New Research Finds Limited Evidence of Cognitive Benefits from Physical Exercise

Analyzing Data from Over 100 Trials

New research has shown that there is limited evidence that physical exercise improves cognitive ability, based on analyzing data from over 100 individual trials involving more than 11,000 “healthy participants.” The new study found “inconclusive evidence” that physical exercise improves cognitive ability.

Lead researcher Luis Ciria and his team found during their analysis that claims linking exercise to improved cognitive ability should be advised with caution until “more reliable causal evidence accumulates.” The researchers found little benefit to the healthy person’s brain because they exercised.

A Call for Reconsideration of Public Health Policies

Ciria and colleagues’ findings aim to prompt a reconsideration of public health policies that promote exercise adherence solely based on its purported cognitive benefits. Stephen Rao, the director of the Schey Center for Cognitive Neuroimaging at the Cleveland Clinic, suggests that the research found by Ciria and his team shows the importance of not relying solely on clinical trials and more observational studies should be conducted to find concrete evidence that exercise benefits the brain.

Engaging in physical exercise brings not only physical but also social benefits, as we connect with others by forging social bonds, participating in collective activities that give us a sense of belonging, and building new sources of social support. Therefore, people should still engage in physical activity while policymakers continue to investigate the potential cognitive benefits of exercise.

Effects of BMI on Gut Microbiome Alterations due to Physical Activity

A study published in Frontiers in Microbiology investigated how alterations in gut microbiome composition caused by physical activity and handgrip strength were affected by body mass index (BMI) values among middle-aged adult individuals.

Regular physical activity is associated with various preventative and therapeutic health effects against inflammatory and cardiometabolic diseases. Calorie-dense diets alter gut microbiota composition and functions by reducing beneficial microbe abundance and diversity, hence influencing weight by altered energy utilization from dietary sources. However, physical activity has been shown to increase beneficial microbe abundance and reduce pathogenic microbe counts, leading to increased short-chain-type fatty acid (SCFA) levels and enhanced lactate utilization.

The study cohort included individuals with normal BMI values and those with elevated BMI values. Overweight individuals exhibited greater triacylglycerol (TG) levels and lower levels of lysophosphatidylcholine (LPC) lipids, cholesteryl esters (CE), and sphingomyelin (SM) than individuals with normal BMI values. Among non-obese individuals with normal BMI values, greater physical exercise durations were associated with elevated counts of commensal microbes.

Negative correlations were observed between BMI, TG levels, and Oscillibacter abundance. Positive correlations between physical activity duration/intensity, phosphatidylcholine, LPC, CE lipids, and Prevotella abundance were observed.

Scientific Evidence for Mental Benefits of Physical Exercise

While there is some evidence to suggest that regular physical exercise can help maintain brain health, a combined review of 109 trials involving more than 11,000 healthy people found weak evidence for a positive relationship between regular physical exercise and improved cognition.

Clinical trials have tended to support the idea that regular exercise helps maintain brain health. However, they are often beset by low-quality design, too few participants and potential bias and overlook mixed or contradictory findings. Better clinical trials are needed to better understand the relationship between exercise and brain health.

Heather Snyder of the Alzheimer’s Association agreed that “this study points out a number of still unanswered questions around the relationship between exercise and brain health and indicates that more research is required before definitive conclusions can be drawn.”

In conclusion, while physical exercise has numerous social and physical benefits, there is currently limited scientific evidence to support the proposition that it improves cognitive ability. Policymakers should reconsider public health policies promoting physical exercise solely based on its cognitive benefits, while further research exploring the relationship between physical exercise and brain health is needed.

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