Over a quarter of adults in the UK are estimated to have high blood pressure - a condition often described as a silent killer as it may show no symptoms.
The condition, also known as hypertension, is when the pressure in your blood vessels is higher than normal. The condition usually develops slowly over time and while it cannot be cured, there are ways to manage it, including lifestyle changes and medication, if needed.
Ways to reduce blood pressure include having a healthy diet, cutting back on salt and alcohol, losing weight, exercising regularly and stopping smoking. But research has also identified a particular juice, costing around £1 per carton, that can help patients lower their blood pressure - pomegranate juice.
This fruit's fleshy seed casings contain a ruby-coloured juice that is unusually rich in antioxidant polyphenols, including a unique group of tannins called punicalagins, nutritionist Dr Sarah Brewer wrote on her website. The polyphenols lower blood pressure in several ways by:
- Dilating arteries through effects on nitric oxide)
- Improving the elasticity of artery walls so they perform better and balancing surges in blood pressure as your heart beats
- Blocking the action of angiotensin-converting enzyme (ACE), an enzyme targeted by many drugs prescribed to lower blood pressure
- Reducing platelet aggregation to improve blood flow
The juice also has other important properties as pomegranate is rich in vitamin C, vitamin E, vitamin K, folate, potassium, magnesium and antioxidant carotenoids. These also improve blood pressure control, cholesterol balance, or circulatory health.
Studies assessed the effects of pomegranate juice on blood pressure including a study which involved 10 people whose hypertension remained uncontrolled. After drinking 50ml of pomegranate juice twice a day, for two weeks, their blood levels containing angiotensin II, the converting enzyme (ACE) fell by an additional 36% in seven out of the 10 patients. And their blood pressure fell by an average of 7/1 millimetres of mercury)- a reduction of 5%.
In another piece of research, drinking 200ml of pomegranate juice daily for one year reduced blood pressure by 21%. But drinking more than 240ml did not lower it further. Other studies have shown a small reduction in blood pressure from the juice for four weeks in 51 healthy women without hypertension. And in 21 people with well-controlled hypertension drinking 150ml pomegranate juice a day for two weeks further lowered blood pressure compared with a placebo group who instead drank water.
The effects pomegranate juice can have on blood pressure have been analysed for years, with a study published in 2011 saying: "Pomegranate juice consumption may reduce systolic blood pressure, inhibits serum ACE activity, and is convincingly a heart-healthy fruit." Another study also found that, being a polyphenol-rich fruit juice with high antioxidant capacity, pomegranate juice also has "significant antiatherogenic, antioxidant, antihypertensive, and anti-inflammatory effects."
The abstract reads: "Pomegranate juice significantly reduced atherosclerotic lesion areas in immune-deficient mice and intima media thickness in cardiac patients on medications. It also decreased lipid peroxidation in patients with type 2 diabetes, and systolic blood pressure and serum angiotensin converting enzyme activity in hypertensive patients. Thus, the potential cardioprotective benefits of pomegranate juice deserve further clinical investigation, and evidence to date suggests it may be prudent to include this fruit juice in a heart-healthy diet."
The juice is widely available in supermarkets, health food stores, and online. People should check their sugar content if they want unsweetened juice. Pomegranate extracts can also be bought in capsule form.