Researchers at the Harvard Medical School have discovered a new hormone they have named irisin, after the Greek goddess Iris.  It appears to work magic, changing white adipose tissue cells into cells that resemble brown adipose tissue.  It does not require a fancy drug to activate, it requires exercise.  Mildly elevated levels of irisin result in significantly enhanced metabolic rate.

As I explained in yesterday’s post, brown adipose tissue throws away fat as heat.  In scientific terms this means that normal calorie burning that produces energy (aerobic cellular metabolism) in uncoupled.  Uncoupling of cell metabolism can occur in a healthy way or an unhealthy way.  When it is unhealthy a person makes a lot of heat, inflammation, generates excessive free radicals, makes lots of lactic acid, and feels like garbage (fibromyalgia as an example).  A lower level of this is simply getting too hot too easily.  This is metabolic uncoupling as a disability.  Your body also intentionally uncouples metabolism to dispose of fat.  Your regular brown adipose tissue does this, in part, to help regulate your temperature.  Your body also uncouples metabolism in several other ways that are healthy.

When you do aerobic exercise your body starts to liberate fat to burn as the primary fuel source to sustain your activity level.  It will keep doing this as long as you keep doing aerobics.  Once you stop the aerobics then there is extra fat that has been liberated.  Your body wants to get rid of it, even though you are no longer exercising.  This new study indicates that exercise fitness will build a brown fat cell network, within your muscles, out of white fat cells that reside in your muscles.  This is different than the brown adipose tissue that was discussed yesterday.  For example, a key marker of aging is the increase in white fat that weaves its way through your muscles.  This new study suggests that not only can you get rid of it you can convert it to something useful.  This is a major discovery. 
The researchers showed that exercise turned on genes that activate the uncoupling protein of brown fat, which in called uncoupling protein 1 (UPC1).  Literally, a brown fat-like network of cells was being formed from white fat.  It is interesting that aerobic exercise also turns on another uncoupling protein called UPC3, which can be enhanced by taking coenzyme Q10 prior to exercise.  Any nutrients you take that enhance your ability to do aerobic exercise and get a good response to it should help you build up this irisin-stimulated network of brown adipose tissue cells in your muscles.  Boosting healthy uncoupling of metabolism drastically boosts fat-burning in response to exercise.  If you do it right over a few months you will feel your metabolism rejuvenate.

While this new irisin study is done with mice, irisin is present as a hormone signal in human blood and is identical to mouse irisin.  There is now a grand total of 1 irisin study in the medical literature, albeit by one of the most prestigious medical schools in the country.  Expect to hear a lot about this in the coming years.  No doubt, there will now be a mad Big Pharma dash to make irisin drugs.  Maybe you should be in a mad dash around your closest jogging trail.

Posted by Byron J Richards at 05:32 PM.

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