We know that exercise does a body good (certainly more so than drinking milk!). But even more evidence is being discovered–irisin being the most recent. Named after the greek messenger goddess Iris, this hormone is debuting as a critical communicator between the two different types of fat cells.
A recent Harvard University study found that exercise, via the release of irisin, increases the amount of brown fat stored in our bodies, while at the same time decreasing white fat cells. So what is brown fat exactly, and why should we want more? Brown fat is considered metabolically active because it actually burns calories. Meanwhile, white fat releases hormones and cytokines as described in my previous post (read more). Brown fat was originally thought to reside only in babies and decrease as a child grows older. However, as the knowledge of science is ever-changing, scientists are now discovering otherwise. This gives more credence to why exercise increases a person’s metabolism as the increase in brown fat leads to burning more calories even when not exercising (read more about the study in a recent NYT article). Along with its effects on fat tissue, irisin was also found to improve the study participants’ response to insulin (hormone responsible for the uptake of glucose into working muscles), thereby shedding more light on how exercise plays a role in preventing type 2 diabetes.
Instead of using this as motivation to enhance public health initiatives that encourage us to exercise more, some scientists are racing to find the next quick-fix “cure” for obesity and type 2 diabetes. This could potentially lead to yet another way pharmaceutical companies can profit from this twin epidemic. Unfortunately, there’s not much profit in prevention.
So for those who need yet another reason to get moving instead of waiting for the magic pill, there you have it!