Lactose intolerance and milk drinking around the world
What it found
Many adults worldwide cannot digest lactose, but some can still drink a glass of milk with a meal and have no or minor symptoms.
This was a review of existing research, not a new study in people.
What they found
Studies in people
How common it is
Lactase non-persistence affects 65-70% of the world's adult population.
Milk drinking with a meal
Some lactose intolerant individuals, without co-existent irritable bowel syndrome, are able to consume a glass of milk with a meal with no or minor symptoms.
Milk consumption trends
Milk consumption is decreasing in the USA and is the lowest in countries with a high prevalence of lactase non-persistence.
Genetic advantage of milk
The high frequency of lactase persistence in offspring of Northern European countries and in some nomadic African tribes is due to mutations in the promoter of the lactase gene in association with survival advantage of milk drinking.
Other findings
Ways to get calcium
Educational and commercial efforts to improve calcium and Vitamin D intake have focused on urging consumption of tolerable amounts of milk with a meal, use of lowered lactose-content foods including hard cheeses, yogurt, and lactose-hydrolyzed milk products.
What the authors conclude
- They suggest urging consumption of tolerable amounts of milk with a meal.
- They also point to lowered lactose-content foods including hard cheeses, yogurt, and lactose-hydrolyzed milk products.
How it was done
The authors wanted to evaluate the clinical and nutritional significance of genetically determined lactase non-persistence and potential lactose and milk intolerance.
What it can’t tell you
- We summarised it from the abstract only.
- This is a review of existing research, not a new study, so it cannot prove cause and effect.
- It cannot show how any one person will react to milk or lactose.
Who paid
- Authors work at
- Johns Hopkins University School of Medicine, USA; Johns Hopkins University, USA
The paper
- Title
- Lactase Non-persistence and Lactose Intolerance
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people
- Summarised from
- Abstract only
- Cite
- Bayless TM, Brown E, Paige DM (2017). Lactase Non-persistence and Lactose Intolerance. Current gastroenterology reports. doi:10.1007/s11894-017-0558-9PubMed 28421381DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error