Effects of Microencapsulated Sublingual Glycine (Bidicin) on Cognitive Performance in Healthy Men After an Acute Stressor

The aim of this study is to assess whether intake of Glycine (MSG) leads to an increase of cognitive performance after an acute stressor compared to placebo. One group will receive verum, one group placebo and one group will not receive any intervention. Cognitive testing will be performed in connection with the Trier Social Stress Test (TSST).

Stress can enhance or impair memory performances depending on the timing of the stressor and the timing of the memory processes in relation to the stressor. If stress occurs directly before or during the retrieval of information, the performance is impaired. Decreased performances using an acute stressor were also observed for other domains of cognitive functioning like working memory, interference control, cognitive flexibility and attention tasks.

Glycine, the simplest of the amino acids, is an essential component of important biological molecules, a key substance in many metabolic reactions, the major inhibitory neurotransmitter in the spinal cord and brain stem, and an anti-inflammatory, cytoprotective, and immune modulating substance. Studies have found positive effects of Glycine on episodic memory retrieval and in a word retrieval task.

To assess the effect of Glycine (MSG) on cognitive performance after an acute stressor, subjects perform baseline cognitive testing before intake of investigational products (Glycine (MSG), placebo or nothing) and participation in a stress test (Trier Social Stress Test - TSST). After the TSST stress-induced changes in cognitive performance are assessed. A second treatment intake takes place between the first and the remaining cognitive tests.

Eligibility Criteria:
Inclusion Criteria:

* subject signs the informed consent to participate in the study
* normally stressed subjects as verified by the TICS questionnaire with scores \>3 and \<37

Exclusion Criteria:

* smoker
* any known allergies to the test substances
* lactose intolerance
* any known addiction to drugs and/or alcohol
* hyper- or hypotension (except for those whose blood pressure is stable using medication for more than 3 months)
* known hyper- or hypothyroidism unless treated and under control (stable for more than 3 months)
* any known current/acute or chronic physical or psychological diseases besides minor medical conditions (e.g. seasonal allergies)
* intake of any medication which may affect the cognitive performance (e.g. psychotropics, sedating or stimulating medication)
* any color vision impairment (e.g. red-green deficiency)
* intake of dietary supplements or homoeopathic remedies during 2 weeks before V1 or during the study conduction
* consumption of alcohol during 2 days before V1 or during the study conduction
* excessive caffeine consumption (\>400 mg caffeine/day or \>= 4 cups of caffeinated coffee)
* on a strict diet or practicing sport, extensively
* attending an exam one week before and after the study participation
* subjects having previously participated in the TSST
* employee of the sponsor or Contract Research Organisation (CRO)
* Investigator doubts truthfulness of self-reported health information
* not suitable because of limited verbal and cognitive abilities