A recent, well-controlled sleep study which attempted to identify an optimal suite of nutritional ingredients for sleep support found that a beverage containing a combination of five well-known ingredients did the trick.
 
In a study involving 55 male participants, researchers evaluated the most- and least- optimal dosages of tart cherry juice, high GI carbohydrates, a-lactalbumin (a whey protein), 5-AMP, and theanine. Following supplementation across a wide range of dosages, the researchers assessed blood tryptophan levels (tryptophan is thought to influence neurotransmitters involved in the sleep-wake cycle), and a test called 3CVT which measures reaction time and accuracy, both of which were considered predictive measures of sleepiness.
 
Following the researchers’ determination of optimal and least-optimal dosages for each ingredient, a group of 18 healthy male participants between the ages of 19 and 31 were recruited for a double-blind, placebo-controlled, crossover experiment, in which they attended a sleep laboratory and completed overnight polysomnography on four consecutive nights. During that time participants were administered either the optimized drink, a drink containing the least optimal levels of active ingredients, or a placebo.
 
The authors of the study used a Box-Behnken incomplete factorial design as a model to determine which combinations would be most effective, as, if they used a single factor methodology, the experiment would have required 729 different trials, with groups of 10 or more participants each.
 
Participants were instructed to consume each drink within five minutes, and then had electrodes applied to them to monitor their sleep, with a 9.5-hour sleep opportunity given to them from 10:30 pm to 8:00 a.m. Additionally, participants self-reported their subjective sleepiness level every 30 minutes prior to bedtime, and subjectively rated their sleepiness, sleep quality, sleep duration, sleep latency, and gastrointestinal symptoms shortly after waking up. An hour after waking up, participants were also administered a test battery to assess subjective alertness, self-perceived capacity, cognitive performance, and postural sway. Additionally, the researchers tested each participants’ postural sway, as balance achieved during this test is believed to be indicative of sleep quality.
 
Additional controls in the study included restrictions against alcohol and caffeine consumption, calorie-controlled meals, and prohibitions against sleeping outside of the window of opportunity at night.
 
Following the results of the study, including the preliminary research, the authors suggested that, of the five ingredients, total tryptophan appeared to be dependent only on the amount of valerian and a-lactalbumin within the drink. 3CVT scores, which are lowered by sleepiness, were reduced the most significantly dependent upon 5AMP, theanine, and a-lactalbumin, with 5AMP showing the most direct correlation. It appeared, however, that 3CVT scores were raised by valerian, indicating decreased sleepiness.
 
Across the wide range of dosages and combinations, the authors of the study concluded that their findings suggested the most optimal combination of ingredients for both tryptophan and 3CVT were 10 grams of high GI carbohydrates (carbs which break down quickly), 40 grams of a-lactalbumin, 655 mg of theanine, 53 mcg of 5AMP, and 600 mg of valerian – this combination was shown to increase tryptophan to 2.25 mcg/ml, and decrease 3CVT score by 0.104.
 
By contrast, the worst-performing combination of ingredients was 35 mL tart cherry, 45 g of high GI carbohydrate, 8 grams of a-lactalbumin, 1,000 mg of theanine, 4.5 mcg of 5AMP, and 500 mg of valerian. This combination is predicted to increase tryptophan 0.48 mcg/mL, and decrease the 3CVT score by 0.001.
 
Compared to both the placebo and the least optimal trials, sleep onset latency was significantly lower in the optimal trial. However, none of the other variables were different between trials, including the duration of time spent in sleep stages 1-3 or REM sleep.  
 
“Overall, there was a 49% reduction in sleep onset latency following the consumption of the optimal drink compared to a placebo drink,” the authors concluded. Interestingly, though, even in the least optimal manner, the ingredients still reduced sleep onset latency by 33%.
 
“Importantly, the observed changes in sleep onset latency occurred despite all participants being considered normal or good sleepers. Furthermore, there were no adverse effects on sleep architecture, and the optimal drink did not result in cognitive or balance impairments the following morning. Of note, the improvements in sleep onset latency with optimized intervention in the current study are similar to the improvements observed with pharmaceutical interventions […] in summary, an optimized combination of several nutritional ingredients, which had each demonstrated an influence on sleep independently, was determined.”