Obesity promotes chronic, low-grade inflammation that leaves the immune system on constant alert, generating a succession of false alarms for the body's defense system and, consequently, premature aging of immune cells. This phenomenon, called by scientists as early immunosenescence, contributes to a higher incidence of infectious or even chronic degenerative diseases, such as diabetes, atherosclerosis and other cardiovascular conditions.
In addition to constant levels of inflammation, obesity can also trigger metabolic changes, especially those associated with fat molecules (lipids), another mechanism proven to be involved in the development of type 2 diabetes and other chronic non-communicable diseases.
Studies carried out by researchers at the State University of Campinas (Unicamp), with support from FAPESP, showed that a 16-week physical training protocol – combining weight training and aerobic exercise – was able to reverse the two problems associated with obesity.
“In addition to reducing abdominal circumference, increasing strength and lean mass, the training protocol alone, that is, without controlling food or diets, acted to reverse the process of premature aging of immune cells and changes in metabolism lipid, therefore serving as a non-pharmacological treatment for two factors extremely associated with the development of chronic diseases. These are important results that show, once again, the key role of the muscle as an endocrine organ”, says Claudia Cavaglieri, coordinator of the Exercise Physiology Laboratory (Fisex) at the Faculty of Physical Education at Unicamp.
As the researcher explains, reversal is only possible because active muscle tissue releases substances, known as myokines or exerkines, which act on different mechanisms throughout the organism. “Muscle has an important endocrine role. Combined training changes body composition, generates loss of visceral fat and gains in lean mass, improving lipid metabolism and mitochondrial function [das organelas que produzem energia para as células]as well as reducing inflammation and, consequently, promoting improvements in health markers”, he comments.
In cases of obesity, mitochondria are unable to transform fat into energy molecules (a chemical reaction known as phosphorylation). “With training, mitochondria begin to phosphorylate fat. So, the individual ends up using fat to generate energy and this improves the lipid metabolic condition of the body as a whole and contributes to weight loss”, he explains.
In the group's studies, the researchers also evaluated markers associated with immunosenescence and lipid metabolism in the same cohort, made up of 167 individuals divided into three groups: obese, obese with type 2 diabetes and healthy individuals without comorbidities. Study participants were between 40 and 60 years old.
In work conducted during Diego Trevisan Brunelli's postdoctoral studies, researchers verified, in cells of the immune system (T lymphocytes), the expression of inflammation gene expression markers that are involved in the process of premature aging, as well as markers of cellular aging.
In another study resulting from Renata Garbellini Duft's doctoral project, under the supervision of Julian Griffin, from Imperial College of London, in the United Kingdom, lipidomics techniques were used, which identify and quantify the set of lipids (fat molecules) in the blood and in samples of volunteers' adipose tissue (lipidome).
It is worth noting that lipids play vital roles in cell membranes, acting as energy reserves, providing structural support, as hormone precursors, transporting vitamins and enabling cell signaling. However, in obesity, lipid metabolism is deregulated, leading to the accumulation of body fat and abnormal deposition of lipids in the liver.
“When we measured gene expression markers related to immunosenescence, we found that, although there was a lot of similarity between the indices presented by obese and obese participants with diabetes, the result was completely different from lean individuals without comorbidities. This similarity between obese and obese diabetics was probably due to the fact that all diabetic participants were under drug treatment”, explains Cavaglieri.
Immunosenescence markers, however, partially returned to optimal levels after 16 weeks of training. During the period, participants performed three weekly one-hour training sessions, which involved half an hour of weight training and half an hour of running, walking or cycling on an exercise bike.
The researcher emphasizes that the relationship between obesity and the two factors studied forms a vicious circle. “The more obesity, the greater the release of fats into the blood, the greater the inflammation and, consequently, the greater the risk of developing chronic non-communicable diseases”, says the researcher to Agência FAPESP.
“But physical exercise can reverse this situation. It is a simple protocol, which has been tested in different populations and is recommended by the main medical societies. We show, however, that, in addition to aesthetic gains, training reverses two processes of great relevance to health and which are related to obesity”, he highlights.
The article Moderate-intensity Combined Training Induces Lipidomic Changes in Individuals With Obesity and Type 2 Diabetes can be read at:
The article Combined Training Improves Gene Expression Related to Immunosenescence in Obese Type 2 Diabetic Individuals can be read at:
This content was originally published in Physical exercise alone reverses factors of premature aging in obesity on the CNN Brasil website.
Source: CNN Brasil