Parents who maintain moderate physical activity have offspring with better cognitive conditions, according to a study with mice.
“Sometimes genetic research also brings joy.” José Luis Trejo not only makes this statement: he is also in charge of bringing us one of these good news. He is one of the researchers at the Cajal Institute, the Spanish center that has directed a study that indeed brings us good news. Or at least for those who had parents who exercised before they came into the world. Because as seen in the results of the study in which this center of the Higher Council for Scientific Research (CSIC) has participated, laboratory mice that had parents who performed moderate physical exercise also have brains in better cognitive conditions. In other words, even if the parents had a healthy corpore, their sons and daughters will enjoy a healthy mens as an inheritance.
Trejo is a leading researcher who has spent years studying the role of various hormones both in the generation of neurons and in the formation of the part of the brain known as the hippocampus in adult brains. For years he has directed the Adult Individual Neurogenesis Group at the Instituto Cajal, in Madrid, Spain, which focuses its research on the role played by these new neurons in memory and their possible use in therapies against various diseases or stress . He is now part of the team that has studied how exercise affects the brain of mice. Not only from the direct benefit for the practitioner, but also from the one who inherited his offspring.
As Trejo explains, neuroscientific researchers have long known that the effects of stress are inherited, and not just among rodents. “The children – and even the grandchildren – of those who suffered from famine and war can continue to feel the damage of these traumatic experiences.” This does not mean that a genetic change has been made in that family. It is an epigenetic factor. What does that mean? Well, in the words of the researcher: “genes are like a book: even if the pages do not change, you may be paying more attention to some pages, or giving more intonation to others.” That intonation or focus would be the epigenetic factor, which literally means on or near the genes. They are conditions of the gene without being part of it. Traumas would make us tend to turn to the darkest pages of this genetic book. Moderate physical exercise would have the opposite effect.
Researcher José Luis Trejo, in his laboratory at the Cajal Institute. (Photo: Cesar Hernandez)
It has been known for decades that our bodily activity has a positive effect on our neurons. More recently, it has been discovered that new neuron creation continues in adult individuals, and particularly in the area of the brain known as the hippocampus. “That the increase in neurons in this area of the brain can be inherited is a particularly important fact, because it is the hippocampal neurons that are associated with conditions such as depression or anxiety,” Trejo explains. It is also this area of the brain that is in charge of memorization, which plays a crucial role in learning and in the lasting retention in memory of what we learn. It is also the hippocampus that is in charge of orienting us spatially, so we could say that an athletic father will help us park the car better.
This neurogenesis or birth of neurons is a direct consequence of exercise, and has an effect on depression. According to the studies of the Cajal Institute, the virtues would go beyond our own organism, improving the quality of life of our descendants. In order to verify this inherited benefit, it has been necessary to have some mice with a moderate exercise plan and some descendants without physical activity, so that it is clear that their better mental functioning is entirely due to that previous exercise of the parent mouse. The offspring of sedentary mice have been compared with those of those who exercised, but previously sedentary mice have also been given an exercise regimen, which later became parents again. Also in this case the same benefit was observed for the pups.
For the moment, the study has focused on the parents, detecting that the mice that had a lifestyle that included moderate exercise patterns transmitted this epigenetic improvement to their offspring through spermatozoa. In the future, it is expected that the possible transmission of these epigenetic conditioning factors from the mother to her daughters and sons will also be explored. It is also planned to further study whether the effects extend beyond that first generation and, if so, how strong the benefits are for the grandchildren of active mice.
More exercise does not equal more health
Another important conclusion of the study directed by Trejo is that the benefits of exercise for the body do not rise exponentially. More sport does not mean more health, at least when it comes to the effects of this practice on our brain. It is not just that the person will not continue to improve, it is that it will have negative consequences for them. “Unlike what happens with the heart muscle, for example, that the more exercise you do, the better, until there comes a time when, no matter how much more you do, it will not improve, not with the brain: in the brain there are a turning point; If you continue to exercise, you begin to lose the effects of stress, because cortisol rises in your blood and what you are gaining on one hand, you lose on the other.” According to the description of the Cajal Institute researcher, it is as if the different epigenetic factors “compete with each other”. The benefits of sport would be on one side of the scale, while the mental stress of over-exercising would be on the other. Our goal should be balance, the middle ground that allows our brain to get the most out of the exercise. Our brain activity will improve and our descendants will thank us.
Is it possible to know what is that optimal point that we should not exceed? According to Trejo, yes it is. Specifically, there are two methods to find out. One is with the measurement of the blood lactate threshold, which would mark when that inflection point arrives that causes the effects of exercise on the brain to be negative. At the moment, it is not a viable methodology for most athletes. Another simpler method is to measure -through a professional- your heart rate and mark an intensity curve that should not be exceeded.
Trejo also has some general advice for people who want to be in shape: do not look for generic exercise (or diet) plans, but look for your own threshold and regulate physical activity according to this data, also taking into account that it will vary as you progress. the person is fitter. This would also apply to diet.
The study has been the result of collaboration between the Cajal Institute and the National Center for Biotechnology, also from the CSIC, as well as the National Center for Genomic Analysis, the National Institute of Agricultural and Food Technology, the University of Valencia, the University of Seville, in Spain all these entities, as well as the University of Cambridge in the United Kingdom. (Source: Victor Lloret Blackburn / CSIC)