A mouse study has found that obese mice had high levels of interleukin 1 in both their blood and their brains, and this was associated with:
- high levels of inflammation,
- low levels of a biochemical important to synapse function, and
- impaired cognitive function.
Moreover, when fat was removed from the obese mice, interleukin levels dropped dramatically, and cognitive performance improved.
Putting obese mice on an exercise program had a similar effect, even though they didn’t lose weight — but they gained muscle and lost fat.