crossover
    2018

    Neuro-Cognitive Effects of Acute Tyrosine Administration on Reactive and Proactive Response Inhibition in Healthy Older Adults

    Bloemendaal M, Froböse MI, Wegman J, Zandbelt BB, van de Rest O, Cools R, Aarts E

    Published in eNeuro

    Methodology

    Double-blind, counterbalanced, placebo-controlled within-subject fMRI study of acute tyrosine administration in healthy adults aged 61-72

    Key Findings

    Tyrosine did not alter reactive or proactive inhibition across the group, and with increasing age it worsened proactive response slowing and reduced fronto-striatal signal.

    Conclusions

    Acute tyrosine can have age-dependent detrimental neurocognitive effects, arguing against blanket dopamine-precursor loading in older adults.

    Limitations

    Very small sample, acute single-dose design, exploratory age-interaction analyses

    Supplements Studied

    L-Tyrosine
    Amino Acid

    Across the group, tyrosine did not alter reactive or proactive inhibition behaviorally but did increase fronto-parietal proactive inhibition-related activation.

    Outcomes Measured

    Tyrosine negatively affected proactive response slowing and associated fronto-striatal activation in an age-dependent manner.

    Study Details

    Year:2018
    Sample Size:24
    Quality Score:6/10

    Disclosures

    Funding

    Academic (Radboud University)

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