"Pomegranate: A Natural Treatment for Rheumatoid Arthritis"
In a landmark case that made it all the way up to the
U.S. Court of Appeals before being denied review
by the Supreme Court, POM Wonderful (the pomegranate juice company)
vs. Federal Trade Commission, a panel of judges concluded that
many of POM’s ads made misleading or false claims
touting medical studies ostensibly showing that pomegranate products
could help treat various ailments, including heart disease,
prostate cancer, and erectile dysfunction,
and the First Amendment does not protect
deceptive and misleading advertisements.
Striking a blow to its billionaire owners, the Court ruled
that at least one randomized clinical trial could be required
to substantiate any claims of treating or preventing disease.
If you look at the medical literature on the benefits of pomegranates
in general, you’ll see reviews like this, with diagrams like this
on the “medicinal effects of pomegranate.”
But if you dig a little deeper you see this is based on studies
like this: “antiobesity effects of pomegranate leaf extract
in a mouse model.”
First of all, who eats pomegranate leaves?
And second of all, who’s a mouse?
And if you do have a fat pet mouse, maybe just feed them less lard.
Does pomegranate consumption affect weight in humans?
If you look at all the randomized controlled clinical trials
(meaning human trials), pomegranates have no significant effect
on body weight, BMI, belly fat, or even body fat percentage
in those randomized to pomegranate product consumption.
What about for the prevention and treatment of cardiovascular diseases?
Researchers reviewed 25 clinical trials, looking at cholesterol,
blood pressure, artery function, atherosclerotic plaque formation,
and platelet function, and... even in the best studies,
they did not find significant indications of benefit.
Here’s a study on pomegranate juice and erectile dysfunction.
It was funded by the POM company, and yet it failed as well.
No benefit for diabetes markers and no benefit
for chronic obstructive pulmonary diseases like emphysema.
They were banking on the antioxidant activity of pomegranate juice
to help, but that’s antioxidant activity 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 convincing evidence
of pomegranate intake having a significant increasing effect
on total antioxidant capacity of your bloodstream
because some of the most potent antioxidants
don’t even seem to be absorbed into the human body.
No wonder pomegranate supplementation didn’t seem to affect
oxidative stress in tissue samples
taken from prostate cancer patients.
But, of course, what we care about is whether
it affects the cancer Itself.
The strongest evidence for the anticancer activity of pomegranates
is said to come from studies on prostate cancer.
Unfortunately, early promising results were not conﬁrmed
when they were actually put to the test.
For example, daily pomegranate intake was found in a randomized
controlled trial to have no impact on PSA levels,
a marker of tumor progression.
And, indeed, a randomized, double-blind, placebo-controlled trial
found essentially no difference when it came to
prostate cancer disease progression.
They were banking on the anti- inflammatory activity of
pomegranate juice to help, but again,
that had been demonstrated in vitro.
In people, a meta-analysis based on five randomized controlled trials
published in 2016 concluded that pomegranate juice did not
have a significant effect on C-reactive protein levels,
a key marker of inflammation.
If you look at the forest plot, though, you’ll see
all five trials tended towards lower C-reactive protein levels
such that the data combined almost reached statistical significance.
And indeed, an updated meta- analysis published in 2020
based on seven studies did indeed get tipped over into
significance and found a significant drop
in two other inflammatory markers as well.
Huh, okay. Well, maybe pomegranate juice could help
in the control of inﬂammatory diseases after all.
But you don’t know...until you put it to the test.
Osteoarthritis involves the degeneration of the cushioning cartilage
within joints, particularly the knees.
If you take some human osteoarthritic cartilage samples
and drip on a pomegranate extract,
you can show cartilage-protective effects.
Here’s how much cartilage disintegration was happening at baseline.
Add some inflammation and cartilage breakdown triples,
but then add more and more of this pomegranate extract,
and you can calm things down. But again, that’s in a petri dish.
How do we know that when we eat pomegranates,
the active components actually get into our bloodstream
so they can find their way into our joints?
Cartilage-protecting components were found to be bioavailable
(at least in rabbits), raising the possibility that pomegranates
could be a safe and non-toxic treatment with no side effects,
as opposed to the drugs currently in use. But is it effective?
Clinical trials are in progress, and so many questions
will be answered...right now!
The first and only clinical trial to date
on pomegranate juice and osteoarthritis.
It’s not a placebo-controlled trial, but instead randomized people
to pomegranate juice or nothing at all.
Those drinking the juice did report less stiffness and impairment
of physical function, but not significantly better
than just doing nothing. Shoot.
But just as I was about to give up on pomegranates, I saw this study:
Consumption of a pomegranate extract suppresses joint damage
in rheumatoid arthritis. But no... it was just the POM
‘Not-So-Wonderful’ company inducing joint damage in a mouse
as a model of rheumatoid arthritis. Come on!
What about this open-labeled study, where the patients knew
what they were getting?
Eight people with active rheumatoid arthritis took some
pomegranate extract every day, and the six who stuck with it
reported fewer tender joints.
But as we learned from the osteoarthritis study,
if you don’t have a control group you have no sense at all of what role,
if any, the treatment actually plays.
So finally, we come to this: a randomized, double-blind,
placebo-controlled trial. It’s about time!
Half of the subjects unknowingly got some pomegranate extracts;
the other half unknowingly got the equivalent of a sugar pill and...
significant improvement in the number of swollen joints,
tender joints, pain intensity, a disease activity score,
a health assessment questionnaire, and morning stiffness
compared to placebo. So, if you have rheumatoid arthritis,
I would indeed recommend you start eating pomegranates.
Why not just pop pomegranate pills?
After all, it was a pomegranate extract
that alleviated disease activity.
One good reason to stick to the fruit is that when 19 pomegranate
supplements were actually tested in a laboratory,
most didn’t actually appear to have any pomegranate in them at all!
Only 6 out of 19 appeared to be authentic.