Jan. 10, 2008 -- Consuming sweets and chewing gum with sugar substitutes may help the weight-conscious slash calories, but excessive use of the sweetener sorbitol can cause extreme weight loss and other problems, according to a new report.
In this week's BMJ, Juergen Bauditz, MD, of the University of Berlin, and colleagues describe two patients with a sorbitol habit who had dramatic, unexplained weight loss until their excessive use of the sweetener was discovered.
Sugar-Free Sweeteners and Side Effects: Case Histories
After she was asked about diet, she said she chewed sugar-free gum with sorbitol daily, taking in about 18 to 20 grams a day. One stick typically has 1.25 grams.
Once she eliminated sorbitol from her diet, the gastrointestinal problems stopped and she gained back more than 15 pounds.
The second patient, a 46-year-old man, had been hospitalized because of diarrhea and a weight loss of more than 48 pounds during the previous year. His blood work and other exams came back normal, but when asked about diet, he, too, reported excessive consumption of sorbitol. He chewed 20 sticks of sugar-free gum daily and also ate about 7 ounces of sweets daily, totaling about 30 grams of sorbitol.
When he cut out the sorbitol, he gained back 11 pounds within six months and his diarrhea problems disappeared.
The message for doctors, the authors conclude, is to inquire about dietary habits when a patient has unexplained weight loss.
Sugar-Free Sweeteners and Side Effects: A Food Scientist's View
Reports of side effects such as abdominal pain and diarrhea with high amounts of sorbitol consumption are nothing new, says Roger Clemens, DrPH, a spokesman for the Institute of Food Technologists and professor of pharmacology and pharmaceutical sciences at the University of Southern California, Los Angeles.
"The laxative effect is very well documented," Clemens tells WebMD. "It could be these individuals [in the case histories] were particularly sensitive." And they did consume excessive amounts, he notes. "We would not expect the average consumer to consume upwards of 20 sticks of gum a day."
"Sorbitol is not well absorbed," Clemens says. As a result, excess water enters the gastrointestinal tract and diarrhea can occur. Those who rely on artificially sweetened products to help manage their diabetes or to reduce overall calories, he says, should use a variety of such products and consume them in moderation. Sorbitol is found in toothpastes as well as chewing gum and sweets.
What's a 'Safe' Amount of Sorbitol?
The FDA requires a warning label on a product with sorbitol if the manufacturer thinks the consumption would exceed 50 grams a day, according to an FDA spokesperson.
But levels under 50 grams of sorbitol daily may cause problems for some people, says Patti Truant, a spokeswoman for the Center for Science in the Public Interest in Washington, D.C. In 1999, the center petitioned the FDA to require a better label on sorbitol-containing products, noting that problems such as diarrhea can occur with as few as 10 grams a day of the sweetener.
Sorbitol Manufacturers Respond
The cases reported in BMJ involved excesses, says Chris Perille, a spokesman for the William Wrigley Jr. Company, which makes chewing gum containing sorbitol (including its brands Extra, Orbit, Freedent, and Eclipse).
"To reach the threshold of excessive consumption of sorbitol through use of gum alone [at levels set by the FDA], someone would have to chew close to 50 sticks or 100 pellets of gum daily," he says. In the U.S., he adds, the average per capita gum consumption is just one stick every other day.
The ingredient is safe and effective "when used as directed," adds Tonia Elrod, a spokeswoman for Procter & Gamble, the manufacturer of Crest toothpaste, which contains sorbitol.