Little tummies, big issue: How to manage lactose intolerance in babies and kids

When primary lactose intolerance happens in children, it usually occurs after the child turns five. — Photos: Handout

FROM the day a child is born, it is important that the infant is fed with milk. It is the one food that will help the baby grow up healthy, with all the necessary vitamins, minerals and nutrition.

However, if a baby starts experiencing diarrhoea, constant crying and restlessness, as well as loss of appetite after milk feeding, parents will need to be wary as the child may be suffering from lactose intolerance.

Paediatric gastroenterology and hepatology consultant Dr Ong Sik Yong says lactose intolerance is a common condition, caused by the inability to digest and absorb dietary lactose.

Dr Ong says lactase levels in babies will decline after weaning period.

Lactose and its benefits

Lactose is the main carbohydrate in breast milk as well as cow’s milk. It is also present in dairy products such as cheese and yoghurt. The lactose ingested by humans needs to be broken down through hydrolysis by lactase, bound to the small intestine membrane, before it is absorbed.

Infants do not absorb all of the ingested lactose from breast milk. This is then fermented in the colon into short-chain fatty acids, hydrogen, carbon dioxide and methane. Increased good gut bacteria and short-chain fatty acids provide a protective effect on colonic mucosal integrity and are beneficial for early immune development.

“Newborns usually express sufficient lactase to digest about one litre of breast milk daily, and in many populations, lactase levels will decline after weaning period. Approximately 70% of the world population are affected by lactase non-persistence, which causes lactose intolerance,” Dr Ong says, adding that in general, primary lactose intolerance does not manifest in children before they turn five.

Children with lactose intolerance have one or more symptoms upon consumption of food containing lactose. These include abdominal discomfort, bloating, farting, and/or diarrhoea. Symptoms often begin about 30 minutes to two hours after consumption.

While primary lactose intolerance might happen in children after they are five years old, it may also happen to a child as young as two years old. And when this happens, the symptoms can be managed by limiting lactose in his or her diet.

Managing lactose intolerant diet

Children who show signs of lactose intolerance should only be fed dairy products with naturally lower lactose content. After a period of limiting food with lactose, the child can consume small amounts of food and drinks containing lactose.

Symptoms should be observed throughout this trial period and over time, the parents or even children themselves would be able to tell how much of lactose they can take.

Dr Ong says children with lactose intolerance may have limited source of calcium and vitamin D in their diet, which are typically provided by dairy products like milk, cheese and yoghurt. "Therefore, it is important to make sure that these children consume other non-dairy foods which are rich in these nutrients, like fish with soft edible bones (like salmon and sardines) as well as green leafy vegetables," he says.