These are beneficial to lung & skin health. They are high in tryptophan this is a precursor to serotonin the feel good brain chemical & melatonin the sleep hormone. They are a good source of manganese needed for joint health & protein & fat metabolism. Haricot beans have the following benefits n ul style text align justify n These are beneficial to lung & skin health. n They are high in tryptophan this is a precursor to serotonin the feel good brain chemical & melatonin