Health effects
Overconsumption of sugars has been linked to adverse health effects, and most of these effects are similar for HFCS and sucrose. There is a striking correlation between the rise of obesity in the US and the use of HFCS for sweetening beverages and foods, but it is not clear whether this is coincidence or a causal relationship. Some critics of HFCS do not claim that it is any worse than similar quantities of sucrose would be, but rather focus on its prominent role in the overconsumption of sugar, for example encouraging overconsumption through its low cost.
Possible differences in health effects between sucrose and HFCS could arise from the fact that glucose and fructose in sucrose are bound in a disaccharide or from the 10% difference in fructose content. At least in beverages, sucrose often separates into glucose and fructose before the beverage is consumed anyway, according to an industry-funded study [17].
Studies on the effect of fructose, as reviewed in [18], implicate increased consumption of fructose (due primarily to the increased consumption of sugars but also partly due to the slightly higher fructose content of HFCS as compared to sucrose) in obesity and insulin resistance.
One study concluded that foods with increased pure fructose "produced significantly higher fasting plasma triacylglycerol values than did the glucose diet in men" and "if plasma triacylglycerols are a risk factor for cardiovascular disease, then diets high in fructose may be undesirable".[19] Bantle, et al. "noted the same effects in a study of 14 healthy volunteers who sequentially ate a high-fructose diet and one almost devoid of the sugar."[20]
A study in mice suggests that fructose increases obesity.[21] Large quantities of fructose stimulates the liver to produce triglycerides, promotes glycation of proteins and induces insulin resistance[22].
The above-referenced studies have addressed fructose specifically, not sweeteners such as HFCS or sucrose that contain fructose in combination with other sugars. Thus, although they indicate that high fructose intake should be avoided, they don't necessarily indicate that HFCS is worse than sucrose intake, except insofar as HFCS contains 10% more fructose. Studies that have compared HFCS to sucrose (as opposed to pure fructose) find that they have essentially identical physiological effects. For instance, Melanson et al (2006), studied the effects of HFCS and sucrose sweetened drinks on blood glucose, insulin, leptin, and ghrelin levels. They found no significant differences in any of these parameters.[7]
Perrigue et al (2006) compared the effects of isocaloric servings of colas sweetened HFCS 45, HFCS 55, sucrose, and aspartame on satiety and subsequent energy intake. They found that all of the drinks with caloric sweeteners produced similar satiety responses, and had the same effects on subsequent energy intake. Taken together with Melanson et al (2006), this study shows that there is little or no evidence for the hypothesis that HFCS is different from sucrose in its effects on appetite or on metabolic processes involved in fat storage. Interestingly, both the Perrigue et al study and the Melanson et al study were funded by "the American Beverage Institute and the Corn Refiners Association."[23][24]
One much-publicized recent study found an association between obesity and high HFCS consumption, especially from soft drinks.[25] However, this study did not provide any evidence that this association is causal. And in fact, one of the study coauthors, Dr. Barry M. Popkin, is quoted in the New York Times (July 2, 2006, A Sweetener With a Bad Rap) warning that ?I don't think there should be a perception that high-fructose corn syrup has caused obesity until we know more.? In the same article, Walter Willets, chair of the nutrition department of the Harvard School of Public Health Nutrition Department Chairman, is quoted as saying that ?There's no substantial evidence to support the idea that high-fructose corn syrup is somehow responsible for obesity, [and that] If there was no high-fructose corn syrup, I don't think we would see a change in anything important.? In essence he is saying high fructose corn syrup is just as bad as other sugars. Walter Willets also recommends drinking water over soft drinks containing sugars or high fructose corn syrup.[26]
In summary, the evidence in peer-reviewed publications shows that overconsumption of fructose, whether from sucrose or HFCS, may be responsible for many of the adverse effects associated with overconsumption of sugars in general. However, industry-funded studies, also in peer-reviewed publications, have shown that the differences between the metabolic effects of HFCS and sucrose are small. Nonetheless, there are many people who believe that the health effects of HFCS are significantly worse than those of sucrose, based on anecdotal evidence or studies that don't directly examine this difference. [5] It can be difficult to find direct support for these claims in peer-reviewed journals; it is also difficult to find direct evidence against them in studies not supported by the beverage industry.