Exercise can prevent cognitive decline even when energy lags, researchers discover

Even on days when you're lagging in energy, exercise can give your brain a boost.

The study, published in the journal Physiology, examined what happens to the brains of individuals who have limited ketone production in the liver.

When the body is low on glucose, its usual fuel, the liver produces ketones, which help generate energy and power the brain, according to the study's press release.

These findings are also promising for those who have liver conditions that prevent the body from producing ketones.

Lead study co-researcher R. Scott Rector, Ph.D., a professor in the School of Medicine and director of the NextGen Precision Health Building, commented on the study in an interview with Fox News Digital, noting that the body's natural production of ketones is important for keeping the brain healthy.

"It helps maintain memory, learning abilities, and the health of the brain's energy factories (mitochondria)," he said. 

"Exercise can still protect the brain even when the liver isn't making ketones, which might be relevant to individuals with liver disease, which causes reduced ketone production."

These findings were surprising to the researchers, according to Rector, who expected that exercise might not improve brain health when ketone production was limited.

Another lead researcher, Taylor Kelty, a postdoctoral fellow in Rector's lab, noted that previous research has begun to show the link between severe liver dysfunction and a high risk of dementia.

"If ketone production in the liver is disrupted, it could be a potential cause of cognitive decline, ultimately leading to conditions like dementia," Kelty said in the press release.

Rector noted that exercise activates "many other pathways" in the liver that could also help the brain, although that wasn't a focus of this study. 

"Exercise's brain health benefits are particularly important for those who have liver conditions like MASLD (metabolic dysfunction-associated steatotic liver disease)," Rector added.

"Scientists are finding more and more evidence that liver health affects brain diseases like Alzheimer's disease," he said.

The research was funded by the National Institutes of Health as part of the NIH Molecular Transducers of Physical Activity Consortium.