Beta-casomorphin-7 (BCM-7) which is an opioid peptide during digestion of A1 milk, has been claimed as a possible cause of some health problems. There are some studies about the role of β-casomorphin-7 in some diseases such as type 1 diabetes, cardiovascular diseases, autism, schizophrenia, sudden infant death syndrome, apnea, constipation. For example, β-casomorphin-7 destroys pancreatic β cells, leading to the emergence of type 1 diabetes. It effects T and B cells related to immunity and negatively effects the autoimmune system. The aim of this study is to reveal the diseases that can caused by β casomorphin-7 in terms of both animal and human health, in this way to contribute to the reduction of the costs of animal and human health and to create an awareness.