Lactose intolerance

Lactose intolerance is a digestive disorder in which the body is unable to properly digest lactose, a type of sugar found in milk and dairy products. The symptoms are gastrointestinal: abdominal pain and cramps, bloating and gas, diarrhea, nausea, vomiting, and rumbling sounds in the abdomen. For a dairy processor, this condition defines a large and growing consumer segment whose needs shape product formulation, ingredient selection and process design.

There are three recognised causes. Primary lactose intolerance is the most common type and occurs when the body naturally reduces its production of lactase after weaning off breast milk or formula during infancy. Secondary lactose intolerance is caused by an underlying condition or injury that affects the small intestine, such as gastroenteritis, celiac disease or radiation therapy. Congenital lactase deficiency is a rare, genetic condition in which a baby is born with little or no lactase enzyme, and symptoms typically appear soon after birth when the baby is fed with breast milk or formula containing lactose.

The market response spans both dairy and non-dairy categories: lactose-free dairy products, plant-based milk, dairy-free yogurt, non-dairy ice cream, and non-dairy spreads and margarine. Each of these lines carries its own process implications, from ingredient handling and formulation through to segregation and labelling on the plant floor.

Hard and aged cheeses occupy a special position. The lactose content in cheese decreases during the cheese-making process for two reasons: whey removal, which draws off lactose with the liquid fraction, and fermentation, in which most of the remaining lactose is fermented by lactic acid bacteria and converted into lactic acid. As a result, the longer the cheese is aged, the lower its lactose content — which is why many lactose intolerant consumers can eat hard and aged cheeses.