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 The difference between lactose and milk protein

When someone says “I can’t tolerate milk,” the first thing we think of is lactose intolerance.

Lactose is a sugar found in milk.

To digest it, we need an enzyme called lactase, which is produced in the small intestine.

When this enzyme is missing, lactose is not digested, causing symptoms such as abdominal pain, gas, diarrhea, and bloating.

This is an intolerance, not an allergy, because the immune system is not involved.

But… did you know that milk can cause discomfort even in people who digest lactose well?

Beta-casein A1 vs. A2: the other side of intolerance

Milk not only contains sugar (lactose), but also proteins.  One of the most important is beta-casein, and here’s the key:

A1 can release a peptide called beta-casomorphin-7 (BCM-7) when digested.

A2 produces almost no of this peptide.

BCM-7 acts like an opioid in the gut and, in some people, can cause:
Intestinal inflammation
Increased mucosal permeability
Digestive discomfort similar to lactose intolerance

What does the science say?

People with digestive discomfort from drinking regular milk often feel better with only A2 milk.

Some studies suggest that BCM-7 may be associated with chronic inflammation and even metabolic risks (insulin resistance, high cholesterol).

Research is even being conducted to determine whether it could influence neurodevelopment, although the results are still controversial.

Where does each type of milk come from?  

Common cow’s milk (especially from Holstein and Friesian breeds) contains a mixture of A1 and A2 proteins.

Traditional breeds such as Jersey, Guernsey, and Zebu, and sheep, goat, and buffalo milk, contain almost only A2.

Nowadays, “A2 milk” is already being marketed, genetically selected to be easier to digest.

Practical Conclusion

If your discomfort is due to lactose, the solution is to choose lactose-free milk.

If your discomfort persists even with lactose-free milk, your problem may be in the A1 protein. In that case, trying A2 milk (or sheep, goat, or buffalo milk) can make a difference.

In the era of personalized nutrition, differentiating between lactose and A1/A2 beta-casein is key to knowing which type of milk is best for each person.

Raulayalamd
@mydoctoroncall.com