Previous studies had determined that diets rich in fruits and vegetables could reduce blood pressure. However, the researchers were not able to pin down which nutrients exactly were in charge in these blood-pressure-lowering effects.

Swedish scientists studied a group of 17 young adults to determine if there were any benefits from short-term nitrate supplementation.

The study participants were receiving dose of nitrate supplement equivalent to the amount normally found in 150 to 250 grams of a nitrate-rich vegetable (spinach, lettuce, or beetroot) for three days and then placebo for another three days.

After the study had ended, the results showed that the average diastolic blood pressure (the bottom number) was 3.7 mm Hg lower after three days of nitrate supplementation than it was after taking the placebo for three days.

Similar results have been found in other studies such as the Dietary Approaches to Stop Hypertension (DASH) diets, which granted further studies about natural lowering blood pressure.