If for most people eating is a pleasant experience, for others eating certain foods means feeling unwell and various gastrointestinal disorders, as is the case for those who have intolerances.
“Food intolerance is an adverse reaction of the body that occurs mainly in the digestive system due to the difficulty of digesting certain foods,” explains Karina Gama, clinical nutritionist at the Dante Institute. Pazzanese cardiology. According to her, discomfort can be caused by both the absence and the violation of the action of enzymes that “break down” some food components, as well as substances present in food that cause difficult digestion.
Among food intolerances, lactose intolerance is the most common and occurs when there is a deficiency of the lactase enzyme responsible for the digestion of lactose, the sugar found in milk and its derivatives such as cheeses and yogurts.
But there is also gluten intolerance (or non-celiac gluten sensitivity), fructose intolerance (a sugar found in fruits, some vegetables and grains, and processed foods), sucrose (table sugar), and undigested carbohydrates that are later fermented. intestinal bacteria, also known as fodmap (derived from milk, fruits, grains, legumes, and some sweeteners).
Anyone can have a food intolerance, and the factors that predispose to it depend on the individual’s condition, such as genetics, health status, immunological status, or the food itself, such as allergenic potential, preservation, and the amount consumed, according to Helsio Maranhao, a gastroenterologist. and pediatrician. nutrologist, professor at the Department of Pediatrics UFRN (Federal University of Rio Grande do Norte).
How can you tell if you have a food intolerance?
Symptoms and signs may vary, but are usually associated with the digestive system: abdominal cramps or pain, bloating, bloating, rumbling (abdominal gurgling), nausea, regurgitation, flatulence, constipation, and even diarrhea. Systemic symptoms such as irritability, fatigue, migraine, urticaria, and joint pain may also be present, according to Auselivia Rego Falcao, gastroenterologist, professor in the Department of Gastrointestinal Diseases and Coloproctology at the Department of Comprehensive Medicine at UFRN.
Symptoms may begin shortly after or some time after eating and may last for several hours. Relief usually occurs after the complete fermentation of undigested components by intestinal bacteria or excretion of the substance in the feces.
But it’s important to be clear that just feeling unwell after eating is not a food intolerance. “That’s because there are other diseases of the digestive system that can cause similar symptoms, including food poisoning,” says Falcao.
To suspect the disease, the continuity and constancy of symptoms when eating food at different times is necessary. “Keeping a food diary describing symptoms and foods eaten that day can help,” the gastroenterologist adds.
If a person suspects that they have an intolerance, it is recommended that the food in question be avoided. “It is expected that this measure will contribute to the reduction and disappearance of symptoms. After a few weeks, she may return to eating to see if such symptoms return. If so, there is a high possibility that she has the disease.” , says Maranhao.
If manifestations of clinical symptoms persist, a doctor or nutritionist may perform a detailed evaluation to confirm the diagnosis. This includes examining medical history, medications or supplements used, lifestyle habits, bowel function, and dietary habits.
What tests can be done?
Some laboratory and special tests may help in the diagnosis. Among them is the oral tolerance test, which helps to identify, for example, lactose intolerance. This test consists of offering the person the test substance on an empty stomach and, at 30, 60, 90, and 120 minutes, collecting blood to see if there was an increase in fasting blood glucose of at least 20 mg/dl. , as a result of the digestion of the test substance. If the blood glucose level is lower, then it is believed that digestion was incomplete and there was not adequate absorption.
The exhaled hydrogen test uses the same principle as the oral tolerance test, but instead of assessing the change in blood glucose, the patient blows into a device that measures the amount of exhaled hydrogen on an empty stomach after ingestion of the test standard solution, at intervals of 2 to 4 hours .
“In an intolerant patient, the undigested and absorbed matter is fermented by bacteria present in the terminal part of the intestine to produce hydrogen. Therefore, the increased detection of hydrogen in the breath reflects an inability to digest and absorb matter properly.” , explains Karina Gama, Master of Food Science.
There are other tests that can be used, such as a stool acidity test, which is commonly used in infants or children, intestinal biopsy, and genetic tests, which are more indicated when traditional tests fail. To detect gluten sensitivity that is not associated with celiac disease, tests are performed to study celiac disease.
Intolerance and Allergy
Tests to confirm the diagnosis are important even to avoid confusing food intolerance with food allergy, which are separate conditions.
As already explained, food intolerance is a lack of an enzyme responsible for the digestion of a certain food, which makes it difficult to digest. This is a condition that causes more localized symptoms related to the gastrointestinal tract.
On the other hand, allergies, since they are immunological phenomena, may have general reactions or affect various organs such as the skin and the respiratory system, in addition to the gastrointestinal tract.
How is the treatment going?
According to the experts interviewed in the report, the treatment of food intolerance should be individualized and based on the reduction or elimination of foods that cause the problem.
Some people may be able to tolerate a small amount of the product, but this limitation varies from person to person. If you are lactose intolerant, preference should be given to lactose-free or low-lactose products. It is also possible to use the lactase enzyme in the form of tablets or powder to be diluted in liquid before or along with products containing lactose. This may reduce the onset of symptoms, but may not be entirely effective.
Dietitian Gama emphasizes that “any intolerance must be correctly diagnosed by a medical professional so that unnecessary food restrictions are not introduced.”
Sources: Auselivia trench Hawkgastroenterologist, professor of the Department of diseases of the gastrointestinal tract and coloproctological from the Department of Comprehensive Medicine at the UFRN (Federal University of Rio Grande do Norte), also works at the Onofre López University Hospital (HUOL/UFRN); Helsio Maranhaogastroenterologist and pediatric nutrologist, professor of the Department of Pediatrics of the UFRN, secretary of the Department of Nutrology of the Brazilian Society of Pediatricians; Karina GamaClinical Nutritionist at Instituto Dante Pazzanese in Cardiology and a Master of Science in Nutritional Sciences from the USP Faculty of Pharmaceutical Sciences (University of São Paulo).