BackgroundPsychosocial stress leads to altered neuroendocrine functions, such as serotonergic dysfunction, as well as alterations of the autonomic nervous system and the hypothalamic-pituitary-adrenal (HPA)-axis activity resulting in an imbalance between inhibitory and excitatory neurotransmitters. Poor dietary intake of L-tryptophan as a precursor of serotonin increases sensitivity to stress.MethodsThis randomized, double-blind, placebo-controlled study investigated the effect of a specific amino acid composition with micronutrients on neurovegetative disorders and the cardiometabolic risk profile in psychosocially stressed patients. 32 patients (18–65 years) were eligible for protocol analysis. Points in the Psychological Neurological Questionnaire (PNF), clinical and blood parameter, in particular the serotonin level, salivary cortisol levels, and dietary intake were evaluated at baseline and 12 weeks after supplementation.ResultsThe intervention in the form of either verum or placebo resulted in both groups in a significant decrease of neurovegetative symptoms. However, patients of the placebo group achieved significantly less points in the PNF compared to the verum group. But the rate of responders (≥10 points loss in PNF) was not significantly different between the groups. The macronutrient intake did not differ between verum and placebo group. On average, the HPA-axis was not disturbed in both groups. Blood serotonin indicated in both groups no significant correlation with dietary tryptophan intake or PNF.ConclusionsDaily supplementation of a specific amino acid composition with micronutrients in psychologically stressed patients resulted in no improvement of neurovegetative disorders as measured by the PNF when compared to the placebo group.Trial registrationClinical Trials.gov (NCT01425983)Electronic supplementary materialThe online version of this article (doi:10.1186/s12937-015-0030-3) contains supplementary material, which is available to authorized users.

Brain food, e.g. L-tryptophan, antioxidative substances, B vitamins and magnesium are thought to be beneficial for obesity, inflammation and insulin resistance. In the present pilot study we hypothesised that a specific amino acid mixture with micronutrients improves the cardiometabolic situation of chronically stressed persons. Cardiovascular and metabolic parameters were analysed as per protocol in 32 patients. Chronic stress disorders in the same patients were assessed by a psychological neurological questionnaire (PNF). After dietary intervention a reduction of the fasting serum insulin concentrations occurred in the treatment group. An association was found between PNF values, insulin concentrations at baseline and an insulin reduction after 12 weeks. The results support the use of our specific dietary supplement for improved stress management and a decrease in metabolic dysfunction.