Food makers could one day face demand for fructose-free products as two new studies link the sugar found in fruits to a role in gastrointestinal disorders.
Research to be presented today at the annual meeting of the American College of Gastroenterology looks at the role that diet plays in gastrointestinal disorders such as irritable bowel syndrome (IBS) and dyspepsia.
The preliminary findings suggest that both fructose, the simple sugar found in honey and many fruits, and fat contribute to symptoms of IBS. IBS is characterized by abdominal discomfort, bloating, and change in bowel habits (constipation and/or diarrhoea).
Although lactose intolerance is well-known, fructose intolerance is just beginning to be recognised. Dr Young K. Choi and colleagues from the University of Iowa Hospitals and Clinics found previously that one-third to one-half of patients with IBS symptoms are fructose intolerant.
"A fructose-restricted diet significantly improved symptoms in patients with IBS and fructose intolerance," said Dr Choi. "Fructose intolerance is yet another piece of the IBS puzzle, whose treatment -- when adhered to -- confers significant benefits."
The University of Iowa researchers tested 80 patients with suspected IBS and found that 30 were fructose intolerant. Patients were taught about eliminating fructose from their diet, and after one year, 26 were interviewed to assess their symptoms. Only one-half of the patients complied with the fructose-restricted diet.
For those who were compliant, symptoms (such as abdominal pain, bloating, and diarrhoea) declined significantly from their reported symptoms before the diet modification. Also, the prevalence of IBS in this group declined, said the researchers. For the group that did not comply with the diet modification, bowel symptoms stayed the same over the study period.
In the second study, Dr Yuri A. Saito and colleagues of the dof Gastroenterology and Hepatology at Mayo Clinic and Foundation carried out a population-based study on 221 participants aged 20 to 50 years old. 53 cases and 58 controls were asked to record their diet for one week.
Dr Saito and colleagues found that those with IBS or dyspepsia reported consuming a significantly higher proportion of fat in their diet (33.0 per cent for those with GI disorders, 30.7 per cent for controls). No significant differences were found for protein, fibre, iron, calcium, niacin, or vitamins B1, B2, B6, B12, C, D, or E.
"Future studies are needed to determine whether fat intake causes gastrointestinal symptoms," said Dr Saito. Further studies are also needed to confirm the results of the first, smaller study.