How ‘Exercise Hormone’ Helps Improve Your Weight and Health

Health

Teens With PCOS Tend to Have Higher Irisin Levels

In the current study, presented at the Annual European Society for Pediatric Endocrinology Meeting,11 Greek researchers compared the hormone panels of 23 teenage girls diagnosed with PCOS with those of 17 healthy girls of the same age and body mass index (BMI).

Those with PCOS had significantly higher levels of irisin, which in turn was associated with higher levels of testosterone (a marker of PCOS). Next, the researchers will investigate the actual role irisin plays in the condition, with the hopes it might improve and expand treatment options.

One important treatment strategy is to dramatically reduce your net carbs (total carbohydrates minus fiber), as this is foundational for weight loss and insulin sensitivity. Since insulin resistance is a central issue in PCOS, cutting back on added sugars and grains will help control the disease.

I believe the foundational issue with PCOS is severely diminished insulin receptor sensitivity. If you can restore that with fasting and nutritional ketosis, the problem should resolve.

Optimizing your vitamin D is another important step, and progesterone may be helpful. You can read more about this in Lee’s article on PCOS.12

The Benefits of Brown Fat

Getting back to the main focus of this article, irisin appears to be an important player in weight loss associated with exercise. As mentioned, a key part of this benefit is due to its ability to transform white fat cells into brown fat cells, the latter of which primarily burn energy rather than storing it.

Based on animal models, researchers estimate that just 50 grams of brown fat (which is less than what most study volunteers have been found to have) can burn about 20 percent of your daily caloric intake, so the impact of having more brown fat can be rather significant.

Research has shown that certain groups of people tend to have more brown fat than others, and there are direct correlations between the activation of brown fat and metabolic measures of good health. For example:

Slender people have more brown fat than obese people do
Younger people have more brown fat than older people
People with normal blood sugar levels have more brown fat than those with high blood sugar

Brown Fat Is More Akin to Muscle Than Fat

As newborns we have a healthy supply of brown fat to keep warm, but by adulthood we lose most of our brown fat stores, which are typically found in the neck area, around blood vessels (which helps warm your blood), and “marbled” in with white fat in visceral fat tissue. The good news is you can increase your supply of brown fat. In addition to exercise, brown fat can be activated through cryotherapy,13,14 meaning exposure to cold temperatures such as ice baths or cold showers.

Interestingly, brown fat actually behaves more like muscle than fat, which helps explain its fat-burning capabilities. Bruce Spiegelman, Ph.D., has published a number of studies on brown fat,15 and in one, he identified a “master switch” that promotes the production of brown fat. This molecular switch, known as PRDM16, regulates whether immature cells will turn into brown fat or into muscle cells.

So white and brown fat cells have very different origins. Brown fat is more closely related to muscle. Another set of researchers from Harvard’s Joslin Diabetes Center found yet another trigger for brown fat — a bone morphogenetic protein called BMP-7, which also promotes bone growth.16,17,18 BMP-7 acts as a growth factor for brown fat.

The Importance of Brief, High-Intensity Workouts

As mentioned, irisin is a kind of myokine, or muscle-derived chemical messenger or protein. In 2014, I interviewed Dr. Doug McGuff on this topic. In that interview (included above for your convenience), he explained the significance of myokines and the most effective way to boost their production. Myokines are very anti-inflammatory, and research suggests myokines may play an important role in combating metabolic syndrome and cancer, for example. As noted by McGuff, myokines: