New work produced by Pfizer and Amgen cast doubt on the manner in which health supplement resveratrol is said to work. Resveratrol is a substance found in moderate quantities in red wine, and is believed to help prevent the negative side effects of aging. As we discussed in our previous article about resveratrol, prominent researchers supposed that it worked by activating a certain gene, SIRT1. This activation is thought to produce the benefits of a caloric restriction diet even among those with high fat and high caloric intake. In the October 2009 volume of Chemical Biology and Drug Design, Amgen offered experimental results that indicate resveratrol does not, in fact, activate SIRT1. Pfizer, in the January 2010 volume of the Journal of Biological Chemistry, offers similar results, showing that resveratrol (and related substances such as SRT1720) do not active SIRT1 and did not reduce blood sugar in mice fed a high fat diet. This last effect (or lack thereof) is in direct contradiction to previous resveratrol research published by David Sinclair of Harvard University in Nature. To simplify: Pfizer and Amgen are saying that resveratrol doesn't work in the way people thought, and may, in fact, not work at all.
Considering the complexity of this research, there isn't much to be said by us non-scientists at this time. As I mentioned in our previous resveratrol installment, it's going to take years of more research, and many rounds of conflicting results, before anyone is likely to conclusively know if and resveratrol works on mice...let alone humans. Those proponents of the substance should take heart in the fact that SIRT1 activation is just one possible mechanism by which resveratrol could induce the benefits of a caloric restriction (CR) diet. Opponents should point out that Pfizer's mice didn't show any benefits of CR, so that no matter what mechanism resveratrol is supposed to be using, it didn't seem to work. Pfizer also points out that resveratrol (and especially related substance SRT1720) did not improve mitochondrial capacity, and had many other effects on cells, some of which could complicate its use in humans.
Cynics, like myself, are happy to call attention to a potential conflict of interest. Pfizer and Amgen are competitors with GSK, one of the companies spending millions of dollars in clinical trials to see how resveratrol works. One would think that Pfizer and Amgen had something to gain by proving that GSK's potential products wouldn't work. That being said, they would have even more to gain if they found that resveratrol does work and if they could determine a way to market a SIRT1 activator themselves.
Again, I find myself advocating a "wait and see" policy to resveratrol. There are very few health supplements with undeniable scientific support. Even Vitamin D and Fish Oil are having to jump through hoops at the moment. Resveratrol, and the entire SIRT1 activation posse, are in need of more research and a resolution to conflicting results. Eventually there will be supplements, genetic treatments, and nanotechnology to preserve your body. In the meantime, those looking to live forever may find benefits from regular exercise, eating right, and staying stress free.
[photo credit Wiki Commons, Zereshk]