Lactose malabsorption is common worldwide, but estimates differ substantially by geography and by the method used to identify it. A 2017 systematic review and meta-analysis estimated that 68% of adults worldwide had lactose malabsorption, while a 2022 review found a pooled estimate of 54% among people meeting criteria for irritable bowel syndrome (IBS). These figures describe malabsorption or study-defined intolerance, not necessarily the same experience of symptoms after eating dairy.
Contents
- How common is lactose malabsorption worldwide?
- How does lactose malabsorption vary by region?
- Country estimates in the Americas and Europe
- Country estimates in Asia and the Middle East
- Country estimates in Africa and Oceania
- What IBS studies show
- How testing, symptoms, and dose affect the numbers
How common is lactose malabsorption worldwide?
The main global estimate comes from the 2017 systematic review and meta-analysis, whose underlying studies were published through 2016. It estimated lactose malabsorption in 68% of adults worldwide, with a 95% confidence interval of 64%–72%. The review’s result changed when researchers restricted the evidence or used different assessment methods.
Using genotype studies alone, the estimated global prevalence was 74% (95% CI 69%–80%). Using lactose-tolerance tests alone produced an estimate of 55% (95% CI 46%–65%), while hydrogen-breath tests alone produced 57% (95% CI 46%–67%). These are method-specific estimates, so they should not be treated as interchangeable measurements of exactly the same outcome.
Several sensitivity analyses show how evidence selection affected the estimate:
- Excluding secondary-source studies produced a global estimate of 67% (95% CI 61%–72%).
- Excluding studies with quality scores below 8 produced an estimate of 69% (95% CI 65%–73%).
- Excluding funnel-plot outliers reduced the estimate to 61% (95% CI 56%–66%).
- Excluding both funnel-plot outliers and studies scoring 8 or below produced an estimate of 62% (95% CI 57%–67%).
The broad pattern is therefore consistent—lactose malabsorption affects a substantial share of adults—but the exact percentage depends on study design, test choice, and which studies are included. The source reports estimates from its 2017 analysis; they should not be read as a newly measured 2026 prevalence.
Source: Country, regional, and global estimates for lactose malabsorption in adults: a systematic review and meta-analysis (2017 meta-analysis; underlying studies through 2016).
How does lactose malabsorption vary by region?
The same meta-analysis reported large regional differences. Estimated prevalence was 64% in Asia excluding the Middle East (95% CI 54%–74%) and 70% in the Middle East (95% CI 57%–83%). Northern Africa was estimated at 66% (95% CI 45%–88%), while sub-Saharan Africa was estimated at 63% (95% CI 54%–72%).
Europe showed a wide split between regions. The estimate for eastern Europe, Russia, and former Soviet republics was 47% (95% CI 33%–61%). By comparison, northern, southern, and western Europe had an estimated prevalence of 28% (95% CI 19%–37%).
The Americas also varied. Latin America was estimated at 38% (95% CI 18%–57%), while northern America was estimated at 42% (95% CI 13%–71%). Oceania was estimated at 45% (95% CI 19%–71%). The confidence intervals are especially broad for some regions, which signals substantial uncertainty around the point estimates.
| Region in the 2017 analysis | Estimated prevalence | 95% confidence interval |
|---|---|---|
| Middle East | 70% | 57%–83% |
| Northern Africa | 66% | 45%–88% |
| Asia, excluding Middle East | 64% | 54%–74% |
| Sub-Saharan Africa | 63% | 54%–72% |
| Eastern Europe, Russia, former Soviet republics | 47% | 33%–61% |
| Oceania | 45% | 19%–71% |
| Northern America | 42% | 13%–71% |
| Latin America | 38% | 18%–57% |
| Northern, southern, and western Europe | 28% | 19%–37% |
Source: Country, regional, and global estimates for lactose malabsorption in adults (2017 meta-analysis; underlying studies through 2016).
Country estimates in the Americas and Europe
Reported country estimates ranged from 4% to 80% across the Americas and Europe. Ireland and Denmark were each estimated at 4%, while the United Kingdom was estimated at 8%. Belgium was estimated at 15%, Spain at 29%, and France and the United States at 36% each.
Higher estimates appeared in several other countries. Mexico was estimated at 48%, Canada at 59%, Brazil at 60%, and Russia at 61%. Italy was estimated at 72%, and Colombia at 80%.
These country figures are estimates reported in the 2017 review, not a single contemporaneous survey conducted across all countries. Differences may reflect population composition, sampling, diagnostic methods, and the evidence available for each country. A country percentage should therefore be used as a study-era estimate rather than as a precise prediction for every resident.
Source: Country, regional, and global estimates for lactose malabsorption in adults (2017 meta-analysis; underlying studies through 2016).
Country estimates in Asia and the Middle East
The reported Asian and Middle Eastern country estimates also covered a broad range. Cyprus was estimated at 16%, Saudi Arabia at 28%, Pakistan at 58%, and Egypt at 68%. Thailand was estimated at 84%, Israel at 89%, and South Korea at 100%.
Across the reported Asian country extremes, the estimate ranged from 58% in Pakistan to 100% in South Korea. That range should not be interpreted as a ranking of current national health conditions. The source combines evidence gathered through the period covered by the 2017 meta-analysis, and the country estimates may be based on different tests and populations.
The difference between regional and country estimates is also important. Asia excluding the Middle East had a pooled estimate of 64%, but the reported country values included both 16% in Cyprus and 100% in South Korea. A regional pooled estimate summarizes the included evidence; it does not imply that every country sits near the regional midpoint.
Source: Country, regional, and global estimates for lactose malabsorption in adults (2017 meta-analysis; underlying studies through 2016).
Country estimates in Africa and Oceania
The reported African country values ranged from 13% to 93%. Niger was estimated at 13%, Kenya at 39%, Tanzania at 45%, Western Sahara at 53%, and Sudan at 55%. Ethiopia was estimated at 77%, Botswana at 88%, and Namibia at 93%.
The review stated that across most of sub-Saharan Africa, country estimates were 77%–100%, with Niger, Kenya, Sudan, and Tanzania identified as major exceptions. This statement describes the pattern reported by the review and should be read alongside the individual country estimates, rather than as a universal value for every sub-Saharan African population.
At the regional level, sub-Saharan Africa had an estimated prevalence of 63% (95% CI 54%–72%), while northern Africa had an estimate of 66% (95% CI 45%–88%). The country-level spread is wider than either regional point estimate, illustrating why geography alone cannot determine an individual’s result.
Source: Country, regional, and global estimates for lactose malabsorption in adults (2017 meta-analysis; underlying studies through 2016).
What IBS studies show
A 2022 systematic review examined non-malignant organic gastrointestinal disorders that can be misdiagnosed as IBS. Among 6,700 patients meeting IBS criteria, pooled lactose-malabsorption prevalence by breath testing was 54% (95% CI 44%–64%). The crude estimates across those studies ranged from 4.1% to 93.3%, partly depending on the lactose dose used for testing.
When symptom response was included with breath-test evidence, the pooled lactose-intolerance prevalence among 3,303 IBS patients was 46% (95% CI 35%–57%). The crude estimates in those lactose-intolerance studies ranged from 21.0% to 85.0%. The difference between 54% malabsorption and 46% intolerance illustrates why a positive physiological test does not automatically equal the same level of reported symptoms.
Genotype-based results varied as well. In five genotype studies covering 970 IBS patients, the crude rate associated with homozygous C/C-13910 was 37.9%, with individual study estimates ranging from 15.1% to 100.0%. In two genotype studies covering 225 IBS patients, the crude rate associated with G/G-22018 was 60.4%, ranging from 47.2% to 68.0%.
Source: A systematic review and meta-analysis on the prevalence of non-malignant, organic gastrointestinal disorders misdiagnosed as irritable bowel syndrome (2022 systematic review).
How testing, symptoms, and dose affect the numbers
The dose used in a challenge can materially affect the measured result. In a 1996 randomized dose trial of 13 lactose-maldigesting adults, 2 g of lactose did not significantly increase breath hydrogen or intolerance symptoms compared with 0 g. Breath hydrogen increased at 6 g, although up to 6 g was reported as tolerated. Abdominal-pain intensity increased at 12 g, and flatulence episodes did not increase until the dose reached 20 g.
These findings help explain why prevalence figures from different tests are not directly interchangeable. A test may identify malabsorption under a particular challenge dose, while a person’s everyday symptoms depend on dose, food context, and individual response. The trial was small and involved 13 adults, so its dose findings should not be generalized beyond that study without caution.
In a March 2018–April 2019 Indian crossover trial, 50 of 67 tested adults had a positive lactose hydrogen-breath test, and 47 completed the treatment comparison. The trial used a 25-g lactose challenge and defined malabsorption as hydrogen at least 20 ppm above baseline. Among the 47 participants, lactase supplementation reduced cumulative hydrogen-breath output over 180 minutes by 55% versus placebo.
The Indian study’s result is a treatment comparison within that trial, not a population prevalence estimate. Its 25-g challenge also differs from the doses used in the 1996 trial and from the protocols represented in the global and IBS reviews. For that reason, lactose intolerance statistics are most useful when the population, measurement method, challenge dose, symptom definition, and study period are all reported together.
Sources: How much lactose is low lactose? (1996 randomized dose trial); Effect of lactase on symptoms and hydrogen breath levels in lactose intolerance: a crossover placebo-controlled study (March 2018–April 2019).