Milk sugar requiring specific enzyme for digestion.
A disaccharide composed of glucose and galactose found exclusively in milk and dairy products, requiring lactase enzyme for digestion.
Lactose is a disaccharide naturally present in mammalian milk, consisting of glucose bonded to galactose. Its digestion requires lactase, an intestinal enzyme that cleaves lactose into monosaccharides for absorption. Lactase production decreases after weaning in most humans, leading to lactose intolerance—characterized by digestive discomfort when consuming dairy. However, many populations maintain lactase persistence into adulthood through genetic adaptation. Lactose provides nutritional value in dairy contexts alongside protein, calcium, and other nutrients, but lactose-free alternatives are available for those unable to digest it.
Provides carbohydrate energy in dairy products while delivering calcium and protein for bone health and muscle function.
If lactose intolerant, choose lactose-free milk, fermented dairy (yogurt, kefir, aged cheese), or plant-based alternatives. Consider gradual exposure, as some lactose-intolerant individuals tolerate fermented products better. Ensure alternative calcium and vitamin D sources if avoiding all dairy.
Lactose is milk sugar beneficial for those who can digest it, but lactose intolerance is common and manageable with alternatives.
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