Lactose Intolerance by Country 2026
- Lactose intolerance rates were estimated by subtracting percentages of lactase tolerance (the inverse of lactose intolerance) from 100%, as direct lactose intolerance measurements are not widely available.
- Source data represent the frequency of lactase persistence (ability to digest lactose) in populations.
- BioInteractive reports phenotype frequencies based on direct testing or dietary tolerance studies.
- The Itan et al. PMC study provides both phenotype frequencies and genotype data, showing how genetic potential relates to observed tolerance.
- The COBLAB/UGR (Computational Biology Laboratory at University of Granada) dataset compiles global phenotype frequencies (“Frequency of Digestor”) from multiple published studies.
- Data from all three sources compile lactase persistence frequencies and genotypes from multiple published studies conducted across various years, so the figures represent aggregated results rather than a single specific year.
Lactose intolerance is a digestive disorder caused by the inability to digest lactose. Those with lactose intolerance don’t make enough of the enzyme lactase, which is needed to digest lactose. Lactose is the main carbohydrate in dairy products. Lactose intolerance can start at birth or can develop suddenly later in life, even if the individual has never had a problem with dairy before. Lactose intolerance in infants is caused by a mutation of the LCT gene, resulting in life-long intolerance. In adults, the disorder is caused by decreasing activity of the LCT gene, resulting in an increasing inability to digest lactose as an individual ages. About 65% of the adult human population has this type of lactose intolerance.
The disorder is relatively very common, affecting millions of people in the U.S. alone. Lactose intolerance is generally harmless but its symptoms can cause extreme discomfort. Symptoms of lactose intolerance appear after consuming lactose or dairy and include bloaring, abdominal cramps, diarrhea, and gas. Lactose malabsorption causes the digestive symptoms of lactose intolerance. Not everyone with lactose malabsorption has digestive symptoms after consuming lactose. Only those who have symptoms have lactose intolerance.
Treatment for the disorder includes avoiding dairy, the use of lactase supplements (such as Lactaid), and the use of lactose-free products. While treatment can help prevent symptoms, there is no cure for this condition. Those who have lactose intolerance and need to avoid consuming dairy products run the risk of not receiving enough nutrients, specifically calcium and vitamin D. A lack of calcium can lead to osteoporosis, a condition in which one’s bones become brittle and more likely to break. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) has guidelines on how to eat with lactose intolerance without sacrificing your nutritional needs.
Lactose Intolerance Around the World
In the United States, individuals who are from or whose families are from parts of the world where lactose malabsorption is more common are more likely to have lactose intolerance. According to the NIDDK, those who are American American, American Indian, Asian American, or Hispanic/Latino are more likely to have lactose malabsorption. Lactose intolerance is generally most common in Asian countries, especially in East Asian, where about 70-100% of people show lactose intolerance; it is least prevent in Northern and Central Europe, where only about 5% of the population has lactose intolerance.
