Brain tryptophan islow in fibromyalgia. Intake of protein rich in large neutral amino acids isreported to lower brain tryptophan. This study was undertaken to assess whether any reduction ofsuch proteins by exclusion of animal protein from the diet reduced pain and morbidity in fibromyalgia patients. It was an open, randomized controlled trial. 37subjects with fibromyalgia were enrolled in the vegetarian diet and 41 in the amitriptyline groups. The outcome…