A1 and A2 beta casein: Twin faces of milk

Abstract

Proteins in bovine milk are common source of bioactive peptides. Components in milk show various constructive actions but some of the studies found that metabolites of it show severe threat to human health. The BCM-7 peptide which is released by gastrointestinal proteolytic digestion of bovine beta-casein variants A1 and B but not from A2 posses a deleterious effect on health. Epidemiological evidences proposes that consumption of beta-casein A1 is associated with higher mortality rates from Ischemic heart disease, cardiovascular diseases and type 1 diabetes and even neurological disorders, such as autism and schizophrenia. Therefore this review aims at enlighting the differences between the consumption of milk containing A1 and A2 type beta casein and its effects on human health.