Buzz
High fructose corn syrup is harmful, and I want to be clear about that. However, if you're avoiding it by obsessing over ingredient labels or choosing products like Jones Soda or Mexican Coke because they contain 'real' sugar, you might be misguided.
Both sucrose (table sugar) and high fructose corn syrup are types of sugar. Across the globe, especially in the U.S., sugar consumption is on the rise, contributing to obesity and metabolic issues. The 2015 dietary guidelines will, for the first time, recommend limits on the amount of added sugar we consume. Sugar is harmful, there's no doubt about it. But is there a real difference between high fructose corn syrup and table sugar?
Understanding the Difference Between High Fructose Corn Syrup and Sugar
Fructose and glucose are distinct sugar molecules, each containing six carbon atoms. When they bond together, they form sucrose, or table sugar, which consists of 50% glucose and 50% fructose.
Traditional corn syrup is primarily composed of glucose, but when it's processed into 'high fructose' corn syrup, the fructose content increases to either 42% or 55% (with the 55% version used in soft drinks). While the fructose content in high fructose corn syrup and table sugar isn't exactly the same, they are quite comparable.
When you ingest sucrose, it travels through your mouth, esophagus, and stomach without being altered, until it reaches your small intestine, where it's broken down by the enzyme sucrase attached to the intestinal walls. This process splits sucrose into glucose and fructose, which are then absorbed into the cells lining the small intestine. From there, the sugar enters your bloodstream. Congratulations, you've just consumed and absorbed sugar.
Unlike sucrose, high fructose corn syrup doesn't require breaking down, as its glucose and fructose components are already separate. It is absorbed directly through the same glucose and fructose transporters as in the previous case.
Once either sweetener reaches your bloodstream, it is essentially a mixture of glucose and fructose, which makes it difficult to explain why high fructose corn syrup would have a different impact on your body compared to sugar.
Fructose may have negative effects on your health, but that doesn’t mean high fructose corn syrup is any worse for you than sugar.
Consider the argument that fructose is far worse for your health than glucose. While controversial, it’s a notion worth exploring. Robert Lustig, a leading advocate of this perspective, has repeatedly asserted that high fructose corn syrup is essentially as harmful as sugar. Both substances are rich in fructose.
High fructose corn syrup can indeed contain more fructose than regular table sugar. However, Examine.com offers an important reality check, suggesting that the difference might not be as significant as it seems.
In extreme cases, high fructose corn syrup may consist of 55% fructose. For every 100g (400kcal) of sugar consumed, this results in an additional 5g of fructose compared to an equivalent amount of sucrose.
In practice, the extra fructose from high fructose corn syrup is usually too minimal to have any meaningful impact. Excessive consumption of this syrup often correlates with overall sugar overconsumption, which is where the real concern lies.
Examine.com’s research found no distinct difference between high fructose corn syrup and sucrose when it comes to hunger levels, leptin (a hunger-regulating hormone), or insulin response. A 2007 review in Critical Reviews in Food Science and Nutrition concluded that high fructose corn syrup plays no unique role in weight gain compared to sucrose.
Wasn't there a study that showed high fructose corn syrup is more "toxic" than sugar?
Yes, a few months ago, a study from the University of Utah was released stating that high fructose corn syrup is more "toxic" than sucrose.
The research involved wild-type mice (as opposed to inbred lab mice) who were housed in specially constructed "mouse barns" where they had the freedom to fight, mate, and reproduce. The scientists compared two groups: one that received 25% of their calories from sucrose (table sugar), and the other that got 25% of their calories from a fructose-glucose mixture, similar to high fructose corn syrup. Published in The Journal of Nutrition, the study revealed that female mice consuming the fructose-glucose mixture had fewer offspring and shorter lifespans. The university released a press statement with the headline, "Fructose more toxic than table sugar in mice."
To clarify the results, I reached out to toxicologist John DeSesso, an expert in designing animal studies to assess the effects of substances on reproduction and development.
"I'm not particularly convinced by their conclusions," DeSesso remarked, noting that there are established guidelines for evaluating reproductive toxicity in animal studies, which the Utah study did not follow. The researchers made general observations about the entire mouse population, such as birth rates and mortality during certain periods, but couldn’t pinpoint the exact cause. Furthermore, they didn’t offer an explanation for why the sugar seemed to have a more significant "toxic" effect on female mice compared to males. They also failed to confirm their results by examining the pancreases or livers of the mice, which could have verified if the sugar was causing diabetes or other metabolic changes.
DeSesso also mentioned that since this kind of experiment is a novel approach, it's difficult to interpret the results. "This paradigm isn't necessarily bad, but it remains relatively untested." He expressed interest in seeing whether the results could be replicated and better understood, but cautioned that it's not valid to conclude from this study that high fructose corn syrup is definitively problematic.
We're All Suckers
Here’s a thought-provoking idea: What if our criticism of high fructose corn syrup is just a way for us to feel better about consuming large amounts of sugar?
It’s tempting to choose "Pepsi-Cola Made With Real Sugar" (formerly Throwback) over regular Pepsi, or to support brands like Jones or Whole Foods that avoid high fructose corn syrup. This way, you can sip on your premium soda or organic lemonade while looking down on others sipping Coke—even though you’re both consuming the same amount of sugar.
What would be more challenging—but ultimately healthier—is to focus on reducing sugary foods and drinks in your diet overall. We've written previously about strategies to cut down on sugar and make it less damaging. So if you're still inclined to check labels for high fructose corn syrup, don't forget to keep an eye out for sugar as well.
Images provided by Blan-k, Brent Hofacker, David Goehring, distillated, Tambako the jaguar, and torbakhopper.
