Exogenous opioid peptides derived from food proteins and their possible uses as dietary supplements: A critical review

Endogenous opioid peptides are neuro-hormones and neurotransmitters involved in several physiological actions such as stress reactions, nociception control, sedation, breathing tone, depression, hypotension, appetite, digestion, etc. It is now clear that hydrolysis by the digestion of certain food-proteins can lead to the production of bioactive peptides. Commonly diffused foods like milk, wheat, meat, and spinach may produce after enzymatic digestion a variable amount of opioid peptides. The aim of this review is to provide arising perspectives on opioid peptides, focusing on their production from milk, their potential benefits, drawbacks, and safety issues related to infants' feeding.