for National Geographic News
March 22, 2005
In the mythology of ancient Babylonia, pomegranate was considered an agent of resurrection. Now there is scientific evidence for the fruit's restorative powers.
According to a new study, antioxidants contained in pomegranate juice may help reduce the formation of fatty deposits on artery walls. Antioxidants are compounds that limit cell damage.
Scientists have tested the juice in mice and found that it combats hardening of the arteries (atherogenesis) and related diseases, such as heart attacks and strokes.
"In this experimental study, we have established that polyphenols [antioxidant chemicals] and other natural compounds contained in the pomegranate juice may retard atherogenesis," said Claudio Napoli, a professor of medicine and clinical pathology at the University of Naples, Italy.
The research is published this week in the Proceedings of the National Academy of Sciences.
Pomegranate (Punica granatum) is native to a region ranging from Iran to the Himalaya. It later spread to the Mediterranean area and now grows in most of the United States.
The apple-size fruit, which grows on rounded plants 15 to 20 feet (4.6 to 6 meters) tall, contains a sack of seeds and a juicy pulp.
In ancient Greece pomegranate was known as the fruit of the dead. In Hebrew tradition pomegranates adorned the vestments of the high priest. Ancient Persians believed that pomegranate seeds made their warriors invincible. In China the fruit symbolized longevity.
Scientists have long known about health benefits of pomegranates. The latest study, in particular, shows that the juice limits the genetic tendency toward hardening of the arteries.
"The protective effects of pomegranate juice were higher than previously assumed," Napoli said.
The study was done at the University of Naples, Italy, and the University of California, Los Angeles.
Pomegranate Juice Fights Heart Disease, Study Says
The researchers used mice to test the health effects of pomegranate juice. The fruit juice is rich in natural polyphenols, including tannins and anthocyanins, which have protective effects on the arterial wall.
"Although it is difficult to extrapolate human indications from experimental data, it is conceivable that 500 milliliters [1 pint] of pomegranate juice may exert some beneficial effects in patients with early stages of atherosclerotic diseases," Napoli said.
The antioxidant level in pomegranate juice was found to be higher than that in other natural juices, such as blueberry, cranberry, and orange juices, as well as red wine.
Scientists have found that polyphenols from red wine can reduce LDL ("bad" cholesterol). Black tea consumption also reverses endothelial dysfunction (damage to the linings of the arteries) in patients with chronic heart disease.
Similarly, the polyphenols contained in purple grape juice have also been found to have beneficial effects on patients with coronary heart disease.
Napoli points out that not every antioxidant study has confirmed that the chemicals can help prevent heart attacks. "Certain large clinical trials employing different antioxidants have failed to show any beneficial effects in the prevention of major cardiovascular events," He said.
He said the models employed in experimental studies may not precisely reflect the disease in humans.
"We need to study the effects of these substances in patients with early stages of atherosclerotic diseases," Napoli said. "Aged patients with advanced stages of atherosclerosis are not the best candidates to this therapeutic approach."