1. Moderate whisky consumption in combination with an evening meal reduces tryptophan availability to the brain but does not influence performance in healthy volunteers.
- Author
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Markus CR, Sierksma A, Verbeek C, van Rooijen JJ, Patel HJ, Brand AN, and Hendriks HF
- Subjects
- Affect physiology, Aged, Amino Acids blood, Analysis of Variance, Biological Availability, Blood Glucose analysis, Choice Behavior physiology, Ethanol blood, Humans, Insulin blood, Male, Middle Aged, Reaction Time, Serotonin metabolism, Tryptophan blood, Alcohol Drinking adverse effects, Brain metabolism, Cognition physiology, Eating physiology, Tryptophan pharmacokinetics
- Abstract
Brain serotonin (5-HT) synthesis is controlled by nutrients that influence the availability of plasma tryptophan (Trp) as compared with the sum of the other large neutral amino acids (LNAA; Trp:LNAA). Alcohol consumption is found to change mood and performance and this might well be due to alterations in the plasma Trp:LNAA ratio and brain 5-HT. In the present study, we tested whether whisky consumption as part of a meal may alter the plasma Trp:LNAA ratio and influence mood and performance in healthy volunteers. Twenty-four healthy male subjects participated in a within-subjects cross-over study. Subjects consumed whisky (125 ml; 40 g alcohol) or water (125 ml) as part of a standard evening meal. Effects of whisky consumption were tested on mood and choice reaction time and blood samples were taken to measure changes in plasma amino acids, glucose and insulin. The plasma Trp:LNAA ratio showed a significant decline 2 h after whisky consumption of alcohol (P<0.001). No effects were found on choice reaction time or mood as compared with the control condition. The present findings reveal that whisky consumption alters available plasma Trp for uptake into the brain, whereas there were no effects on mood and performance.
- Published
- 2004
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