Many international studies have linked the A2 form of beta casein to lower rates of disease.
Results of these studies include the findings that:
- Populations that drink milk containing higher amounts of A2 beta casein have lower rates of heart disease
- Children in Scandinavia that drank milk with higher levels of A2 beta casein have lower rates of type 1 or childhood diabetes
These benefits are thought to be due to the bioactives that are released from the beta caseins on digestion. It is the digestion or break down products of beta casein which have been shown to have the effects on the body.
When beta caseins are digested they produce a range of protein fragments or ”peptides”, which have been identified as having biological activity or “bioactivity”.
It is thought that steps utilized in milk processing, such as pasteurization and homogenization is thought to affect the digestion of the caseins and release of bioactives.
The structural difference between A1 and A2 beta caseins results in each releasing its own unique set of bioactive peptides on digestion gut enzymes.
The release of bioactive peptides from beta caseins
Beta Casomorphins
Some of the bioactives from milk are opiates (morphine-like) and are known as the Beta Casomorphins (BCMs) due to their morphine like behavior, as they activate opioid receptors in the same way as morphine, important for the vascular and immune systems.
The one amino acid difference at position 67 of the beta casein protein chain affects how they are digested by gut enzymes, which cut the protein chain next to the Histidine amino acid but cannot cut the chain next to the Proline amino acid, resulting in the release of the highly bioactive peptide beta casomorphin 7 (BCM 7) from A1 beta casein, but not A2.
The unique pattern of bioactives released from A1 or A2 is believed to cause the important effects that have been noted between the two major beta caseins.
The beta casomorphins are made up of amino acids that run from position 60 to 70 of the beta casein protein chain which is a highly important part of the beta casein protein for the release of bioactives.
BCM7 is made up of the amino acids which run from position 60 to 66 of the beta casein protein chain. The release of BCM7 from A1 beta casein prevents the release of many peptides in this region that have important effects.