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Related Experiment Video

Updated: Jun 11, 2026

Measuring Lactase Enzymatic Activity in the Teaching Lab

Measuring Lactase Enzymatic Activity in the Teaching Lab

Published on: August 6, 2018

Lactose intolerance and health.

Timothy J Wilt, Aasma Shaukat, Tatyana Shamliyan

Evidence Report/Technology Assessment

|July 16, 2010

Summary

Lactose intolerance (LI) prevalence varies by race and age, with most individuals tolerating up to 12 grams of lactose. Dairy interventions may benefit bone health in children with low lactose intake, but evidence for other management strategies is insufficient.

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Measuring Lactase Enzymatic Activity in the Teaching Lab

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Site-Specific Lysine Lactylation via Genetic Code Expansion in E. coli and Mammalian Cells

Site-Specific Lysine Lactylation via Genetic Code Expansion in E. coli and Mammalian Cells

Published on: February 24, 2026

Area of Science:

Nutritional Science
Gastroenterology
Public Health

Background:

Lactose intolerance (LI) is a common condition affecting digestion of lactose, a sugar in milk.
Prevalence and management strategies for LI require further investigation, particularly regarding bone health and dietary interventions.

Purpose of the Study:

To systematically review the evidence on lactose intolerance (LI) prevalence.
To assess bone health outcomes in individuals on dairy-exclusion diets.
To determine the tolerable lactose dose and effective management strategies for diagnosed LI.

Main Methods:

Systematic review of original studies published in English from 1967-2009.
Extraction of patient and study characteristics, comparing outcomes based on diagnostic tests (lactose challenge, biopsies, genetic tests, symptoms).
Analysis of fracture risk, bone mineral content (BMC), and bone mineral density (BMD) in relation to lactose intake; evaluation of symptom tolerability and management interventions.

Main Results:

LI prevalence shows significant race and age differences, with higher rates in African American, Hispanic, Asian, and American Indian populations.
Most individuals with LI can tolerate up to 12 grams of lactose daily, with symptoms increasing above this dose.
Low-level evidence suggests potential increased fracture risk with low milk consumption and possible bone benefits from dairy interventions in select populations, though evidence for probiotics and other agents is insufficient.

Conclusions:

Accurate U.S. population prevalence of LI remains undetermined due to insufficient evidence.
Children with low lactose intake may experience positive bone health outcomes from dairy interventions.
Further research is necessary to establish the effectiveness of various LI management strategies and agents.