August 4, 2013

Lactose tolerance hotspots

From Nature:
Most people who retain the ability to digest milk can trace their ancestry to Europe, where the trait seems to be linked to a single nucleotide in which the DNA base cytosine changed to thymine in a genomic region not far from the lactase gene. There are other pockets of lactase persistence in West Africa (see Nature 444, 994–996; 2006), the Middle East and south Asia that seem to be linked to separate mutations3 (see 'Lactase hotspots'). 
The single-nucleotide switch in Europe happened relatively recently. Thomas and his colleagues estimated the timing by looking at genetic variations in modern populations and running computer simulations of how the related genetic mutation might have spread through ancient populations4. They proposed that the trait of lactase persistence, dubbed the LP allele, emerged about 7,500 years ago in the broad, fertile plains of Hungary. 
Once the LP allele appeared, it offered a major selective advantage. In a 2004 study5, researchers estimated that people with the mutation would have produced up to 19% more fertile offspring than those who lacked it. The researchers called that degree of selection “among the strongest yet seen for any gene in the genome”. 
Compounded over several hundred generations, that advantage could help a population to take over a continent. But only if “the population has a supply of fresh milk and is dairying”, says Thomas. “It's gene–culture co-evolution. They feed off of each other.”

Much of Northwestern Europe comprises difficult land for growing crops, but grows grass abundantly. Without dairying, the population density would have stayed low outside the rich river valleys, keeping this largely a fringe area, like Finland. (This lactose tolerance-centric theory of history was put forward by Irish dairy farmer/economist Raymond D. Crotty.)

28 comments:

eah said...

OT

BBC: Boston bomber 'had far-right books'

You'll be hearing more about that.

Wm Jas said...

And yet milk and milk-based drinks (caffe latte, papaya milk, etc.) are extremely popular in Taiwan.

San Francisco non-monk said...

OT: Steve, are you going to give us a review of the Neill Blomkamp movie, Elysium?

Anonymous said...

Something is a little off about the map. I read in some studies that the lactose intolerance rate is actually quite low in Mongolia and lower than shown on this map in Korea. But those facts wouldn't produce a map with conveniently smooth gradients.

Anonymous said...

Something is a little off about the map.

Also, it doesn't explore degrees of lactose intolerance. It implies that it's merely an on/off characteristic, which is difficult to accept.

I have a half-Korean friend who can't eat pizza because of the cooked cheese. Yet I also know many full-blooded Koreans who are tolerant to dairy products, most if not all of the time.

Maya said...

"I read in some studies that the lactose intolerance rate is actually quite low in Mongolia and lower than shown on this map in Korea. But those facts wouldn't produce a map with conveniently smooth gradients."

Don't know much about Mongolia, but I've spent over a year in South Korea, and milk products are a problem for the majority of people I met there. "Fake cheese" and lactose-free ice cream are commonly sold. Of course, for most, milk isn't something deadly, but merely a cause of bad, bad stomachaches and very smelly bathrooms, as my students put it.

Maya said...

What's up with that western tip of Africa? I just looked it up, and those people aren't of Bantu ancestry. The Bantus in Africa are something like 90% lactose intolerant.

Anonymous said...

You'll be hearing more about that.

And I've downloaded a reasonable amount of Marxist/Communist literature. Doesn't make me a commie.

Anonymous said...

@Maya I guess I'm one of the 10% because I'm lactose tolerant as is my entire family. We are all of Ghanaian ancestry with no known European ancestry.

My maternal uncle did one of those DNA test to show where you're from and it did show he had significant shared ancestry with folks from Guinea. So this may explain our tolerance.

Bill said...

I have a half-Korean friend who can't eat pizza because of the cooked cheese. Yet I also know many full-blooded Koreans who are tolerant to dairy products, most if not all of the time.

Doesn't this have to be something other than lactose intolerance, though? Like an allergy? Cheese has very little lactose, generally---the mold eats the lactose first.

Or does the phrase "lactose intolerance" sometimes mean "can't digest lactose 'cause got no lactase" and sometimes mean "allergic to dairy?"

Anonymous said...

Is there a hate issue with offering milk products?

goatweed

Anonymous said...

Dairy products like yogurt, cheese, etc. remove some of the lactose, which is why they can be consumed fairly widely, more so than milk, which retains the lactose.

Paul Mendez said...

Milk is a white supremacist food.

Modern Abraham said...


BBC: Boston bomber 'had far-right books'

You'll be hearing more about that.


Sorry for piling on this off-topic subject, but I saw this quoted today in Esquire (since when did it become such a left-wing rag?). First line: "Uh-oh, the narrative just done got broke" (reverse use of narrative a hat-tip to Steve?). We need separatism between blue staters and red staters right now, as rebutting their incredible stupidity is so unchallenging I am becoming stupid in the process.

It's like those cat sisters in the Washington Post using Nidal Hasan as an example of non-minority, non-immigrant mass shooting violence.

Speaking of which, the Ft. Hood shooter is renouncing his citizenship:

http://www.huffingtonpost.com/2013/08/01/nidal-hasan-citizenship_n_3692533.html

"White privilege is not being asked why you were ever let into this country after shooting 50 soldiers and then renouncing your U.S. citizenship..."

Auntie Analogue said...


Two words:

"Got Milk?"

Anonymous said...

OT

BBC: Boston bomber 'had far-right books'

You'll be hearing more about that.

yeah i heard this on the BBC and I couldn't believe it - the attempt to frame the narrative -
some here will say the left has lost its mind, but no they haven't they know they have the bullhorn.
They can make this 'work'

The global elite are obviously waiting for the first opportunity to more or less make it illegal to oppose open borders globalism. This is no longer conspiracy theory - they WILL be coming for isteve readers and Isteve..

Anonymous said...

Milk -the new hate food.

Anonymous said...

what about that northwest part of india? who are they??

Kibernetika said...

Wait a minute. I've just returned from a place in Central Asia (i.e., just east of China) where milk is a major part of the traditional diet. From horses, camels, etc. In both liquid and solid states. Camel milk tastes better than horse, IMHO. Thicker and less bitter.

As anon @ 8/4/13, 11:39 PM wrote, I'd wager that lactose intolerance is pretty darned low in those populations descended from ~ Mongolia.

Anonymous said...

The patterns of lactose intolerance make no sense to me. I mean, why does the territory of the Masai people (in eastern Africa) indicate only mild lactose tolerance, when several groups of people in that region are herdsmen who have lived on cow's milk/cow's blood for millenia?

The areas of West Africa that show lactose tolerance do make some sense to me, as some of them are regions in which herders, as opposed to farmers or hunters, have been dominant for centuries.

As for India, I'm surprised that the whole sub-continent (to use its old name) isn't lactose-tolerant, because that nation has been obsessed with the cow and its products for longer than anyone knows. Few dishes in India are prepared without some portion of butter, milk or cream. For heaven's sake, we're talking about a place in which many people still pat cow-dung on to the walls of their houses. Why on earth are ANY Indians lactose-intolerant?

Alias Clio

David Davenport said...

Is there a hate issue with offering milk products?

Milk is problematic for people who keep kosher.

Sigmund F. said that adults who consume milk are "infantile."

Kibernetika said...

Err, just WEST of China ;)

Anonymous said...

I'm a contrarian on this. I think that lactose tolerance can be obtained by diet. Being American born and of 100% east Asian descent I had problems with dairy in college/grad school. I'm my 40's I figured that drinking slightly out of date milk would give me the digestive bacterial fauna that allows for lactose tolerance. It worked, I drink 2-3 glasses of milk a day and enjoy my wife's cooking. There are a few web sites out there on how to obtain lactose tolerance. BTW I have a quite a few friends of N. European descent who claim lactose intolerance in their middle age.

Anonymous said...

south indians are much more avid consumers of curd

nsam said...

India, the world's largest milk producer is something of a paradox. Apparently most Indians don't actually digest milk. However they can ingest other forms such as yogurt and cheese which are very popular. But clearly this must account for some of the malnutrition that's rampant in that country.

http://sciencelife.uchospitals.edu/2011/09/14/lactose-tolerance-in-the-indian-dairyland/

Anonymous said...

"Maya said...
What's up with that western tip of Africa? I just looked it up, and those people aren't of Bantu ancestry. The Bantus in Africa are something like 90% lactose intolerant."

Especially odd if it maps onto the same regions where people are R1b.

Anonymous said...

I was stationed in ROK (South Korea) for a while years back and noted a couple things regarding milk.

First, the government there provided free milk to schools, so almost all Koreans kids of that era (70's) drank milk.

Second, Koreans ate shaved ice with sweetened Azuki beans and bits of fruit during the summer as a very popular snack, rather like our ice cream. One of the major ingredients of this snack is condensed milk. I would go to a Korean bakery and see dozens of people eating it.

It seemed to me that if Koreans were supposedly lactose intolerant, they were pretty mildly intolerant.

Anonymous said...

BTW, lactose intolerance rate is surprisingly high in Scandinavia -- something about the Nordics not having enough cow hundreds of years ago when the land was a barren waste.