Once touted as a low-calorie natural sweetener, fructose is now uncovered as the culprit in some medical problems. University of Iowa researcher Satish Rao has studied Irritable Bowel Syndrome, which affects ten to fifteen-percent of the population, and found the concentrated sweetener causes problems for some.It’s an alternative to sugar, but unlike table sugar or sucrose, our bodies don’t have an enzyme to break down fructose, so the body can’t absorb it well and if we “overwhelm” our digestive capacity he says we’ll have unpleasant symptoms. Rao compares it to Olestra, a cooking oil that was touted as a diet food a few years ago since fried chips and other foods wouldn’t be digested well and consumers wouldn’t absorb many calories….but they’d often have digestive “symptoms” from that. In the case of the popular sweetener, Dr. Rao says patients already had some problems.About a third of the Irritable Bowel Syndrome, or IBS patients, had mal-absorption problems with fructose and had symptoms from it, and that’s the group studied for this project. The patients all saw dietitians who gave them written instructions for following a fructose-restricted diet, and when evaluated a year later the two-thirds who’d complied were symptom-free, while the remaining third of people who did not observe the diet continued to have symptoms. Fructose is found not only in processed foods but also naturally in foods like fruits and vegetables. In fruits and other natural forms the fructose is usually combined with other natural sugars like glucose, so it’s easily digested along with them. Dr. Rao says it’s harder than it may seem to give up fructose, since the sweetener is used in many processed food products including soda pop. Support groups estimate 25 to 45-million people in the U.S. suffer from irritable bowel syndrome. The University of Iowa research is being released today (Monday) at the annual scientific meeting of the American College of Gastronenterology in Baltimore.