The quest to find new food-based approaches to improve wellness continues, and the latest scientific research points to the potential power of walnuts to provide better sleep.
A new study published in the journal Food & Function reveals that eating a handful of walnuts (40 grams or about 1.5 ounces) a day may help improve overall sleep quality and reduce daytime sleepiness in healthy young adults. The research was funded by the California Walnut Commission and conducted by an interdisciplinary team at the University of Barcelona, in Spain.
The scientists looked into the potential impact that daily walnut intake could have on specified urine biomarkers, which in turn reveal changes in the levels of sleep-regulating hormone, melatonin, in the body.
Overall sleep quality improvement in a nutshell
As part of the study, the research team investigated the impact of the fruit on sleep quality parameters, such as daytime sleepiness, how long it takes for someone to fall asleep after lights out (sleep latency), how many times and for how long you wake up after effectively falling asleep (wake after sleep onset and awakenings), and the percentage of sleep time compared to total bed time (efficiency).
Researchers found that after four weeks eating walnuts, melatonin, significantly increased in participants’ evening urine samples compared to the control cohort. Walnut intake also shortened the time it took participants to fall asleep by 1.3 minutes, improved overall sleep quality scores, and reduced self-reported daytime sleepiness.
“With over one in three American adults not meeting the recommended amount of sleep per night, our results open the door to future research in other age groups and in people with sleep disorders,” said Maria Izquierdo-Pulido, professor at the Departament of Nutrition Sciences and Gastronomy at the University of Barcelona, and lead researcher of the study.
A natural sleep-inducing cocktail
The researchers explain that walnuts have a unique combination of sleep-supportive nutrients. Among them, are plant-based melatonin, tryptophan (a precursor to melatonin), magnesium, and an array of various types of vitamin B.
This study is among the first to demonstrate walnuts’ potential as a sleep-supporting food, and though findings are positive, more research is needed to fully understand the physiological dynamic linking walnuts to a good night sleep.