Country rankings

Lactose Intolerance by Country

Denmark has the highest Phenotype Frequency (GLAD) (96.0%), followed by Ireland (96.0%) and United Kingdom (95.0%). Iran has the lowest (1%).

Health59 countries · 9 metricsUpdated Oct 22, 2026Original page
5 sources
55 of 235 countries
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Phenotype Frequency (GLAD)

Darker means higher. Click a place to highlight it.

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All 55 ranked

Highest first.

Distribution Median and middle halfThe median is the middle value: half of places are above it, half below. The middle half is the range holding the central 50% of places.More in the glossary →

Each dot is one country; the lines mark the median and the middle half.

Median
36.0%
Middle half 20.0% – 65.0%
Average
43.0%
55 countries
Highest
96.0%
Denmark
Lowest
1%
Iran

Data

Click a column to sort, a row to highlight that place on the charts.

58 countries · # = rank by Phenotype Frequency (GLAD)
#
1DenmarkDanes96.0%91
1IrelandNative Irish96.0%50
3United KingdomBritish95.0%150
4GermanyNorthwest Germans91.0%341
5KenyaMaasai88.0%26
6NigerTuareg87.0%118
7AustriaTirol Austrian83.0%124
7FinlandFinns83.0%638
9CzechiaCzech82.0%17
10FranceFrench76.0%102
10JordanUrban/agricultural Jordanian Arabs76.0%162
12EstoniaEstonian75.0%112
13SenegalDiolas73.0%40
14SpainGalician66.0%338
15PolandPolish64.0%85
16CanadaQuebec Mixed ancestry60.0%30
17HungaryHungarian59.0%262
18RwandaHutu-Hutu58.0%36
19Brazilwhite Campinas55.0%40
19GreeceContinental Greeks55.0%600
21ItalyNorthern Italians49.0%208
22EthiopiaEthiopians45.0%294
23Saudi ArabiaArabs43.0%109
24KuwaitAsian Kuwaiti42.0%79
25PakistanPunjabi41.0%322
26GabonBantu40.0%20
27IndiaIndians36.0%100
27New ZealandMaori36.0%28
29TanzaniaSandawe35.0%23
30United StatesChippewa (took Round Lake, Minnesota)34.0%156
30CyprusGreek Cypriots34.0%50
32TurkeyWestern Anatolia and European Turkey30.0%126
33RussiaKhanty (Northern)29.0%115
33MexicoHuamantia mixed29.0%193
35JapanJapanese28.0%40
35Sri LankaSri Lankans ("Ceylonese")28.0%200
37EgyptNile Delta27.0%291
38SudanDinka25.0%208
39ChileSantiago mixed army recruits24.0%98
40Papua New GuineaE and W Sepik provinces23.0%35
41LebanonLebanese22.0%74
42AfghanistanTajik18.0%79
43NigeriaYoruba17.0%48
44AustraliaAboriginal16.0%45
44TunisiaTunisian16.0%43
44OmanOmani16.0%50
47TaiwanChinese12.0%50
48South AfricaZulu11.0%47
48UzbekistanTajiko-Uzbek11.0%100
50BotswanaShua9%22
51ChinaNorthern Han8%248
51MyanmarBurmese8%50
53ThailandThai3%140
53Namibia!Kung3%40
55IranKurd1%100
—ColombiaBogota students—0.44
—UgandaUgandan Bantu——
—ZambiaBantu of Zambia—26

What correlates with Phenotype Frequency (GLAD)?

Pearson r against 1,729 other country metrics sharing at least 33 countries. Correlation is not causation.

Higher together

Places that have a higher Phenotype Frequency (GLAD) tend to score higher on these

  1. Sales TaxAutomobile Tariffs by Country
    r = +0.69 · strong · n = 33
    Plot
  2. Electricity Cost per kWhCost of Electricity by Country
    r = +0.67 · strong · n = 52
    Plot
  3. Green Future Index Score (MIT)Most Environmentally Friendly Countries
    r = +0.67 · strong · n = 36
    Plot
  4. Sales TaxHighest Taxed Countries
    r = +0.64 · strong · n = 53
    Plot
  5. Decaffeinated or Roasted Coffee Consumption per CapitaCoffee Consumption by Country
    r = +0.64 · strong · n = 44
    Plot
  6. Restaurant Price IndexCost of Living by Country
    r = +0.62 · strong · n = 50
    Plot

Opposite directions

Places that have a higher Phenotype Frequency (GLAD) tend to score lower on these

  1. LI Users Aged 25-34LinkedIn Users by Country
    r = −0.61 · strong · n = 53
    Plot
  2. RichAds 2024Tier 1 Countries
    r = −0.59 · strong · n = 46
    Plot
  3. Human RightsFailed States
    r = −0.54 · strong · n = 54
    Plot
  4. FSI Index Secrecy ScoreBest Countries to Hide Money
    r = −0.54 · strong · n = 45
    Plot
  5. Strongest Quake Past 10 YrsCountries Without Earthquakes
    r = −0.53 · strong · n = 53
    Plot
  6. Avg Weekly Hours Worked ILOAverage Workweek by Country
    r = −0.53 · strong · n = 53
    Plot

Quick answers

Which country has the highest Phenotype Frequency (GLAD)?
Denmark has the highest Phenotype Frequency (GLAD), at 96.0%, followed by Ireland (96.0%) and United Kingdom (95.0%).
Which country has the lowest Phenotype Frequency (GLAD)?
Iran has the lowest Phenotype Frequency (GLAD), at 1%.
What is the median Phenotype Frequency (GLAD) across countries?
The median is 36.0% across the 55 countries with data.
Where does this lactose intolerance by country data come from?
Rankodex compiles it from World Population Review and the primary sources it cites: Patterns in the Distribution of Lactase Persistence - BioInteractive; A worldwide correlation of lactase persistence phenotype and genotypes - ItanPMC; Genetics of Lactose Intolerance: An Updated Review and Online Interactive World Maps of Phenotype and Genotype Frequencies - COBLAB/UGR; Genetics of Lactose Intolerance: An Updated Review and Online Interactive World Maps of Phenotype and Genotype Frequencies - Map - COBLAB/UGR.