The “67 Craze” You Didn’t Expect: Why Milk’s 67th Amino Acid Is the Real Influencer

If you’ve been on the internet longer than five minutes, you’ve probably seen some kind of “67 craze.” Maybe it was a dance move, maybe it was a meme involving a confused cat, maybe it was a TikTok trend where people pretend to do their taxes while salsa dancing.

But today, I’m here to blow the lid off the real 67 craze—one that actually matters. One that’s inside your fridge. One that’s… inside your milk.

Meet the 67th Amino Acid: The Beyoncé of Casein

Milk contains a protein called beta-casein, which is basically the protein equivalent of a boy band. It comes in different versions—most famously, A1 and A2.

The difference?

A single amino acid at position 67.

One tiny molecular diva swap.

• In A1 milk, amino acid number 67 is histidine.

• In A2 milk, amino acid number 67 is proline, which has the audacity to hold everything together nicely.

That’s it. That’s the whole “67 craze.” But this tiny swap makes a big difference in how your body deals with milk.

Why the 67th Amino Acid Has Beef With Your Stomach

When A1 milk (the type most modern Holsteins produce) is digested, that histidine at position 67 can break in a way that releases BCM-7—a small peptide with a big reputation. BCM-7 has been associated with digestive discomfort in some people.

A2 milk, on the other hand, keeps it classy. Proline at position 67 holds on tight, making it harder for BCM-7 to break free like a lactose-intolerant Houdini. This means people who feel lousy on regular milk sometimes feel totally fine with A2 milk or non-BCM7 milk.

Basically, the 67th amino acid is either the friend who shows up with snacks…or the one who shows up with drama.

Goat Milk Enters the Chat

While cow milk is having its A1/A2 identity crisis, goat milk is standing in the corner sipping its herbal tea.

Goat milk naturally has a beta-casein profile that more closely resembles A2. Translation: its 67th amino acid is also the quiet, well-behaved proline. This is one of the reasons many people report fewer issues drinking goat milk—even if cow milk makes them feel like they swallowed a brick wrapped in regret.

The Completely Unofficial, Definitely Accurate “67 Milk Ranking”

From most likely to spark digestive drama → least:

1. A1 milk

2. Anything calling itself “normal milk”

3. A2 milk

4. Goat milk, wearing sunglasses, judging everyone else

Final Thoughts: Respect the 67

So while the world was out there obsessing over meaningless “67 challenges,” milk scientists were quietly discovering that one tiny amino acid at position 67 could make the difference between: “I love cereal!” and “Cereal has betrayed me and I’m never eating again.”

If you’re one of the many people who feel off after drinking milk, you might not be lactose-intolerant at all—you may just be caught up in the wrong 67 craze.

Try A2. Try goat milk. Your stomach—and the 67th amino acid—will thank you.

Our goal is to get our NonBCM7 Certified stamp on those dairy products which meet our standard to take the guesswork out of consumers trying to figure out what dairy to select for least digestive discomfort.

#67