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Fresno, CA – August 9, 2019 – An analysis conducted by researchers Dr. Jack Losso and Millicent Yeboah-Awudzi at Louisiana State University in partnership with American Pistachio Growers found that American pistachios contain significant amounts of melatonin, much higher than most fruits, vegetables, cereals, legumes and seeds.


Melatonin is a hormone produced by the pineal gland to regulate the body’s internal biological clock and control daily sleep cycles. Melatonin supplements are commonly used by people with insomnia or with irregular sleep patterns which may arise from frequent travel or irregular work schedules, among other causes.

The study was significant due to the fact it showed pistachios contain relatively high levels of melatonin compared to other foods and that researchers identified two protective bioactive compounds, lunasin and the Bowman-Birk Inhibitor, which have anti-inflammatory, anti-angiogenic activity that may help manage type 2 diabetes. Additionally, researchers proposed that these compounds together, with other protective compounds found in pistachios, such as lutein, zeaxanthin and polyphenols may support overall health.

“Pistachios are a highly nutritious snack containing not only melatonin, but a wide variety of vitamins and antioxidants that benefit an individual’s overall health and wellness,” said Losso.

Key Insights

In this study, melatonin was extracted from raw and roasted pistachios grown in the United States. The results were surprising, finding that pistachios contained about 660 nanograms melatonin per gram of pistachio, which was more than various other foods1.

According to Losso, pistachios contain certain phenolics which can reduce the breakdown of tryptophan to toxic compounds so that it is converted to melatonin. The increase in tryptophan has the potential to help with delayed sleep onset, sleep duration and quality. Additionally, Yeboah-Awudzi, recommends pistachios as a natural food option worth considering if anyone is looking to increase their melatonin intake.

Of note, the roasting of the pistachios had no effect on the melatonin.

1Meng, W. et al. Dietary Sources and Bioactivities of Melatonin. Nutrients, 2017.

The abstract for the study can be found here

Friday, August 9, 2019

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