Behavioral and cognitive effects of tyrosine intake in healthy human adults

Abstract

The amino acid tyrosine is the precursor to the catecholamine neurotransmitters dopamine and norepinephrine. Increasing tyrosine uptake may positively influence catecholamine-related psychological functioning. We conducted a systematic review to examine the effects of tyrosine on behavior and cognition. Fifteen studies were reviewed. All studies except one involved tyrosine loading during a single test session. In most behavioral studies, there were no significant effects of tyrosine on exercise performance. In contrast, cognitive studies employing neuropsychological measures found that tyrosine loading acutely counteracts decrements in working memory and information processing that are induced by demanding situational conditions such as extreme weather or cognitive load. The buffering effects of tyrosine on cognition may be explained by tyrosine's ability to neutralize depleted brain catecholamine levels. There is evidence that tyrosine may benefit healthy individuals exposed to demanding situational conditions. For future research we recommend moving from studying the acute effects of a single tyrosine load in small samples to studying the behavioral and cognitive effects of tyrosine in larger groups over multiple weeks.

Psychophysiology of sport, exercise, and performance: Past, present, and future.

“…Third, Hase, Gorrie-Stone and Freeman (2019) evaluate challenge and threat states as candidate mechanisms to explain the effects of a nutritional supplementtyrosineon performance. In accord with previous supplementation research (e.g., Hase, Jung & Rot, 2015), tyrosine ingestion benefited motor performance. While tyrosine did not directly influence cardiovascular reactivity, regression analyses revealed that more threat-like cardiovascular responses were associated with better performance during the tyrosine supplementation.…”

Influence of nutritional tyrosine on cognition and functional connectivity in healthy old humans

“…Recent research was able to show evidence for positive effects of dietary tyrosine intake on cognitive function in healthy humans (Kühn et al, 2017), which were similar to the ones observed after single high dose intake of tyrosine (Hase et al, 2015, Jongkees et al, 2015.…”

Blood‐based metabolic signatures in Alzheimer's disease

“…Moreover, vanylmandellic acid—an end-product of the tyrosine pathway—was found to be increased in the CSF of AD patients [37], suggesting disturbances of the tyrosine pathway. Dopamine has been associated with cognitive control [38], and oral supplementation of tyrosine has been shown to improve working memory and information processing during demanding situations in healthy human adults [39]. Experimental studies are needed to establish if the alterations in peripheral tyrosine metabolism we found in our study also affect the function of dopamine and tyrosine in the central nervous system of AD patients.…”