pomegranate juice
Meaning of pomegranate juice: A tart red juice studied mostly for its plant polyphenols, with laboratory findings that human trials have not matched.
Definition of pomegranate juice
Pomegranate juice is the liquid pressed from the fruit of Punica granatum, a small tree grown across the Middle East, South Asia and the Mediterranean. It is rich in polyphenols, a family of plant compounds that includes the punicalagins and the red pigments that give the juice its color. Laboratory work has examined these compounds for effects on inflammation, blood vessels and tumor cells.
What is actually in it?
| Component | What it is |
|---|---|
| Punicalagins | Large tannin molecules, the main polyphenols of the juice |
| Anthocyanins | The red and purple pigments |
| Ellagic acid | A smaller phenol released as tannins break down in the gut |
| Sugars | Chiefly fructose and glucose, in amounts comparable to other fruit juices |
| Potassium | Present in quantities that matter in kidney disease |
What has research actually found?
In cells and in animals, pomegranate polyphenols mop up reactive oxygen species, which is why the juice is often described as an antioxidant. Laboratory studies have also reported slowed growth of tumor cell lines and reduced formation of new blood vessels, a process called angiogenesis that tumors depend on. Findings of that kind are a starting point rather than evidence of benefit. Human trials have been small, short and inconsistent, and none has established that drinking the juice treats or prevents cancer. Trials in prostate cancer looking at how quickly PSA rises have not shown a convincing effect. Work on blood pressure and cholesterol has been more promising but remains limited.
How does it differ from an extract?
Juice is a whole food. It carries the polyphenols along with sugar, acid and potassium, and its composition varies with the variety of fruit, ripeness and processing. A pomegranate liquid extract or a capsule concentrates the polyphenols and strips out most of the sugar, so the dose of active compounds is far higher and less predictable across brands. Because supplements are not regulated in the way medicines are, the amount stated on a label may not match the contents. The clinically relevant point is that concentration changes the exposure without changing what is known about the effect.
Does it interact with medicines?
Pomegranate juice has been suggested to slow the liver enzyme system that clears many drugs, in the way grapefruit juice does. Laboratory results point that way, but studies in people have been inconsistent and no interaction of the size seen with grapefruit has been confirmed. The clearer issues are simpler. The juice carries potassium, which matters in advanced kidney disease, and its sugar content is comparable to other fruit juices, which matters when carbohydrate intake is being counted.
Used in a sentence
The trial compared daily pomegranate juice with a matched placebo drink of similar color and taste.
Good to know
Laboratory and animal findings for pomegranate polyphenols have not translated into proven treatment benefit in people, and the juice also supplies sugar and potassium in amounts that are relevant in diabetes and kidney disease.
Word origin
Where “pomegranate juice” comes from
Pomegranate comes from the Latin pomum, meaning apple or fruit, and granatum, meaning seeded, after the many seeds packed inside the fruit.