The suspicion that physical activity can protect the brain against Alzheimer's has just gained a scientific increase in weight. A study led by Brazilian researchers revealed that a protein that is released after exertion works on the brain that protects the neurons and facilitates communication between them, which ultimately benefits the memory, usually the first one caused by the disease. affected.
The results, published on Monday 7 in the journal Nature Medicine, were obtained only in mice, but opened a door to a new research line for therapies in humans. Researchers, led by neuroscientist Sergio Ferreira of the Federal University of Rio de Janeiro, discovered that the hormone irisin, released by muscles after performing physical activity – and already known to work in other organs – reaches the brain. Moreover, they discovered that the brain itself also produces the substance when animals exercise.
In the study, mice were genetically engineered to develop an Alzheimer-like condition for one hour of swimming per day for five weeks or were given doses of irisine in the laboratory.
"Animals with a model of the disease have no memory, can not learn tasks, and with this treatment they come back, they were indistinguishable from normal animals, and we observed with 100% that irisine, besides that it is good for it memory, degeneration occurs in the neurons of the mice – has a neuroprotective effect and strengthens the synapses, that is, it allows the brain to function, "Ferreira told the newspaper O Estado de S. Paulo.
In another phase of the study, the group, which had a collaboration of American and Canadian scientists, observed a reduced amount of irisin in the brain and cerebrospinal fluid of human Alzheimer patients compared with healthy patients. The same shortage was observed in the mice with the studied disease model.
However, it does not mean that the treatment that is tested on the animals would have the same effect in humans, the researcher thinks. On the basis of research it is not yet possible, for example, to determine how much or how much physical activity it would be possible to produce irisin at protective levels for the brain.
"There is a lot to know about working on mice, but it does not work for people, we do not know if irisine plays the same role in people's brains.
"But what our research suggests is that in the future, if the benefits of irisin are replicated to humans, it could be used as a kind of hormone replacement, just as with insulin for diabetics," he says. For the researcher, because the disease affects the elderly, physical activity would serve as prevention, but not as treatment.
"It is a work that also shows how strategic it is to invest in this type of research, especially in Brazil, where the population is getting older," Ferreira said. "If you do not have a clear policy, the country will have a very hard time," he said, adding that the number of people with Alzheimer's in the country is rising by more than a million, not just family, social, but also economic ", he adds.