Why are so many people of asain descent lactose intolerant?
Most people are lactose intolerant. The major populations with adult lactase production are in the British Isles, and northern Europe. Pretty much everywhere else the rate is well over 50%, but 75% isn’t unusual. Eastern Asia has rates over 90%, likely influenced by historically low dairy consumption.
Lactose intolerance is the default for adult mammals. Certain people groups developed adult lactose tolerance in situations where milk was a convenient source of nutrition, but most people who didn’t descend from equestrian nomads or bovine ranchers just never had the need or opportunity to retain lactase production into adulthood.
Take lacoste pill before you consume and dairy . After a while of taking of them you can stop taking the pill and will not gave a reaction
Most mammals actually become lactose intolerant after they stop weening. You need an enzyme called lactase to digest dairy and most mammals stop producing that as they get older. Amongst humans, 65% of adults are lactose intolerant, so the real question is why can some people digest lactose after they’ve grown up?
We’re not really sure. I’ve seen speculation that thousands of years ago, there was a famine that forced people to drink milk for sustenance. The people who had an ability to digest milk had an advantage, so natural selection favored them during the famine. And it probably wasn’t one famine. Lactose tolerance seems to have evolved around 4 times independently in different populations.