Cognitive Impairment, Healthy, Stress, Psychological
Conditions
Keywords
Verbal Learning and Memory Test (VLMT), Stroop Test, Attention, Working Memory, Learning and recognition, CogTrack
Brief summary
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).
Detailed description
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.
Interventions
DIETARY_SUPPLEMENTMicroencapsulated Sublingual Glycine (MSG)
Glycine (MSG) tablet
DIETARY_SUPPLEMENTPlacebo
Lactose tablet manufactured to mimic Glycine (MSG) tablet
Sponsors
OOO MNPK BIOTIKI
Daacro
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)
Masking description
Partly double-blind (Glycine (MSG), Placebo, control without treatment)
Eligibility
Sex/Gender
MALE
Age
18 Years to 40 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Delayed memory performance after the TSST (correct words) | 20 minutes after second product intake | Efficacy of the intake of Glycine (MSG) on performance in the Verbal Learning and Memory Test (VLMT) delayed recall task (number of correct words) compared to placebo and control group |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| VAS sleepiness | 20 minutes, 37 minutes and 46 minutes after first product intake | Efficacy of the intake of Glycine (MSG) on subjective evaluation of acute sleepiness compared to placebo and control group measured on a Visual Analogue Scale (VAS). The VAS is a 10cm bipolar visual scale ranging from not at all to highly. VAS scores are obtained by using a ruler and measuring the position of the participant's mark with millimeter precision. To control for possible variations due to printing, the total length of the line is also measured and percentage scores for each subject are computed. Percentage scores range from 0-100. |
| Delayed memory performance after the TSST (perseverations, wrong words) | 20 minutes after second product intake | Efficacy of the intake of Glycine (MSG) on performance in the Verbal Learning and Memory Test (VLMT) delayed recall task (decreased number of perseverations and wrong words) compared to placebo and control group |
| Cognitive performance before and after the TSST (Stroop) | 10 minutes before first product intake and 23 minutes after second product intake | Efficacy of the intake of Glycine (MSG) on performance in the Stroop test (speed and accuracy) compared to placebo and control group |
| Cognitive performance before and after the TSST (CogTrack) | 40 minutes before first product intake, immediately after second product intake | Efficacy of the intake of Glycine (MSG) on performance in attention, working memory, learning and recognition tasks of CogTrack compared to placebo and control group |
| Heart rate | Continous measurement starting 10 minutes after first product intake and ending 10 minutes after second product intake | Efficacy of the intake of Glycine (MSG) on heart rate in response to the TSST compared to placebo and control group |
| Salivary Cortisol | 45, 10 minutes before first product intake, 28, 46, 55 minutes after first product intake, 10, 20, 35 and 50 minutes after second product intake | Efficacy of the intake of Glycine (MSG) on salivary cortisol raw values in response to the TSST compared to placebo and control group |
| Delayed memory performance before and during the TSST | 15 minutes before and 42 minutes after first product intake | Efficacy of the intake of Glycine (MSG) on performance in the Verbal Learning and Memory Test (VLMT) delayed recall task (number of correct words, number of perseverations and wrong words) compared to placebo and control group |
| Immediate memory performance before and after the TSST | 44 minutes before, 13 and 48 minutes after first product intake | Efficacy of the intake of Glycine (MSG) on Performance in the Verbal Learning and Memory Test (VLMT) immediate recall task (number of correct words, decreased number of perseverations and wrong words) compared to placebo and control group |
| VAS stress | 20 minutes, 37 minutes and 46 minutes after first product intake | Efficacy of the intake of Glycine (MSG) on subjective evaluation of acute stress compared to placebo and control group measured on a Visual Analogue Scale (VAS). The VAS is a 10cm bipolar visual scale ranging from not at all to highly. VAS scores are obtained by using a ruler and measuring the position of the participant's mark with millimeter precision. To control for possible variations due to printing, the total length of the line is also measured and percentage scores for each subject are computed. Percentage scores range from 0-100. |
| VAS anxiety | 20 minutes, 37 minutes and 46 minutes after first product intake | Efficacy of the intake of Glycine (MSG) on subjective evaluation of acute anxiety compared to placebo and control group measured on a Visual Analogue Scale (VAS). The VAS is a 10cm bipolar visual scale ranging from not at all to highly. VAS scores are obtained by using a ruler and measuring the position of the participant's mark with millimeter precision. To control for possible variations due to printing, the total length of the line is also measured and percentage scores for each subject are computed. Percentage scores range from 0-100. |
| VAS insecurity | 20 minutes, 37 minutes and 46 minutes after first product intake | Efficacy of the intake of Glycine (MSG) on subjective evaluation of acute insecurity compared to placebo and control group measured on a Visual Analogue Scale (VAS). The VAS is a 10cm bipolar visual scale ranging from not at all to highly. VAS scores are obtained by using a ruler and measuring the position of the participant's mark with millimeter precision. To control for possible variations due to printing, the total length of the line is also measured and percentage scores for each subject are computed. Percentage scores range from 0-100. |
| VAS tension | 20 minutes, 37 minutes and 46 minutes after first product intake | Efficacy of the intake of Glycine (MSG) on subjective evaluation of acute tension compared to placebo and control group measured on a Visual Analogue Scale (VAS). The VAS is a 10cm bipolar visual scale ranging from not at all to highly. VAS scores are obtained by using a ruler and measuring the position of the participant's mark with millimeter precision. To control for possible variations due to printing, the total length of the line is also measured and percentage scores for each subject are computed. Percentage scores range from 0-100. |
| VAS lack of energy | 20 minutes, 37 minutes and 46 minutes after first product intake | Efficacy of the intake of Glycine (MSG) on subjective evaluation of acute lack of energy compared to placebo and control group measured on a Visual Analogue Scale (VAS). The VAS is a 10cm bipolar visual scale ranging from not at all to highly. VAS scores are obtained by using a ruler and measuring the position of the participant's mark with millimeter precision. To control for possible variations due to printing, the total length of the line is also measured and percentage scores for each subject are computed. Percentage scores range from 0-100. |
| STAI-state | 20 minutes and 46 minutes after first product intake | Efficacy of the intake of Glycine (MSG) on state anxiety as measured by the State Trait Anxiety Inventory (STAI) compared to placebo and control group. The STAI-state measures anxiety as a temporary emotional state and comprises 20 items. Answers are given on a four-point rating scale ranging from 1 = not at all to 4 = very true. Some STAI questions relate to the absence of anxiety, and are reversely scored. For analysis of the STAI-scale, items are combined in one scale, which then informs about state anxiety. The score range is 20-80; higher scores indicate more anxiety. |
| Systolic and diastolic blood pressure | 25 minutes and 46 minutes after first product intake | Efficacy of the intake of Glycine (MSG) on blood pressure in response to the TSST compared to placebo and control group |
Other
| Measure | Time frame | Description |
|---|---|---|
| Mental arithmetic performance during the TSST | 37.5 minutes after first product intake | Efficacy of the intake of Glycine (MSG) on arithmetic performance compared to placebo and control group. One part of the Trier Social Stress Test (TSST) is a mental arithmetic task. The subject is asked to stepwise subtract 17 from 2023 as quickly and correctly as possible. Performance will be measured by counting how many numbers the subject enumerates and how many times the subject has to restart. Furthermore, the lowest correct number and the shortest run will be recorded. |
| eCB levels | 45, 10 minutes before first product intake, 28, 46, 55 minutes after first product intake, 10, 20, 35 and 50 minutes after second product intake | Exploration of endocannabinoid levels (eCB) |
| Blood Glucose levels | 75 minutes before first product intake, 25 and 46 minutes after first product intake | Exploration of blood glucose levels |
| STAI-trait | Baseline | Do State Trait Anxiety Inventory (STAI) trait scores differ between groups? The STAI-trait measures anxiety as a personality trait and comprises 20 items. Answers are given on a four-point rating scale ranging from 1 = almost never to 4 = almost always. Some STAI questions relate to the absence of anxiety, and are reversely scored. For analysis of the STAI-scale, items are combined in one scale, which then informs about trait anxiety. The score range is 20-80; higher scores indicate more anxiety. |
| TICS | Baseline | Do Trier Inventory for Chronic Stress (TICS) scores differ between groups? The TICS includes 57 items. Stress chronicity is measured by the frequency of stressful events perceived retrospectively within the last 3 months. Answers are given on a five-point rating scale, where 0 resembles never and 4 very often. For analysis the questionnaire items are assigned to 10 scales: Work overload (range 0-32), Social overload (0-24), Pressure to succeed (0-36), Work dissatisfaction (0-32), excessive demands at work (0-24), Lack of social recognition (0-16), Social stress (0-24), Social isolation (0-24) and Chronic worrying (0-16); the last scale presents a Screening scale for chronic stress (0-48). Scores are obtained by summing up the values of the scale specific questionnaire items. |
Countries
Germany
Outcome results
None listed