Find the share of adults who can't fully digest lactose, by region and ethnic group. Every figure cites the primary study it comes from.
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How to read these numbers. Figures are the share of adults with lactase non-persistence (the genetic loss of lactase enzyme after childhood). Not everyone in that share has uncomfortable symptoms — many have only mild malabsorption.
Regional figures are aggregates across many cohorts and inherit wide confidence intervals.
"Specific populations" use individual peer-reviewed studies; the citation below each estimate is the primary source.
The widely-cited Storhaug et al. 2017 Lancet meta-analysis was retracted in January 2025 and is not used here.