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.