Beta casein (β-casein) has gained considerable interest among scientists and farmers as it provides promising factors to milk that enhance its quality and concentration. It is believed that the A1 β-casein variant shares an association with numerous human diseases. Since there are numerous hypotheses concerning the link between variants of β-casein and human diseases, many researchers across the globe have genotyped the cattle in terms of A1, A2 β-casein variants. This paper catalogs the A1 and A2 β-casein genotypes shared by different cattle breeds across the globe. Various literature encompassing the adverse effects of β-casein variants were assessed adequately. This paper suggests that the effects of undertaking the A1 β-casein variant on human health are ambiguous. Adequate research providing stronger evidence is needed for understanding the effects imparted by the consumption of both A1 and A2 β-casein variants on human health.