Subject: a review article describing the exaggerated claims made for the
herb graviola in the treatment of cancer.
Last summer a patient asked me what I knew about
the herb Graviola in treating cancer. I admitted ignorance, promised
to see what I could find out and went from there. When I did my
homework I was rather perplexed. There were innumerable websites
promoting this obscure herb as a miracle treatment for cancer and yet
at the same time I could find nothing in the published scientific literature
to support the claims of those marketing this product. My answer
at the time to my patient could be summed up as,"Doesn't look like
it's going to hurt, maybe it will help, but honestly I don't know."
I've recently come across an article by Ralph
Moss who has written about alternative treatments for cancer for years
and who I pay attention to. His experience sounds so close to mine and
his viewpoint matches my own so closely that I am tempted to sign my name
to his article. I'll paste his article here.
For August 29, 2003
A FRIENDLY SKEPTIC LOOKS AT GRAVIOLA
Hardly a day goes by that I am not asked for my opinion of some new
cancer treatment. When it comes to evaluating the merits of any
treatment, conventional or unconventional, I try to maintain a mindset
of "friendly skepticism." On the one hand, I remain receptive
promising new approaches. Lord knows, conventional oncology leaves much
to be desired and society desperately needs new ideas. On the other
hand, we live in a world filled with hustlers and opportunists, and we
have to be constantly on our guard against expensive and dangerous
rip-offs. We want to protect patients while at the same time not
discouraging innovative researchers.
A reader once called me a "soft-core quackbuster". Although
retracted the charge, I have to confess that I wasn't terribly upset at
the label. As I see it, quackery exists on both sides of the medical
divide: neither conventional medicine nor alternative medicine is immune
from this scourge or has a monopoly on probity. A major problem with the
self-proclaimed "quackbusters" is that their one-sided and tendentious
attacks on alternative medicine leave the impression that conventional
medicine is the only valid way of treating most forms of cancer. They
come across as knee-jerk defenders of a status quo that genuinely needs
to be reformed, not supported unquestioningly. On the other hand, I am
exaggerated claims made for any cancer treatments, whether those
treatments originate in orthodox or alternative medicine, because such
overblown claims are often based on (let us be generous) commercial
considerations rather than solid science.
A case in point is an herbal treatment called Graviola. This burst onto
the Internet in early 1999 and is now incorporated into many patients'
regimens. An increasing number of alternative practitioners are
recommending it to their patients.
What exactly is Graviola? It is a common name for Annona muricata, also
known as soursop or Brazilian paw-paw. This is a small,
upright evergreen tree growing 15 to 18 feet in height with large,
glossy dark green leaves. (It is not to be confused with Asimina
triloba, a deciduous tree of the eastern and southeast United States .)
Graviola is indigenous to warm tropical areas in the Americas , including
the Amazon. It produces a 6-to-9 inch, heart-shaped edible fruit,
yellow-green in color, with white flesh. This is sold in tropical
markets under the name guanabana or Brazilian cherimoya. It is said to
be is excellent for making drinks and sherbets and, though slightly
sour-acid, can be eaten out-of-hand.
If you enter the term "Graviola" into Google you come up with
12,300 citations, over 2,000 of which relate to cancer. You also get a
rash of sidebar advertisements such as "A great product to fight
cancer," "Graviola helps to fight cancer," and "How
Cancer," presumably with the help of this herb. The plant is also
subject of several dedicated websites. According to www.graviola.org
the plant is "an astounding cancer-fighting tree from the Amazon!"
reputedly "10,000 times stronger in killing colon cancer than
Adriamycin, a commonly used chemotherapeutic drug" and has the ability
to "hunt down and destroy prostate, lung, breast, colon, and pancreatic
cancers... leaving healthy cells alone!"
These are formidable claims. Adriamycin (doxorubicin) is one of the most
powerful (and toxic) drugs in chemotherapy. Adriamycin was discovered
Italy in the 1970s, hence the "Adria-tic" name. I well remember
introduction into oncology and how it revolutionized the treatment of
several forms of cancer. But now, we are told, an herb has come to light
that is not only as powerful as Adriamycin, but 10,000 times more
powerful, and non-toxic to boot. The mind reels. Reading this statement,
one cannot wait to find out more about this herbal product and how it
be used to help cancer patients. One pictures the evil demon Cancer,
beaten and cringing in its corner, knowing that its days on earth are
I don't know who first penned these effusive statements about Graviola
but the claims have taken on a life of their own. I found two dozen
other websites that contained the exact phrasing about Graviola being
"10,000 times stronger than Adriamycin," all equally unsupported
scientific references. It seems that astounding claims concerning cancer
cures spread like a virus from Website to Website.
Since there are now hundreds of sites featuring and selling Graviola,
figured that this herb would also be well represented in PubMed, the
National Library of Medicine's database of peer-reviewed articles.
PubMed contains 12 million citations to nearly all medical journal
articles published since the mid-1960s. But when I entered the term
"Graviola" into this comprehensive search engine all I came
up with was
a single item. And this was not a clinical report at all but chemical
arcana about screening Brazilian fruits for their aromas.
There had to be something wrong. I went back to the www.graviola.org
website (although exactly whose organization the '.org' refers to is not
apparent) and I clicked on the "clinical references" link at
of the page. All I got was a blank screen. The same thing with "data
base entries" and "Graviola products." It looked as if
hastily removed some documentary material, but had then forgotten to
remove the links.
I then found a more productive tack. I read that the "active
ingredients" in Graviola are a group of "annonaceous acetogenins"
are only found in the Annonaceae family, to which Graviola belongs.
"These phytochemicals are being researched around the world for their
active biological properties and potential uses," one website
The phrase "annonaceous acetogenins" gave a new and promising
point. Indeed, this term yielded 121 citations in PubMed. A lot of these
were about the chemical constituents of the fruit. But taken
cumulatively, one gathers that there is indeed a class of very
interesting and potentially useful compounds in various branches of the
Annona family. To quote scientists at Purdue University's highly
regarded School of Pharmacy, "Annonaceous acetogenins are an extremely
potent class of compounds, and their inhibition of cell growth can be
selective for cancerous cells and also effective for drug resistant
cancer cells, while exhibiting only minimal toxicity to 'normal'
non-cancerous cells" (Oberlies 1995). Graviola thus joins the list
hundreds of other biologically active plants that are of potential
importance to the future of medicine.
Further searching in PubMed revealed that it was in fact scientists at
Purdue who had first come up with the widely-circulated "more powerful
than Adriamycin" claim. Here is what Dr. X.X. Liu and colleagues
in 1999: "Annoglacins A and B were selectively 1000 and 10,000 times,
respectively, more potent than Adriamycin against the human breast
carcinoma (MCF-7) and pancreatic carcinoma (PACA-2) cell lines in our
panel of six human solid tumor cell lines."
This is very exciting in principle. However, to an inquiring, healthily
skeptical mind, several questions immediately suggest themselves. One
is, how much "annoglacin B" is found in a typical Graviola capsule
purchased over the Internet? Quite probably it is infinitessimally
small. Also lost in the promotional hoo-hah is the fact that the
particular annoglacins investigated by Dr Liu and colleagues were
derived not from Graviola at all but from a related, but entirely
different, species, Annona glabra. This is a Polynesian tree called the
pond or alligator apple.
Additionally and most importantly, what do actual clinical studies
about the effectiveness of this agent against cancer? Back at the
www.graviola.org website we read
that "three separate research groups
have isolated novel compounds in the seeds and leaves of Graviola which
have demonstrated significant anti-tumorous, anti-cancerous and
selective toxicity against various types of cancer cells, publishing
eight clinical studies on their findings."
Really? If we enter the search term Annona into PubMed, but limit our
search with the modifier "clinical trials" (which includes any
phases of clinical work), we come up with exactly...zero!
My understanding of the term "clinical studies" is that they
involve the treatment of human beings (or, more inclusively, pet and
farm animals). Webster says that the term 'clinical' is an observation
that "involves or is based on direct observation of the patient."
Cancerweb dictionary states that the word 'clinical' pertains to or is
founded on "actual observation and treatment of patients, as
distinguished from theoretical or basic sciences."
But where are these "clinical studies" of Annona derivatives,
are not to be found among the 12 million peer-reviewed journal articles
The anonymous authors of the www.graviola.org
website seem to have
misspoken. They can't really mean clinical studies. They mean laboratory
experiments that take place in test tubes with cell lines, which many
knowledgeable researchers view as not directly equivalent to human
cancer tissue. (See Gerald B. Dermer's book The Immortal Cell for
corroboration of this point of view.) With this self-serving "slip
the tongue" the anonymous promoters of Graviola have undoubtedly
convinced many cancer patients to buy their product.
Have any of these patients been helped? Or have they been harmed by
unknown or unmentioned side effects? Have they been deprived of precious
time and thereby the opportunity to undergo other, more effective,
treatments? Or have they simply been relieved of unspecified sums of
money? In the vast majority of cases, we'll never know.
Sadly, Graviola has now entered the netherworld of alternative cancer
treatments. It promises much based on real, but very preliminary,
scientific facts. Now its reputation has been tarnished by misstatements
and over-promotion. Is there any way for a promising treatment to find
its way back from the Purgatory of Cancer Cure-Alls? Or shall we remain
forever in the dark about the merits of such treatments? Thousands of
cancer patients are waiting for an answer to that riddle.
--Ralph W. Moss, Ph.D.
Hey! You're getting these newsletters either because you've signed up
to be on the list or because we took the liberty of putting you on.
If you want your name removed simply leave a message at the office (303-337-4884)
or go to the website: denvernaturopathic.com and unsubscribe, or reply
with the message "REMOVE" in the subject line. If on the
other hand you want to be added to the mailing list follow the prior instructions
but subscribe. We are finally trying to keep up with our website and are
posting most of these newsletters in our 'archive' section. Frequently
we also post abstracts of references quoted for the intellectually curious.
Enter your email to recieve the latest Health and Wellness newsletters
from the clinic.