The Claim

In neonatal dairy calves, consumption of milk containing A2 β-casein for 21 days results in plasma β-casomorphin-7 levels that are nearly five times lower than those observed after consumption of A1 milk, indicating that the A2 variant reduces enzymatic cleavage of β-casein into β-casomorphin-7.

Source: Comparative Effects of Milk Containing A1 versus A2 β-Casein on Health, Growth and β-Casomorphin-7 Level in Plasma of Neonatal Dairy Calves

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
19score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

How it works
1 study reviewed
In plain English

Neonatal dairy calves fed A2 milk for 21 days have plasma β-casomorphin-7 levels that are nearly five times lower than calves fed A1 milk, demonstrating that A2 β-casein produces less of this peptide during digestion.

See the scientific wording

In neonatal dairy calves, consumption of milk containing A2 β-casein for 21 days results in plasma β-casomorphin-7 levels nearly five times higher after consumption of A1 milk compared to A2 milk, suggesting that the A2 variant reduces enzymatic cleavage of β-casein into this opioid peptide, which may influence gastrointestinal and opioid signaling pathways in early development.

Why this might work

When a calf drinks milk with the A2 version of a milk protein, the protein doesn't break apart in the gut the same way as the A1 version. This means a specific opioid-like chemical doesn't form. Because the calf's gut is still developing, it normally lets large protein pieces into the blood, but since the A2 protein doesn't release this chemical, very little of it enters the bloodstream.

Verified mechanismbased on 1 study

What the research says

1 study

  1. Study: Comparative Effects of Milk Containing A1 versus A2 β-Casein on Health, Growth and β-Casomorphin-7 Level in Plasma of Neonatal Dairy Calves

    Calves that drank milk with the A2 protein had about one-fifth the amount of a certain opioid-like chemical in their blood compared to calves that drank milk with the A1 protein, meaning the A2 protein doesn’t break down as much into this compound during digestion.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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