Sweet, cheap and dangerous

A lot of people believe that the letters HFCS spell danger.

"HFCS" stands for high fructose corn syrup, a form of sugar which helps to extend the shelf life of processed foods. For that reason -- and also because the stuff is so darned cheap (thanks to government corn subsidies) -- you can find HFCS lurking in innumerable products throughout your grocery store.

A number of people also believe that HFCS products simply don't taste like products sweetened with other types of sugar. You may recall the "New Coke" debacle of 1985, which ended when the Coca-Cola company switched back to the old formula. A number of cynics suggested that the reversion to the original was illusory, since the beverage was now made with high fructose corn sugar. Mexicans still make Coca-Cola with sucrose, as in ye olden days -- and they even sell the stuff in the traditional green glass bottles. In blind taste tests, experts found the Mexican variety to be a bit sweeter and "more complex."

But is cane sugar safer than corn-created fructose? Is there any truth to the argument that the near-ubiquity of HFCS has contributed to the obesity epidemic?

HFCS is produced from corn starch, which is mostly glucose. Toss in some enzymes, add a fungus, and glucose magically transforms into fructose -- the stuff that makes strawberries taste sweet. Today, the average American consumes roughly 38 pounds of HFCS each year, along with another 47 pounds of "natural" sucrose (i.e., table sugar).

Critics have pointed out that, as HFCS consumption has risen, so has obesity. For years, fructose consumption and the fat-factor have tracked with uncanny precision. Correlation, of course, does not mean causation.

The Corn Refiners Association has come out swinging against those who would bad-mouth their product. Here are some excerpts from a 2008 email sent by the association to a critic:

The American Medical Association (AMA) recently concluded that “high fructose corn syrup does not appear to contribute to obesity more than other caloric sweeteners.”

Many studies claim that the body processes high fructose corn syrup differently than other sugars due to the fructose content. Conclusions from these studies cannot be extrapolated to high fructose corn syrup. That is because the studies looked at the effects of fructose independently.

Like sugar, honey and some fruit juices, high fructose corn syrup contains almost equal portions of fructose and glucose. As noted by the U.S. Food and Drug Administration in 1996, “the saccharide composition (glucose to fructose ratio) of HFCS is approximately the same as that of honey, invert sugar and the disaccharide sucrose (or table sugar).”

Kathleen J. Melanson, et al. at the University of Rhode Island reviewed the effects of high fructose corn syrup and sucrose on circulating levels of glucose, leptin, insulin and ghrelin in a study group of lean women. The study found “no differences in the metabolic effects” of high fructose corn syrup and sucrose.

No credible research has demonstrated that high fructose corn syrup affects appetite differently than sugar. Research by Pablo Monsivais, et al. at the University of Washington found that beverages sweetened with sugar and high fructose corn syrup as well as 1% milk all have similar effects on feelings of fullness.

All of which seems quite persuasive.

Nevertheless, in that same year (2008), the American Journal of Physiology published a troubling study conducted by researchers at the University of Florida in Gainesville, Florida:

We hypothesized that chronic fructose consumption causes leptin resistance, which subsequently may promote the development of obesity in response to a high-fat diet. Sprague-Dawley rats were fed a fructose-free control or 60% fructose diet for 6 mo and then tested for leptin resistance. Half of the rats in each group were then switched to high-fat diet for 2 wk, while the other half continued on their respective diets. Chronic fructose consumption caused leptin resistance, while serum leptin levels, weight, and adiposity were the same as in control rats that were leptin responsive.

Subsequent exposure of the fructose-mediated, leptin-resistant rats to a high-fat diet led to exacerbated weight gain...

Our data indicate that chronic fructose consumption induces leptin resistance prior to body weight, adiposity, serum leptin, insulin, or glucose increases, and this fructose-induced leptin resistance accelerates high-fat induced obesity.

The problem, then, may not be fructose per se, but fructose in conjunction with highly fatty foods. And that's precisely what you encounter when you walk into most fast food restaurants.

HFCS was developed in the 1970s in order to offset the skyrocketing prices of sucrose. Fructose drastically lowered the cost of sweetener, which the most expensive aspect of soft drink production. Thus, the fructose invasion gave us the "all you can drink" beverage bar now seen in most fast food restaurants.

If you could time-travel back to (say) 1978, and if you visited a nice coffee shop or Mexican restaurant, you might see a shocking item on your tab: "They're charging for that second glass of Coke?" Yep. Such was the common practice. Nowadays, thanks to the miracle of corn, you can slurp the sweet stuff until it comes spraying out of your navel, for no extra fee. Naturally, this "endless gulp" policy increases your overall sugar intake. Who can resist that third king-sized goblet brimming with Dr. Pepper? Hey, they're giving the stuff away.

Even the Corn Refiners Association would have a hard time arguing against the problem of Endless Gulp Syndrome. They've made sweet cheap. Cheap can be dangerous.

Even if we discount the hidden dangers of low prices, HFCS may pose a health risk. A 2010 study conducted by Princeton University researchers found increased body fat and trigyceride levels in rats fed HFCS, as opposed to rats fed table sugar.

In summary, rats maintained on a diet rich in HFCS for 6 or 7 months show abnormal weight gain, increased circulating TG and augmented fat deposition. All of these factors indicate obesity. Thus, over-consumption of HFCS could very well be a major factor in the “obesity epidemic,” which correlates with the upsurge in the use of HFCS.

Of course, the corn industry was quick to disagree with this conclusion. Cynics may sneeringly remind us that the tobacco industry denied that cigarettes cause cancer.