Nutrition and Health News This Week by Nina Teicholz and Gary Taubes 20.4.24
What’s the Best Diet for IBS?
A clinical trial in Sweden published this week in The Lancet Gastroenterology and Hepatology, found that a low-carbohydrate diet was just as effective as the “low-FODMAP” approach for reducing symptoms of irritable bowel syndrome (IBS), and both were more effective than drug treatment.
Widely considered the standard of care for IBS, low-FODMAP diets restrict nuts, most dairy products, and several types of “fermentable” carbohydrates such as wheat, legumes and many fruits. The approach is usually combined, as it was in this trial, with general IBS dietary advice: to chew food thoroughly, eat regularly, and avoid excessive fat.
For the Swedish subjects, food was delivered to their homes for a month. The results were impressive for both diet groups: 71–76% of participants reported significant improvements in their gastrointestinal symptoms. Only 58% did in the drug treatment group. Six months later, the diet-group participants still had fewer symptoms than they did at the start of the trial, even though they followed the diet less closely.
The fact that both dietary approaches had similar benefits raises new research questions. FODMAP stands for “fermentable oligosaccharides, disaccharides, monosaccharides and polyols,” all short-chain carbohydrates that are absorbed poorly by the small intestine. These are thought to be the cause of IBS, yet people in the low-carb group continued to consume some fermentable carbs while still experiencing significant improvement in gastrointestinal symptoms. Additionally, they increased their fat intake, which is believed to exacerbate IBS.
The trial was funded by the Dietary Science Foundation, a Swedish non-profit whose mission is to fund clinical trials on diet and health. Since our own government has largely abandoned funding meaningful clinical trials on this important topic, grassroots science is now our best bet.