By Dr. Nicola Sacchi - Author of the book: Drugs and doping in sport -
That physical activity contributes to maintaining cognitive functions is by now an established fact. The benefits on the cardiovascular system are obvious and these also affect circulation in the brain; all this allows to improve the oxygenation of neurons and the exchange of nutrients between neurons and blood flow, thus promoting their vitality. These benefits allow us to maintain cognitive functions.
The studies on the subject are controversial, this because in order to make evaluations of similar nature it is necessary to organize population studies following the sample under examination for several years. As Alzheimer's is a chronic disease that develops over the course of years and is not diagnosable before symptoms appear, a very large sample of people must be followed to make assessments of this nature and this sample must be followed for many years before to be able to obtain valid data from a statistical point of view. Therefore, it is easy to understand how complex it is to formulate reliable studies on the incidence of this disease in different population groups made different only by the practice or otherwise of regular physical activity.
Despite these difficulties, some studies have been done and the results are comforting, in the sense that we actually see a lower incidence of the disease in question in active people and not only: some studies show how physical activity can also contribute to the treatment of the disease same.
Alzheimer's disease is characterized, from the histological point of view, by neuronal atrophy: over time the brain progressively loses mass and weight, consequently reducing its activity, thus decreasing cognitive functions such as memory. Alzheimer's disease is due to widespread destruction of neurons, caused mainly by the betamyloid protein. This protein forms deposits that grow over time between the neurons themselves, forming plaques that are visible under a microscope during advanced disease; all this leads neurons to die.
The pathology is accompanied by a strong decrease in a particular neurotransmitter, acetylcholine, in the brain. The consequence of these cerebral modifications is the impossibility for the neuron to transmit the nerve impulses, therefore the reduction of its functionality until neuronal death is reached.
Currently there are some population studies developed on long-term research, lasting over 20 years, that verify how the regular practice of physical activity reduces the risk of Alzheimer's disease. These results could be mediated by the ability of regular exercise to reduce cardiovascular risks (hypertension, atherosclerosis, overweight, obesity, etc.) which appear to be key factors for the development of amyloid plaques. Another possible reason for this result could lie in the ability of physical exercise to promote the production of neurotrophins (proteins that promote the vitality of neurons). also key factors for the maintenance of cognitive functions in general.
Probably it is the set of these effects that has shown how physical activity has the ability to reduce the incidence of 50% of this serious pathology; however further research must be carried out to have greater clarity on the subject.
There are also some studies that have evaluated the benefits of physical activity in patients who already suffer from Alzheimer's: it has been verified that exercise improves the motor skills of patients, compromised by the progression of the disease, and also other cognitive parameters used to evaluate the evolution of the pathology itself.
These results are made more credible by the better knowledge of the pathogenesis of Alzheimer's itself and by the biological benefits that physical activity promotes.
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