Is Sugar Toxic?

Is Sugar Toxic?
http://www.nytimes.com/2011/04/17/magazine/mag-17Sugar-t.html

Unfortunately, we’re unlikely to learn anything conclusive in the near future. As Lustig points out, sugar and high-fructose corn syrup are certainly not “acute toxins” of the kind the F.D.A. typically regulates and the effects of which can be studied over the course of days or months. The question is whether they’re “chronic toxins,” which means “not toxic after one meal, but after 1,000 meals.” This means that what Tappy calls “intervention studies” have to go on for significantly longer than 1,000 meals to be meaningful.

At the moment, the National Institutes of Health are supporting surprisingly few clinical trials related to sugar and high-fructose corn syrup in the U.S. All are small, and none will last more than a few months. Lustig and his colleagues at U.C.S.F. — including Jean-Marc Schwarz, whom Tappy describes as one of the three best fructose biochemists in the world — are doing one of these studies. It will look at what happens when obese teenagers consume no sugar other than what they might get in fruits and vegetables. Another study will do the same with pregnant women to see if their babies are born healthier and leaner.

Only one study in this country, by Havel and Stanhope at the University of California, Davis, is directly addressing the question of how much sugar is required to trigger the symptoms of insulin resistance and metabolic syndrome. Havel and Stanhope are having healthy people drink three sugar- or H.F.C.S.-sweetened beverages a day and then seeing what happens. The catch is that their study subjects go through this three-beverage-a-day routine for only two weeks. That doesn’t seem like a very long time — only 42 meals, not 1,000 — but Havel and Stanhope have been studying fructose since the mid-1990s, and they seem confident that two weeks is sufficient to see if these sugars cause at least some of the symptoms of metabolic syndrome.

So the answer to the question of whether sugar is as bad as Lustig claims is that it certainly could be. It very well may be true that sugar and high-fructose corn syrup, because of the unique way in which we metabolize fructose and at the levels we now consume it, cause fat to accumulate in our livers followed by insulin resistance and metabolic syndrome, and so trigger the process that leads to heart disease, diabetes and obesity. They could indeed be toxic, but they take years to do their damage. It doesn’t happen overnight. Until long-term studies are done, we won’t know for sure.