The research comes at a time when some recent, widely discussed research is casting doubt on the extent to which exercise strengthens thinking and memory. But the new findings, which analyzed data from nearly 350,000 people, make the strongest case yet that regular exercise can improve cognition.
These studies reinforce the idea that “exercise is, of course, one of the best things for your brain.” Mathieu BoisgantierAn associate professor at the University of Ottawa, who oversees a study.
‘Miracle-Grow’ for your brain
The first glimpses that exercise rewires the brain and mind came decades ago in mouse studies. In these experiments, the active, running animals scored much higher on rat intelligence tests than the sedentary rats, and their brain tissues were filled with higher levels of a substance known as brain-derived neurotrophic factor, or BDNF, which is often referred to as “Miracle-Grow.” the brain
BDNF prompts the formation and maturation of new brain cells and synapses. It bulks up the brain.
Studies in humans have since established that exercise also increases BDNF levels in our bloodstream, although it’s difficult to look inside our brains and see if it’s increased there. more than one, big size Epidemiological studies, meanwhile, have linked more exercise to better memory and thinking skills and a lower risk of neurodegenerative diseases, such as Alzheimer’s.
However, doubts about how powerful exercise is for our brains have long persisted.
A study published last year of more than 500 older adults found little cognitive benefit from 18 months of regular walking or other light exercise, while a major Review of past research published in March that many human studies of exercise and cognition are too small or otherwise limited to show the benefits induced by exercise for brain health.
In some scientific circles, debate has begun over whether exercise should continue to be recommended as a way to maintain mental acuity as we age, Boisgantier said. But we say, ‘No, no. don’t stop Look at our findings first,'” he said.
Research from Boisgontier and his colleagues, Published last week in Scientific ReportsIt uses a novel and complex type of statistical analysis to go beyond traditional observational research and firmly establish that exercise improves your brain’s efficiency.
They are DNA and Mendelian randomization, a recently popular method of using genetic variation to characterize and sort people. Each of us is born with or without certain snippets of DNA, some of which are known to contribute to the likelihood of being physically active. From before birth, we are, in fact, randomized by nature to be prone to movement or not. Other gene snippets play similar roles in cognition.
By cross-checking the cognitive scores of those with the exercise-promoting snippet or those lacking gene variants associated with cognition, scientists can understand how much exercise contributes to thinking skills.
From two huge databases of health information, they pulled genetic data for about 350,000 people of all ages, objective measures of physical activity for about 91,000 of them, and cognitive scores for about 258,000. People with a genetic predisposition to exercise exercised more often, they found, and scored better on tests of thinking, if their exercise was at least moderate, compared to jogging.
And, yes, you can get brain benefits from exercise even if you don’t have the gene snippet.
The interaction between exercise and thinking was strong enough to indicate causation, Boisgontier said, meaning, in this large study, the right exercise sharpened the mind.
6 minutes of intense exercise increases BDNF
the other New researchAlthough relatively small, it can help explain how exercise keeps your brain healthy.
In this test, 12 healthy, young men rode an exercise bike at a very leisurely pace for 90 minutes, followed by a six-minute break consisting of 40 seconds of all-out pedaling followed by 20 seconds of rest. Before, during and after each session, the researchers tracked BDNF in the people’s blood.
They also measured lactate levels. Muscles release lactate, often called lactic acid, during exercise, especially if it’s strenuous. It can travel and be absorbed by the brain as fuel.
Past studies in mice suggest that this change in brain fuel is what jump-starts the production of BDNF. When the animals’ brains began slurping up lactate instead of sugar, they began to secrete more BDNF, and the mice soon turned into rat brainiacs.
Now, researchers have hinted at something similar happening in humans. During an easy ride, people’s blood lactate levels rose slightly after about 30 minutes, as did their blood levels of BDNF. But during and after six minutes of hard, fast pedaling, lactate rose and so did BDNF. (Another part of the study examined the effects of a 20-hour fast, but found it had no effect on BDNF.)
What these findings suggest is that “exercise is good for your brain and the benefits can be maximized when it’s prolonged or particularly, strenuous exercise,” said Travis Gibbons, a postdoctoral fellow at the University of British Columbia in the Okanagan, who led the study.
Boisgontier agreed. “Always, with exercise and the brain, it involves BDNF,” he said, adding that in his group’s study, both moderate and more vigorous exercise — brisk walking and brisk running — improved cognition, possibly because they induced an increase in BDNF.
Many questions remain, Gibbons noted, including how long BDNF remains elevated after exercise, the ideal type and amount of exercise to increase BDNF, and whether its effects are similar in older or less-healthy men and women, as well as why fasting. BDNF was not increased in this experiment. He and Boisgontier have follow-up studies planned or underway.
But for now, this research tells us that exercise, fast or slow, should reliably protect our ability to think.
Do you have a fitness question? email YourMove@washpost.com And we can answer your questions in a future column.
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