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We all know that being overweight is bad for your health, but results from a new study show that it can also be bad for your brain. In fact, it can make you stupider.
From past experiments, scientists know that obese lab animals have poor memory and lower learning skills as compared to their normal-weight peer. For example, lab mice don't recognize familiar objects and do not navigate mazes as well, but the exact reason why wasn't discovered until now.
In a paper published last month in the Journal of Neuroscience, Alexis Stranahan and colleagues at the Medical College of Georgia at Georgia Regents University found that as lab mice grow obese, their blood show increased levels of interleukin 1 proteins. These proteins, a type of signalling molecules released by cells that affect the behavior other cells, play a central role in the regulation of immune responses and is known to cause inflammation.
In obese lab mice, interleukin 1 can pass through the blood-brain barrier and enters the hippocampus, a part of the brain that's important in learning and memory. There, interleukin 1 molecules cause inflammation and lower neuron activities - essentially the molecules are clogging things up there.
Removing the fat by mini-liposuction of the mice cause the blood interleukin 1 level to drop and return of cognitive performance. In reverse, surgically putting fat in thin mice cause their interleukin 1 levels to shoot up and their cognitive performance to drop.
Now here's a good news you can use: turns out that exercise works just as well. When the researchers put the obese mice on a daily treadmill regimen, they noticed that after 12 weeks, these mice have lost significant amount of belly fat and did better on cognitive tests as compared to sedentary mice.
So, get out there and exercise! It's good for your body and your brain!