I received an email asking about a post I published a bit back about beet juice and hypertension. The reason that beet juice helps in lowering high blood pressure because they are high in dietary nitrate and increase the amount of nitric oxide in the body. Nitric oxide (NO) helps blood vessels relax, lowering blood pressure. Nitric oxide has anti-inflammatory activity and discourages blood clot formation.
The research that supported this stated that two cups (500 ml) of beet juice lowered blood pressure by approximately 10 points and the effect lasts up to 24 hours.
I hope that helps and good luck!