Dr Chad Cowan, Harvard Stem Cell Institute
With the Christmas party season in full swing, some of us may be piling on the pounds after a bit of overindulgence. So wouldn't it be great if you could just pop a little pill that melts away that unsightly flab?
This week scientists at the Harvard Stem Cell Institute announced the discovery of a drug that can turn white fat - the flabby stuff that stores energy and stops you fitting into your jeans - into healthier brown fat, which burns calories to generate heat. But, as researcher Chad Cowan explained to Kat Arney, it's not going to replace the benefits of a healthy diet and a bit of exercise any time soon...
Chad - We had previously shown that we could make, in a dish, human white fat. It’s the one that stores energy. When we eat too much this white fat is stored in excess and we get obesity and this contributes to all the diseases we hear about such as diabetes. We also made in a dish that other type of fat, brown fat which actually burns off the energy content in the form of heat. We’ve done this using some genetic tricks and we wondered whether we might be able to replace those genetic tricks with small molecule compounds, much like the ones that you find in the pharmaceutical drugs. So, we teamed up with a company, Roche Pharmaceuticals. Together with their team we screened small molecules to ask, “Could we convert these white fat cells into brown fat cells?” We were very happy to discover that in fact, two molecules from the screen that we did were very effective at changing the metabolic activity on the fats so that it resemble brown fat. So, they still knew they were white fat cells, but instead of just storing energy, they became more metabolically active like brown fat cells can actually burn off that energy more readily.
Kat - Now, some of the coverage of this discovery has said, “This is a fat pill. You'll be able pop it and the pounds will melt off.” Obviously, that’s probably an exaggeration. Where are you with these studies at the moment?
Chad - That’s definitely an exaggeration. This is early days. The compounds that we’ve found, we’ve just begun to move in to pre-clinical studies to see if we in fact treated them with the sort of doses that you might give, would actually accomplish the metabolic change we would hope, which is maybe burning off fat or perhaps even prevent diabetes. Those experiments have really just begun and we won't have any answer even from that phase of it for about another year. We are more encouraged by the fact that we’ve begun discussions with multiple companies about expanding the screen to find new compounds that might do this even more efficiently than the two we originally identified.
Kat - This does sound like the stuff of dreams. I'm someone who likes her cake. Do you think that it would even be a good thing to have a pill that you could pop that would alter your fat metabolism or would it be maybe only suitable for certain people?
Chad - That is my major reservation because you don’t want research like this to send the message that it’s okay not to go to the gym or not to be physically active because the benefits of physical activity are well beyond burning calories. Increases muscle mass, bone mass, improve mobility. There are so many benefits to exercise that a simple pill that’s going to increase the metabolic activity of fat and reduce the caloric burden that we’re all under is not the overall solution. I think it is a piece of the puzzle in our war against obesity and it could probably help those people who have trouble being physically active to try to combat obesity. But it certainly should not be viewed as a cure all.
Kat - What would be the effect of switching it from being this kind of storage fat cells to the kind of fat cells that create heat? Would you just get incredibly hot?
Chad - Some people estimate that if you had several grams more brown adipose tissue, your overall body temperature might run a little bit warmer. Probably, less than a degree, maybe half a degree, but even a degree or 2 degrees increase in body temperature could feel rather uncomfortable. We really won't know about the main effect of this in terms of body temperature change until we complete our studies in mice. The hope would be that you could use this pill to convert some cells over to these more metabolically active cells. This is a relatively stable change and then you could go off the medication for a certain amount of time and keep those cells working without a noticeable change in body temperature.
Kat - Wouldn’t it be better to invest all the money that’s going into this kind of research in just trying to get people to eat less cake and move a bit more?
Chad - I completely agree. Sadly, we’ve had three cures for obesity around for a very long time: you can exercise more, you can eat less or you can get gastric bypass surgery. Unfortunately, none of the three are making a big dent in the problem. So, I think if we just add more tools to our arsenal, I think that it could make a bigger difference in society in reducing our health burden. But I completely agree that making a bigger public push to making sure people are physically active and watch their diet is exactly the right approach in the long term.
Ginny - Chad Cowan speaking with Kat Arney.
Chris - Just make the food harder to reach is the answer. Put the fridge at the top of the stairs or something.