https://matteocampagna.com/en/registry/health/tryptophan-score Changes to this claim in Matteo Campagna's evidence registry: its status, its year-by-year history, revisions of the page. en-gb https://matteocampagna.com/en/registry/health/tryptophan-scoreThere is a single study, from Iran, of 45 provincial-level recurve archers. Tryptophan was estimated from a seven-day weighed food record, and the score is the official one from a qualification round of 36 arrows at 70 metres. The link is there, and it is strong for a study of this size: the correlation is 0.53, it holds at 0.49 once training hours are taken into account, and those above 400 milligrams a day shot an average of 318 points out of 360, against 278 for those below 250. The archers who took in more also reported less cognitive anxiety an hour before competing and more self-confidence, and anxiety accounts for part of the link with score. It is, however, an association measured once: people who eat more meat, dairy and pulses may differ in many other ways, and the study cannot say that adding tryptophan raises scores. One of the reported values, moreover, does not square with the means in its own table, and the study appears in a journal with questionable editorial standards: the registry reports it but does not use it to decide the status, which remains not studied.claim:triptofano-punteggio:revision:2026-10-02:2Fri, 02 Oct 2026 08:00:00 GMT https://matteocampagna.com/en/registry/health/tryptophan-scoreclaim:triptofano-punteggio:new_claim:2026-09-02:non_studiatoWed, 02 Sep 2026 08:00:00 GMT