Cows milk

 People started drinking cow’s milk surprisingly early — thousands of years after they first domesticated cattle. The shift happened when humans discovered they could digest lactose into adulthood, which wasn’t originally possible.

Short answer

• When: Around 7,000–9,000 years ago
• Where: First evidence in Europe, the Middle East, and parts of Africa
• Why: Reliable nutrition, especially during food shortages — and later, genetic adaptation made milk easier to digest.

Before milk drinking

Early humans could not digest lactose (milk sugar) after childhood. That’s still true for most mammals today. Drinking raw milk as an adult would cause symptoms of Lactose intolerance like bloating and diarrhea.

So at first, people did not drink fresh milk.

Instead, they:

• Turned milk into cheese
• Fermented it into yogurt
• Made butter

Fermentation reduces lactose, making dairy tolerable even without genetic adaptation.

The turning point: cattle domestication

After the Neolithic Revolution, humans domesticated animals like cows, sheep, and goats. This gave them a continuous food source — milk.

Advantages:

• Available daily
• High in fat, protein, calories
• Doesn’t require killing the animal
• Useful during crop failures

This created strong evolutionary pressure to tolerate milk.

The genetic mutation that changed everything

Some populations evolved lactase persistence — the ability to digest lactose as adults.

This spread quickly in:

• Northern Europe
• East Africa (pastoral groups)
• Some Middle Eastern populations

Today:

• ~90% of Northern Europeans digest milk easily
• Most East Asians and many South Asians remain lactose intolerant

Archaeological evidence

Scientists found:

• Milk fat residue in pottery (7,000+ years old)
• Dairy proteins in ancient human teeth
• DNA showing lactase mutation spreading after dairy use began

This means:
People started using milk first → then evolved to digest it better.

Why cow’s milk specifically?

Cows became dominant because they:

• Produce large volumes of milk
• Adapt well to farming
• Provide meat + traction + manure

So cow’s milk became the most common dairy in many regions.

Interesting twist

Many traditional cultures still don’t drink fresh milk, but consume:

• yogurt
• fermented milk
• ghee
• cheese

This avoids lactose problems.

If you’re curious, I can also explain:

•  why some people today suddenly become lactose intolerant
•  whether humans are “meant” to drink milk
•  why milk is more common in Europe than Asia