What is lactose? Why does lactose intolerance occur?
Lactose is a type of sugar found in milk and dairy products. It is made up of two smaller sugar molecules, glucose and galactose, which are joined together. Lactose is unique to mammalian milk and serves as an important source of energy for infants.
Lactose intolerance, on the other hand, is a condition where the body is unable to fully digest lactose due to a deficiency of an enzyme called lactase. Lactase is produced in the small intestine and is responsible for breaking down lactose into glucose and galactose, which can then be absorbed into the bloodstream.
When lactose is not properly digested, it remains in the digestive system and can cause a range of uncomfortable symptoms. These symptoms may include bloating, gas, diarrhea, and abdominal pain. The severity of the symptoms can vary from person to person, with some individuals experiencing mild discomfort while others may have more severe reactions.
There are three main types of lactose intolerance: primary, secondary, and congenital. Primary lactose intolerance is the most common type and occurs when the body naturally decreases its production of lactase after infancy. This decrease in lactase production is a normal part of the aging process and is more prevalent in certain ethnic groups, such as Asians, Africans, and Native Americans.
Secondary lactose intolerance can occur as a result of damage to the small intestine, such as from an infection, surgery, or certain medical conditions like celiac disease or Crohn’s disease. In these cases, the reduced production of lactase is temporary and can improve once the underlying condition is treated.
Congenital lactose intolerance is a rare genetic disorder where infants are born with little to no lactase enzyme. This condition is typically diagnosed shortly after birth when infants experience severe diarrhea and dehydration after consuming breast milk or formula.
The symptoms of lactose intolerance usually appear within 30 minutes to 2 hours after consuming lactose-containing foods or drinks. The severity of the symptoms can depend on the amount of lactose consumed and the individual’s level of lactase deficiency.
To diagnose lactose intolerance, doctors may perform a lactose tolerance test or a hydrogen breath test. In a lactose tolerance test, the individual drinks a liquid containing a high concentration of lactose, and their blood sugar levels are measured over a period of time. If the blood sugar levels do not rise significantly, it indicates that the body is not properly digesting lactose.
In a hydrogen breath test, the individual drinks a lactose solution and then breathes into a device that measures the amount of hydrogen gas produced. When lactose is not digested, it ferments in the colon and produces hydrogen gas, which is then absorbed into the bloodstream and exhaled through the breath.
While there is no cure for lactose intolerance, there are several ways to manage the condition and reduce symptoms. The most common approach is to avoid or limit the consumption of lactose-containing foods and drinks. This may involve reading food labels carefully, choosing lactose-free or lactose-reduced products, and substituting dairy with non-dairy alternatives like almond milk or soy milk.
Some individuals with lactose intolerance may still be able to tolerate small amounts of lactose without experiencing symptoms. Gradually increasing lactose intake over time can help some people build up their tolerance. Additionally, taking lactase supplements before consuming lactose-containing foods or drinks can help break down the lactose and reduce symptoms.
It is important to note that lactose intolerance is different from a milk allergy. A milk allergy is an immune response to proteins found in milk, whereas lactose intolerance is a digestive disorder. The symptoms of a milk allergy can be more severe and may include hives, wheezing, vomiting, and in severe cases, anaphylaxis.
In conclusion, lactose is a sugar found in milk and dairy products, and lactose intolerance occurs when the body is unable to fully digest lactose due to a deficiency of the enzyme lactase. Lactose intolerance can cause a range of uncomfortable symptoms, but it can be managed through dietary changes and lactase supplements. It is important to differentiate lactose intolerance from a milk allergy, as they are distinct conditions with different underlying causes and symptoms.