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The Truth About High-Fructose Corn Syrup


In 2004, high-fructose corn syrup—the corn-based substance used to sweeten and preserve many of the foods we eat—was being singled out as one of the major contributors to the epidemic of obesity in the United States. But about three years ago, scientists began to question whether or not high-fructose corn syrup was as dangerous as previous research had indicated.

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Today, while registered dietitians and other nutrition experts recognize that too much sugar presents health risks, there continues to be controversy surrounding high-fructose corn syrup. Many agree that it doesn't appear to contribute more to obesity than any other calorie-heavy sweetener.

With more than 10 years of research into high-fructose corn syrup, we now have a clearer picture of what high-fructose corn syrup is and what it does, the benefits, and the risks.

High-Fructose Corn Syrup by the Numbers

4 calories
The number of calories per gram in both sugar and high-fructose corn syrup

47.2 pounds
The estimated average per capita sugar consumption in the U.S. in 2008

37.8 pounds
The estimated average per capita high-fructose corn syrup consumption in the U.S. in 2008

How High-Fructose Corn Syrup Works

There are four kinds of sugars:

  1. Sucrose: It occurs naturally in sugar cane and beets, used to make white sugar
  2. Fructose: Found in fruits and vegetables 
  3. Glucose:  Found in carbohydrates
  4. Lactose: A sugar derived from milk

High-fructose corn syrup, as defined by the American Diabetes Association, is a thick, sweet syrup derived from cornstarch that consists of a combination of fructose and glucose. It's widely used as a sweetener and preservative in processed foods. Think sodas, candies, cookies, and baked goods, plus hundreds of other packaged foods that aren't considered desserts (cereals and condiments, for example), making up almost half of all caloric sweeteners on the market.

During processing, the glucose in cornstarch is changed into fructose by introducing enzymes. The final high-fructose corn syrup product contains either a little more than 40 percent fructose and slightly more than 50 percent glucose or more than 50 percent fructose and more than 40 percent glucose.

Compared to white sugar, which is half glucose and half fructose, the contents of high-fructose corn syrup aren't that different. They are both sweet and both contain about four calories per gram. There are conflicting reports on how white sugar and high-fructose corn syrup are processed in the body. Some sources say the body metabolizes both in the same way, but a 2009 study conducted at the University of California, Davis, found that fructose and glucose are processed differently by the body.

Regardless, this doesn't mean you should consume large quantities of sugars or high-fructose corn syrup. The association between excessive sugar intake and being overweight or obese has been established for a long time and is unchallenged, and there is a connection between excessive sugar intake and diabetes.

Eating too much fructose could increase the risk of high blood pressure, according to a study of more than 4,500 subjects that was presented at a meeting of the American Society of Nephrology. Scientists found that an intake of 74 g or more of fructose per day was associated with a 36 percent increased risk of developing hypertension. It's believed that fructose reduces the production of nitric oxide and makes it difficult for blood vessels to dilate.

High-Fructose Corn Syrup Research

Reputable organizations, governmental bodies, and publications have drawn updated conclusions regarding high-fructose corn syrup. These conclusions are based on the changing view of high-fructose corn syrup, and they also take into consideration recent studies regarding the health risks of its consumption. Here are some examples:

  • In June of 2008, the American Medical Association (AMA) said, “High-fructose corn syrup doesn't appear to contribute to obesity more than other caloric sweeteners.” The AMA encourages further research into this topic.
  • From the Mayo Clinic: “Recent research suggests that high-fructose corn syrup isn’t intrinsically less healthy than other sweeteners.”
  • A 2008 review of data published in the American Journal of Clinical Nutrition states, “It's unlikely that high-fructose corn syrup caused the current obesity epidemic.”
  • The American Diabetes Association quotes sources saying that the current obesity epidemic is a result of an increase in total food consumption. Too much of everything is more to blame than any specific kind of product containing sugar.

What to Do About High-Fructose Corn Syrup

The easy answer is moderation and variety. If you're going to consume products that contain high-fructose corn syrup or other sugars and sweeteners, do so in moderation. Keep your performance and health goals in mind, and don’t overdo any of them.

The United States Department of Agriculture recommends that people eating a 2000-calorie diet limit themselves to 10 teaspoons (40 g) of added sugars per day (the amount in one 12-ounce soft drink). Here are more specific suggestions from the Mayo Clinic to limit intake of high-fructose corn syrup:

  • Drink fewer soft drinks.
  • Limit foods that contain added sugar.
  • Reduce the amount of processed foods in your diet (foods that come in a box).
  • Eat fresh fruits rather than juices and fruit-flavored drinks.
  • Look for fruit preserved in its own juices instead of those canned in heavy syrup.

Tags: Health, Food


  1. American Diabetes Association
  2. American Journal of Clinical Nutrition
  3. American Medical Association
  4. American Society of Nephrology
  5. Journal of Nutrition
  6. MayoClinic.com
  7. Medical News Today
  8. United States Department of Agriculture