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Cited by 296Tryptophan and brain disordersStress Responses and CortisolProtein Hydrolysis and Bioactive Peptides

The DOI matches its Crossref record; 62 of the 64 references it cites were found in a registry or an index.

The bovine protein α-lactalbumin increases the plasma ratio of tryptophan to the other large neutral amino acids, and in vulnerable subjects raises brain serotonin activity, reduces cortisol concentration, and improves mood under stress

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Markus, C Rob, Olivier, Berend, Panhuysen, Geert EM, Van der Gugten, Jan, Alles, Martine S, Tuiten, Adriaan, Westenberg, Herman GM, Fekkes, Durk, Koppeschaar, Hans F, de Haan, Edward EHF·2000·The American Journal of Clinical Nutrition
DOI 10.1093/ajcn/71.6.1536
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Abstract

Background Increased brain serotonin may improve the ability to cope with stress, whereas a decline in serotonin activity is involved in depressive mood. The uptake of the serotonin precursor, tryptophan, into the brain is dependent on nutrients that influence the cerebral availability of tryptophan via a change in the ratio of plasma tryptophan to the sum of the other large neutral amino acids (Trp-LNAA ratio). Therefore, a diet-induced increase in tryptophan availability may increase brain serotonin synthesis and improve coping and mood, particularly in stress-vulnerable subjects.Objective We tested whether alpha-lactalbumin, a whey protein with a high tryptophan content, may increase the plasma Trp-LNAA ratio and reduce depressive mood and cortisol concentrations in stress-vulnerable subjects under acute stress.Design Twenty-nine highly stress-vulnerable subjects and 29 relatively stress-invulnerable subjects participated in a double-blind, placebo-controlled study. Subjects were exposed to experimental stress after the intake of a diet enriched with either alpha-lactalbumin or sodium-caseinate. Diet-induced changes in the plasma Trp-LNAA ratio and prolactin were measured. Changes in mood, pulse rate, skin conductance, and cortisol concentrations were assessed before and after the stressor.Results The plasma Trp-LNAA ratio was 48% higher after the alpha-lactalbumin diet than after the casein diet (P = 0.0001). In stress-vulnerable subjects this was accompanied by higher prolactin concentrations (P = 0.001), a decrease in cortisol (P = 0.036), and reduced depressive feelings (P = 0.007) under stress.Conclusions Consumption of a dietary protein enriched in tryptophan increased the plasma Trp-LNAA ratio and, in stress-vulnerable subjects, improved coping ability, probably through alterations in brain serotonin.

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Crossref · 10.1093/ajcn/71.6.1536

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Metadata

Authors
Markus, C. R., Olivier, B., Panhuysen, G. E., Van der Gugten, J., Alles, M. S., Tuiten, A., Westenberg, H. G., Fekkes, D., Koppeschaar, H. F., & de Haan, E. E.
Affiliations
  • Utrecht University (NL)
  • Netherlands Organisation for Applied Scientific Research (NL)
Corresponding author
Markus, C Rob
ORCID
Olivier, Berend
Venue
The American Journal of Clinical Nutrition
Publisher
Elsevier BV
Published
2000-06
Volume
71
Issue
6
Pages
1536-1544
ISSN
0002-9165 (ISSN-L)
DOI
10.1093/ajcn/71.6.1536
OpenAlex
W1963138513
Semantic Scholar
75d65911966009bb4a453b746af6df1362e7f8b7
Cited by
296
References
64
Citations by year
2026: 9 · 2025: 7 · 2024: 14 · 2023: 8 · 2022: 8 · 2021: 14 · 2020: 14 · 2019: 14 · 2018: 14 · 2017: 12 · 2016: 9 · 2015: 16 · 2014: 11 · 2013: 20 · 2012: 14
FWCI
2.75
Type
journal article
Language
en
Open access
Licence
Locations
  • American Journal of Clinical Nutrition (publishedVersion)
  • PubMed (publishedVersion)
  • Research Publications (Maastricht University) (publishedVersion, other-oa)
  • EUR Research Repository (Erasmus University Rotterdam) (publishedVersion, other-oa)
  • Radboud Repository (Radboud University) (submittedVersion)
  • Research Publications (Maastricht University) (submittedVersion, other-oa)
Topics
  • Life Sciences › Neuroscience › Biological Psychiatry › Tryptophan and brain disorders
  • Life Sciences › Neuroscience › Behavioral Neuroscience › Stress Responses and Cortisol
  • Life Sciences › Agricultural and Biological Sciences › Food Science › Protein Hydrolysis and Bioactive Peptides
Keywords
alpha-lactalbumin, brain serotonin, acute stress, stress vulnerability, depressive mood, cortisol, prolactin, whey protein, casein, dietary protein, coping
MeSH terms
Adolescent, Adult, Affect, Amino Acids, Animals, Caseins, Cattle, Double-Blind Method, Electric Conductivity, Female, Humans, Hydrocortisone, Lactalbumin, Male, Placebos, Prolactin, Pulse, Serotonin, Skin Physiological Phenomena, Stress, Physiological, Tryptophan, Multivariate Analysis

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