Glutamic acid, an amino acid found in vegetable protein, may be linked to lower blood pressure, reports a new study in Circulation: Journal of the American Heart Association. Vegetable protein is most commonly found in whole grains (e.g., cereals, breads, rice), beans, and tofu. Glutamic acid makes up about a quarter of the total protein in vegetable protein, and about a fifth of the protein in animal products.

Researchers from Imperial College London and Northwestern University studied data from the International Study on Macro/Micronutrients and Blood Pressure (INTERMAP), which sought to determine connections between eating habits and blood pressure. The participants included 4,680 men and women (ages 40−59) from various regions in the U.S., U.K., China, and Japan.

The team found that a 4.72% increase in the consumption of vegetable protein was associated with lower systolic and diastolic blood pressures. Systolic pressure is the pressure when the heart contracts during a beat (the top number in a blood pressure reading), and diastolic is the blood pressure when the heart is relaxing between beats (the bottom number). The differences the research team found were not large – 1.5−3.0 mm Hg systolic and 1.0−1.6 mm Hg diastolic – but when it comes to the health of a whole population, these numbers are actually fairly impressive.

“It is estimated that reducing a population’s average systolic blood pressure by 2 mm Hg could cut stroke death rates by 6 percent and reduce mortality from coronary heart disease by 4 percent,” said lead author Jeremiah Stamler. He also underlines the fact that cardiovascular health represents a serious problem in this country: “We have a massive public health problem, and trying to address it by the strategy that has prevailed for years — diagnosis and drug treatment — is inadequate. While clinically useful, it fails as a long−term approach for ending this massive problem.”

Whether glutamic acid supplements would be effective in reducing blood pressure is still an unknown, but Stamler isn’t particularly interested in that question. He stresses instead that people should focus on “improved habitual food intake for the prevention and control of hypertension, not popping pills.” Stamler especially recommends the DASH eating plan, devised by the National Institutes of Health, for improved cardiovascular health, including lower blood pressure. The plan is high in vegetables, fruits, whole grains, nuts, beans, non− and low−fat dairy and lean poultry, and low in salt, red meat, and sugars.

“The DASH eating pattern resembles the Mediterranean eating style for the 21st century, including reduced salt intake,” said Stamler. “Multiple modifications supply multiple nutrients helpful for the prevention and control of high blood pressure, including glutamic acid.