DOES CARBOHYDRATE-RICH, PROTEIN-POOR FOOD PREVENT A DETERIORATION OF MOOD AND COGNITIVE PERFORMANCE OF STRESS-PRONE SUBJECTS WHEN SUBJECTEDTO A STRESSFUL TASK

This study investigates whether in stress-prone subjects, carbohydrate -rich, protein-poor food (CR/PP) prevents a deterioration of mood and performance under uncontrollable laboratory stress conditions. The ass umption was that in stress-prone subjects there is a higher risk of se rotonin deficiency in the brain and that carbohydrates may prevent a f unctional shortage of central serotonin during acute stress, due to th eir potentiating effect on brain tryptophan. Twenty-four subjects with a high stress-proneness (HS) and 24 subjects with a low stress-pronen ess (LS) participated in an uncontrollable stress situation under both a CR/PP and a protein-rich, carbohydrate-poor (PR/CP) diet condition. The plasma ratio of tryptophan to the other large neutral amino acids (LNAA) (ratio Tryptophan/Sigma LNAA) was determined as a measure indi cating the dietary effect on brain tryptophan and serotonin levels. Si gnificant increases were found in the ratio tryptophan/Sigma LNAA duri ng the CR/PP diet compared with the PR/CP diet. Experimental stress ha d significant effects on pulse rate, skin conductance, cortisol and mo od in all subjects. During the CR/PP diet only the HS subjects did not show the stress-induced rise in depression, decline in vigour and cor tisol elevation that they showed after the PR/CP diet. With respect to cognitive performance, significant dietary effects were found on reac tion time. It is suggested that CRI PP food in HS subjects may increas e personal control, probably under the influence of higher levels of b rain tryptophan and serotonin. (C) 1998 Academic Press.