Lactase Persistence - Distribution

Distribution

Human group Individuals examined Intolerance (%) Reference Allele frequency
Dutch N/A 1 N/A
Danes N/A 4 N/A
Europeans in Australia 160 4 0.20
Swedes N/A 5-7 N/A
Basques 85 8.3 N/A
British N/A 5–15 0.184-0.302
Germans 1805 6-23 N/A
Swiss N/A 10 0.316
European Americans 245 12 0.346
Tuareg N/A 13 N/A
Finns N/A 14-23 N/A
Belorusians N/A 15 N/A
Russians N/A 16 N/A
Ukrainians N/A 13 N/A
Austrians N/A 15–20 N/A
Spaniards (non-Basque) N/A 15 N/A
Northern French N/A 17 N/A
Central Italians 65 19 N/A
Indians N/A 20 N/A
African Tutsi N/A 20 0.447
African Fulani N/A 23 0.48
Bedouins N/A 25 N/A
Portuguese adults 102 35 N/A
Southern Italians 51 41 N/A
African American Children N/A 45 N/A
Saami (in Russia and Finland) N/A 25–60 N/A
Northern Italians 89 52 N/A
North American Hispanics N/A 53 N/A
Balkans N/A 55 N/A
Mexican American Males 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
Jews, Mizrahi (Iraq, Iran, etc.) N/A 85 N/A
Jews, Ashkenazi 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 from northwest Xinjiang 195 76.4
Lebanese 75 78 N/A
Central Asians N/A 80 N/A
Alaskan Inuit 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
Thais 134 98 0.99
Native Americans 24 100 1.00

The statistical significance of these figures vary greatly depending on number of people sampled.

Lactose intolerance levels also increase with age. At ages 2 – 3 yrs., 6 yrs., and 9 - 10 yrs., the amount of lactose intolerance is, respectively:

  • 6% to 15% in white Americans and northern Europeans
  • 18%, 30%, and 47% in Mexican Americans
  • 25%, 45%, and 60% in black South Africans
  • approximately 10%, 20%, and 25% in Chinese and Japanese
  • 30–55%, 90%, and >90% in Mestizos of Peru

Chinese and Japanese populations typically lose between 20 and 30 percent of their ability to digest lactose within three to four years of weaning. Some studies have found that most Japanese can consume 200 ml (8 fl oz) of milk without severe symptoms (Swagerty et al., 2002).

Ashkenazi Jews can keep 20–30 percent of their ability to digest lactose for many years. Of the 10% of the Northern European population that develops lactose intolerance, the development of lactose intolerance is a gradual process spread out over as many as 20 years.

Read more about this topic:  Lactase Persistence

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