Too Much of a Sweet Thing: What's Wrong with Sugar

Americans are overindulging in sugar, and it may be hurting more than our waistlines. According to an increasing number of nutritionists and scientists, our taste for high sugar foods is increasing the risk of illnesses, such as heart disease and osteoporosis-as well as obesity.

In July, 2002 a report from the American Heart Association highlighted Americans' sugar problem. The report, published in the journal Circulation on July 23^rd, 2002, suggests that high sugar diets may contribute to an elevated risk of heart disease, help bring on obesity, and lower HDL-our "good cholesterol." Such diets may also raise our level of triglycerides, a type of fat that increases the risk of atherosclerosis-the accumulation of plaque in the inner lining of the arteries that leads to heart disease.

"What we're worried about is that sugar adds a lot of calories to the United States diet, and takes away other essential nutrients," says Barbara Howard, PhD, author of the report, and chair of the nutrition committee of the American Heart Association.

"Sugar is empty calories, and empty calories are the biggest nutritional problem in this country," adds Walter Willett , MD, chair and professor of the department of nutrition at the Harvard School of Public Health. The huge doses of sugar in our diet are squeezing out wholesome foods like fruits, vegetables and skim milk, which supply nutrients that may help protect us against illnesses like heart disease, cancer and osteoporosis, Willett says.

Consumption of sugar and sugary snacks has skyrocketed in the U.S., rising 20% since 1986. The average American gets 20 teaspoons daily from added sugars-those not naturally present in foods. And some people with high sugar diets get a lot more. The USDA Food Pyramid advises no more than 12 teaspoons a day for a healthful 2,200 calorie diet.

An Institute of Medicine report, however, has set an upper limit of 25% of calories from sugar for most Americans. "At 20 to 25% we start to see problematic effects, such as obesity and a dilution effect on vitamins and minerals in the diet," says Benjamin Caballero, MD, PhD, professor and director of the center for human nutrition at Johns Hopkins University.

It's not just white refined sugar that's the problem. Americans are also guzzling down high fructose corn syrup used to sweeten sodas and processed foods, and sugars such as honey and maple syrup.

"We're living in the age of unlimited refills for soft drinks, a decade where consumption of sugary fast foods like milkshakes has soared, " says Bonnie Liebman, director of nutrition for the Center for Science in the Public Interest, a consumer watchdog group.

A teen-age girl now gulps twice as much sweetened soda as milk, and gets 40% less calcium than she needs to feed her growing bones, according to Liebman. And lack of calcium before age 18 leads to an increased risk of osteoporosis later on, because children build most of their bone mass by age 18. USDA studies also show that people with high sugar diets sacrifice many other essential nutrients, such as vitamin A, vitamin B12, folate and magnesium, important for strong bones and preventing heart disease, among other illnesses.

Yet many Americans are unaware of the huge amounts of sugar in sodas, cereals and processed foods, Liebman says. An average 12 oz. serving of cola, for instance, has 40 grams or 10 teaspoons of sugar, while an average sweetened cereal has 15 grams or almost 4 teaspoons of sugar, the same as a piece of apple pie.

"The problem is that the sugar in foods is often hidden," Liebman says. Though the total amount of sugars is listed on product labels, you can't distinguish between healthy sugars, such as those present in fruit and milk, and added sugars such as corn sweeteners. The FDA should add a separate category on food labels for "added sugars," Liebman says.

High sugar diets are also one reason for the epidemic of obesity in the U.S, according to Liebman. Studies on children and obesity have found that for every serving of sugar-sweetened drink consumed, the odds of becoming obese rose by 60%. Recent research has also revealed that obese children and adults tend to have higher intakes of sweetened sodas and foods, such as pies and cakes.

Obesity-whether it comes from high intake of sugar or other foods-can have real consequences. If you are obese, sedentary and insulin resistant, you can go on to develop diabetes. Insulin resistance is a genetic condition in which the body's cells become resistant to the action of insulin, needed to process the glucose from our foods, and give our body energy. It's thought to affect 70 to 80 million Americans.

People with insulin resistance tend to have lowered HDL and high triglyceride levels, increasing their risk for heart disease. In fact one indication that you are insulin resistant is low HDL and high triglyceride levels.

People who are insulin resistant can also be "carbohydrate sensitive"-sensitive to sugars as well as starches. "The metabolic stress of being overweight and insulin resistant, having diabetes, or having high triglycerides increases your sensitivity to carbohydrates in general, including sugar," says Ann Coulston, a former clinical researcher at Stanford University, and now a nutrition consultant. In other words, these problems will only get worse with a high sugar diet.

Several studies have also shown that diets high in sweets-with greater than 20% of calories from sugars- raise triglyceride levels in anyone. High sugar diets have also been consistently associated with lowered HDL cholesterol, according to the AHA paper.

In a study of the dietary habits of 75, 521 nurses, published in the American Journal of Clinical Nutrition in June, 2000, Willett and fellow researchers also found that overweight women who consumed diets high in sugar as well as processed starches had an increased risk of heart disease. Those who were overweight and had diets with the highest glycemic load-foods that cause a heightened rise in blood glucose, often associated with refined starches and sweets-had double the risk of heart disease compared to those who consumed the least. Lean people with high glycemic diets did not have an elevated heart disease risk.

Willett theorizes that the increased risk for heart disease occurs because copious amounts of insulin are needed to process the high levels of blood glucose created by diets with a large glycemic load. This is especially true for people who are overweight, sedentary, and are already insulin resistant. "High levels of blood insulin may be involved in the same metabolic pathways that lower HDL and raise triglyceride levels, increasing the risk of heart disease," he says.

Still, no matter the health risks, it's hard for many people to avoid sugary foods. Some controversial research suggests that sugar may be addictive, some alternative health practitioners claim. "It's the most commonly abused substance on earth," says Jack Taylor, a dietitian in Springfield, IL, who is a member of the editorial board of the Journal of the American Nutraceutical Association..

But Western practitioners are less sure. The evidence that sugar is addictive is slim, they say. A few small studies have found that some obese or overweight people are attracted to foods high in fats and sugars. They may crave sweets because these foods stimulate endorphins-the body's natural opiates, some scientists theorize. "This research is interesting, but it's still preliminary and not yet proven," Liebman says. It's more likely that many sweets, also high in fat, are exceptionally tasty, and thus easy to overeat, says Barbara Rolls, PhD, professor of nutrition at Penn State University.

So what's the real story on sugar? High sugar diets surely lead to increased health risks of heart disease, cholesterol problems and obesity, and perhaps other diseases as well. Americans, in fact, may just be getting too much of a sweet thing.