1.1 Background information Berries from the Vaccinium genus have been reported to improve some measures of cognitive function in healthy adults (Travica et al., 2020). There is evidence that the polyphenols contained in berries and other plant foods may play a role in this regard (Lamport et al., 2020). Among the plant sources of polyphenols, lemon balm (Scholey et al., 2014; Kennedy et al. 2002; Kennedy et al, 2004) and tart cherry (Chai et al., 2019) have been reported to have positive effects on cognitive function in randomized controlled trials (RCTs).~L-theanine is an amino acid present almost exclusively in the tea plant (Camellia sinesis). L-theanine crosses the blood-brain barrier and has been shown to increase serotonin and dopamine production in rats (Yokogoshi et al, 1998). A recent systematic review of RCTs that evaluated the effect of supplemental L-theanine on stress concluded that L-theanine may assist in the reduction of stress (Williams et al., 2020).~Given that plant bioactives may have varying mechanisms to support cognitive health, the aim of this study is as follows:~Aim 1: To determine the effect short-term dosing (7 days) of a placebo beverage, cranberry juice, cranberry juice + lemon balm extract, cranberry juice + tart cherry powder, or cranberry juice + L-theanine or L-theanine beverage on cognitive function and mood in healthy adults (18-45 years). The study will include measures of attention, alertness, performance, and mood/stress.~1.2 Investigational product~Beverage to be tested:~100% cranberry juice (8 oz, Ocean Spray)~100% cranberry juice (8 oz) + lemon balm extract (300 mg)~100% cranberry juice (8 oz) + tart cherry powder (3 g)~100% cranberry juice (8 oz) + L-theanine (200 mg)~L-theanine (200 mg) + placebo (matched for color, taste, calories)~placebo (matched for color, taste, calories) 1.3 Rationale for conducting the clinical trial There is scientific support for Vaccinium berries to be of benefit to cognitive health. However, this has not be specifically tested in cranberries (Vaccinium macrocarpon). Furthermore, the individual effects of the other ingredients to be tested in this trial have been found to have positive effects on cognitive health but whether there are added effects with cranberry is not known.~2 OBJECTIVES 2.1 Primary objective To evaluate in healthy adults the effect of 7-day consumption of cranberry beverages compared to placebo on attention.~2.2 Primary endpoint variable~Change in Accuracy of Attention composite scores outcomes from Baseline to each treatment phase (V3-8), assessed using the COMPASS cognitive assessment tool.~Change in Speed of Attention composite scores outcomes from Baseline to each treatment phase (V3-8), assessed using the COMPASS cognitive assessment tool.~2.3 Secondary objectives To evaluate in healthy adults the effect of 7-day consumption of cranberry beverages compared to placebo on measures of focus, alertness, and cognition.~To evaluate in healthy adults the effect of 7-day consumption of cranberry beverages compared to placebo on mood and stress.~2.4 Secondary endpoint variables~Focus: Change in Overall % accuracy scores outcomes from Baseline to each treatment phase (V3-8), assessed using the STROOP task in the COMPASS cognitive assessment tool.~Alertness: Change in Alertness scores outcomes from Baseline to each treatment phase (V3-8), assessed using the self-rated Alertness VAS scale in the COMPASS cognitive assessment tool.~Cognitive Performance:~Change in Accuracy of Performance composite scores outcomes from Baseline to each treatment phase (V3-8), assessed using the COMPASS cognitive assessment tool.~Change in Speed of Performance composite scores outcomes from Baseline to each treatment phase (V3-8), assessed using the COMPASS cognitive assessment tool.~Mood: Change in Total Mood Disturbance scores from Baseline to each subsequent visit (V3-8), assessed using the Profile of Mood States-Short Questionnaire.~Stress: Change in salivary cortisol from Baseline to each treatment phase (V3-8).~2.5 Exploratory objectives Dependent upon the outcome of the Primary and Secondary objectives, additional outcomes from the COMPASS cognitive assessment tool may be analyzed further to assess the impact of the investigational product on various domains of cognition.
This study aims to determine the effect short-term dosing (7 days) of a placebo beverage, cranberry juice, cranberry juice + lemon balm extract, cranberry juice + tart cherry powder, or cranberry juice + L-theanine or L-theanine beverage on cognitive function and mood in healthy adults (18-45 years). The study will include measures of attention, alertness, performance, and mood/stress.