Lactose intolerance is a common gastrointestinal condition often causing painful and embarrassing symptoms from the consumption of dairy products. People with lactose intolerance have a low activity level of lactase, the enzyme responsible for breaking down lactose, a sugar commonly present in dairy products.
Patients with lactose intolerance experience one or more of the following cardinal symptoms when they consume dairy products:
- Abdominal pain
Symptoms can be painful, embarrassing, and socially difficult to manage to the point that it can significantly impact one’s quality of life. According to the American Academy of Pediatrics Committee on Nutrition (2006), “the symptoms of lactose intolerance can lead to significant discomfort, disruption of the quality of life, and loss of school attendance, leisure and sports activities, and work time, all at a cost to individuals, families and society.” Furthermore, in an Engage Health 2008 study on lactose intolerance, 82% of patients reported that their lactose intolerance affects their daily activities.
Causes of Lactose Intolerance
There are two commonly known factors which can lead to lactose intolerance:
- Primary causes include one’s heredity. As infants mature, there is a genetically programmed decrease in lactase activity. This decrease in lactase production tends to be stronger in non-dairy consuming societies, for example certain African and Asian populations. Symptoms of lactose intolerance typically become present in children and young adults, but can also develop in older individuals.
- Secondary causes may include less common factors, such as intestinal parasites, chemotherapy, penicillin reactions, surgery, pregnancy, or dairy avoidance. In rare cases, infants can be born with a genetic disorder that prevents the production of lactase.
Lactose intolerance is often diagnosed through an individual’s clinical history which reveals a relationship between lactose ingestion and onset of symptoms. Hydrogen breath test, a validated diagnostic method may be utilized to diagnose problems with lactose digestion, as well as a milk challenge may be used to recognize one’s symptom severity. Further tests can be conducted to rule out other digestive diseases or conditions, including: stool examination to document the presence of a parasite, blood tests to determine the presence of celiac disease, and intestinal biopsies to determine mucosal problems leading to malabsorption, such as inflammatory bowel disease or ulcerative colitis.