Nitrates Lower Blood Pressure

(WebMD)  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 (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.

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SOURCE: Larsen, F. New England Journal of Medicine, Dec. 28, 2006; vol 355: pp 2792-2793.

By Jennifer Warren
Reviewed by Louise Chang

[alphaa10-2009]

Nitrates are not chemically identical with the nitrites used to preserve processed meat, and which are thought to become nitrosamines-- and cancer agents-- in the stomach. Yet, there may be a concern about exactly what form of nitrate supplementation is safe. For example, are nitrates safe in only plant-origin food? Has anyone researched this aspect?