Lifestyles

Personal Health: The Sweet Slurp of Excess

Processed foods, from sodas to sport drinks, from dairy products to baked goods, are awash in high-fructose corn syrup. So what should we do about it?

By Joan Stephenson

It’s no secret that over the past few decades, an increasing number of Americans have been coping with a personal energy crisis: an over-consumption of body “fuel” that has contributed to soaring rates of obesity, adult-onset diabetes, and a host of related health problems. While many dieters have focused on cutting their intake of fat-laden foods such as ice cream, chips, and french fries, there’s another element that has caught the attention of scientists, the media, and the public—the ubiquity of high-fructose corn syrup (HFCS) and other sweeteners added to soft drinks and a wide variety of other beverages and foods.

Studies suggest that genetics and a number of other factors, including lack of exercise, inadequate sleep, reduced consumption of milk and other high-calcium foods, frequent snacking, aggressive marketing of food products, and the proliferation of supersized portions, have contributed to America’s expanding waistline. In the past few years, however, the public’s thirst for soft drinks and other beverages sweetened with HFCS has come under particular scrutiny.

Caloric Overload

Many experts say it’s not HFCS itself that’s the overriding problem, but the quantities we consume. Consumers are simply gulping and gobbling too much added sugar in general, particularly refined white table sugar (sucrose) and HFCS (a mixture of glucose and fructose). In fact, despite the public’s perception of HFCS as a nutritional villain, it’s unlikely that simply replacing it with sucrose, a glucose–fructose disaccharide, would have much of an impact on human health. That’s because when sucrose enters the intestine, it is quickly cleaved into equal amounts of glucose and fructose—roughly the same proportion of glucose and fructose found in the HFCS used in soft drinks.

“On average, Americans consume about 100 pounds of different types of sugar per person per year from a variety of sources.”

“I think [HFCS] is the same as sugar,” says Marion Nestle, a professor of nutrition, food studies, and public health at New York University. Although HFCS, like sucrose, provides calories but no nutrients, “it isn’t poison, and there’s nothing wrong with sugar—as long as it’s in reasonable quantities.”

But quantity is the problem, she adds. Many people eat “phenomenal amounts” of HFCS and sucrose, much of it in sweetened beverages. “I’ve had pediatricians tell me they have obese patients, kids, who drink 1200, 1500, 2000 calories a day from soft drinks alone.”

On average, Americans consume about 100 pounds of different types of sugar per person per year from a variety of sources. These sugars, known as caloric or nutritive sweeteners, include monosaccharides, such as glucose and fructose, and disaccharides, such as maltose, lactose, and sucrose. Traditional sources of caloric sweeteners include table sugar (sucrose, derived from sugar cane or sugar beets), honey (a fructose–glucose mix), regular corn syrup (mostly glucose), molasses (sucrose), and maple syrup (sucrose). Processed foods may contain these products, as well as HFCS or fruit juice in concentrated form. There is no evidence supporting the oft-made claim that honey is better for you than more processed sweeteners.

Many of those pounds of sweetener are gulped in the form of gallons of soft drinks and so-called sports drinks. Between 1977 and 2001, the amount of calories Americans were taking in from sweetened beverages more than doubled, according to scientists from the University of North Carolina (UNC)–Chapel Hill. Soft drinks (which, in the United States, are usually sweetened with HFCS) are now the largest source of refined sugars in the American diet, according to the American Dietetic Association, with sports drinks climbing rapidly in the sugar rankings.

Health experts suggest that this increased appetite for sugary beverages is a particular concern, because there is evidence that the body doesn’t register calories from soda pop and other watery drinks in the same way it does more viscous fluids or solid foods. As a result, people who slurp down quantities of beverages sweetened with HFCS or other caloric sweeteners don’t seem to naturally compensate by cutting back on calories elsewhere in their diet.

Sugar Alert

It’s not always obvious which processed foods contain added sugars—they’re not necessarily sweet—so it helps to check the ingredients list. If one of the following appears high on the list (or if several are listed), it’s a signal that the product is likely to be high in sugars:

• Brown sugar
• Corn sweetener
• Corn syrup
• Fructose
• Fruit juice concentrate
• Glucose (also known as dextrose)
• High-fructose corn syrup
• Honey
• Invert sugar
• Lactose
• Maltose
• Malt syrup
• Maple syrup
• Molasses
• Raw sugar
• Sucrose
• Sugar
• Table sugar

Children of the Corn

Up until the 1970s, sucrose was the main caloric sweetener in use. HFCS was first produced in the late 1960s with the introduction of enzymatic isomerization, which converts some of the starch in corn into fructose. The most commonly used formulations contain either 42% (HFCS-42) or 55% (HFCS-55) fructose. Pure fructose is sweeter than sucrose; HFCS-55, the form typically used in soft drinks, is comparable in sweetness to sucrose.

In the United States, HFCS is much less expensive than sucrose, thanks to corn subsidies and sugar import tariffs. In addition to being cheaper than sucrose, it has other properties that prompted food companies, especially soft-drink manufacturers, to embrace this sweetener. Because it’s a liquid, HFCS is easier than sucrose to blend into beverages such as soda pop, lemonade and other fruit beverages, and sports and energy drinks.

Its ability to reduce crystallization and help prevent freezer burn makes it an appealing ingredient for use in frozen foods, such as ice cream and juice concentrates. It’s used in baked goods, from hamburger buns to granola bars, because it helps such products brown and keeps them soft. It’s also found in yogurt and other dairy products, canned fruits, jams and jellies, and a wide variety of other foods.

Today, HFCS represents about 40% of all added caloric sweeteners. The average American (excluding youngsters under the age of two) consumes 318 calories per day from added sucrose and HFCS, or 16% of daily calories, according to a survey published in 2002 by scientists from UNC–Chapel Hill. And researchers from the Harvard School of Public Health noted in a report published in August 2006 that about one-third of all carbohydrate calories in the American diet come from added sweeteners, with beverages (in many cases, soft drinks that nutritionists regard as empty calories with no redeeming nutritional qualities) accounting for about half this amount.

Metabolizing Fructose

Over the past two to three decades, increasing numbers of Americans have become overweight and obese, a trend that mirrors the increase in their consumption of products with added sweeteners, especially HFCS. Total fructose intake, from HFCS and from the fructose component of sucrose, has increased nearly 30% between 1970 and 2000, according to researchers at UNC–Chapel Hill. But scientists caution that many factors underlie being overweight or obese, including a sedentary lifestyle and consuming too many calories from a variety of foods, including those with a high fat content. This, and the fact that obesity rates are increasing in places where little or no HFCS is used, argue against drawing the conclusion that HFCS is the main reason so many people are piling on pounds.

There is, however, some evidence that increased fructose intake, whether from HFCS or from table sugar, may have some specific disadvantages that arise from how the body metabolizes fructose. As scientists from the University of Toronto noted in a review article published in 2005, for most of human history, the human body was called on to metabolize relatively little fructose, largely from fresh fruits. In the past century or so, many people—notably those with a sweet tooth—began to consume massively higher amounts of fructose than did our ancestors. (Although the fructose content of fruit is relatively low, concentrated forms such as apple juice concentrate, used to sweeten products such as fruit drinks, may have up to 65% fructose content.)

Unlike glucose, which is the key energy source for cells and is metabolized through glycolysis and the Krebs cycle to yield carbon dioxide and water, fructose is metabolized almost exclusively in the liver. This metabolic pathway is more likely to result in the production of fats, including triglycerides and very low density lipoproteins, which increase the risk for heart disease.

And whereas fructose causes relatively slow and gentle increases in blood sugar levels, which is considered a plus (carbohydrates that cause rapid spikes in blood sugar have been linked to increased risk for both diabetes and heart disease), pure fructose fails to trigger the production of insulin, which plays essential roles in the metabolism of carbohydrates, fats, and proteins. Studies have also suggested that high fructose levels may affect the levels of the appetite-regulating hormones leptin and ghrelin, which could blunt sensations of fullness (satiety) and foster overeating.

But at this point, definitive proof that large quantities of fructose pose human health risks (other than those related to excess calories) is lacking, notes Barry M. Popkin, director of UNC–Chapel Hill’s Interdisciplinary Obesity Center. Further research on fructose, especially controlled studies in humans, is needed, he says.

Looking for High-Fructose Corn Syrup

High-fructose corn syrup is used in a wide range of foods and beverages, including many products not considered sweet in taste.

Beverages

Soft drinks

Sports drinks

Energy drinks

Fruit drinks and juices

Instant breakfast drinks

Meat Products

Bacon

Chicken products

Seafood

Hot dogs

Ham

Cereals and Bakery Goods

Breakfast cereals

Low-carb breakfast cereals

Granola bars

Breads

Pastries

Miscellaneous Foods

Peanut butter

Jams, jellies, preserves

Sherbets

Canned soups

Tomato paste

Condiments

Mustard

Catsup

Mayonnaise

Pickles

Relish

Salad dressing

Snack Foods

Crackers

Granola bars

Potato chips

Pretzels

Dairy Products

Cheese spreads

Ice cream

Yogurt

Flavored milk

Syrups and Sweeteners

Chocolate syrup

Cocoa

Dessert toppings

Cutting Back

In the meantime, nutritionists say there is enough scientific evidence about the adverse health effects related to sugar consumption that people should limit how much added sugar they consume. In 2003, the World Health Organization issued recommendations that individuals limit their intake of added sugars in foods and beverages to no more than 10% of their daily calories. According to these guidelines, a person with an intake of 2000 calories per day should consume no more than 200 calories worth of added sugar. How much is 200 calories? It’s a bit less than 13 teaspoons a day, or not much more than a single 12-ounce can of soda, which contains about 150 calories and nearly 10 teaspoons of sugar in the form of HFCS.

Last year, a group of U.S. health experts convened and proposed a “guidance system for beverage consumption” that recommends water and beverages with no or few calories over those with a higher calorie count. The group recommends not drinking more than eight ounces of calorically sweetened beverages (soda, juice drinks, or sports drinks) per day. “We advise leaving caloric beverages out of the diet as much as possible,” says Popkin.

People should also learn to become savvy readers of food labels, explains Nestle. The ingredient list shows the ingredients in descending order by weight, so if HFCS or some form of sugar is one of the first three mentioned in the list (or if several are listed), that’s a red flag. It’s also important, she adds, to check both the calories per serving and the manufacturer’s declared “serving size” (which is often ludicrously small), and then recalculate the total number of calories in the package or in the amount to be consumed.

Joan Stephenson, Ph.D., is a dedicated coffee drinker—milk, no sugar—and almost never touches a can of soda, or pop, as they call it in Chicago, where she works as an award-winning science and medical writer.