Fructose--the simple sugar found in honey, many fruits, and some soft drinks--is one of the principal sweeteners in the Western diet. Not everyone has the ability to absorb fructose properly, however, and now researchers are discovering that it may play an important role in the onset of common gastrointestinal symptoms, such as bloating, cramps, and diarrhea. These symptoms arise when the fructose is allowed to pass through the digestive tract to the colon, where some bacteria can use the sugar as a food source. Unfortunately, in the process, hydrogen gas is liberated.
After the subjects were given 25 grams of fructose, which is about how much is in a 12-ounce can of soda sweetened with high fructose corn syrup, the researchers collected breath samples. The analysis revealed an abnormal level (greater than 20 parts per million) of hydrogen gas in nearly one-half of the subjects. Hydrogen gas would not be present in breath unless fructose was not digested normally. On a subsequent day, the subjects received 50 grams of fructose, and about three-quarters had hydrogen levels greater than 20 parts per million.
"When given levels of fructose commonly consumed in the Western diet, a significant number of
our subjects had both objective and subjective evidence of fructose malabsorption, meaning that the breath analysis showed hydrogen in excess of 20 parts per million and they had symptoms like gas and diarrhea," said Peter Beyer, M.S., R.D., of the Dietetics and Nutrition Department at the University of Kansas Medical Center. "When patients present with such symptoms, doctors should consider adding breath analysis for fructose intolerance to the arsenal of routine diagnostic tests."
Last year, at ACG's 66th Annual Scientific Meeting, Young K. Choi, M.D. and colleagues from the University of Iowa performed fructose breath tests on 219 patients with unexplained gas, bloating, and pain. The analysis revealed the abnormal presence of hydrogen or methane gas in 78 percent of the patients and gastrointestinal symptoms in 58 percent.
"If a patient is found to be fructose intolerant and symptomatic, the doctor may recommend a low-fructose diet," said Beyer. "But in severe cases, antibiotic therapy may be required to provide relief."
The ACG was formed in 1932 to advance the scientific study and medical treatment of disorders of the gastrointestinal (GI) tract. The College promotes the highest standards in medical education and is guided by its commitment to meeting the needs of clinical gastroenterology practitioners. Consumers can get more information on GI diseases through the following ACG-sponsored programs:
- 1-800-978-7666 (free brochures on common GI disorders, including ulcer, colon cancer, gallstones, and liver disease)
- 1-800-HRT-BURN (free brochure and video on heartburn and GERD)
- www.acg.gi.org (ACG's Web site)