SEPTEMBER 2007

Should You Sour on Aspartame?
Balancing cancer fears about sweetener vs. sugar’s waistline woes.

TWO YEARS AFTER a Euro - pean study on rats reignited the long-simmering debate over aspartame’s safety, a second study from the same lab has consumers once again eyeing their soft drinks with suspicion. Researchers at the European Ramazzini Foundation (ERF) in Italy, writing in Environ - mental Health Perspectives, link high doses of the artificial sweetener to increased leukemia, lymphoma and breast cancer in rats.

“The results of this carcinogenic bioassay not only confirm, but also reinforce the first demonstration of [aspartame’s] multipotential carcinogenity at a dose level close to the acceptable daily intake (ADI) for humans,” wrote lead author Morando Soffritti, MD. “Furthermore, the study demonstrates that when lifespan exposure to [aspartame] begins during fetal life, its carcinogenic effects are increased.” The ERF’s 2005 study found that aspartame consumption in female rats at levels “very near those which humans can be exposed” led to increases in lymphoma and leukemia.

The US Food and Drug Administration (FDA), however, while saying it is interested in reviewing the latest ERF findings, remains confident about aspartame. Michael Herndon, an FDA spokesman, told Reuters, “At this time, FDA finds no reason to alter its previous conclusion that aspartame is safe as a general-purpose sweetener in food.” The FDA said the ERF results are not consistent with more than 100 previous studies evaluated by the agency.

“These included three studies in which rats were fed aspartame in proportions 100 times higher than humans would likely consume,” according to Laura Tarantino, PhD, director of the FDA’s Office of Food Additive Safety.

Most recently, a large epidemiological study of 566,990 men and women sponsored by the National Cancer Institute found no statistically significant link between aspartame intake and risk of leukemia, lymphoma or brain tumors.

After reviewing the earlier ERF study, the FDA concluded it failed to provide sufficient evidence to reverse the agency’s classification of aspartame as safe for human consumption.

Aspartame, sold under brand names such as NutraSweet and Equal, is 200 times sweeter than ordinary sugar. It has about the same calorie count as sugar (four per gram), but because it can be used in such tiny amounts, effectively aspartame is considered calorie-free.

Although it was first discovered in 1965, early, never-confirmed cancer concerns kept aspartame from earning FDA approval as a tabletop sweetener until 1981. Its use was broadened to soft drinks in 1983 and to all foods and drinks in 1996. Today, aspartame accounts for 62% of the dollars spent in the “intense sweetener” market, and is used in some 6,000 products worldwide.

The FDA set the Acceptable Daily Intake of aspartame at 50 milligrams per kilogram of body weight, which means a 150-pound person could safely drink about seven and a half cans of aspartame-sweetened soda per day. The latest ERF study found a cancer risk at the equivalent of roughly double that level of consumption.

The new study tested the effects of a lifetime of high aspartame intake on more than 4,000 rats. Unlike previous studies, in which rats were killed at age two to test for tumors, the ERF researchers allowed the rats to live a natural lifespan. That may have allowed time for more cancers to develop.

“On the basis of the present findings,” the Italian researchers concluded, “we believe that a review of the current regulations governing the use of aspartame cannot be delayed. This review is particularly urgent with regard to aspartame-containing beverages, heavily consumed by children.”

But the International Sweeteners Association, a trade group, criticized the methodology of both ERF studies, arguing that the cancer incidence was “the result of variations in the high spontaneous rates of cancers in this animal group. Replication of flawed data does not make the data any less flawed.”

Besides cancer concerns, you might be prompted to avoid aspartame because of the claims rocketing around the Internet that it causes everything from lupus to multiple sclerosis to Gulf War Syndrome. These “dangers” are little more than urban legends, according to the American Council on Science and Health: “The scientific evidence does not support any of these alleged associations.”

In fact, MIT scientists debunked these fears nearly a decade ago, in a four-month clinical trial of 48 subjects. One group got the daily equivalent of 17 to 24 12-ounce aspartame-sweetened beverages for males and 14 to 19 12-ounce drinks for females. At up to 45 milligrams per kilogram of body weight, that’s 15 times the average Americans’ aspartame intake. Subjects showed no changes in mood, memory, behavior, electroencephalograms or physiology that could be tied to aspartame. There was no difference in incidence of headaches, fatigue, nausea and acne between the aspartame group and groups receiving sugar or placebo.

It is true that the body converts aspartame to methanol and the amino acids aspartic acid and phenylalanine, which Internet postings can make sound scary. But apple juice has more methanol than the body gets from aspartame—and you’d have to down at least 100 quarts of juice at a sitting to get a fatal dose. Phenylalanine is a concern only for people with a rare genetic disease, phenylketonuria, who can’t metabolize it.

While the latest cancer controversy might be cause for moderation in dietsoda guzzling—just in case—don’t make the mistake of substituting large quantities of sugar- or fructose-sweetened drinks instead. You’d be consuming empty calories by the bottleful, and the negative health effects of obesity aren’t just a matter of speculation. A half-dozen sugary soft drinks a day can add up to an extra pound of weight in just a week.

According to the American Dietetic Association, “Because products with aspartame are lower in calories than their sugar-sweetened counterparts, using products with aspartame together with regular physical activity can help with weight management. Simply substituting a packet of tabletop sweetener with aspartame for two teaspoons of sugar three times daily in coffee, on cereal or in ice tea, for example, saves about 100 calories.” A three-year Harvard study, the association points out, showed that aspartame was a valuable aid to a long-term weightmanagement program including diet and physical activity.

Besides, satisfying your sweet tooth with caloric sweeteners can be bad for your teeth. Unlike artificial sweeteners, nutritive sweeteners such as sugar and fructose cause cavities.

Maybe now is a good time to learn to drink your coffee black, and to switch from “sweet tea” to unsweetened iced tea.

Consumption of high-fructose corn syrup (HFCS)—the sweetener most commonly found in non-diet sodas and other beverages —jumped 135% from 1977 to 2001. Critics suggest that the booming popularity of high-fructose corn syrup is linked to the rise in obesity over much the same period of time. Industry groups such as the Fructose Information Center dismiss such a connection as “based on poorly conceived experimentation of little relevance to the human diet.”

Fructose, mostly made from corn in the US, is almost twice as sweet as table sugar (sucrose) and comparatively cheap. That’s made it attractive to soft-drink bottlers and other food packagers. HFCS is actually made from a combination of 42% to 55% fructose plus glucose, another simple sugar derived from plants.

Two new studies are adding fuel to both sides of the HFCS debate. One suggests that drinking fructose-sweetened beverages can put overweight adults on the fast track to atherosclerosis—hardening of the arteries. A second new study, however, rebuts the common claim that fructose-sweetened drinks don’t have as much satiating power, leaving consumers more likely to scarf down other calories.

Fructose and your arteries: In a study presented at a recent American Diabetes Association scientific meeting, University of California-Davis researchers reported that overweight men and women who got 25% of their calories from fructose-sweetened beverages developed signs of atherosclerosis in as little as two weeks. The 10-week study of 23 volunteers, ages 43 to 70 with BMIs of 25 to 35, randomly assigned 13 to drink fructose-sweetened beverages and the rest to get an identical percentage of calories from glucosesweetened drinks.

After just two weeks, the fructose group—but not the glucose group—had already developed a lipid profile typical of atherosclerosis. A measurement of post-meal blood-fat levels more than doubled, with triglycerides up 212%, in the fructose group. By study’s end, the fructose group also showed increases in fasting blood concentrations of LDL (“bad”) cholesterol, while the glucose group did not.

Investigators, led by Kimber Stanhope, MS, said that people who are already at risk for cardiovascular disease should think twice before consuming large quantities of fructose-sweetened drinks. Stanhope added that the increased popularity of HFCS could partly account for the rise of metabolic syndrome, a precursor of diabetes and heart disease, in recent years.

Sugars and satiety: Researchers at the University of Washington put to the test the popular theory that HFCS in beverages has little satiating power—leaving consumers feeling less satisfied and more prone to overeating. They compared five beverages: two sweetened with different HFCS formulations, cola sweetened with ordinary sugar (sucrose), diet cola and 1% low-fat milk.

The 37 volunteers, ages 20 to 29, consumed one of the five beverages or no beverage at all, then rated their hunger, thirst and satiety at 20-minute intervals. More than two hours later, lunch was served and investigators measured how much the subjects ate.

“We found no differences between sucrose- and HFCS-sweetened colas in perceived sweetness, hunger and satiety profiles, or energy intakes at lunch,” reported lead author Adam Drewnowski, MD, PhD, in the American Journal of Clinical Nutrition. “The four caloric beverages tended to partially suppress energy intakes at lunch, whereas the no-beverage and diet beverage conditions did not; the effect was significant only for 1%-fat milk. Energy intakes in the diet cola and the no-beverage conditions did not differ significantly.”

The researchers concluded, “There was no evidence that commercial cola beverages sweetened with either sucrose or HFCS have significantly different effects on hunger, satiety or short-term energy intake.”

What’s a thirsty consumer to conclude? If you’re concerned about artificial sweeteners (see main story), there’s one more thing to consider before switching to HFCS-sweetened alternatives: An eight-ounce serving of a typical non-diet soda adds about 100 “empty” calories to your diet. See if you can be satisfied with zerocalorie options instead, such good ol’ H2O.