Lactose intolerance: what it is, symptoms in adults, treatment

What is lactose intolerance?

Lactose intolerance (or hypolactasia) Is the inability to digest sugar (lactose) due to the lack of the digestive enzyme lactase, which leads to diarrhea and intestinal colic. Lactose intolerance is caused by a lack of the enzyme lactase.

Symptoms seen in children include diarrhea and poor weight gain, while symptoms in adults include bloating and cramping, diarrhea, flatulence, and nausea. The diagnosis is based on the observation that symptoms appear after a person has eaten dairy products and can be confirmed by a hydrogen breath test. Treatment includes taking the enzyme lactase as a supplement and eliminating lactose from the diet, especially in dairy products.

Lactose, the main sugar found in milk and other dairy products, is broken down by the enzyme lactase, which is secreted by cells in the inner lining of the small intestine. Lactase breaks down lactose, which is a complex sugar, into its two components, glucose and galactose. These simple sugars are then absorbed into the bloodstream through the intestinal wall. If lactase is absent, lactose cannot be broken down and absorbed. As a result, high concentrations of lactose attract fluid into the small intestine, causing watery diarrhea. The lactose then travels to the large intestine, where it is fermented by bacteria, which produces gases that lead to flatulence, bloating, and abdominal cramps.

Cow's milk allergy different from lactose intolerance. Unlike lactose intolerance, people who are allergic to cow's milk can digest milk properly, but the proteins in the milk initiate a reaction from the immune system. general information about allergic reactions). Allergies to cow's milk are usually prone to children.

Signs and symptoms

People with lactose intolerance usually cannot tolerate milk and all other dairy products that contain lactose. Symptoms in adults usually appear only after they consume more than 250–375 milliliters of milk. Some people realize early enough that milk and other dairy products are causing them gastrointestinal distress, and consciously or subconsciously avoid dairy products.

Children with lactose intolerance have diarrheaand they may not gain weight if dairy products are part of their diet.

Adults may have bloating and colic, watery diarrhea, flatulence, nausea, gurgling or gurgling noises in the intestines (rumbling in the stomach) and the urge to defecate, which occurs within 30 minutes to 2 hours after eating foods containing lactose. In some people, severe diarrhea can interfere with proper absorption of nutrients because they are cleared from the body too quickly. However, symptoms resulting from lactose intolerance are usually mild. In contrast, the symptoms caused by malabsorption in diseases such as celiac disease, tropical sprue and intestinal infections are more severe.

- Allergy to cow's milk.

Children with cow's milk allergy also develop symptoms after consuming milk or dairy products. However, these symptoms, such as itching, rash and / or wheezing, resemble others allergic reactions. Sometimes children have gastrointestinal symptoms such as vomiting, abdominal pain and, rarely, diarrhea.

Cow's milk allergy is rare in adults and can also cause vomiting and gastroesophageal reflux symptoms.

Causes

Infants in their first year of life have high levels of lactase, which allows them to digest milk. However, in most ethnic groups (80% of people of African and Latino descent and more than 90% of people of Asian descent), lactase levels decline after weaning. These declines mean that older children and adults in these ethnic groups are unable to digest large amounts of lactose. However, 80-85% of the white population, natives of the northwestern regions of Europe, produce lactase in the course of life, and thus, these people are able to digest milk and dairy products as an adult age. Thus, due to the ethnic composition of the population of the United States, between 30 million and 50 million people in the United States appear to be lactose intolerant. It is interesting to note that this "intolerance" is indeed a normal condition for over 75% of the world's population.

Temporary lactose intolerance can develop when a disorder such as an intestinal infection (see general information about gastroenteritis), damages the mucous membrane of the small intestine. Once people recover from these disorders, they are able to digest lactose again.

Intolerance to other sugars also occurs, but is relatively rare. For example, a lack of the enzyme sucrase prevents sucrose from being absorbed into the bloodstream, and a lack of the enzymes maltase and isomaltase prevents maltose from being absorbed into the bloodstream.

Pathophysiology

The enzyme lactase is found in the brush border of the mucous membrane of the small intestine. Lactase deficiency results in the presence of unabsorbed lactose in the intestine. This leads to an influx of fluid into the intestinal lumen, which leads to osmotic diarrhea. Colon bacteria ferment unabsorbed gas to produce lactose (hydrogen, carbon dioxide and methane), which hydrolyzes lactose to monosaccharides. This leads to an additional inflow of fluid into the lumen. The overall effect of these mechanisms results in a variety of abdominal signs and symptoms.

Epidemiology

Lactose intolerance (hypolactasia) is a common disease; however, it is rare in children under 5 years of age. Most often seen in adolescents and young adults. On average, 65% of the world's population is lactose intolerant. The prevalence of lactose intolerance varies among different ethnic groups. The disease is most common in African Americans, Hispanics and Asians, and is least common in people of European descent.

Diagnostics

Diagnostics include:

• a doctor's assessment of the symptoms that occur after consuming lactose;
• hydrogen breath test.

Lactose intolerance is suspected when a person experiences symptoms after consuming dairy products. If following a dairy-free diet during the 3-4 week study period results in disappearance of symptoms, and the symptoms then return; when a person consumes dairy products, then the diagnosis is considered confirmed.

Special tests are rarely needed, but in some cases, doctors confirm the diagnosis with a hydrogen breath test. In this 4-hour test, people ingest a small measured amount of lactose. Before and after taking lactose, doctors measure the amount of hydrogen in a person's breath at 1-hour intervals. They measure hydrogen because gut bacteria produce hydrogen when they break down unabsorbed lactose. If the amount of hydrogen in exhaled air increases significantly after consuming lactose, then this indicates a person's intolerance to lactose.

The lactose tolerance test is an alternative, less sensitive test that is rarely used today. After a person has taken a measured amount of lactose, doctors monitor the symptoms and measure their blood sugar (glucose) levels several times. People who can digest lactose do not develop any symptoms and their blood glucose levels rise. People who cannot digest lactose develop diarrhea, bloating, and discomfort after 20 to 30 minutes, but their blood glucose levels do not rise.

Treatment

Lactose intolerance can be controlled through diet - avoiding foods containing lactose, especially dairy products. Yogurt is often tolerated because it naturally contains lactase, which is produced by lactic acid bacteria Lactobacilli. Cheese contains less lactose than milk and is often well tolerated depending on the amount eaten. Milk and other lactose-reduced foods are available in many supermarkets.

People who must avoid dairy products should take calcium supplements to prevent calcium deficiency. Lactase enzyme supplements are available over the counter and can be taken with meals or with lactose-containing beverages.

Forecast

Lactose intolerance has an excellent prognosis. Most patients experience significant improvement in signs and symptoms only with a change in diet.

Complications

Complications include:

• osteopenia;
• osteoporosis;
• malnutrition;
• weight loss.