When there is so much fructose in our gut that most of it cannot be absorbed into the blood and we lose that sugar, we also lose the tryptophan attached to it. Tryptophan, for its part, is needed by the body to produce serotonin—a neurotransmitter that gained fame as the happiness hormone after it was discovered that a lack of it can cause depression. Thus, a long-unrecognized fructose intolerance can lead to depressive disorders.
High sugar intake connected to depression.
