Why To Exercise Today: In Mice, Running Offsets Fat Effects On Brain

The latest Phys Ed column in The New York Times offers some intriguing findings in mice suggesting that exercise may be particularly good for your brain if you're overweight.

Columnist Gretchen Reynolds describes a Journal of Neuroscience report that the chemical effects of obesity appear to seep past the blood-brain barrier, causing inflammation and apparently making fat mice perform worse on memory tests. Those effects could be reversed by surgically removing great quantities of fat from the mice, but those operations went far beyond any human form of liposuction. So the researchers tried exercise. Reynolds reports:

After 12 weeks, the running mice still weighed about the same as the unexercised animals. But they had lost significant amounts of fat from around their middles, while adding lean muscle. More telling, they did much better on cognitive tests than the sedentary mice and, when the researchers examined tissue from their hippocampi, showed little evidence of inflammation and robust levels of the chemical marker of synaptic health. The results suggested that, as the scientists write in the study, “treadmill training normalized hippocampal function,” even in animals born to be fat and that remained heavy.

Of course, these studies were conducted in mice, not people, whose brains may respond very differently. But the possibility that humans, too, may respond in similar ways is tantalizing, Dr. Stranahan said, and the takeaway from her study worth repeating. “Get out and move,” she said, even — and especially — if you carry extra weight.