Although milk is among the most consumed foods in the world, a significant portion of the population has some degree of intolerance to lactose, which is the natural sugar present in the food. In Brazil, it is estimated that more than 50% of people are prone to developing the condition, according to a study by the Genera laboratory. This occurs when the body produces little or no lactase, the enzyme responsible for digesting lactose in the intestine and allowing its adequate absorption by the body. Without this enzyme in sufficient quantity, milk sugar is not processed correctly, which can lead to symptoms after consuming dairy products.
Lactose intolerance: understand the condition that affects millions of people
Although milk is among the most consumed foods in the world, a significant portion of the population has some degree of intolerance to lactose, which is the natural sugar present in the food. In Brazil, it is estimated...
According to Dr. Renato Zorzo, doctor and professor of nutrition at Afya Ribeirão Preto, intolerance can appear at different stages of life and vary greatly in intensity. "Many people start to show symptoms in adolescence or adulthood because lactase production tends to naturally decrease over the years. Lactose intolerance is the clinical expression of lactase insufficiency, and most people are somewhere between the extremes, there are those who tolerate small amounts of milk without symptoms and there are those who experience discomfort with much smaller doses", he explains.
The specialist emphasizes that lactose intolerance is usually acquired throughout life, as babies, in general, do not present the condition, except in rare genetic cases. He explains that lactase production tends to decrease from the first years of life and can intensify with aging, which makes intolerance more common in the elderly and also influenced by genetic factors. Among the most common symptoms are abdominal pain, bloating, excess gas, nausea, diarrhea and a feeling of poor digestion after consuming milk and dairy products, generally appearing shortly after ingestion. According to the doctor, intense abdominal distension, rapid increase in gas, cramps, intestinal noises, urgency to evacuate and, in some cases, malaise, sweating and significant discomfort may also occur.
Diego Righi, professor of Nutrition at Afya Centro Universitário Itaperuna, highlights that it is not always necessary to completely exclude dairy products from the diet, as lactose intolerance tends to be dose-dependent. He explains that each organism has its own tolerance level, which varies depending on the amount ingested, the type of food, the intestinal microbiota and even the form of consumption, which means that many people are able to ingest small portions of derivatives without showing relevant symptoms. According to him, the current recommendation is to individualize diet and avoid excessive restrictions, adopting in practice an approach that involves reducing lactose, testing each person's tolerance and preserving, whenever possible, important sources of calcium, protein, vitamin D and vitamin B12.
Lactose intolerance x milk allergy
Lactose intolerance and milk protein allergy are separate conditions. The first is related to the body's difficulty in digesting lactose, the sugar present in milk, and mainly causes gastrointestinal symptoms, such as gas, bloating, cramps, nausea and diarrhea. This is a dose-dependent condition, which does not involve the immune system and, in general, is not associated with serious reactions.
Milk allergy is an immunological response to milk proteins, such as casein and whey proteins. In these cases, even small amounts can trigger reactions that affect the skin, intestine, respiratory system and circulation, such as itching, hives, swelling, vomiting, wheezing, shortness of breath, blood in the stool and, in more serious situations, anaphylaxis. More common in childhood, the condition requires the total exclusion of milk and its derivatives, including lactose-free versions. The nutrition professor reinforces that the central difference is in the reaction mechanism: "Intolerance is a reaction to milk sugar, while allergy involves an immune system response to dairy proteins. Therefore, the correct diagnosis is essential to define the appropriate treatment."
He also adds that lactose-free products are not recommended for people with milk allergies, as they continue to be dairy derivatives and maintain the proteins responsible for allergic reactions. “Removing lactose does not eliminate milk proteins, which are precisely those responsible for allergies, which is why these products are not safe in these cases”, explains the nutritionist.
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