Weight gain and memory loss

The holidays mean music, family get togethers, and of course, food. And then more food.

And while a few extra pounds earned over the holidays are no big deal, a Kent State researcher says the problems created by obesity are far reaching.

Neuropsychologist John Gunstad says one of the side effects of weight gain is memory loss, and obesity causes problems with heart disease, and blood pressure, and diabetes. "This is another type of side-effect, another consequence of weight gain.”

Gunstad and an international team of researchers are working with a group of overweight people who have taken a drastic step to shed pounds: bariatric surgery. That’s where part of the stomach is removed or restricted to force people to eat less. Gunstad tested the brain functions of hundreds of obese people before the surgery, and after.

“And we know that many individuals have reported that their memory has improved, or their memory feels better in the process of losing weight.  And we don’t know that’s simply because their feeling better or they’re actually noticing these memory changes. But on testing, when we have a chance to put them on a computer and see what their memory can actually do, we see that they get better. And they get better as fast as three months later.”

Testing the theory 

I’m not a candidate for bariatric surgery. Still, Gunstad offers to show me the computer test he uses to measure brain function in his subjects.

It’s an hour-long test that looks at a series of brain functions like memory, attention, impulsiveness and to some degree dexterity as numbers flash on the screen and my poor brain is asked to match them…

Gunstad has run hundreds of these tests over the years. And the data shows a clear link between losing weight and improved brain function. He says a lot of things could be tied to that link.

“At this point, we have 35 different possibilities that we’re in the process of sorting out. And that’s probably an incomplete list.”

One theory is that obesity hurts overall health. Your heart has to work harder, heavy people may have trouble sleeping, high blood pressure, and often, diabetes -- and the brain like any other organ, suffers.

But Gunstad says new research is pointing to a more troubling effect of excess weight on the brain.

Obesity ages the brain 

“We found that obese individuals, in a recent paper that came out, obese individuals actually started to show pathological changes in the brain similar to Alzheimer’s disease at a much higher rate than their lean counterparts. So it’s arguing that whatever obesity is causing in the body is actually damaging the brain in a way that speeds the aging process, that speeds the Alzheimer's disease process far before it really ever should.”

Again, Gunstad ’s work shows a link between obesity and bad effects on the brain, but not the cause.

“It might be things that are genetic. It’s possible that there’re some particular genes that causes a person to have both of those: You’re at a higher risk for obesity and memory loss.”

The good news is that not everyone with a weight problem is at risk for memory loss. Much depends on the “make-up” of the person’s brain, what Gunstad calls its “cognitive reserve.”

“Some people’s brains are just wired better than others. They’re somehow more resilient to disease or more resilient to damage than other people. And we’re not sure how that happens, if it’s at the chemical level or at the tissue level, or where it may actually be.”

Gunstad says the main thing to remember is that losing weight improves health in the body and in the brain, and that’s food for thought.

The Centers for Disease Control reports two-thirds of Americans are overweight, nearly one-third are actually obese.

Gunstad and his colleagues warn that America’s obesity epidemic is no longer just a risk for individuals. It could impact American productivity and competitiveness. 

I’m Jeff St. Clair with this week’s exploradio.