A new study published in Nature Metabolism adds another piece of evidence to the growing consensus that exercise can alter brain health and lessen cognitive decline.
The new study was conducted in mice, which means it should not and cannot lead directly to human conclusions. But it is an important step to show that biologically, exercise can change a brain. How so? The research found that irisin, a hormone that is produced in muscles during exercise, can improve the health and function of brain neurons. That, in turn, leads to better memory retention and thinking skills in both healthy mice and mice with animal Alzheimer’s.
The study was kicked off by 2019 research that found that irisin in the brains of mice after they exercised. That same hormone was found in most human brains that were donated to a brain bank, but not in people who had Alzheimer’s at the time of their death.
The researchers bred mice who were unable to produce irisin and normal adult mice and had them exercise to see what happened to their memory and learning skills. The mice that could produce irisin experienced improvements in memories and cognitive function. Those that couldn’t saw improvements to a far lesser degree.
The researchers then gave the irisin-less mice the hormone and found that their cognitive abilities improved greatly, even among unhealthy mice, and those who were starting to develop animal Alzheimer’s.
The significance of giving the genetically modified mice irisin shows that it can get across the blood-brain barrier and that irisin could be a strong link between exercise and cognitive ability. It also means that medicine with irisin in it could be developed to potentially help Alzheimer’s patients regain some cognitive function.
And while the study is clearly limited — and it has not been conducted on humans yet — it’s certainly not the only research that suggests that regular exercise can improve brain health by boosting memory and thinking capacity, reducing stress and anxiety, and more.
In fact, the study joins dozens of others that show that exercise is great for not just the body but also the mind. The Centers for Disease Control and Prevention has long maintained that physical activity can improve cognitive health — and that any amount of physical activity can “help improve sleep, brain health, and quality of life.”
One 2015 study cited by the CDC has found that cognitive decline is “almost twice as common among adults who are inactive compared to those who are active.” Other studies, cited by The New York Times, have found that exercise can literally aid the creation of new neurons, then helps the neurons integrate into the brain’s neural network. The Times also cites studies that have found that people who are active and exercise are way more likely to not develop Alzheimer’s and dementia.
In other words, working out isn’t just about getting shredded and having a sense of moral superiority over those who don’t. Exercise can also safeguard and even improve your brain health. It can have returns on investment for decades as you age.
So, go for a long walk, pick up a pair of weights now and then, or do some yoga. You don’t need to be an ultra-marathon runner to protect your brain health and slow cognitive decline with exercise. The CDC, for example, recommends dancing at home, marching in place while watching TV, finding ways to walk more, or getting a pet like a dog that requires exercise or a daily walk.