For any of you that might still be reading this blog after yesterday's extremely nerdy post, this may be as bad, though it has nothing to do with computers. Browsing through Google News headlines early this morning I noticed a link to an article from the New York Times Magazine about sugar and its possible toxicity, i.e., not just that it may make us fat and diabetic but that it may be poisoning us by promoting hypertension, heart disease and cancer. That last part caught my eye. We certainly don't think of sugar as a culprit in cancer or, for that matter, in the other two diseases. The article, which I'm guessing is going to appear in this Sunday's edition of the paper, is quite long, but fascinating. The piece is inspired by the ongoing research into the toxic effects of sugar by Robert Lustig, who is a leading expert on childhood obesity at the University of California, San Francisco, medical school. Lustig considers both refined sugar, the stuff we put in our coffee and on our cereal, as well as high fructose corn syrup (HFCS), the current bad guy in the sugar/obesity debate, to be essentially the same. According to Lustig, refined sugar consists of one molecule of glucose bonded to one molecule of fructose, making it a 50-50 mixture of the two. HFCS is 55% fructose and the remaining 45% is almost all glucose. Also, the more fructose, the sweeter tasting, which, along with the fact that it is cheaper, may explain the food processors' preference for using HFCS over refined sugar. An interesting sidelight is that HFCS began to replace sugar in soft drinks and other processed foods in the early 1980's because refined sugar was seen as the villain. Of course, now we've come full circle and HFCS is the villain, though it is still found in sodas and many other processed foods. The point of the article is that both are equally bad and for reasons beyond those we think of now.
I'll try to summarize Lustig's thesis: the difference between sugar consumed eating fresh fruit and that in processed foods like soda, fruit juices and bakery products is that in the latter the glucose and fructose hit the liver more quickly. If fructose hits the liver in sufficient quantity and with sufficient speed, the liver will convert much of it to fat, which induces insulin resistance. This phenomenon has been observed in experiments involving rodents. (An aside: There is no question that what occurs physiologically in animals in the lab will not necessarily happen to humans. However we can not ethically feed large doses of something to human subjects that we suspect to be harmful to them. So, as with the relationship between smoking and cancer, we can only demonstrate what may be called circumstantial evidence or an association between increased sugar consumption and diseases like heart disease and cancer, and then infer that there is likely a causal relation. We have shown experimentally that smoking causes cancer in lab rats, but cannot ethically perform the same experiments on humans. However comparisons of smoking rates and cancer in humans have consistently shown a positive relationship. Few people believe any more that smoking does not cause cancer.) To continue, metabolic syndrome, which is also called insulin resistance syndrome and includes risk factors like abdominal fat and high levels of triglycerides and LDL cholesterol, is itself a major risk factor for coronary heart disease. According to the author, when you deposit fat in the liver (as in consuming sugar from processed foods) you become insulin resistant.
But what about cancer? The connection between obesity, diabetes and cancer was first reported in 2004 in large population studies by researchers from the World Health Organization and is not controversial, according to the author. The basic mechanism: Insulin resistance leads to secreting more insulin and insulin promotes tumor growth.The author quotes Craig Thompson, the head of the Memorial Sloan-Kettering Cancer Center in New York, to the effect that insulin provides the fuel and materials cancer cells need to grow and multiply. Also, insulin and insulin-like growth factor provide the signal for them to do it. Finally, the author quotes Lewis Cantley, the director of the Cancer Center at Beth-Israel Deaconess Medical Center, who states that "...up to 80 percent of all human cancers are driven by either mutations or environmental factors that work to enhance or mimic the effect of insulin on the incipient tumor cells."
That's a very brief and imperfect summary of a nine-page article. For anyone who wants to read the article, I will embed
a link to the article here. It may or may not work. The new policy of the Times online allows 20 free articles per month; after that you have to subscribe. But they also allow free access beyond that to articles linked to from another website. Finally, I know it's hard to get excited about another health study when so many previous studies and their conclusions have later been contradicted. But personally I'd like to eat less sugar than I do now.
Tomorrow we head to Boston for my follow-up visit, then we'll go from there to Lenox.