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The Truth about High-Fructose Corn Syrup

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Found in foods ranging from soda and salad dressings to cold cuts and wheat bread, this sweetener is at the center of one of the most heated debates in nutrition history. But is it really hazardous to your health and waistline? Cynthia Sass, R.D., investigates.

These days you can't turn on the TV without hearing something about high-fructose corn syrup (HFCS). A staple in the cookie and soft drink aisles, the additive also lurks in some unexpected places, such as dairy products, processed meats, packaged bread, cereals, and condiments. Its popularity among manufacturers is simple, really: It's an inexpensive way to add sweetness to foods while extending their shelf life.

But for the consumer, the "news" about HFCS is a bit murkier. It's the dietary demon behind the obesity crisis and a host of chronic health conditions, say critics. Yet ads from the Corn Refiners Association tout the benefits of the sweetener, maintaining it's perfectly safe when consumed in moderation. And at the same time, companies like Pepsi and Kraft are removing HFCS from some of their products and going back to good old sugar instead. So what are you to believe? We asked experts to weigh in on four of the controversies surrounding the sweetener.

1. Claim: It's all-natural.
Truth: For proponents, the fact that high-fructose corn syrup is derived from corn technically removes it from the "artificial ingredients" category. But others don't share that perception, pointing to the complex series of chemical reactions required to create the plant-based sweetener. To make HFCS, corn syrup (glucose) is treated with enzymes to convert it to fructose, explains George Bray, M.D., a specialist in obesity and metabolism at the Pennington Biomedical Research Center at Louisiana State University. It's then blended with pure corn syrup to produce a substance that's 55 percent fructose and 45 percent glucose. Although table sugar has a similar makeup (a 50-50 fructose-to-glucose ratio), the bonds between fructose and sucrose are separated in the processing of HFCS, making it more chemically unstable--and, some say, more harmful to the body. "Anyone who calls that 'natural' is abusing the word," says Bray.

2. Claim: It makes us fat.
Truth: The average person gets 179 calories from HFCS a day--about twice as much as in the early 1980s--plus 209 calories from sugar. Even if you just cut those numbers in half, you'd lose nearly 2 pounds a month. But with the sweetener popping up in every aisle of the supermarket, scaling back is easier said than done," says Andrew Weil, M.D., director of the University of Arizona Center for Integrative Medicine. "And it doesn't help that the products containing it tend to be more affordable than those made with other sweeteners."

Aside from contributing excess calories to our diet, high-fructose corn syrup is thought to pack on the pounds because of its effect on the brain. One study from Johns Hopkins found that fructose stimulates appetite triggers, making you feel less satisfied and prone to overeating. But is HFCS more likely to have these effects than sugar, which also packs a fair amount of fructose? Not according to a recent review published in the American Journal of Clinical Nutrition. After analyzing 10 previous studies comparing the two sweeteners, researchers found no difference in terms of blood glucose and insulin responses, hunger ratings, and levels of the hormones that control hunger and satiety. Still, it's important to remember that just because they behave the same way in the body doesn't mean that high-fructose corn syrup, or sugar for that matter, is waistline-friendly. "For weight control, you need to eat less of both and focus on 'good-fructose' whole foods," says Bray. "Fruit not only contains much less fructose than products made with HFCS, it comes bundled with vitamins, minerals, and filling fiber."

3. Claim: It can make us sick.
Truth: While high-fructose corn syrup is similar to sugar in many ways, one key difference may be the cascade of health conditions it's been associated with, from diabetes to heart disease. In one study from Rutgers University, researchers found that sodas sweetened with HFCS had high levels of reactive carbonyls, compounds believed to cause tissue damage and up your risk of type 2 diabetes.

However, it's the sheer volume of fructose we're consuming--be it from high-fructose corn syrup or sugar-sweetened foods--that seems to pose the greatest threat to our well-being. "Whereas glucose is metabolized in every cell in the body, fructose breaks down in the liver," explains Weil, lowering HDL ("good") cholesterol and inflating levels of LDL ("bad") cholesterol and triglycerides. A new study published in the American Journal of Clinical Nutrition found that women who drank two or more sweetened beverages a day increased their risk of heart disease by 35 percent. High-fructose levels have also been linked to an increase in blood uric acid, which can lead to kidney damage and gout as well as prevent blood vessels from relaxing, increasing blood pressure. "Our bodies have a limited capacity to handle fructose in such high amounts," says Weil, "and we're just now seeing the side effects."

4. Claim: It contains mercury.
Truth: The latest scare du jour focused on two recent studies that found traces of mercury in HFCS: In one report, nine out of 20 samples of HFCS were contaminated; in the second, nearly a third of 55 brand-name foods were tainted. The suspected source of the contamination was a mercury-based ingredient used to separate cornstarch from the corn kernel--a technology that has existed for years and is still used in some plants. The bad news is that you can't be sure if your HFCS-sweetened snack contains mercury.

"While this must be taken very seriously, we shouldn't panic," says Barry Popkin, Ph.D., a professor of nutrition at the University of North Carolina and author of The World Is Fat. "It's new information, so the studies need to be repeated." In the meantime, check out the growing number of HFCS-free products on the market. Just be sure to scan labels--even organic foods can contain the ingredient.

And while you're at it, limit your intake of sugar and other added sweeteners. While many of these concerns about high-fructose corn syrup are as yet unresolved, there's one thing everyone can agree on: Cutting back on empty calories is the first step toward maintaining a healthy weight—and ultimately, preventing disease.

Click here for a statement from the Corn Refiners Association.