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Comment by ravenscrow | Hacker News Reader

> So one special genetic characteristic of Proto-Indo-Europeans is their capacity to digest milk

A significant number of PIE were and a significant number of PIE descendants today are lactose intolerant. It is primarily northern europeans who consume milk and are the least lactose intolerant. Most PIE descendants consumes milk-products like cheese, yogurt, butter, etc.

Also, none PIE cultures ( mongols, turks, arabs, siberians, etc ) are primarily lactose intolerant but they consume milk-based products.

I think I read that processing milk into yogurt, cheese, butter, etc removes lactose or makes it easier for the lactose intolerant to consume. But don't quote me on that.

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> I think I read that processing milk into yogurt, cheese, butter, etc removes lactose or makes it easier for the lactose intolerant to consume. But don't quote me on that.

I've read that too I think it breaks down the lactose sugar molecule which is why lactose intolerant people can eat Greek yogurt (not just any yogurt) and cheese.

It's kind of odd we call people lactose intolerant when probably only 5% of the world is able to digest lactose. The majority of the world cannot digest lactose but that's normal not a disease.

I don't think 95% are lactose intolerant globally. Also, being lactose intolerant from birth is a disorder, and it's extremely rare.

The Wikipedia article on the subject mentions that the number of people who are lactose intolerant as adults is unknown, but goes on to say "One estimate puts the average at 65% of the global population.[8] Rates of lactose intolerance vary between regions, from less than 10% in Northern Europe to as high as 95% in parts of Asia and Africa.[3]"

It goes on to say that evidence suggests that lactase persistence has evolved multiple times independently, so it's not just a one time European mutation.

See: https://en.wikipedia.org/wiki/Lactose_intolerance

The lactose persistence gene variant found in Europeans is a one time mutation. It has evolved independently in Africa a few times too, but these variants are not found in ethnic Europeans.

Far less than 35% of the worlds population is lactose tolerant as an adult. I will take a look at the review linked on wiki and try to see how robust this number is.

Edit. Ok trekking back through the literature the estimate is based on old measures of the lactase persistence phenotype which is not very reliable, not on genetic data. It is likely to be wrong just on demographic growth alone in the last 40 years. My guess is around 15% of the worlds population is actually able to digest lactose in adulthood.

The phrase ‘lactose intolerant’ does not imply that it is a disease, it is just stating a fact. How else would you describe it?

I think he/she meant instead of giving the normal (the 95% of the population) a label, it would make more sense to give the special case (the 5% of the population) a label.

It's probably due to being able to digest lactose as a benefit it's not a problem so that throws off our perception of it.

If 5% of the world developed the ability to see UV light would be call the other 95% UV-intolerant.

For the record I am not lactose intolerant my northern European ancestors developed that ability (plus blue eyes, blond hair & red hair).

This is anecdotally true from my experience.

LI here, it's true, Greek yogurt is fine for me but regular 2% fat yogurt isn't. Most hard cheeses like Gouda and Irish Cheddar are fine for us too but others like Mozzarella aren't.

Indians (note the Indo- of PIE) also consume significant amounts of milk as well, so not just northern Europeans.

Generally not as fresh milk, but cultured. Fresh milk tends not to last very long in hot climates without refrigeration, while forms like yogurt last much better.

There are lots of dairy products in Indian food, so, yes there's plenty of cultured ones like yoghourt & paneer ("cheese"), but significant numbers of Indians drink fresh milk (actually fresh milk - as in milked that day). When the Indian cricketer M.S. Dhoni was younger and was just coming into the lime light, there was an interview with him where the interviewer asked him his 'secret' and he said it he was drinking a glass of milk every day (or two glasses or something).

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