To determine the prevalence of cow´s milk allergy and lactose intolerance in a sample of late adolescents.

Through a population-based study, data corresponding to students with aged 15 to 18 years were analyzed.

A total of 1992 adolescents was analized. The prevalence of cow´s milk allergy was 1.4% (95% CI: 0.2% to 0.8%) and the prevalence of lactose intolerance was 0.5% (95% CI: 0.2% to 0.8%). Adolescents with cow´s milk allergy had fewer gastrointestinal symptoms (p = 0.036), but more skin (p < 0.001) and respiratory (p = 0.028) ailments than adolescents with lactose intolerance.

The manifestations associated with cow's milk consumption in late adolescents seem to correspond mainly to cow´s milk allergy than to lactose intolerance.

Milk is related to many gastrointestinal disorders from the cradle to the grave due to the many milk ingredients that can trigger gastrointestinal discomfort and disorders. Cow's milk protein allergy (CMPA) is the most common food allergy, especially in infancy and childhood, which may persist into adulthood. There are three main types of CMPA; immunoglobulin E (IgE)-mediated CMPA, non-IgE-mediated CMPA, and mixed type. CMPA appears before the first birthday in almost all cases. Symptoms may start even during the neonatal period and can be severe enough to simulate neonatal sepsis. CMPA (often non-IgE mediated) can present with symptoms of gastroesophageal reflux, eosinophilic esophagitis, hemorrhagic gastritis, food protein-induced protein-losing enteropathy, and food protein-induced enterocolitis syndrome. Most CMPAs are benign and outgrown during childhood. CMPA is not as common in adults as in children, but when present, it is usually severe with a protracted course. Lactose intolerance is a prevalent condition characterized by the development of many symptoms related to the consumption of foods containing lactose. Lactose intolerance has four typical types: Developmental, congenital, primary, and secondary. Lactose intolerance and CMPA may be the underlying pathophysiologic mechanisms for many functional gastrointestinal disorders in children and adults. They are also common in inflammatory bowel diseases. Milk consumption may have preventive or promoter effects on cancer development. Milk may also become a source of microbial infection in humans, causing a wide array of diseases, and may help increase the prevalence of antimicrobial resistance. This editorial summarizes the common milk-related disorders and their symptoms from childhood to adulthood.