Researchers say that a diet rich in vegetables rather than meat can help to reduce blood pressure, and the more plant protein consumed the better.
The team of researchers from Imperial College London say most adults either have high blood pressure or are heading in that direction.
High blood pressure is associated with an increased risk of heart disease and stroke.
Their study involved as many as 4,680 people aged 40-59, living in the United Kingdom, the United States, Japan and China, and they say though it is unclear why, the more vegetable protein the subjects said they consumed, the lower their blood pressure was.
The researchers say they suspect amino acids, the building blocks of protein, or vegetable components, such as magnesium, may be key.
They believe a better understanding of vegetarian proteins could lead to a way of preventing or treating heart and circulatory diseases.
Previous studies have shown that vegetarian diets are healthier for the heart than diets heavy in meat, and some types of amino acid have been shown to influence blood pressure, for instance arginine has been shown to dilate the blood vessels.
But study author Paul Elliott does say that after adjusting for height and weight, the study did not find that the more meat protein consumed in the diet, the higher the blood pressure, but meat eaters overall had higher blood pressure than vegetable-eaters.
Apparently they found no strong evidence that high meat consumption is linked to high blood pressure.
Professor Elliott, says more research is needed to pin down exactly why vegetables help lower blood pressure.
Other experts have also said that previous research has also shown that blood pressure was better controlled with a vegetarian diet.
The report is published in the journal Archives of Internal Medicine.