By Lorraine L. Janeczko
NEW YORK (Reuters Health) - 23/5/2019
"The study demonstrates that a low FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet does not significantly impact the quality of nutrient intake or the diversity of one's diet but it can lead to lower diet quality, meaning lower intake of suitable fruits, vegetables, and whole grains," said Dr. M. Elizabeth Swenor, a physician specializing in metabolic and nutritional medicine at the Henry Ford Center for Integrative Medicine in Northville, Michigan, who was not involved in the study.
"Poor diet - high saturated fats, processed foods, and high added sugars - is one of the causes of IBS," she told Reuters Health by email.
For the study, online April 24 in the Journal of the Academy of Nutrition and Dietetics, Dr. Miranda C. E. Lomer of King's College London and colleagues analyzed data from two randomized controlled trials involving 130 adults with diarrhea-predominant (IBS-D), mixed, or unsubtyped IBS, at one academic medical center.
Patients in the first study were referred to the center for treatment, including advice from a specialist dietitian, in 2010 and 2011, and those in the second study were referred in 2013 and 2014.
In one study, patients received either low FODMAP dietary counseling or sham control dietary counseling. In the other, they received either low FODMAP dietary counseling or advice to continue their usual diet. The usual dietary intake for all participants was recorded at baseline and after a four-week intervention period, using seven-day food records.
A total of 63 participants were randomized to a low FODMAP diet, and 67 to a control diet (48 ate a "sham diet" and 19 ate their habitual foods).
Among participants in the habitual-diet group, fiber intake was low, with only six (5%) of them reaching the target 30 g/day.
Among participants receiving low-FODMAP advice, intake of most nutrients was similar to the intake of the controls. But they consumed significantly less starch than the habitual controls (109 g/day vs. 128 g/day) and more vitamin B-12 than those on the habitual and sham control diets (6.1 mg/day, 3.9 mg/day and 4.7 mg/day).
Overall diet quality scores were significantly lower after low FODMAP advice than after the habitual control diet.
Dr. Swenor said she was not surprised by the results as they highlight the habitually poor diet quality of people with IBS-D individuals.
The supervision of a specialist dietitian was a limitation, Dr. Swenor said. "Studies of compliance, dietary diversity, nutrient intake, and quality need to be investigated with individuals who are not under close dietitian supervision."
"IBS-D is a pervasive medical concern," she explained. "The study of the gut microbiome and IBS-D, and the inclusion and exclusion of specific nutritional intake and its effect on the symptomatology of IBS-D warrant further investigation."
The National Institute for Health Research (NIHR) funded the study.
Dr. Lomer was unable to comment on the study by press time. She reports be the co-inventor of a mobile application involving the low-FODMAP diet.
J. Acad Nutr Diet 2019