Is High Fructose Corn Syrup Really Bad for You?

One minute you read that high fructose corn syrup is making America fat. The next, you see a commercial in which happy people laugh at anyone who'd be foolish enough to think that corn could be bad for you.

One thing's for sure: High fructose corn syrup seems to be in everything you buy at the grocery store these days. That's because humans love sweet, and this sweet is cheaper than regular sugar. But is it really so bad? Is the healthy set's collective freakout really justified? Are our children in danger? In other words: Is high fructose corn syrup really any worse for you than sugar?

You may be be surprised to hear that the jury is still out. HFCS has been so thoroughly vilified that you would assume the FDA or NIH or someone had databases overflowing with proof that HFCS was terrible for you. Nope.

HFCS and sugar are actually pretty similar. Sucrose, A.K.A. regular sugar, is half fructose and half glucose. Pay attention because these ingredients all end in -ose. HFCS contains the same ingredients at slightly different ratios: approximately 55-percent fructose (like the name says, it's high in the stuff) and 45-percent glucose.

The ingredients also come from different places. Sucrose exists naturally in sugar cane, sugar beets, sugar-maple sap, dates, and honey. High fructose corn syrup comes from straight corn syrup, which, before it is processed, is 100 percent glucose. To make the ingredient in your soda, an enzyme turns 92 percent of that glucose into fructose. Then glucose is added back into the mix, and, voila! High fructose corn syrup. While the 55-percent fructose 45-percent glucose ratio is pretty standard, studies measuring the stuff in sodas turned up fructose levels over 60 percent.

Why does that matter? Studies have shown that fructose can be hard on the body. A study published in the Journal of Clinical Investigation compared the effects of fructose-sweetened drinks with glucose-sweetened drinks over the course of 10 weeks in overweight and obese subjects. About 25 percent of the energy requirements over that time period came from the drinks (read: soda). While study participants gained about the same amount of weight regardless of sweetener, the fructose group—but not the glucose group—saw increases in belly fat as well as a dulling of insulin sensitivity.

But both regular sugar and HFCS are at least 50 percent fructose, and it's not enough for a HFCS indictment. "It definitely hasn't been proven that that is true," says Kimber Stanhope, a molecular biologist at the University of California at Davis, and author of the above study. "There is no data at this point showing a difference between the two. There is no reason at this point to think high fructose corn syrup is a bigger problem than sucrose."

A study out of Princeton found that rats consuming high fructose corn syrup gained more weight than those consuming table sugar. But studies in humans, Stanhope explains, have not backed up the animal evidence.

All of this hand-wringing about HFCS is overshadowing the real problem: The astronomical amount of sugar of all kinds we eat on a daily basis. Government dietary guidelines say added sugar can be 25 percent of our daily caloric intake and we can still be healthy. But Stanhope's research says that's too much. Her most recent sugar study, published in the Journal of Clinical Endocrinology & Metabolism, found that consuming that volume of sweets increased LDL cholesterol, triglycerides and levels of apolipoprotein-B: three big risk factors for heart disease. And in previous studies, sucrose has been shown to bump up lipid levels and fat storage in the liver.

There was a big jump in obesity in the 1970s, right around the same time HFCS entered the food and beverage industry. That might seem like pretty damning evidence. But it's likely that this cheaper way to make sweets only led to easier, less-expensive access to high sugar foods, which in turn led to a jump in consumption; it doesn't necessarily mean HFCS is some magic make-you-fat bullet.

The good news is that all this outcry over corn syrup is spurring a lot of research into the effects of all sugars on the human body, which means that the Food Justices may have a ruling soon on whether or not to avoid the stuff. While you wait for a verdict, why not snack on some veggies?


Rachel Swaby is a freelance writer living in San Francisco.

Image: Flickr/BetsyWeber

Giz Explains is where we break down whatever science or tech questions are scratching at the backs of our noggins. Got questions of your own? Email them to us at explains@gizmodo.com and we'll see about answering them.