the stomach to reduce the amount of food that the stomach can hold.

Before the surgeries, each participant was put through several cognition tests, with some being read lists of words and numbers and being asked to recall them later. They showed mild impairment on the tests, and this can translate into the same types of issues in everyday life according to experts. Twelve weeks later, after those who had weight loss surgery lost around 50 pounds, those who had surgery showed improvement on all four memory tests. Those who did not have surgery actually performed worse on two of the test, and the same on the other two.

One theory is that changes in blood pressure may be the reason for the improvement in memory since it has been well known for a while that high blood pressure is bad for the whole body including the brain. But it is pretty certain that the weight loss itself does not directly affect memory, meaning that that there are other factors related to the weight loss that causes the improvement. Future studies are planned to examine whether weight loss achieved in ways other than weight loss surgery have the same effect on the memory.