Caloric restriction lowers blood pressure in the spontaneously hypertensive rat.

In the spontaneously hypertensive rat (SHR), caloric restriction without sodium restriction is associated with reduced blood pressure. Four days of fasting lowered blood pressure 19% while 4 days of eating 50% of ad lib intake reduced blood pressure 10%. Similar dietary changes had less effect on blood pressure in normotensive rats of the same strain (Wistar-Kyoto--WKY). These data are consistent with the hypothesis that caloric restriction lowers sympathetic activity.