Do Nitrates Lower Blood Pressure

A type of nutrient found in vegetables like spinach and lettuce may be Mother Nature's way of keeping blood pressure in check. A small new study suggests the nitrates in many vegetables may keep blood vessels healthy and lower blood pressure. Previous studies have shown that a diet rich in fruits and vegetables, such as the Dietary Approaches to Stop Hypertension Hypertension (DASH) diet, can reduce blood pressure. But it's been difficult to determine exactly which nutrients in fruits and vegetables are responsible for these blood-pressure-lowering effects, researchers in this study say.

Nitrates Lower Blood Pressure

In the study, published in the New England Journal of Medicine, scientists at the Swedish School of Sport and Health Sciences examined the effects of short-term nitrate supplementation in a group of 17 healthy, nonsmoking young adults. Each participant rotated between taking a daily dose of nitrate supplement equivalent to the amount normally found in 150 to 250 grams of a nitrate-rich vegetable -- such as spinach, lettuce, or beetroot -- for three days, and taking a placebo for a different three days.

The results showed that average diastolic blood pressure (the bottom number in a blood pressure measurement) was 3.7 mm Hg lower after three days of nitrate supplementation than it was after taking the placebo for three days. The researchers say these benefits are similar to those found among healthy participants in the DASH trials and suggest that nitrates' blood-pressure-lowering effects merit further study. The studies to date suggest that dietary nitrate acutely lowers blood pressure in healthy humans. An inverse relationship was seen between dose of nitrate consumed and corresponding systolic blood pressure reduction, with doses of nitrate as low as 3 mmol of nitrate reducing systolic blood pressure by 3 mmHg.

Frequently Ask Questions:

Single dose administration of dietary inorganic nitrate acutely reduces blood pressure in normotensive healthy volunteers, via bioconversion to the vasodilator nitric oxide.

Sodium nitrite infusion increases plasma levels of nitrite, nitrate, NO and cyclic guanosine monophosphate (cGMP) Sodium nitrite infusion lowers the peripheral and central blood pressure.

Essentially, nitrates dilate – that is, widen or relax – the arteries and the veins not only in the heart but also elsewhere in the body. By dilating the blood vessels of the heart, nitrates can reduce the stress on the heart by improving blood flow to the heart muscle.

Other medications that contain nitrates that you would not purchase in a pharmacy include: Nitropress (sodium nitroprusside): a strong medication given as an intravenous infusion. Nitropress immediately lowers blood pressure in a hypertensive crisis.

Eat a diet high in antioxidants. Vitamin C and certain other vitamins can reduce the conversion of nitrates and nitrites to nitrosamines.

Banana, broccoli, cabbage, cucumber, potato crisps, pumpkin, salami and strawberries also contain nitrates, but at lower concentrations of between 100 to 450mg/kg.

A majority of ingested nitrate is excreted in the urine within 24 hours.