The Lowdown on High-Fructose Corn Syrup

Reviewed By:
Susan Janoff, MS RD LD/N

Why have rates of obesity skyrocketed in America and worldwide? Overeating and lack of exercise are major causes, but there may be other factors as well.

In recent years, some experts have pointed the finger of blame at high-fructose corn syrup, a sweetener that has replaced cane and beet sugar in many foods and beverages. According to this argument, high-fructose corn syrup reacts with the body's metabolism in a unique way that causes weight gain.

So, what is high-fructose corn syrup, the newest villain in the battle of the bulge?

What is it?

High-fructose corn syrup is a concentrated liquid made from corn starch, with added amounts of two substances -- fructose (the sugar found naturally in fruit) and glucose (another simple sugar). These substances help make high-fructose corn syrup about 75 percent sweeter than table sugar (sucrose), which is made of fructose and glucose.

Today, the average American consumes about 2.5 times as much added sugar as recommended by federal dietary guidelines. Nearly half of those sugars come from high-fructose corn syrup, according to the American Dietetic Association. This sweetener is used because it has several advantages over sugar, including being sweeter, less expensive and more easily mixed into foods and beverages.

Soft drinks and fruit drinks such as lemonade are a major source of high-fructose corn syrup. The sweetener is also found in cookies, gums, jams and jellies, and baked goods. Even healthful foods, such as low-fat yogurt and marinara sauce, may have significant amounts of high-fructose corn syrup.

High-fructose corn syrup prevents freezer burn and is often found in frozen foods. It is also used to keep breads brown and soft.

High-fructose theories

In recent years, some experts have sounded the alarm that high-fructose corn syrup may be responsible for rising obesity rates. Food manufacturers began using high-fructose corn syrup in large quantities in the early 1980s, just about the time that obesity rates began to climb.

Some experts believe this is no coincidence. They argue that consumption of fructose changes hormonal patterns inside the body. As a result, appetite levels increase. The body also becomes predisposed to storing greater amounts of fat, according to this theory.

Some studies have suggested a particular link between high-fructose corn syrup and disorders such as obesity, metabolic syndrome, type 2 diabetes and high cholesterol. The National Cancer Institute has fingered the introduction of high-fructose corn syrup as one of the causes of the obesity epidemic. However, it remains unclear whether high-fructose corn syrup does more harm than other sweeteners.

In fact, many experts believe that high-fructose corn syrup may is responsible for higher obesity rates only because Americans consume much greater amounts of calories than in the past. According to this theory, there is no unique effect of high-fructose corn syrup on the body.

Until further research settles the question, most experts simply advise people to avoid consuming excess amounts of high-fructose corn syrup and other sweeteners. Decreasing your intake of soft drinks – which has grown five-fold in the past 50 years in America – is a good start.

You can keep your calorie intake down by eating and drinking fewer products loaded with high-fructose corn syrup. But remember, nothing helps you maintain a healthy weight as effectively as exercising regularly and eating a well-balanced diet in appropriate portions.

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