Lactose Intolerance Around the World

Approximately 90-95% of black individuals and 20-25% of white individuals throughout the world will have a partial or complete lactose intolerance. Most often people of African, Asian, and Mediterranean descent have it.

Most humans, like other mammals, gradually lose the intestinal enzyme lactase after infancy and with it the ability to digest lactose, the principle sugar in milk. At some point in prehistory, a genetic mutation occurred and lactase activity persisted in a majority of the adult population of North and Central Europe, and in some ethnic groups around the Mediterranean and Near East, in Noth Africa, and on the Indian subcontinent are those that have developed a gentic mutation to allow them to digest the lactose in milk. allowing carriers to have milk as a nutritional resource, especially useful in times of food shortage.

These people share the longest known tradition of dairying, since humans first domesticated livestock and practiced milk-based pastoralism (6000–9000 years ago), making milk abundant for adults.

Descendants of these polutations carried this genetic mutation with them to Noth America and Austalia.

For the majority of the world's populations, however, the absence of genetic challenge has meant that this genetic change did not occurred.

Lactose intolerance by group

Human groups	Individuals Examined	Percent Intolerant	Allele Frequency Allele frequency is the proportion of all copies of a gene that is made up of a particular gene variant . In other words, it is the number of copies of a particular allele divided by the number of copies of all alleles at the genetic place in a population.
Basques	85	0.3%	N/A
Dutch	N/A	1%	N/A
Swedes	N/A	2%	0.14
Europeans in Australia	160	4%	0.20
Northern Europeans and ScandinaviansScandinavians	N/A	5%	N/A
Danes	N/A	5%	N/A
British	N/A	5–15%	0.184-0.302
Swiss	N/A	10%	0.316
European Americans	245	12%	0.346
Tuareg	N/A	13%	N/A
Germans	N/A	15%	N/A
Eastern Slavs (Russians, Belarusians, Ukrainians)	N/A	15%	N/A
Austrians	N/A	15–20%	N/A
Northern French	N/A	17%	N/A
Finns	134	18%	0.424
Central Italian	65	19%	N/A
Indians	N/A	20%	N/A
African Tutsi	N/A	20%	0.447
African Fulani	N/A	23%	0.48
Bedouin	N/A	25%	N/A
Portuguese	102	35%	N/A
Southern Italian	51	41%	N/A
African American	N/A	45%	N/A
Saami	N/A	25–60%	N/A
Northern Italian	89	52%	N/A
North American Hispanic	N/A	53%	N/A
Balkans	N/A	55%	N/A
Mexican American	N/A	55%	N/A
Cretans	N/A	56%	N/A
African Maasai	21	62%	N/A
Southern French	N/A	65%	N/A
Greek Cypriots	N/A	66%	N/A
Bangladesh	N/A	70%	N/A
Jews, Mizrahi (Iraq, Iran, etc)	N/A	85%	N/A
Jews, North American	N/A	68.8%	N/A
Jews, Sephardic	N/A	62%	N/A
Jews, Yemenite	N/A	44%	N/A
Sicilians	100	71%	N/A
South Americans	N/A	65–75%	N/A
Rural Mexicans	N/A	73.8%	N/A
African Americans	20	75%	0.87
Kazakhs	195	76.4%
Lebanese	75	78%	N/A
Central Asians	N/A	80%	N/A
Alaskan Eskimo	N/A	80%	N/A
Australian Aborigines	44	85%	0.922
Inner Mongolians	198	87.9%
African Bantu	59	89%	0.943
Asian Americans	N/A	90%	N/A
Northeastern Han Chinese	248	92.3%
Chinese	71	95%	0.964
Southeast Asians	N/A	98%	N/A
Thai	134	98%	0.99
Native Americans	24	100%	1.00