Learn about foods good for high blood pressure in the Mediterranean diet and what researchers have uncovered about which foods to eat to lower blood pressure.
We’ve all heard about how a Mediterranean diet is linked to good cardiovascular health and lower blood pressure. Until recently, researchers could only speculate on which foods within a Mediterranean diet were responsible for its blood pressure-lowering effects and how they worked, but the results of a new study may solve the mystery.
Olive Oil and Lettuce From the Mediterranean Diet
Researchers from King’s College London in the UK discovered that the combination of unsaturated fats and nitrate-rich vegetables is the key. In addition to olive oil, the typical Mediterranean diet comprises foods rich in unsaturated fats, such as fish, nuts, and avocados. When these fatty foods are eaten along with vegetables rich in nitrates, such as leafy greens and certain other vegetables like celery and red beetroot, the unsaturated fatty acids react with the nitrogen compounds in the vegetables to make what are known as nitro fatty acids. These nitro fatty acids then go on to block an enzyme called soluble epoxide hydrolase. Blocking this enzyme then inhibits a series of reactions that results in dilation of blood vessels and, consequently, lower blood pressure.[1]
The classic Mediterranean diet pairing of olive oil and green leafy vegetables like lettuce and spinach is particularly good at producing the enzyme-blocking fatty acids, the researchers found.
Study Details on the Mediterranean Diet
The authors, who published their findings in the journal Proceedings of the National Academy of Sciences, note that previous studies have already suggested that blocking soluble epoxide hydrolase lowers blood pressure. For their study, the researchers compared normal mice to mice engineered with a version of the enzyme that could not bind with nitro fatty acids. After inducing high blood pressure in the two groups of mice, the researchers then fed them a Mediterranean diet, which generated nitro fatty acid. Blood pressure went down in the normal mice but not in the genetically modified mice in which the nitro fatty acids could not bind to the soluble hydroxide hydrolase enzyme, showing that this is the mechanism by which the Mediterranean diet lowers blood pressure.
“The findings of our study help to explain why previous research has shown that a Mediterranean diet supplemented with extra-virgin olive oil or nuts can reduce the incidence of cardiovascular problems like stroke, heart failure and heart attacks,” said Philip Eaton, one of the study authors and professor of Cardiovascular Biochemistry at King’s College London.[2]
Vegetables High in Nitrates
Have you considered switching to a Mediterranean diet to help treat your hypertension? There are numerous books and online resources outlining various versions of Mediterranean diets and providing menu plans, recipes, nutritional information, and more. While none of them provide lists of fruits and vegetables high in nitrates, it’s important to make sure you include them in your diet plan if your goal is to lower blood pressure. The following table shows how different vegetables compare according to their nitrate content.[3]
Nitrate Content by Vegetable:
- Very low (<20): Artichoke, asparagus, eggplant, garlic, onion, green bean, mushroom, pea, pepper, potato, summer squash, sweet potato, tomato, watermelon
- Low (20 to <50): Broccoli, carrot, cauliflower, cucumber, pumpkin
- Middle (50 to <100): Cabbage, dill, turnip, savoy cabbage
- High (100 to <250): Celeriac, Chinese cabbage, endive, fennel, kohlrabi, leek, parsley
- Very high (>250): Celery, lettuce, rocket (arugula), spinach, red beetroot, watercress, chervil
Additional Foods to Eat to Lower Blood Pressure
Combine vegetables from the higher nitrate categories with olive oil, nuts, avocados, and fish to form your own favorite blood pressure-lowering combos. Make a salad with beets, celery, avocado, and olive oil-based dressing and voila! And don’t forget about additional specific foods to eat to lower blood pressure: pomegranate juice, berries, dark chocolate, hibiscus tea, and more. There’s no doubt about it, food is medicine. Use it to start treating your high blood pressure today.
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