Optimisation and validation of a nutritional intervention to enhance sleep quality and quantity

The intervention provided was a combination of nutritional ingredients designed to influence sleep. Three interventions were provided: 1. A optimised combination of nutritional ingredients intended to enhance sleep 2. A least optimised combination of nutritional ingredients intended to enhance sleep (i.e. have a reduced positive effect in comparison to 1). 3. Placebo The duration of each intervention was 1 night per intervention, performed on three consecutive nights. Including a familiarisation night at the beginning of the study (where no intervention was provided), the total duration was 4 nights in the sleep laboratory. Participants stayed for 4 nights and 4 days in the laboratory and consumption of the intervention was observed by a study supervisor. Participants were allowed outside twice per day for group, supervised light exercise. For the duration of the study and including the provision of the intervention, participants were housed in a purpose-built accommodation suite at Central Queensland University’s Appleton Institute. This ensured control over dietary intake and physical activity. The ingredients and their source were: 1. Tart Cherry Juice (Cherry Active Australia) 2. Glucose (PolyJoule, Australia) 3. alpha-lactalbumin (Davisco Foods, USA) 4. Adenosine-5-monophosphate (5-AMP)- (Sigma, USA) 5. Valerian (Martin Baeur Group, Germany) 6. Theanine (Sun Theanine, Japan) The combination and dosage of the above ingredients for the 3 trials were: 1) Most optimal combination: 10g glucose, 40g alpha-lactalbumin, 655mg theanine, 53 mg 5'AMP, and 600mg of valerian. 2) Least optimal combination: 35ml tart cherry, 45g glucose, 8g alpha-lactalbumin, 1000mg theanine, 4.5mg 5'AMP, and 500mg of valerian. 3) Placebo: artificially flavoured and coloured water These ingredients were mixed together by a qualified dietitian with over 10 years experience (independent to the study authors) and added to 250ml of water The intervention was provided in person to participants by a member of the study team. On each night, participants consumed the intervention at 21:00h and were instructed to consume it within 5 min.