We have reported enthusiastically about the mental benefits of physical exercise-- increased cognitive function, protection from dementia, etc.-- but a growing body of evidence is revealing that the pro column is balanced by some risks. Advances in brain imaging technology have uncovered subtle brain damage in even amateur participants in athletics. While professional athletes, especially those in football and boxing, should now be cognizant of the evidence that concussions contribute to neural problems later in life, amateurs will probably be surprised to see that recent studies document less dramatic but still substantial damage at lower levels of competition.
By the end of their careers, approximately 15% of professional boxers become "punch drunk," a euphemism for the very serious brain damage that can result from the blunt trauma and rapid acceleration of punches. Some even suspect that this is how Muhammad Ali developed Parkinson's so young. While his example is tragic, it probably did little to frighten amateurs because they do not fight as often or face the staggering blows of professionals. However, a new study from the Heidelberg Medical Center employed a sensitive MRI to find that amateurs might also be at higher risk of brain damage than the general population.
The Heidelberg researchers found that 3 out of 42 amateurs had microhemorrhages while none of the 37 nonboxers did. The authors admit that the sample size is not large enough to confirm the statistical validity of this technically infinite difference. However, there is some circumstantial evidence that the observed microhemorrhages really were caused by head-trauma: all three microhemorrhages were in the temporal and frontal lobes, where the shear forces from a punch are most violent. While this proves nothing, the results of this study are troubling enough to warrant further exploration.
This month, an article in Scientific American outlines the building case for the risk of another physical challenge-- mountain climbing. As far back as the 1890s, it was recognized that severe oxygen deprivation could damage the most ambitious climbers. However, back then, Angelo Mosso had to take advantage of a freak skull injury to physically pear into a brain. New imaging technology allows Dr. Nicolas Fayed to clearly identify the wreckage left by clots and swelling. His most alarming study followed a group of 13 climbers attempting to scale Mount Everest. None of these people reported signs of acute altitude sickness, but 12 out of 13 showed brain damage when scanned. This surprised the climbers, but it probably did not entirely shock them as anyone who climbs the deadly Everest is aware that there are great risks. More troubling is the fact that Dr. Fayed's team found brain damage even for amateur climbers on the relatively mild Mont Blanc. Of the seven subjects who reached the 4,810-meter summit, two showed deformed Virchow-Robin spaces.
None of the findings discussed above should serve as excuses to avoid challenging exercise. Rather, the lesson to be learned is that Descartes' division of mind and body has broken down. Our brains are strongly effected by physical exertion, and they can be either protected or damaged depending on the exact circumstances. As long as participants are fully cognizant of the risks, and they take proper precautions, they will be able to improve both body and mind together.
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