Fitness fanatics, power lifters and bodybuilders work out nearly every day in the gym, and during their workouts they end up lifting literally tons of weight. This heavy work is good for their brains, going by a study done by American epidemiologists at the National Institute of Environmental Health Sciences, which was published in Neurology.
The study shows that regular heavy physical exertion offers protection against Parkinson's disease.
Parkinson's, a disease in which brain cells die off as the cells that produce dopamine no longer function, is on the increase as the population ages. In the US already 1 percent of the elderly suffer from the disease. Policy makers want to keep this figure down and are therefore searching for lifestyle factors that may help to reduce the incidence of the disease. The most obvious is physical exercise, so the researchers analysed the data on almost a quarter of a million Americans aged between 50 and 71.
The data had been collected during the NIH-AARP Diet and Health Study. The researchers knew how active the participants had been from the age of 35 to 39 and during the last ten years. They discovered that the participants who between their 35th and 39th year had exercised moderately or heavily for at least seven hours a week had forty percent less chance of developing Parkinson's disease than participants who exercised little.
The same was the case for the participants who had exercised for over seven hours a week in the last ten years.
The researchers have no real explanation for how heavy exercise protects against Parkinson's, but point to a couple of likely mechanisms that have been shown in animal studies.
"Forced exercise induced the secretion of neurotrophic factors which might in turn contribute to the neuroplasticity and survival of dopamine neurons", they write. "Further, exercise downregulates dopamine transporter and decreases its ratio to vesicular monoamine transporter. This may reduce cytosolic dopamine turnover and the susceptibility of dopaminergic neurons to neurotoxicants."
Neurology. 2010 Jul 27;75(4):341-8.