The amount of sugar in a single can of pop. Image credit Lloyd Alter
The New York Times Magazine cover article has the provocative title Is Sugar Toxic? which they have ever so kindly let loose outside their new pay wall. Author Gary Taubes has become convinced it isn't the dietary fat that is causing the explosion of obesity, diabetes, heart disease and hypertension, but the sugar. It is a thesis put forward by Robert Lustig of University of California, San Francisco, School of Medicine, who says "sugar should be thought of, like cigarettes and alcohol, as something that's killing us."
Robert Lustig on Sugar: The Bitter Truth
Lustig doesn't care whether it is high fructose corn syrup or good old pure sugar;
Marketing aside, the two sweeteners are effectively identical in their biological effects. "High-fructose corn syrup, sugar -- no difference," is how Lustig put it in a lecture that I attended in San Francisco last December. "The point is they're each bad -- equally bad, equally poisonous."
They both have fructose, (HFCS slightly more) that is metabolized by the liver and turned into fat.
The fructose component of sugar and H.F.C.S. is metabolized primarily by the liver, while the glucose from sugar and starches is metabolized by every cell in the body. Consuming sugar (fructose and glucose) means more work for the liver than if you consumed the same number of calories of starch (glucose). And if you take that sugar in liquid form -- soda or fruit juices -- the fructose and glucose will hit the liver more quickly than if you consume them, say, in an apple (or several apples, to get what researchers would call the equivalent dose of sugar). The speed with which the liver has to do its work will also affect how it metabolizes the fructose and glucose.
The idea that sugar, not fat, causes heart disease has long been controversial; in the seventies, a British scientist, John Yudkin proposed it, and was so thoroughly discredited that his name became an insult. But now it is recognized that "metabolic syndrome" and insulin resistance could be major causes of heart disease, and Lustig claims that this is caused by sugar.
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.
Author Taubes then goes further than Lustig, and suggests that sugar may well cause cancer. He concludes:
I've been reporting on this subject and studying it for more than a decade. If sugar just makes us fatter, that's one thing. We start gaining weight, we eat less of it. But we are also talking about things we can't see -- fatty liver, insulin resistance and all that follows. Officially I'm not supposed to worry because the evidence isn't conclusive, but I do.
Read it all in the New York Times; For an opposing view, read David Katz in Huffington Post, who says "The notion that sugar is evil and the only dietary consideration that matters is, in a word, humbug."
More on Sugar, Fructose and HFCS:
Pepsi Throwback Uses Real Sugar, But Is It Better For You?
Fructose is Fructose and Sugar is Sugar, And No Better Than HFCS.
High Fructose Corn Syrup to be Rebranded as "Corn Sugar"
Study Shows You Get Fatter From HFCS Than From Sugar