Are Pistachios The Most Underrated Bedtime Snack?

The review digs into the nutrients and plant compounds packed into pistachios and makes the case that this one snack checks an unusual number of sleep-supporting boxes at once. We're talking vitamin B6, magnesium, fiber, tryptophan, and even a plant form of melatonin itself. Here's what the science says about why pistachios deserve a sport in your night-time routine, and where the research still has gaps.

This makes sense when you break down the nutrients that support sleep. Your body builds melatonin from the amino acid tryptophan, by way of serotonin, and it needs magnesium and B vitamins to finish the job. Pistachios supply all of them.

One serving of pistachios provides close to 40% of your daily vitamin B6, the most of any tree nut. Your body uses B6 to turn tryptophan into serotonin, which then becomes melatonin. B6 also helps produce GABA, a calming brain chemical involved in sleep.

In the CARDIA study3, young adults with the highest total magnesium intake from food and supplements tended to report better sleep quality and were less likely to fall short of seven hours a night. One systematic review4 linked higher magnesium intake to better sleep quality and less daytime sleepiness. Lots of people take magnesium supplements to support sleep and recovery, but shifts in magnesium intake from whole foods like pistachios remains understudied, the authors note.

In a survey of over 11K Spanish university students5, higher tryptophan intake was associated with longer sleep and a lower risk of insomnia. In adults ages 55 to 75, a week of eating tryptophan-enriched cereal helped participants fall asleep faster6 and sleep longer than a standard cereal did. Plus, their melatonin output rose.

The estimates of how much phytomelatonin is in a serving of pistachios vary, but one analysis of American pistachios that researchers cited found about 18.7 micrograms per serving. That's similar the range of tart cherry and tomato, which are well-studied for improving sleep or melatonin levels. Other sources report lower levels of phytomelatonin, so more research is needed.

Pistachios also rank second among tree nuts in polyphenols, and roasting barely changes those levels. In a recent meta-analysis8 of people with sleep disorders, polyphenol supplements helped participants fall asleep faster and sleep longer, though most trials used extracts rather than whole foods.

No clinical trial has directly tested whether eating pistachios improves sleep, so more research is needed. It's also worth noting that this review was partially funded by American Pistachio Growers.

Human trials are needed to test the nut directly, but nobody knows your body like you do. If you notice a handle of pistachios before bed corresponds with longer, deeper sleep for you, then that's all the data you need to keep up this habit.