by Andre on 4 June 2007
The diet pill industry is worth billions per year in the US alone so there’s huge incentive for companies to market miracle pills and the 1994 Dietary Supplement Act makes it easy. Just ask Bob Park. This means that neither safety nor efficacy need to be proven for “natural” remedies and this has predictable results.
Despite this, the idea that drugs can help with weight loss and even improve fitness is plausible. Indeed, the possibility that some future drug might live up to the claims made by these pill pushers seems ever more likely. Take the recent announcement from Ronald Evans’s lab at the Salk Institute. They are “now able to chemically switch on PPAR-d, the master regulator that controls the ability of cells to burn fat. Even when the mice are not active, turning on the chemical switch activates the same fat-burning process that occurs during exercise.” As we get better and better at controlling metabolic activity with drugs, we will undoubtedly see more applications like this. If life is just chemistry (albeit exquisitely complex and subtle chemistry) there’s nothing stopping us from controlling biology with clever pills. Jake puts it this way at Pure Pedentry
True, the signaling cascades activated by exercise are just that — signaling cascades. Exercise works because it changes the molecular biology of cells, and there is no reason that we can’t enforce that same type of activation sans all the running around.
It also seems probable that something similar will eventually work for muscle building, but do these effects require some exercise or could someone lie in bed for a few months, pop pills, eat chocolate, and emerge a body builder? That’s an interesting question to me not only because I like lying in bed, but also because its answer might reveal an essential role for force in fitness. Put another way, do some signaling cascades critical for fitness involve more than just chemical but physical signals? Maybe that’s why they call it physical activity.
We already know of examples of cryptic sites in proteins involved in signaling that are exposed in response to force (check out this interesting work from Harold Erickson’s lab available freely from Pubmed) and if some of these processes are also activated during exercise it might not be possible even in principle to use pills to develop good overall fitness. But don’t despair, maybe a combination of fat burning, muscle building drugs and a therapeutic stretching rack would do the trick…