Provided are: a hypotensive composition； a use of a raw material as a substance for lowering blood pressure； and a method for lowering blood pressure. Also provided are: a blood-pressure-elevation suppressing composition； a use of a raw material as a substance for suppressing blood pressure elevation； and a method for suppressing blood pressure elevation. It has been discovered that a heat-treated product of a plant-derived peptide exhibits hypotensive action. Accordingly, the present invention provides a novel means for preventing or improving hypertension, and preventing or improving various diseases attributed to hypertension such as cerebral apoplexy, heart disease, and kidney failure.本發明為提供降血壓用組成物、使用於降血壓的原料之用途及降血壓方法。進一步亦提供血壓上升抑制用組成物、使用於抑制血壓上升的原料之用途及抑制血壓上升方法。本發明者們發現來自植物之肽的熱處理物具有降壓作用。因此，本發明亦提供使用於高血壓症之預防或改善，或腦中風、心臟疾病及腎衰竭等高血壓症所引起的種種疾病的預防或改善之新穎方法者。
