The results showed that hormone irisin helps convert calorie-storing white fat cells into brown fat cells that burn energy and may be an attractive target for fighting obesity anddiabetes.
“Exercise produces more irisin, which has many beneficial effects including fat reduction, stronger bones and better cardiovascular health,” said Li-Jun Yang, Professor at the University of Florida.
The hormone works by boosting the activity of genes and UCP1 — a protein crucial to turning white fat cells into brown cells.
Further, irisin, which surges when the heart and other muscles are exerted, also inhibits the formation of fatty tissue.
For the study, researchers collected fat cells donated by 28 patients who had breastreduction surgery.
After exposing the samples to irisin, they found a nearly five-fold increase in cells with protein UCP1 — crucial to fat “burning”.
“We used human fat tissue cultures to prove that irisin has a positive effect by turning white fat into brown fat and that it increases the body’s fat-burning ability,” Yang said.
Moreover, among the tested fat-tissue samples, the team found that irisin also reduced the number of mature fat cells by 20 to 60 per cent compared with those of a control group.
That suggests irisin reduces fat storage in the body by hindering the process that turns undifferentiated stem cells into fat cells while also promoting the stem cells’ differentiation into bone-forming cells, the researchers said.
The findings about irisin’s role in regulating fat cells sheds more light on how working out helps people stay slender, Yang said.
The study was published recently in the American Journal of Physiology — Endocrinology and Metabolism.