Pomegranates are rich in micronutrients with potential antioxidant and anti-inflammatory effects and are often compared favorably with red wine and green tea in terms of health benefits. But there’s little good evidence that the level of nutrients found in the fruit translates into true gains for human health, said Dr. Brent Bauer, director of the Mayo Clinic’s complementary and integrative medicine program, because few clinical trials have been done.
“There’s a suggestion pomegranate can do a lot of things,” Dr. Bauer said. “The trouble is there’s very limited data.”
Among the active ingredients in pomegranates are polyphenols such as ellagitannins, which inhibit the activation of inflammatory pathways, and anthocyanins, which give the fruit its deep red color and also have antioxidant activity. Diets high in these compounds have been linked to a reduced risk for chronic diseases, including heart disease and some cancers.
One 2008 study found that pomegranate juice had greater antioxidant activity and polyphenol content than red wine, Concord grape juice, blueberry juice, cranberry juice, acai juice, apple juice and orange juice. Another study found that pomegranate juice and seed extracts had two to three times the antioxidant capacity of either red wine or green tea.
Some small human trials have found that drinking pomegranate juice on a daily basis may aid cardiovascular health by improving vascular health, blood pressure and levels of “good” HDL cholesterol.
There is also research showing that pomegranate extract inhibits the growth of prostate, breast, colon and lung cancer cells in lab cultures, and may inhibit the growth of some tumors in animals. Human trials are now looking at whether pomegranate juice can help slow prostate cancer progression. A trial funded by the National Institutes of Health is currently recruiting men with localized prostate cancer who are being closely monitored but not actively treated for their disease, to assess whether pomegranate extract pills will slow progression of the disease.
Pomegranate may affect the metabolism of some medications, Dr. Bauer warned, so people who are on blood thinners or blood pressure drugs called ACE inhibitors may want to talk to their doctor if they’re eating a lot of the fruit.