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@ARTICLE{Hildebrand:190223,
author = {Hildebrand, P. and Königschulte, W. and Gaber, T. J. and
Bubenzer-Busch, S. and Helbold, K. and Biskup, C. S. and
Langen, Karl-Josef and Fink, Gereon Rudolf and Zepf, F. D.},
title = {{E}ffects of dietary tryptophan and phenylalanine-tyrosine
depletion on phasic alertness in healthy adults - {A} pilot
study},
journal = {Food $\&$ nutrition research},
volume = {59},
issn = {1654-661X},
address = {Häggeby [u.a.]},
publisher = {Co-Action Publishing},
reportid = {FZJ-2015-03147},
pages = {26407},
year = {2015},
abstract = {Background: The synthesis of the neurotransmitters
serotonin (5-HT) and dopamine (DA) in the brain can be
directly altered by dietary manipulation of their relevant
precursor amino acids (AA). There is evidence that altered
serotonergic and dopaminergic neurotransmission are both
associated with impaired attentional control. Specifically,
phasic alertness is one specific aspect of attention that
has been linked to changes in 5-HT and DA availability in
different neurocircuitries related to attentional processes.
The present study investigated the impact of short-term
reductions in central nervous system 5-HT and DA synthesis,
which was achieved by dietary depletion of the relevant
precursor AA, on phasic alertness in healthy adult
volunteers; body weight–adapted dietary tryptophan and
phenylalanine–tyrosine depletion (PTD) techniques were
used.Methods: The study employed a double-blind
between-subject design. Fifty healthy male and female
subjects were allocated to three groups in a randomized and
counterbalanced manner and received three different dietary
challenge conditions: acute tryptophan depletion (ATD, for
the depletion of 5-HT; N=16), PTD (for the depletion of DA;
N=17), and a balanced AA load (BAL; N=17), which served as a
control condition. Three hours after challenge intake
(ATD/PTD/BAL), phasic alertness was assessed using a
standardized test battery for attentional performance (TAP).
Blood samples for AA level analyses were obtained at
baseline and 360 min after the challenge intake.Results:
Overall, there were no significant differences in phasic
alertness for the different challenge conditions. Regarding
PTD administration, a positive correlation between the
reaction times and the DA-related depletion magnitude was
detected via the lower plasma tyrosine levels and the slow
reaction times of the first run of the task. In contrast,
higher tryptophan concentrations were associated with slower
reaction times in the fourth run of the task in the same
challenge group.Conclusion: The present study is the first
to demonstrate preliminary data that support an association
between decreased central nervous system DA synthesis, which
was achieved by dietary depletion strategies, and slower
reaction times in specific runs of a task designed to assess
phasic alertness in healthy adult volunteers; these findings
are consistent with previous evidence that links phasic
alertness with dopaminergic neurotransmission. A lack of
significant differences between the three groups could be
due to compensatory mechanisms and the limited sample size,
as well as the dietary challenge procedures administered to
healthy participants and the strict exclusion criteria used.
The potential underlying neurochemical processes related to
phasic alertness should be the subject of further
investigations.},
cin = {INM-3 / INM-4},
ddc = {610},
cid = {I:(DE-Juel1)INM-3-20090406 / I:(DE-Juel1)INM-4-20090406},
pnm = {572 - (Dys-)function and Plasticity (POF3-572)},
pid = {G:(DE-HGF)POF3-572},
typ = {PUB:(DE-HGF)16},
UT = {WOS:000354054800001},
doi = {10.3402/fnr.v59.26407},
url = {https://juser.fz-juelich.de/record/190223},
}