" Pistachios are not just the most melatonin-rich nut, they are off the charts as the most melatonin-rich food ever recorded.2957 To get a physiological dose of melatonin, all you have to eat is two. Two cups? Two handfuls? No, just two pistachios. Pistachio nuts were found to contain 0.2 mg of melatonin per gram.2958 It only takes 0.3 mg of melatonin to cause the normal daily spike our brains give us, so just two nuts would presumably do the trick.2959 "

― Michael Greger , How not to diet