Systematic Review of the Effect of Tyrosine Administration on Behavioral Alterations Caused by Psychological Stress in Human

Objective To integrate existing data and analyze the effect of dietary tyrosine supplement on deficits, emotional disorders and physical symptoms induced by psychological stressor in human. Methods Relevant research information was collected from various authentic databases such as China Journal Full-text Database, Chinese Biomedical Databases,Wanfang Digital Journals,VIP Full-text Database,China Medical Academic Conference and MEDLINE, EMBASE, SCIENCEDIRECT, SPRINGERLINK, PubMed databases by literature study, assess the quality of the studies and the data were integrated using methods of evidence-based medicine. Results Seven qualified clinical trials were adopted in this study, among which six were of high quality and one was of medium quality. The qualitative systematic review rather than the meta-analysis were conducted in this study as the clinical trials adopted were heterogenous in various aspects, findings from present clinical trials shown that Tyrosine supplement may relieve the abnormal physical symptoms and behaviors caused by various psychological stressors, in addition, there was interaction between Tyrosine supplement and psychological stressors. Conclusions The Tyrosine supplement on psychological stressor-induced cognitive and emotional defects is protective, and there is interaction between Tyrosine supplement and psychological stressors. More homogeneous researches are needed to elucidate this protective effect quantitatively, while further researches are expected to explore the potential mechanism.