DOES IT WORK?Pomegranate - and its juice - are a most useful source of antioxidants in a proper, varied diet
POMEGRANATE JUICE has received much attention in the past couple of years, although the fruit remains relatively unfamiliar in much of the west. The fruit grows on a small tree, Punica granatum, that is native to Iran, Afghanistan, the Himalayas and parts of the Mediterranean.
Grenadine was originally made from the fruit, giving it its blood-red colour, though other fruits and flavourings are now used.
The name pomegranate comes from the Latin term for seeded apple. The fruit looks like an apple with a crown where the flower once blossomed. When opened, hundreds of shiny ruby-shaped seeds spill forth in the midst of an intense red juice.
For this reason, pomegranates have long been seen as a symbol of human fertility. Currently, interest is focused on the potential benefits of pomegranate juice in preventing heart disease and cancer.
Evidence from studies
Pomegranate juice contains several compounds belonging to the class called polyphenols. These are important antioxidants. Oxidation is a chemical reaction by which the body breaks down food to release energy.
But if too much oxidation occurs, cells and tissues can be damaged. The body uses a variety of antioxidants to keep things in balance, including a range of antioxidants from the diet. People who don't eat enough fruits and vegetables often get insufficient dietary antioxidants.
A large amount of evidence has shown that people with lower amounts of antioxidants in their diets are at higher risk of heart disease and some cancers. This finding has been part of the reason why much emphasis is being placed on increasing the amount of fruit and vegetables that people eat.
Analyses of pomegranate juice have found that it has a higher antioxidant potency than any other commonly recommended antioxidant drinks. A study released earlier this year found that the order of potency was pomegranate juice, red wine, grape juice, blueberry juice and black cherry juice. Green tea, another commonly recommended antioxidant, was ninth on the list, with black tea tenth.
Different tests are used to calculate this potency, with some of them finding pomegranate juice more than twice as powerful as the second-ranked red wine.
Such findings have triggered a lot of research into whether the antioxidants lead to better health in those drinking pomegranate juice. A small number of studies have shown that people drinking pomegranate juice daily have reduced oxidative levels in their blood.
This is a good sign that their risk of developing some types of heart disease may be reduced. A very small study (with only 19 patients) found that after three months those drinking the juice daily had less narrowing of their arteries compared to those consuming a placebo drink. A few other studies have shown beneficial effects on blood pressure and cholesterol levels.
Interest has also developed into whether pomegranate juice might lower cancer risk, with some early positive findings with prostate cancer. Research is at the earliest stages, but such benefits would be in keeping with pomegranate's high level of antioxidants.
Problematic aspects
Studies have not revealed any problems with the juice, although very few people have been involved in studies so far. Allergies to the juice and seeds have been recorded. Concerns have also been expressed about anyone with liver problems consuming large quantities of the juice.
Some studies found benefits when people drank 50ml of juice daily, while others recommended drinking 240ml per day. Anyone being treated for any heart condition should talk to his or her doctor before starting to take pomegranate juice regularly.
Recommendations
The importance of having sufficient antioxidants in one's diet is well established. Pomegranate juice is an excellent source of antioxidants. Being new to the dietary supplement scene, little clinical research has been conducted on the juice. As part of a diet that includes a variety of plants and vegetables, pomegranate juice appears to be a healthy option.
• Dónal OMathúna has a PhD in pharmacy, researching herbal remedies, and an MA in bioethics, and is a senior lecturer in the School of Nursing, Dublin City University. He authored Alternative Medicine: The Christian Handbook, Updated and Expanded Edition, Zondervan, 2007.