Study: Eating walnuts may help you fall asleep faster
Jakarta (ANTARA) – A new study has found that eating walnuts, which are rich in melatonin, may help people fall asleep faster.
According to a report published by Health on Thursday (22 October), researchers examined the relationship between walnuts and sleep by recruiting 76 adults aged 20 to 35 for an 18-week trial.
In the first phase of the 2025 study, which lasted eight weeks, participants were divided into two groups. One group ate 40 grams of walnuts with dinner every day, while the other did not.
Participants were instructed not to eat other kinds of nuts during this period. After a two-week break, the groups switched: those who had eaten walnuts stopped, and the other group began eating them.
Throughout the study, participants provided urine samples to measure melatonin production. For seven consecutive days in each phase, they also wore wrist trackers that monitored sleep patterns, activity levels, skin temperature and light exposure.
During the walnut-eating phase, participants experienced a significant increase in melatonin production at night, took less time to fall asleep and scored higher for overall sleep quality. They also reported less daytime sleepiness.
The study also found that walnut consumption helped improve sleep quality. Each serving of walnuts contained an average of 84.6 milligrams of tryptophan, 118 nanograms of melatonin and a tryptophan-to-competing-amino-acid (CAA) ratio of 0.058.
Behavioural sleep medicine psychologist Daniella Marchetti, PhD, DBSM, said each of these factors is important for better rest. Tryptophan is the “biochemical starting point” for the synthesis of serotonin and melatonin, both of which regulate sleep.
Melatonin is known as a hormone because its levels rise at night and signal that it is nighttime.
“Eating foods that contain melatonin can strengthen this signal and help the body prepare for sleep,” Marchetti said.
She added that the tryptophan-to-CAA ratio also plays an important role.
There are many good reasons to eat walnuts as a snack, including supporting heart and cognitive health.
“However, these findings are strong enough to suggest that walnuts are a food that can improve sleep quality, but they cannot currently be considered an adequate replacement for insomnia treatment,” Marchetti said.
For those who want to eat walnuts in the evening, Marchetti recommends 30 to 40 grams after dinner or as a bedtime snack.
This timing gives the body time to increase melatonin, which can take two to three hours after consumption.