Several studies have suggested that PEA is an important modulator of mood and that a deficit may contribute to the pathogenesis of depression. Both PEA and its metabolite, phenylacetic acid, have been shown to be reduced in the biological tissues and fluids of depressed subjects, and replacement with PEA and/or its amino acid precursor, l-phenylalanine, appears to ameliorate some types of depression.
PEA is found in substantial concentrations in chocolate (0.4 to 6.6 μ/g), and some experts have contended that craving for chocolate may be an attempt to self-regulate brain PEA level and mood. However, several other foods, such as some cheeses and sausage, contain substantially greater quantities of PEA and tyramine, yet they are not sought after as chocolate is. In addition, because PEA is rapidly metabolized within the body (half-life=5 to 10 minutes), consumption of PEA does not ensure entry into systemic circulation. In fact, studies have shown that ingestion of 200 g milk chocolate containing 1 g PEA has no noticeable effect on urinary concentrations of PEA or its metabolites.