New Research Review Highlights Potential Sleep Benefits of Pistachios

Pistachios may have potential for supporting healthy sleep, but researchers say direct evidence is still needed to determine whether eating them actually improves sleep.

A narrative review published in Nutrition Research Reviews examined how nutrients and plant compounds in pistachios may influence sleep-related processes, including melatonin production, brain signalling and communication between the gut and brain.

Pistachios contain tryptophan, vitamin B6 and magnesium, nutrients involved in pathways that contribute to serotonin and melatonin production. Melatonin is a hormone that helps regulate the sleep–wake cycle. Pistachios also contain phytomelatonin, a plant form of melatonin, although its absorption and effects after eating pistachios have not been established in humans.

Vitamin B6 and magnesium are also involved in the production and function of gamma-aminobutyric acid (GABA), a neurotransmitter that reduces nerve activity and plays a role in sleep regulation.

Another potential pathway involves the gut microbiome. Pistachios provide fibre and polyphenols that gut microorganisms can ferment and transform into compounds that may influence communication between the gut and brain. Laboratory studies simulating digestion and fermentation suggest that gut microbes can process pistachio components and contribute to a prolonged release of phytomelatonin.

A one-ounce serving of pistachios provides about 71 milligrams of tryptophan. However, the presence of sleep-related nutrients does not establish that consuming pistachios improves sleep.

The review highlights the importance of studying the whole pistachio rather than individual nutrients or supplements. Researchers say the combination of nutrients and bioactive compounds within the food matrix may produce effects that differ from isolated components.

The authors call for randomised controlled trials to assess pistachio intake, dose, melatonin levels, sleep duration and sleep quality. Until such studies are available, pistachios should be considered a promising research area rather than a proven treatment for sleep problems.

REFERENCE: Mixon, A., et al. (2026). Exploring the role of pistachio nutrients and bioactive components in sleep health: a narrative review. Nutrition Research Reviews. DOI: 10.1017/S0954422426100511.