This past week I came across two interesting articles related to the impact of exercise on the brain.
While the two newspapers I found the stories in usually have little in common, this time the two papers seemed to come to the same general conclusion – exercise is good for the brain.
The first story I read was in the Wall Street Journal.
Conventional wisdom used to be that a person is born with all of the neurons (nerve cells) he or she will ever have. However, over the past 15 years, research has shown that new neurons are constantly being born in one tiny area of the brain crucial for learning and memory, and that physical exercise promotes the numbers of these newborn neurons.
But just increasing the number of neurons is not enough. Researchers also noted that while most of the new neurons do die, an enriched environment can enhance the neurons’ survival rate. In other words, physical exercise and enrichment interact synergistically, so combining the two may be most beneficial.
The researchers also noted that other factors can enhance the progression from neuron birth to full installation in the brain’s circuitry. Foods rich in flavonoids – berries, grapes, chocolate and tea – have been linked to improved spatial learning behavior in humans, as have antidepressants such as Prozac. On the other hand, stress suppresses the proliferation of new neurons, as do alcohol and high doses of nicotine.
The second story came from the New York Times.
In one of the studies noted in the story, researchers found that the most physically active elderly volunteers, according to their activity tracker data, had better oxygenation and healthier patterns of brain activity than the more sedentary volunteers — especially in parts of the brain, including the hippocampus, that are known to be involved in improved memory and cognition, and in connecting different brain areas to one another.
Dr. Agnieszka Burzynska, one of the researchers, makes it a point to note that while of the volunteers formally exercised at all, those who walked, gardened and simply moved more each day had brains that appeared to be in better shape than those of the other volunteers. She also notes that while such studies offer some clues as to why exercise may be good for the brain, it does not prove cause and effect. In other words, we still do not know whether and how physical activity changes our minds.
Such a conclusion may be in line with another recent study mentioned in the story. Researchers asked sedentary, elderly men and women, between the ages of 70 and 89, to start walking and doing light resistance training while other volunteers joined a health education program to serve as a control group.
To measure whether exercise made a difference in brain health, all of the participants completed cognitive testing at the beginning and the end of the study. The results appeared discouraging. Scores for the people in the exercise group were unchanged after two years and about the same as the scores for the group that attended health classes, intimating that exercise had had no effect.
However, another interpretation of these results is that the cognitive performance of the volunteers in both groups remained stable, instead of declining, as might have been expected at their ages. So it may be that exercise, as well as the social interaction provided by the health education program, kept the volunteers’ minds sharp.
Obviously more studies are needed to further examine the relationship between exercise and its effect on the aging brain. But Dr. Burzynska believes that it is very likely that exercise enables our brains to age better.
My interpretation is that even if there is no conclusive link yet showing any positive benefits of exercise on the brain, it seems as if exercise certainly did not cause any harm to the cognitive ability of the participants’ brains.
When you add that minimum finding to other research that has shown the benefits of exercise in areas such as cardiac health, bone health, muscle strength, positive outlook, etc. then it seems a no-brainer to exercise throughout your entire life, and that it is never too late to start.