Nutrition Myths

Lactase Persistence

Lactase persistence is the ability of adult humans to digest lactose. This ability has its origins in different parts of the world (which occurred through convergent evolution) such as Central and Northern Europe, West Africa, the Middle East and western India.

Genetic changes allowing for lactase persistence started to spread quickly after the introduction of milkable domestic animals, especially in Northern Europe about 8,000 years ago. (1, 2)

Historically, before the development of agriculture and the domestication of animals milk was only available from the lactating mothers. Its supply stopped after the weaning period.

With a sudden change in diet from breastfeeding through weaning, specifically because of the absence of milk, lactase was not required anymore and so its production by the body was drastically reduced.

Around 8000 years ago, Europe started domesticating milk-producing animals, allowing the consumption of milk on a regular basis. The trend spread to the Middle East and West India. (3)

In Africa, especially in the countries south of the Sahara, lactose persistence most likely originated thanks to the domestication of the camel. (4)

Consistent milk consumption existed in these locations for about 8,000 years which allowed for the genetic mutation to occur resulting in lactase persistence.

To visualize the centers of lactose persistence or see where lactose intolerance is most prevalent, see the following map. Red color represents the most lactose tolerant populations, while blue represents a high percentage of lactose intolerance. The further from the centers, the more lactose intolerant the populations are. (5)

Lactase persistance map

Related Posts

Can you drink too much milk? We all have a different limit of how much milk and other dairy products we can have per day. This limit can be zero, if you have milk allergy, or 2 servings per day, if you are a men and want to avoid increasing the risk...
Milk allergy symptoms and causes Milk allergy, or dairy allergy, is an adverse immune response to the protein in cow’s milk, that mainly affects children. The symptoms depend on the amount of dairy consumed and the severity of the allergy and include vo...
Is milk bad for you? Yes and no. If you drink more than your body can digest, suffer from an allergy to the cow's milk protein, have gastroenteritis or consume milk from bovine hormone injected cows, than the negative effects might outweigh ...
Does milk cause osteoporosis? Milk, dairy products and milk derived supplements are good for bone health. The acid-ash hypothesis, which this myth originated, has been disproven by many studies.
Should lactose intolerant people avoid milk and other dairy foods? Insufficient presence of lactase does not mean that symptoms of lactose intolerance will manifest. If you are lactose intolerant, rather than excluding all dairy foods from your diet, discover your lactose threshold.

Get updates

Receive regular updates on nutrition myths, facts and curiosities. All based on the latest scientific evidence.