A cup of beetroot juice a day can help lower blood pressure in patients with hypertension, according to a new study.
The study was conducted by researchers from Queen Mary, University of London and was published in the American Heart Association journal Hypertension.
The scientists examined the impact consuming nitrate has on blood pressure in rats and then confirmed their findings in a small study involving 15 patients with high blood pressure.
Vegetables rich in nitrates include:
Amrita Ahluwalia, Ph.D., lead author of the study and a professor of vascular pharmacology at The Barts and The London Medical School in London, reported to Medical Xpress:
"Our hope is that increasing one's intake of vegetables with a high dietary nitrate content, such as green leafy vegetables or beetroot, might be a lifestyle approach that one could easily employ to improve cardiovascular health."
The participants (eight females and seven males) all had a systolic blood pressure between 140 to 159 millimeters of mercury (mm Hg), did not have other medical problems, and were not on any medication for their hypertension.
The subjects drank 250 mL of beetroot juice or water consisting of a low amount of nitrate, and over the following 24 hours, had their blood pressure observed.
About 0.2g of dietary nitrate was contained in the beetroot juice. A large bowl of lettuce or two beetroots contain about the same amount of nitrate, according to the scientists.
The participants who consumed this level of nitrate experienced a positive outcome on their blood pressure for 24 hours - an average ten-point decrease in their blood pressure levels.
"We were surprised by how little nitrate was needed to see such a large effect. This study shows that compared to individuals with healthy blood pressure much less nitrate is needed to produce the kinds of decreases in blood pressure that might provide clinical benefits in people who need to lower their blood pressure. However, we are still uncertain as to whether this effect is maintained in the long term," Ahluwalia said.
About 16 million people in the UK have high blood pressure, according to the UK Blood Pressure Association, however, many individuals remain undiagnosed. Hypertension can result in a significantly increased likelihood of experiencing a heart attack or stroke.
People can lower their blood pressure by altering their lifestyle, such as consuming less salt or losing weight. A previous study in Cochrane Library indicated that consuming cocoa powder and dark chocolate may slightly reduce blood pressure. A different study in the American Journal of Clinical Nutrition showed that high doses of vitamin C may lower blood pressure.
Professor Peter Weissberg, Medical Director at the BHF, which funded the research, concluded:
"This promising study shows that it may be possible to reduce high blood pressure by eating more foods that contain large quantities of nitrates, such as green vegetables and beetroot.
It supports current advice that we should all be eating plenty of green veg. But we need larger studies in patients to determine if nitrate-rich vegetables are effective at lowering blood pressure over the long term."