While for most people eating is a pleasant sensation, for others eating certain foods means feeling sick and having various gastrointestinal discomforts, as in the case of those with some intolerance.
“Food intolerance is an adverse reaction of the organism that occurs mainly in the digestive system, due to the difficulty in digesting a certain food”, explains Karina Gama, clinical nutritionist of the Dante Institute Crazy of Cardiology. According to her, the discomfort can derive both from the absence or defect in the action of enzymes that effect the “breaking” of some food components, and from substances present in the food that cause difficult digestion.
Among food intolerances, lactose intolerance is the most common, and occurs when there is a deficiency of the enzyme lactase, responsible for the digestion of lactose, the sugar present in milk and its derivatives, such as cheese and yogurt.
But there is also gluten intolerance (or non-celiac gluten sensitivity), fructose intolerance (sugar found in fruit, some vegetables and cereals and in processed products), sucrose (table sugar) and undigested carbohydrates, which are subsequently fermented by intestinal bacteria and which are also known as fodmaps (derived from milk, fruit, cereals, legumes and some sweeteners).
Anyone can have a food intolerance and the factors that predispose it depend on the individual’s condition, such as genetics, health status, immunological status or the food itself, such as the allergenic potential, storage and quantity ingested, according to Hélcio Maranhão, gastroenterologist and pediatrician nutrologist, professor at the Department of Pediatrics of the UFRN (Federal University of Rio Grande do Norte).
How to recognize if you have an intolerance to any food?
Symptoms and signs may vary, but are generally related to the digestive system: abdominal cramps or pain, stomach bloating, distention, borborygmus (tummy noise), nausea, regurgitation, flatulence, constipation, and even diarrhea. Systemic symptoms such as irritability, fatigue, migraine, hives and joint pain may also be present, according to Auzelivia Rêgo Falcão, a gastroenterologist, a discipline professor of gastrointestinal and coloproctology diseases at the UFRN Department of Integrated Medicine.
Symptoms can begin soon after or sometime after eating food and last for hours. Relief usually occurs after the intestinal bacteria have completely fermented the undigested components or excreted the substance through the stool.
But it is important to clarify that just feeling sick after eating food does not constitute a food intolerance. “This is because there are other digestive diseases that can cause similar symptoms, including food poisoning,” says Falcão.
To suspect the condition, continuity and persistence of symptoms is required when consuming food at different times. “Making a food diary describing the symptoms and foods consumed that day can help,” adds the gastroenterologist.
If the person suspects that they have an intolerance, it is recommended to stop the food in question. “This measure should help reduce and resolve symptoms. After a few weeks, she can go back to consuming food to see if those symptoms recur. If so, there’s a high chance she has the condition,” says Maranhao. .
If the manifestation of clinical symptoms is persistent, the doctor or nutritionist can carry out a detailed evaluation to confirm the diagnosis. This includes an investigation of health history, medications or supplements used, lifestyle habits, bowel function, and eating habits.
What tests can be done?
Certain laboratory and specific tests can 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 under investigation, on an empty stomach, and after 30, 60, 90 and 120 minutes, to collect blood to see if there has been an increase in fasting blood sugar of at least 20 mg / dl , following the digestion of the substance studied. If the rise in blood sugar is lower, it turns out that digestion has been incomplete and there has not been adequate absorption.
The exhaled hydrogen test uses the same principle as the oral tolerance test, but instead of evaluating the change in blood glucose, the patient blows a device that measures the amount of hydrogen exhaled in fasting after ingestion of the standard solution studied, in intervals ranging from 2 to 4 hours.
“In the patient with intolerance, the undigested and absorbed substance is fermented by the bacteria present in the final portion of the intestine, forming hydrogen. Therefore, the increased detection of hydrogen in the breath reflects the inability to digest and absorb the substance properly”, explains Karina Gama, master in food science.
There are still other tests that can be used, such as the stool acidity test, which is usually used in infants or children, intestinal biopsy, and genetic testing, which are more suitable when traditional tests are inconclusive. For non-celiac gluten sensitivity, tests are done to investigate celiac disease.
Intolerance and allergy are different
Tests to confirm the diagnosis are important, also not to confuse food intolerance with food allergy, which are different conditions.
As already explained, food intolerance consists in the lack of the enzyme responsible for the digestion of a certain food, causing difficulties in its absorption. It is a condition that generates more local symptoms, related to the gastrointestinal tract.
Allergies, on the other hand, as immunological phenomena, can have general reactions or compromise various devices, such as the skin and respiratory system, as well as the gastrointestinal system.
How is the treatment?
According to the experts consulted in the report, the treatment of food intolerances must be individualized and is based on the reduction or exclusion of the foods that cause the problem.
Some people can tolerate small amounts of the product, but this limit is individual. In case of lactose intolerance, preference should be given to lactose-free or low-lactose products. There is also the possibility of using the lactase enzyme, in the form of tablets or powder to be diluted in liquids, before or together with foods containing lactose. This can reduce the appearance of symptoms, but may not be fully effective.
Nutritionist Gama reiterates that “all intolerances must be properly diagnosed by a health worker so that unnecessary restrictions on food are not applied”.
Sources: Auzelivia Trench Falcongastroenterologist, professor of the discipline of diseases of the gastrointestinal system e colon proctological from the Department of Integrated Medicine of the UFRN (Federal University of Rio Grande do Norte), also works at the Onofre Lopes University Hospital (HUOL/ UFRN); Helcio Maranhãopediatric gastroenterologist and nutrologist, full professor at the Department of Pediatrics of the UFRN, secretary of the Department of Nutrology at the Brazilian Society of Pediatrics; Karina Gamaclinical nutritionist at Dante Institute Crazy in Cardiology and a Masters in Food Sciences from the Faculty of Pharmaceutical Sciences of the USP (University of San Paolo).