The myth of increased lactose intolerance in African-Americans.
Level 5 - mechanism / opinion, no new human data
Narrative review of dietary patterns and lactose digestion literature without systematic search methodology or new human data
PubMed 16373956 · doi:10.1080/07315724.2005.10719505
What was done
This narrative review synthesized literature on the prevalence of lactase nonpersistence among African-Americans, associated dietary nutrient deficiencies (notably calcium), and management strategies to improve dairy tolerance.
What was found
Approximately 75% of African-Americans exhibit lactase nonpersistence, marked by a 90% to 95% reduction in lactase-phlorizin hydrolase enzyme activity. Despite high rates of maldigestion, research demonstrates that African-American maldigesters can tolerate at least one 8-ounce cup of milk without developing symptoms. Tolerance is further enhanced by consuming milk alongside meals, selecting yogurt or hard cheeses, or using lactase enzyme supplements and lactose-reduced products.
Why it matters
Highlights that genetic lactase nonpersistence does not require complete dairy avoidance, offering practical strategies to help meet dietary calcium recommendations.
Limits
As a narrative review, it presents no systematic search protocol, quality appraisal of cited studies, or meta-analytic data. No primary empirical sample size or detailed quantitative trial outcomes are reported in the abstract.
Cited by
- context Seventy-five percent of African Americans are lactose intolerant.