Lactose is a main ingredient in milk and requires an enzyme to break it down before it can be absorbed by the human gut. A research team from Australia revisited some common misconceptions surrounding lactose intolerance in children in a paper outlining the current research.
Lactose intolerance is a widespread condition in which the body cannot digest and absorb lactose that is found in everyday foods. Lactose has to be broken down by specific enzymes in the body in order to be sufficiently absorbed. Roughly 70% of the world’s population experiences lactose intolerance. Abdominal pain, flatulence and diarrhea are all common symptoms of lactose intolerance. Children under the age of five have a high tolerance for lactose, and intolerance generally arises after this age. Lactose intolerance in children presents with similar symptoms to cow’s milk allergy (CMA) and they are confused often during diagnosis. This is noteworthy because allergies to cow’s milk requires complete abstinence from milk products, whereas lactose intolerance in children is treated with a lactose-free, cow’s milk protein-containing formula. There is still many misconceptions that are present regarding lactose intolerance in children.
Physiological Presentation and Different Types of Lactose Intolerance
Ralf Heine and his colleagues at the Murdoch Children’s Research Institute in Australia tackled the common misconceptions regarding lactose intolerance in children and published some of their findings recently in the World Allergy Organization Journal. Fluid imbalances in the gut and the formation of gas are some of the reasons for clinical characteristics of lactose intolerance. Diarrhea occurs prevalently in children with lactose intolerance because their gut doesn’t have the ability to compensate reabsorption of liquids in the gut.
There are four different types of lactose intolerance:
- Developmental lactase deficiency
- Congenital lactase deficiency
- Lactase non-persistence (LNP)
- Secondary lactose intolerance
Developmental lactase deficiency occurs in premature infants and is only temporary once the lactase deficiency improves throughout their childhood. Congenital lactase deficiency is a rare genetic disorder in newborns where the enzyme lactase is completely absent from the gut.
LNP occurs when there is a continued decline of the enzymatic activity of lactase in infants after they have stopped consuming breast milk. This is the lactose intolerance that occurs in about 70% of the global population. Generally this type of lactose intolerance does not occur in children under the age of five. Lastly, secondary lactose intolerance occurs as a result of other gut conditions. In children some of these conditions may include gastroenteritis, celiac disease, or Crohn’s disease.
Diagnosis of Lactose Intolerance in Children
Lactose intolerance in children is clinically different from that of infants. Infants are usually more at risk of diarrhea than older children. In older children, lactose intolerance is more commonly characterized by bloating and abdominal pain and symptoms. It is important that lactose intolerance is critically diagnosed in the laboratory because the root cause of secondary lactose intolerance in children should strongly be considered during treatment options. To test and diagnose lactose intolerance in children, stool samples are used to observe the absorption of lactose depending on sugars that may be found in the stool sample.
Treatment of Lactose Intolerance in Children
It is recommended that infants who present with lactose intolerance should be maintained on a breast-feeding regimen. If the infant is formula-fed, the doctor should try out a temporary lactose-free formula. For children who show persistent diarrhea, it might be necessary to restrict lactose intake for a short period of time. It should be noted, that reintroduction of lactose is encouraged following the short restriction of lactose. Lactose restriction must be maintained for life as a treatment for infants who have congenital lactose deficiency, but older children might be able to tolerate low amounts of lactose depending on how severe the disease is. It has also been suggested that lactose intolerance in children can be treated with lactase supplementation to help in reducing the severity of symptoms.
In conclusion, there are still many misconceptions about lactose intolerance in children because of confusion that may occur in diagnosis. This may result in unsuitable or inappropriate treatment options. Lactose intolerance in children under five years of age is very uncommon. Children who do present with lactose intolerance at young ages should be considered for underlying causes of gut disease. It is imperative that parents and healthcare providers are educated on these topics to ensure that their children are properly diagnosed and treated in the best way possible. Addressing misconceptions regarding this topic should also be prioritized.
Written by Ingrid Qemo, BSc
Reference: Heine, R.G., et al. 2017. Lactose intolerance and gastrointestinal cow’s milk allergy in infants and children –common misconceptions revisited. World Allergy Organization Journal. DOI 10.1186/s40413-017-0173-0