Table 4.

Adult human interventional studies exploring the effects of polyphenols on sleep.

Author, Year (REF)	Study Type	Population	Sample n	Polyphenol Intervention	Intervention Period	Findings Reported on Polyphenol Effect on Sleep
Kuratsune et al., 2010 [233]	Double-blind, placebo-controlled, cross-over	Healthy men with mild sleep complaint	21	Crocetin, active carotenoid	Two intervention periods of 2 weeks each separated by a 2-week washout	Actigraphic data showed a reduction in the number of wakening episodes compared to placebo. Subjective data showed improvement in sleep quality
Wightman et al., 2015 [234]	Randomized, double-blind, placebo-controlled, parallel	Adults aged 18–30 years	60	Resveratrol	28 days	No effect on PSQI score or its seven factors
Park et al., 2017 [235]	Double-blind, placebo-controlled, cross-over	Healthy adults	9	Chlorogenic acids, most abundant polyphenol in coffee	5 days	Shortened SOL compared with the control with no effect on sleep architecture
Herrlinger et al., 2018 [231]	Double-blind, placebo-controlled, parallel	Older adults with age associated memory impairment	90	Spearmint extract containing 24% total polyphenols	90 days	Improved the ability to fall asleep, alertness, and behavior following wakefulness compared to controls
Um et al., 2018 [236]	Randomized, double-blind, placebo-controlled, parallel	Adults with subjective sleep disturbances	24	Phlorotannin	One week	Sleep duration increased compared to placebo, however no effects were shown on the total PSQI score
Romain et al., 2017 [237]	Randomized, double-blind, placebo-controlled, parallel	Overweight and obese adults	33	Holisfiit®, a polyphenol-rich extract-based food supplement developed from FV	16 weeks	Awakening during the night improved by 38%, total sleep duration by 50%, and sleep quality by 43% compared to baseline and subjective sleep complaints improved significantly compared to controls
Uddin et al., 2018 [238]	Randomized, double-blind, placebo-controlled, cross-over	Pre-hypertensive adults	12	Fruitflow® supplements, tomato extract	24-h period	Both systolic and diastolic blood pressure were lower after FruitFlow® consumption compared to placebo in the wake period whereas during the sleep period, the effect was only shown for systolic blood pressure only
Grassi et al., 2016 [239]	Randomized, double-blind, cross-over	Healthy adults	32	Flavanol-rich chocolate	Consumption of (high or poor flavanol chocolate bars) after one night of total sleep deprivation	High-flavanol chocolate bar reduced high systolic and diastolic blood pressure caused by sleep deprivation compared to low-flavanol chocolate bar consumption
Bigelman et al., 2011 [240]	Randomized, double-blind, placebo-controlled, cross-over	Healthy adults conducting military physical training	58	Quercetin	6 weeks	No effects on sleep quality

Legend: PSQI (Pittsburgh Sleep Quality Inventory), SOL (sleep onset latency), REF (reference), n (number).