Beyond the physical health issues associated with obesity, it may also impair our brains, new research finds. The same study also shows that exercise may help combat obesity-related cognitive decline.
In studies on mice, scientists at Georgia Regents University in Augusta, Ga., found that mice with excess body fat displayed poor brain function and diminished memory compared with leaner rodents.
According to the study published in the Journal of Neuroscience, the cognitive decline in obese mice resulted from pro-inflammatory cytokines — substances secreted by immune cells that serve as signaling chemicals penetrating the blood-brain barrier. These substances affect the hippocampus (a part of the brain that is important for learning and memory) and undermine synaptic function.
To determine whether carrying excess body fat directly caused the cognitive decline, the researchers surgically removed adipose tissue from the mice. Postrecovery, cognitive tests showed that normal brain function was largely restored.
The researchers also tested a less-invasive alternative to surgery: exercise. For three months, a test group of mice ran on a treadmill for 45 minutes a day. After 12 weeks, the animals had lost body fat and were able to perform better on cognition tests. The researchers concluded that regular exercise can help reverse cognitive decline in mice.
While the results are intriguing, it’s unclear how these strategies might affect human brain health. Still, the study backs up previous research showing that maintaining a healthy weight is good for memory function, likely a result of improved insulin resistance.