Lettuce (except iceberg)
One of the major traditional uses of lettuce is as a sleep inducer. Research into the extracts of lettuce resulted in the isolation of a depressant element. This element, when administered in an experiment, showed significant sedative effects. Decreased heart rate and ventricular contractions were also observed. This particular element acts by blocking the excitatory signal processes of muscular and neural tissues, helping to induce sleep.
