Go green to keep your blood pressure in check. A new study shows that having broccoli and cabbage can help reduce BP since they are high in glutamic acid.

Glutamic wonder

Glutamic acid is the most common amino acid and accounts for almost a quarter of vegetable protein and nearly a fifth of animal protein. Whole grain foods like rice, breads and cereals, soy products such as tofu and durum wheat, which is used to make pasta, are other common sources.

The study

The researchers analysed data from 4,680 people aged 40-59, from the UK, USA, Japan and China. Participants were involved in the study for around 3 weeks, between 10 and 13 years ago. During their first visit to the clinic, participants completed a thorough questionnaire and interview about their daily food intake, gave a urine sample and had their blood pressure taken. The participants returned to the clinic the next day for a second questionnaire, interview and blood pressure reading. This process was repeated 2-3 weeks later.

The scientists calculated the amount of 5 different amino acids in the participants' diets and correlated amino acid levels with blood pressure.

What they found

People with a higher proportion of glutamic acid in the protein they consumed (4.7%), had, on average, lower systolic blood pressure (by 1.5-3.0 mm Hg) and lower diastolic blood pressure (by 1.0-1.6 mm Hg).

Professor Paul Elliott, one of the authors of the study from the Department of Epidemiology and Public Health at Imperial College London, said, "A person with high blood pressure might have a reading of 140 mm Hg, so at first sight these differences don't look like much. However, from a population perspective this is important. High blood pressure is a risk factor for cardiovascular disease, so if we can reduce the population's blood pressure by just 1-2 mm Hg, we could reduce overall risk of heart disease."

"Many dietary factors can have small effects on blood pressure. In combination, these effects can become clinically relevant. We hope our research will help to develop optimal diets and advice to prevent and control high blood pressure, and reduce the burden of cardiovascular disease," added Professor Elliott.

No magic bullet though

"Glutamic acid may partly explain the link between vegetable protein and lower blood pressure," study author Dr Ian Brown, an epidemiologist at Imperial College, London, is reported to have said.

"However there is no 'magic bullet' for preventing high blood pressure, and vegetable protein and glutamic acid are individual elements of a broader healthy eating pattern," Brown added.

Pic: Robbie Owen-Wahl