New hormone mimics the effects of physical exercise
A group of researchers at Dana-Farber Cancer Institute and Harvard Medical School, led by Bruce Spiegelman and Pontus Boström, have discovered a hormone that mimics some of the results of a workout by facilitating the transformation of white fat into brown fat. While the purpose of the former is to accumulate excess calories, the latter is used to produce heat. Irisin, named after the Greek goddess Iris, could one day help address obesity and diabetes. However, there is still a long way to go before the hormone is made into an actual drug.
Irisin occurs naturally both in humans and in mice, and its levels surge with physical exercise. Mice have to spend three weeks running on a wheel for the hormone to accumulate in their blood. For humans, the same happens after ten weeks of systematic exercising. A placebo-controlled study showed that boosting the levels of the hormone artificially in mice may induce some of the benefits that would normally be caused by a workout. The cells of the mice injected with irisin needed more oxygen and burned more calories. Obese mice lost several grams within the first ten days from the injection.
The treatment also had a positive effect on the regulation of blood sugar levels, which links the hormone to diabetes prevention. What's more, Spiegelman's team plans to investigate the potential of irisin to advance the treatment of diseases such as muscular dystrophy and muscle wasting. "We are hopeful, though we have no evidence, that this hormone may embody some of the other benefits of exercise, perhaps in the neuromuscular system," he says.
This sounds very promising, but there is still a lot to be done before an irisin-based drug comes to a pharmacy near you. First, whether or not irisin will have the same beneficial effects on humans still remains to be seen. Second, making it into an actual drug may turn out to be very challenging, as pointed out by MIT professor Harvay Lodish. Adiponectin, a hormone Lodish discovered back in the early 1990s, also seems to play a role in staving off obesity and diabetes. It is correlated with the body mass index (BMI) and it increases the metabolic rate in mice without raising the food intake. Still, so far all the attempts at converting the full size adiponectin protein into a viable drug have failed.
Professor Spiegelman, however, is optimistic. In fact, he's optimistic enough to have set up a separate company, called Ember Therapeutics, to conduct brown fat-related research that includes studies on the effects of irisin. Supported by Third Rock Ventures, the company raised US$34 million in the first round of financing. We do hope that all this money and brain power will eventually lead to a treatment for obesity and diabetes. That said, we do recognize that there might be more to it than just swallowing a pill.
We are far from advocating the medicalization of serious social issues, and we warmly encourage our readers to exercise on a regular basis (at least until the magic pill is out, that is).
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Drug?! I want it made into candy!
Thus an appropriately named drug. Science, in its reductionist ways, does not see the dangers it creates alongside of a replacement to exercise, sensible eating.
But for many it\'s not that simple. For many, even exercising one hour a day, every day will do little if nothing. A potential drug like this is geared toward those who are genetically behind the eight ball when it comes to weight loss. As a matter of fact, all \"extreme\" versions of weight loss (liposuction, banding, stapling, etc.) are not designed for the lazy, but for the genetically unfortunate.
And for the rest of us, sometimes it\'s simply not feasible to get in any sort of exercise. I personally know people who have a 3-hour round-trip commute to work, plus they work from home and spend time with their families, which leaves very little time for them to exercise. Should they just quit their jobs? Ignore their families? Let their homes fall to ruin? Something\'s gotta give, and for many of us, exercise is the easiest to drop and the one we\'ll miss the least.
Well, I thought the same until I started to put up 20 kg without change in lifestyle, no matter how much I exercised and what diet I tried (e.g wholefood, high-protein, low-fat, low-carb, vegetarian). Of course, I could settle for a 1500kcal/day diet. Which by the way gives not only constant hunger, headaches and an overall feeling of having a flu. It also reduces my IQ which is unfortunate, if you\'re a software designer. And as soon as I stop, weight goes up again.
The situation for me seems to be like this: I\'m somehow fixed at my weight, I can only transfer kilos from fat to muscles (or back).
On the other hand, there are people that don\'t do sport, eat everything the doctor warns you about and stay skinny. Maybe some fat guys just want the same chance even though their genes think different.