Even if safety weren't an issue, artificial sweeteners might still be a problem because they may set people (especially children) up for bad eating habits by encouraging a craving for sweetness that makes eating a balanced diet difficult.
The counterarguments? Evidence that artificial sweeteners can help with weight control and loss, whatever the effects on the palate. And some experts see the safety concerns as overblown with little, if any, data from human studies to back them up.
One thing is clear: No one with the rare metabolic disorder phenylketonuria should use aspartame because it contains phenylalanine, which they can't metabolize.
Sugar Alcohols
The names of the sugar alcohols (sometimes called polyols) usually end in "-tol." Erythritol, isomalt, lactitol, maltitol, mannitol, polyglycitol (usually listed as HSH, for "hydrogenated starch hydrolysates"), sorbitol, and xylitol have been approved in the United States.
In sweetening power, the sugar alcohols are closer to sucrose and fructose than to the super-sweet artificial sweeteners, but they supply fewer calories than sucrose and the other sugars because they aren't completely absorbed in the digestive tract. They don't affect blood-sugar levels as much as sucrose, a real advantage for people with diabetes, and they don't contribute to tooth decay, so they're the main sweetener in most varieties of sugarless gum.
Sugar alcohols are also used in candies, baked goods, ice creams and fruit spreads. Read the ingredients carefully, and you'll spot them in toothpaste, mouthwash, breath mints, cough syrup and throat lozenges. In foods, they're not as ubiquitous as sugar, high-fructose corn syrup, or for that matter, aspartame or sucralose -- in part, because consuming too much (e.g., more than 50 grams per day of sorbitol or 20 grams per day of mannitol) can cause gas, bloating and diarrhea. Whether they have more serious long-term effects at lower intakes isn't known.
Sweetened Beverages
Sweeteners added to sports and juice drinks are particularly troubling because many people think those drinks are relatively healthful. Between 1977 and 2001, our energy intake from sweetened beverages more than doubled, according to University of North Carolina researchers. And studies have shown that people don't cut back on their overall calorie intake to offset the extra calories from such beverages.
Researchers are beginning to document the adverse health outcomes. Harvard researchers reported that women who drank one or more sugar-sweetened soft drinks per day were 83 percent more likely to develop type 2 diabetes than women who drank less than one a month. Not surprisingly, they were also more likely to gain weight.
When children regularly consume beverages that are sweetened -- with artificial sweeteners, sucrose, high-fructose corn syrup or fruit-juice concentrate -- they're getting used to a level of sweetness that could affect their habits for a lifetime. Diet surveys have found that American adolescents drink two 12-ounce sweetened soft drinks per day -- the equivalent of 20 teaspoons of sugar and 300 calories.
One of the problems with sweetened beverages is that they are beverages -- that is, watery. "Low-viscosity" high-calorie drinks may deceive us by preventing our bodies from "reading" calories, a capacity that depends, in part, on the thickness of a liquid (a milkshake has more calories than whole milk, and whole milk, more than skim).
A 2004 editorial in the Journal of the American Medical Association said that reducing the consumption of sugar-sweetened beverages "may be the best single opportunity to curb the obesity epidemic." And in March 2006, a Beverage Guidance Panel -- which includes Dr. Walter Willett, chair of the nutrition department at the Harvard School of Public Health -- issued its proposed "guidance system for beverage consumption."
The six-level system emphasizes beverages "with no or few calories" -- especially water -- over those with higher calorie content and recommends drinking no more than 8 fluid ounces of calorically sweetened sodas, juice drinks, or energy (or sports) drinks per day. Two months later, former President Bill Clinton and the American Heart Association brokered a deal with the soft-drink industry to remove most sweetened soft drinks from the public schools over a four-year period.
© 2006. President and Fellows of Harvard College. Distributed by Tribune Media Services.
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