Irritable bowel syndrome: the effectiveness of low-carbohydrate diets is confirmed

This is new evidence that diet plays a central role in irritable bowel syndrome (or “functional colopathy”). A study recently published in the journal The Lancet Gastroenterology

To reach this conclusion, researchers at the University of Gothenburg, in Sweden, tested three types of treatments on 300 patients for a month. A first group had to follow a diet low in Fodmaps, that is to say excluding foods containing sugars that are poorly absorbed in the intestine. We can cite lactose, contained in dairy products; fructans, which are found in wheat, rye and barley; fructose, present in fruits, but also added to all industrially prepared meals; or even galactans, which are mainly found in legumes (chickpeas, lentils, etc.).

A second group followed a “Low carb” diet, low in carbohydrates but high in protein. The patients in the third group were, for their part, treated with antispasmodic, laxative or antidiarrheal drugs. After one month of treatment, all three groups saw their symptoms and quality of life improve. But not in the same proportions: three-quarters of patients who followed one of the two diets saw their condition improve, compared to “only” half of the people treated with medication.

The benefits of the diets were even felt over time, since, six months later, the majority of participants were doing well even though they had gradually returned to their usual diet. “This finding indicates that small reductions in Fodmaps and carbohydrate intake could have beneficial effects,” emphasize the authors of the study.

In practice, the low-Fodmap diet is already recommended to treat irritable bowel syndrome, but not the “Low carb” diet, rich in protein, for which evidence of effectiveness is lacking. “The low Fodmaps diet consists of temporarily eliminating all foods containing fermentable sugars because these increase the secretion of water in the small intestine, which generates bloating, and they ferment in the colon, which generates gas,” explains Professor Benoît Coffin, head of the hepato-gastroenterology department at Louis-Mourier hospital, in Colombes (Hauts-de-Seine). Retained water and gases cause distension of the digestive tract, causing pain.

“Many patients think that they are intolerant or allergic to this or that food, in particular to gluten, but this is not the case,” explains Professor François Mion, head of the functional digestive exploration department at the Édouard-Herriot hospital, in Lyon. “Irritable bowel syndrome results from hypersensitivity of the gut-brain axis and fermentable sugars accentuate this phenomenon,” he continues.

On paper, the idea is simple: completely remove Fodmaps sources for six to eight weeks. “If the patient is better, we ask him to gradually reintroduce the different families of foods so that he can determine that they are the acceptable doses for him,” indicates Professor François Mion. The first effects generally begin to be felt after one to two weeks. But in reality, eliminating these sugars from our diet is a big challenge. “It’s a difficult diet to follow because a lot of foods contain it: a lot of fruits and vegetables, all products derived from wheat, industrial dishes…”, lists the gastroenterologist.

Fortunately, there are alternatives. Rather than milk and yogurts, you should, for example, turn to lactose-free milk, plant-based drinks (soy, oats, etc.) or even soy yogurts. On the fruit side, apples, pears, peaches or even apricots must give way to bananas, pineapple, citrus fruits or even melon. “We must also eliminate all foods made from wheat, barley and rye because these contain a type of starch that is resistant to digestion,” specifies Professor Benoît Coffin. Goodbye, therefore, pasta, semolina, flour, bread, cereals. “Buckwheat, spelt, rice or oats, in all their forms, can replace wheat-based products,” argues Professor Mion.

“It’s a diet that works well and is prescribed very often, it’s worth trying,” encourages Professor Coffin, while recognizing the constraints that this represents. Moreover, going without all these fermentable carbohydrates can lead to an unbalanced diet and cause deficiencies. The ideal is therefore to seek help from a nutritionist doctor or a dietitian, especially if you are prone to eating disorders.

“It’s not easy, because you have to find a professional who knows this disease well and you have to have sufficient income to afford this care because it is not covered,” underlines Professor François Mion. In several cities (Lyon, Paris, Rouen, Nancy, Bordeaux, etc.), hospitals have however set up reimbursed care pathways, where it is possible to do everything at once: medical consultation, dietetic sessions and support. psychological burden. But you have to be patient. “In our hospital, the waiting time is three to four months,” explains Professor Mion.