By Lara Holmes

Scientists have discovered a hormone responsible for a portion of the benefits of physical activity and health in the future, which could be used to treat problems such as obesity, according to a study released Wednesday by the journal Nature.

The research, carried out by scientists at Harvard Medical School and Cancer Institute Dana-Farber in Boston (US) has revealed that physical exercise stimulates the production of a hormone called irisin, which acts on white adipose tissue cells.

A study in mice has shown that the slight increase in irisin levels in the blood results in increased total energy expenditure without changing the amount of exercise or food intake of these mammals.

Thus, these mice had a greater resistance to obesity and diabetes, and enjoyed a longer life expectancy, according to Dr. Bruce Spiegelman in Cell Biology.

These changes suggest to the experts that irisin may be the hormone that in humans gives the benefits of physical exercise, especially those related to total energy expenditure and obesity resistance.

Spiegelman believes that irisin could serve as injectable treatment for metabolic diseases in humans and other disorders in which physical exercise can lead to an improvement of the disease.

During the experiment, experts put the mouse on a wheel to run for three weeks and found that the concentration of this hormone in their blood rose 65%.

The scientists detected the same effects in several samples of human muscle taken before and after ten weeks of supervised physical training, after which levels in the blood of irisin doubled compared with the levels of a subject not exposed to exercise.