Serotonergic and tryptaminergic overstimulation on refeeding implicated in "enlightenment" experiences.

The classic "enlightenment" experience is that of Siddhārtha Gautama (a.k.a. Buddha) who fasted and meditated intensely for years but failed to attain his goal of "enlightenment." He gave up his fast, ate rice pudding, and immediately meditated again, whereupon he attained "enlightenment." The hypothesis is that this altered state was a symptom of refeeding after prolonged starvation resulting from the combination of monoamine oxidase (MAO) inhibition followed by tryptophan and carbohydrate intake. Intense fasting inhibited Gautama's MAO activity; eating rice pudding constituted an intake of dietary tryptophan with carbohydrates. Carbohydrates trigger insulin release, which increases unbound tryptophan while reducing levels of competing amino acids at the blood-brain barrier. These effects allow significant amounts of tryptophan into the brain, where it converts into serotonin. Without MAO, serotonin does not degrade, and methyl-transferases convert excess tryptophan and serotonin into endogenous psychoactive tryptamines. The endogenous serotonin and tryptamines cause altered mental states. The absence of psychoactive substances and the prolonged fasting gives this experience its perceived spiritual power. Subjects may have no option but to assume that their experiences were due to either divine intervention or to values and techniques that took many years of hard work to acquire. If validated, this mechanism implicates a specific effect of refeeding syndrome as the trigger for these altered states, and offers an approach to study this phenomenon in untrained subjects from within a scientific framework.