Pomegranates are tested for weight loss, diabetes, COPD, prostate cancer, osteoarthritis, and arthritis.
The case of POM Wonderful (a pomegranate juice company) vs. The Federal Trade Commission made it all the way to the US Court of Appeals before being denied review by the Supreme Court. In that landmark case, a panel of judges concluded that many of POM’s ads contained false or misleading claims and that the company “admired medical research that clearly shows that daily use of its products can treat, prevent, or reduce the risk of various diseases, including heart disease, prostate cancer and erectile dysfunction.” The US First Amendment does not protect misleading and deceptive advertisements. Impressing its billionaire owners, the Court ruled that at least one randomized clinical trial would be required to verify treatment or disease prevention claims.
If you look at the medical literature on pomegranate in general, you will see reviews that show its many benefits, and diagrams like the one below on the therapeutic effects of pomegranates (which you can also see at 1:01 in my video. Pomegranate: A Natural Treatment for Rheumatoid Arthritis).
But if you dig a little deeper, you see this is based on a study like the one that talks about the “antiobesity effects of pomegranate leaf extract in a mouse model.” First of all, who eats pomegranate leaves? And secondly, who is the mouse?
Does the use of pomegranate affect weight in people? If you look at all randomized controlled clinical trials (meaning human trials), pomegranates have no significant effect on body weight, BMI, abdominal fat, or body fat percentage in those randomized to consume pomegranate products. What about the prevention and treatment of cardiovascular disease? Researchers reviewed 25 clinical trials, looking at cholesterol, blood pressure, artery function, the formation of atherosclerotic plaques, and platelet function, and did not find significant indications of benefit even in the best studies.
POM Wonderful helped fund research on pomegranate juice and erectile dysfunction, but failed again. Other studies found no benefit in markers of diabetes and no benefit in chronic obstructive pulmonary disease, such as emphysema. They used the antioxidant of pomegranate juice to help, but that antioxidant activity is in vitro (meaning in a test tube or petri dish). To my surprise, a meta-analysis of data from 11 randomized controlled trials “did not support conclusive evidence” of pomegranate consumption having a significant effect on increasing the total amount of antioxidants in the blood because some of the most powerful antioxidants do not even appear to enter the human body. Not surprisingly, pomegranate supplementation did not appear to affect oxidative stress in tissue samples taken from prostate cancer patients. However, what we care about is whether it affects the cancer itself.
The strongest evidence for pomegranates’ anti-cancer activity is said to come from prostate cancer studies. Unfortunately, the promising early results were not confirmed during testing. For example, daily intake of pomegranate was found in a randomized controlled trial to have no effect on PSA levels, a marker of tumor progression. Additionally, a randomized, double-blind, placebo-controlled trial found no difference when it came to prostate cancer progression, as you can see below and at 3:19 in mine. video.
They used the anti-inflammatory activity of pomegranate juice to help, but again, that had been shown in vitro. In humans, a meta-analysis based on five randomized controlled trials published in 2016 concluded that pomegranate juice did not have a significant effect on the levels of C-reactive protein, the main marker of inflammation. If you look at the forest area, however, you’ll see all five tests aimed at such low levels of C-reactive protein that the combined data almost reached statistical significance, as you can see below and at 3:53 in mine. video.
Indeed, an updated meta-analysis published in 2020 based on seven studies crossed the threshold into statistical significance and found a significant reduction in two other inflammatory markers.
Perhaps pomegranate juice can help control inflammatory diseases. But you never know until you put it to the test.
Osteoarthritis involves the deterioration of the cartilage that lines the inside of joints, especially the knees. Instilling pomegranate extract into osteoarthritic human cartilage samples appears to show cartilage-protective effects. As you can see below and at 4:43 in my video, compared to baseline levels of cartilage breakdown, adding inflammation triples the damage. However, with the increase in pomegranate prices, the decline is beginning to calm down.
But again, that’s in a petri dish. How do we know that when we eat pomegranates, the active components actually enter the bloodstream to find their way to our organs? Anti-cartilage components were found to be detectable (at least in rabbits), suggesting the possibility that pomegranates could be a safe and non-toxic treatment without side effects, in contrast to currently used drugs. But does it work?
The first clinical trial on pomegranate juice and osteoarthritis was not a placebo-controlled trial, but instead randomized people to take pomegranate juice or nothing at all. Those who drank the juice reported less stiffness and impaired physical function, but not significantly better than doing nothing. Shoot.
Just as I was about to give up pomegranates, I saw a study titled “Use of Hydrolyzable Tannins-Rich Pomegranate Extract Suppresses Inflammation and Joint Damage in Rheumatoid Arthritis.” But the “Not-So-Wonderful” POM company appeared, causing joint damage in mice as a model of rheumatoid arthritis. Come on!
There were open-label studies, where patients knew what they were getting. Eight people with active rheumatoid arthritis took pomegranate extract daily, and six who adhered to it reported fewer tender joints. But as we’ve learned in osteoarthritis research, if you don’t have a control group, you have no idea what role, if any, treatment actually plays.
Finally, we come to this randomized, double-blind, placebo-controlled trial. It’s about time! Half of the study participants received pomegranate extract unknowingly; the other half unknowingly got the equivalent of a sugar pill. There were significant improvements in the number of swollen joints, tender joints, pain intensity, disease activity scores, health screening questionnaires, and morning stiffness compared to placebo. So, if you have rheumatoid arthritis, I would really recommend that you start eating pomegranates. Why not just use pomegranate pills? After all, it was the pomegranate medicine that eased the effects of diseases. One good reason to stick with the fruit is that when 19 pomegranate supplements were tested in the laboratory, most were found to have pomegranate in them at all! Only 6 out of 19 appear to be true.
Doctor’s Note
I previously reported on POM Wonderful back in 2011 in my video Is Pomegranate Juice That Amazing?. My other video on this fruit is Flashback Friday: Pomegranate vs. Placebo for Prostate Cancer.
What other way can you be proud? Check out my cooking video Cran-Chocolate Pomegranate BROL Bowl.
