Why can some people digest dairy and others can't

Why are some people lactose intolerant and some are fine with it?

Why can some people drink litres of milk, while for others a sip of milk can trigger a rush to the toilet?

The vast majority of people who are unable to digest dairy have trouble with Lactose: the main sugar molecule in dairy (particularly milk).

The researchers at Examine have gone over the extensive research on dairy:

- All human babies throughout human history are born with the ability to digest lactose.

- 75% of these babies normally lose that ability to digest Lactose soon after breastfeeding stops: their bodies stop producing the Lactase Enzyme needed.

- However, there are large parts of modern human populations (such as Northern Europeans) who can still comfortably digest Lactose their entire lives.

This is because people's bodies and genetic expression adapt to the environment they develop in: they continue to produce Lactase.

In the case of Northern Europeans, a combination of long periods of cold and availability of dairy from large cow populations meant that these people used dairy as a main source of nutrition for thousands of years.

As such, their bodies maintained the ability to produce Lactase enzymes into adulthood.

This happened through a genetic mutation that took place around 10,000 years ago (we know this because of examining the DNA of ancestors from that region).

By contrast, people in the Mediterranean for example didn't have this genetic mutation: their bodies didn't need it since food has always been abundant.

Typically though, cheeses (especially hard cheeses) contain almost no Lactose. So most people should be able to digest them just fine (within reason).

Greek Yoghurt contains much less Lactose than milk. That's because the fermentation process of making Yoghurt digests some of the Lactose.

Goat milk contains a lot less Lactose than cow milk. Sheep milk sits somewhere in between the two.

And just like our Northern European friends developed the ability to digest cow dairy because of its availability for thousands of years, we (Mediterraneans) developed the ability to do the same with sheep and goat dairy.

What if you take Lactase Enzymes (as a supplement) and STILL cannot digest cow dairy?

Another important aspect is protein: typical cow dairy contains a protein called A1. A lot of people have trouble digesting A1 protein. This is why people (such as myself) cannot drink Lactose free cow milk, and why taking Lactase enzymes doesn't help me digest cow dairy.

Sheep milk contains a different protein called A2, which is much easier to digest.

I (for example) don't have much trouble digesting sheep or goat dairy.

So:

- If you're having trouble, avoid dairy for a while and see if it helps.

- If you really crave dairy, try Lactase enzymes and see if it helps (if it does, you're Lactose intolerant).

- If that doesn't help, try sheep or goat.