Walnuts Linked to Improved Sleep Quality in New Study

A recent study conducted by researchers at the University of Barcelona suggests that daily walnut consumption can significantly improve sleep quality and reduce daytime fatigue in healthy young adults. The findings, published in the journal Food & Function, indicate that incorporating walnuts into the diet may be a straightforward, food-based strategy for enhancing sleep.

The eight-week study involved 76 healthy young adults, aged 20-28, who participated in a crossover design, alternating between consuming 40 grams of walnuts daily with dinner and a control period. Researchers monitored urine biomarkers associated with melatonin, a hormone crucial for regulating sleep-wake cycles, and various sleep quality parameters. These included how quickly participants fell asleep, the frequency of nighttime awakenings, and overall sleep efficiency.

Results showed that walnut consumption led to a measurable increase in melatonin levels, evidenced by elevated biomarkers in evening urine samples after just four weeks. This increase correlated with a reduction in the time it took participants to fall asleep, averaging 1.3 minutes. Participants also reported enhanced overall sleep quality and a noticeable decrease in self-reported daytime sleepiness.

Walnuts are rich in nutrients that support sleep, including tryptophan (a precursor to melatonin), plant-based melatonin, magnesium, and B vitamins. The study's lead researcher, Dr. Maria Izquierdo-Pulido, highlighted that this is the first randomized controlled trial to demonstrate such objective improvements in sleep quality and melatonin levels through daily walnut intake, positioning walnuts as a promising natural aid for sleep health.