Effects of food on cortisol and mood in vulnerable subjects under controllable and uncontrollable stress

The aim of this study was to investigate whether in stress-prone subjects, carbohydrate-rich, protein-poor food (CR/PP) diminished depressive mood and a cortisol response under controllable as well as uncontrollable laborator y stress. Twenty-two subjects with high stress proneness (HS) and 23 subjec ts with low stress proneness (LS) participated in a controllable- and uncon trollable-stress experiment during either a CR/PP or protein-rich, carbohyd rate-poor (PR/CP) diet. Both controllable and uncontrollable laboratory str ess significantly increased pulse rate and skin conductance in HS and LS su bjects, whereas uncontrollable stress increased feelings of depression, ang er, tension, and fatigue and decreased feelings of vigor. Only in HS subjec ts, a cortisol response and feelings of depression became lower under the C R/PP diet condition, irrespective of the controllability of the laboratory stressor, suggesting an increased ability to cope with stress. Because the CR/PP diet compared with the PR/CP diet previously has been found to cause a 42% increase in plasma tryptophan/Sigma LNAA, seen as an indirect measure of increases in brain serotonin levels, the present results suggest that a n enhanced serotonin function in HS subjects may be involved. (C) 2000 Else vier Science Inc. All rights reserved.