Constipation, abdominal pain, cramps… Food intolerances lead to many digestive difficulties. They have multiple causes. What test to diagnose it? Who to consult? Can we cure it?
food intolerance is mostly related to bowel irritation. It causes digestive discomfort (abdominal pain, bloating, diarrhea etc.). If their symptoms are similar, the intolerances are different from food allergies. How to make the difference ? How to diagnose a food intolerance? Can we cure it?
What is the definition of a food intolerance?
An intolerance is a irritating reaction of the intestinal system following the ingestion of food.
What is the difference between a food intolerance and a food allergy?
An allergy is a reaction of the immune system to an allergen when “in the case of intolerance, there is no no activation of the immune system“explains Professor François Mion, gastroenterologist. “The allergy will cause symptoms such as skin reactions, swelling of the mucous membranes sometimes associated with digestive signs. Food intolerance always results in digestive symptoms“ continues the doctor.
What are the symptoms of a food intolerance?
A food intolerance is mainly manifested by digestive difficulties: “bloating, abdominal pain, diarrhea, cramps” lists Déborah Ohana, dietitian nutritionist. “We also find sometimes constipation but this sign is less frequent” adds Professor Mion. Food intolerance can also be responsible acne. In case of lactose intolerance, there are associated infections of the ENT sphere (frequent sinusitis for example). “Nowadays, many suspected food intolerances are confused with irritable bowel syndrome“says Deborah Ohana.
What are the most common food intolerances?
The most common intolerances aregluten intolerance (cereals like wheat, rye, barley, spelled and oats) and intolerance to lactose. “The eggs are among the most common food allergies but are rarely intolerances“says the dietitian nutritionist.
Forget them IgG testing (immunoglobulins) in the laboratory to detect food intolerance. For Déborah Ohana as for Professor François Mion, these blood tests that appeared in the 2000s to supposedly detect foods that are not tolerated by the body, have no clinical interest : “It’s a very expensive technique (sometimes more than 500 euros, editor’s note) and unreliable because it has not been validated by a scientific committee“argues the dietitian.”The IGG blood tests only reflect the fact that your body has been in contact with these foods” continues the gastroenterologist. In France, in 2013, the Council of the Order of Physicians has also suspended a biologist for a month which promoted anti-food IgG tests. To diagnose an intolerance:
► Consult the general practitioner (if you go directly through the gastroenterologist (outside the course of treatment), the reimbursement of the consultation by Health Insurance is less)
► On the advice of the doctor, remove the food(s) that could be responsible for the intolerance for several days (duration to be determined with the doctor) to see if the symptoms improve.
► The doctor may prescribe a blood test to look for a possible genetic mutation responsible for the intolerance and a respiratory test depending on the intolerance considered.
In case of lactose intolerance for example, “the respiratory test consists of administering to the subject a certain quantity of lactose orally (approximately 25 grams of lactose diluted in water) then regularly taking samples of the exhaled gases. The detection of hydrogen or methane will reflect the fermentation of the lactose that has not been digested properly (in contact with intestinal bacteria)“ develops Professor Mion.
“With the fashion for gluten-free, many people will wrongly remove gluten, the body will no longer be able to recognize it and they can become really intolerant”
Food intolerance results from a enzyme deficiency, that is to say the insufficient presence or absence of an enzyme that helps digestion of certain compounds. “In the case of lactose intolerance, the subject has a lack of lactase, a lactose-digesting enzyme, in the intestinal mucosa. When lactose is consumed in a slightly excessive quantity, it is not not digested or absorbed by the small intestine and reaches the large intestine, the colon, where it will be fermented by colonic bacteria (intestinal) and produces substances that cause digestive symptoms” explains the gastroenterologist. This deficit may be caused genetics with a mutation in the gene encoding lactase but can also occur later. “This lactose-digesting enzyme is relatively developed in infants and it gradually decreases with age, in some people more than others.” notes Professor Mion. In addition to the genetic background, there are other causes of food intolerance:
- food diversification too late when you are a child
- food poisoning which causes intolerance
- failure of the digestive flora, of the intestinal microbiota related to medication (antibiotics) or by a diet that is too restrictive
“Food intolerances are very present in patients suffering from intestinal hypersensitivity (such as irritable bowel syndrome)” says Deborah Ohana. “With the fashion for gluten-free, many people will wrongly remove gluten, the body will no longer be able to recognize it and they can become really intolerant when there was no intolerance at the base.” emphasizes the nutritionist.
Who to consult in case of food intolerance?
You must first consult the general practitioner in order to then be directed to a gastroenterologist, as part of the coordinated care pathway. It is also possible in parallel for more nutrition advice, consult a dietitian-nutritionist specializing in food intolerances.
Can a food intolerance be cured? What to do ?
You cannot cure a food intolerance. “There is no treatment other than food avoidance for intolerance. We adapt their diet with alternatives“explains the dietician-nutritionist. “In diets indicated for digestive comfort, it is recommended diet low in targeted fermented sugars or diet without “fodmaps” agree the two experts. “These sugars are contained in particular in onions, garlic, cabbage family foods, legumes, wheat derivatives (fructan) or the dairy products“ says the gastroenterologist.
thanks to Deborah Ohanadietitian nutritionist and Pr François Mion, gastroenterologist and professor of physiology.