As we age, our cognitive abilities tend to decline, making us more forgetful and less sharp. This has led to a long-standing debate about whether exercise can help preserve our brain health. Two recent studies exploring the link between physical exercise and brain function have produced two very different outcomes, leaving us with conflicting answers. In this article, we will delve into the details of these studies and what they tell us about the relationship between exercise and brain health.
Physical activity is widely believed to enhance cognitive skills, including thinking, learning, and judgment skills. However, while observational studies have pointed to the benefits of exercise in warding off cognitive decline, they do not show causation. A major critical review recently suggested that there is thin or non-existent hard evidence for the brain-boosting effects of exercise. This was followed by a massive study using a new technique to affirm that the benefits are indeed real. In observational studies, large groups of people are assessed to determine their level of exercise, and it is then checked to see whose cognitive performance has dropped fastest. A meta-analysis of these studies has found that even low-to-moderate exercise levels reduce the risk of subsequent cognitive impairment by up to 35%, and that one in seven cases of Alzheimer’s disease could be prevented by meeting minimum exercise recommendations of 150 minutes per week. Intervention studies, whereby some people are assigned to exercise and others to sit around on the sofa, are a better option for establishing causality. The new critical review, published in Nature Human Behaviour by a team of researchers in Spain led by Luis Ciria of the University of Grenada, focused only on these more rigorous intervention studies.
Their study aggregated the results of 109 individual trials with a total of 11,266 participants and concluded that the current evidence is not strong enough to draw conclusions. However, a group of researchers from Canada, Switzerland, and the United States published their paper in the journal Scientific Reports, using a technique called Mendelian randomization to combine some strengths of observational studies with those of intervention studies. The randomization effectively occurs at birth, and some people are born with particular gene variants that predispose them to exercise more over the course of their lives. These gene variants have no known effect on cognitive function, so if people carrying these variants score better on cognitive tests, it suggests that their higher levels of exercise made the difference. The results showed that those who had gene variants associated with higher exercise levels scored better on cognitive tests. The effects of moderate exercise were found to be around 50% stronger than vigorous exercise, suggesting that individuals do not need to push themselves to exhaustion to gain the benefits.
Although this study does not settle the question once and for all, it is an essential step towards bolstering the World Health Organization’s claims. In the meantime, regardless of controversy, people should continue to exercise for the firmly established physical and social benefits, and the pleasure of doing something for its own sake.
In conclusion, the question of whether exercise can help brain health is not a straightforward one, and the answer is still a matter of debate. Some studies suggest that exercise can improve cognitive function and overall brain health, while others argue that the evidence is not compelling enough. What’s clear is that more research is needed to fully understand the relationship between exercise and brain health. In the meantime, it’s still a good idea to stay active and engage in regular physical activity, as this has numerous benefits for our bodies, including improved cardiovascular health, reduced risk of chronic diseases, and better mental health. So, even though we may not have all the answers yet, it’s still worth making exercise a regular part of our lifestyles.
