When
I wrote Cancer Therapy in the early 1990s, I had the
bright idea of putting my mailing address in the book in the hope
that some readers would send me information on new treatments. Little
did I imagine that such communication would become a torrent of
proposals. Today, hardly a day goes by without my being made aware
of some new "cure." Would that a fraction of these panned
out as well as proponents claimed!
One
of the latest in this long line is an exotic fruit drink called
mangosteen, or XanGo. Mangosteen
should not be confused with mango, an entirely different plant.
It is part of a group known as the Guttiferae, a family of mainly
tropical trees and shrubs that secrete an acrid yellow resinous
juice. Mangosteen's scientific designation is Garcinia mangostana
(Campin 2004). It is reputedly named after a French explorer, Jacques
Garcin (1673-1751). In Europe and North America, the most recognizable
member of this family is the popular herb, St. John's wort.
No
one knows exactly where and when the mangosteen was first cultivated.
One botanist, Julia F. Morton, believes it originated in the Moluccas
and the Sunda Islands. Yet there are also wild mangosteen trees
in the forests of Malaya. Some experts say the trees were first
domesticated in Thailand or Burma. But in the 19th century, botanists
brought seeds to Europe and America. Valiant attempts were made
to cultivate the 18-foot high trees in Africa, the Caribbean and
central America. But the plant is considered "ultra-tropical"
and sensitive: nursery seedlings die at 45º F. In fact, there are
few if any mangosteens growing in the continental US. A lone American
tree in Florida was said to have yielded a single fruit...and then
died. That was the beginning and end of the American mangosteen
"industry."
But
attempts continued to bring mangosteen to Europe and America as
a food. "Despite the oft-repeated Old World enthusiasm for
this fruit," says Morton, "it is not always viewed as
worth the trouble to produce. In Jamaica, it is regarded as nice
but overrated; not comparable to a good field-ripe pineapple or
a choice mango."
The
mangosteen fruit is the size of a small apple, purple colored, with
a hard rind. Inside there are typically five to seven seeds surrounded
by a sweet, juicy cover (or aril). The pulp, which is said to resemble
a pineapple or peach in taste, is reputed to be a very delicious
food - in Asia it is sometimes called the queen of fruits in honor
both of its flavor and its economic importance.
Uses
in Traditional Medicine
For
many years dried mangosteen fruits have been shipped from Singapore
to Calcutta and then on to China for medicinal use. As to its many
uses in folk medicine, here is what botanist Julia Morton has written:
"The
sliced and dried rind is powdered and administered to overcome
dysentery. Made into an ointment, it is applied on eczema and
other skin disorders. The rind decoction is taken to relieve diarrhea
and cystitis, gonorrhea and gleet [a watery discharge, ed.] and
is applied externally as an astringent lotion. A portion of the
rind is steeped in water overnight and the infusion given as a
remedy for chronic diarrhea in adults and children.
"Filipinos
employ a decoction of the leaves and bark as a febrifuge and to
treat thrush, diarrhea, dysentery and urinary disorders. In Malaya,
an infusion of the leaves, combined with unripe banana and a little
benzoin is applied to the wound of circumcision. A root decoction
is taken to regulate menstruation. A bark extract called 'amibiasine',
has been marketed for the treatment of amoebic dysentery."
Morton
also writes that "[t]he rind of partially ripe fruits yields
a polyhydroxy-xanthone derivative termed mangostin, also beta-mangostin.
That of fully ripe fruits contains the xanthones, gartanin, 8-desoxygartanin,
and normangostin. A derivative of mangostin, mangostin-e, 6-di-O-glucoside,
is a central nervous system depressant and causes a rise in blood
pressure." A more complete listing of constituents is given
at ethnobotanist Dr. James Duke's informative and useful Phytochemical
and Ethnobotanical Databases (Duke 2004).
We
can conclude then that mangosteen has many uses in folk medicine,
and as such, it can join a fairly long list of plants that can be
considered as promising sources of new medicines.
XanGo
on the Go
In
this age of frenzied commercialism, entrepreneurs are always on
the lookout for ways to make it big in the natural medicines market.
Under such conditions, however, new medicines of botanical origin
cannot be developed or tested in an orderly way.
A common
feature of the way in which natural medicines such as mangosteen
are promoted is the use of network marketing. This involves the
retailing of products through the use of independent distributors.
These distributors are then encouraged to build and manage their
own sales force by recruiting, motivating, supplying, and training
others to sell products. Compensation in such arrangements includes
the distributor's own sales as well as a percentage of the sales
of his or her entire "downline" (i.e., all those people
signed up by an individual, who in turn go on to become salespeople).
The term network marketing is virtually synonymous with the older
but now somewhat disreputable term 'multi-level marketing' (MLM).
Network
marketing turns mere consumers into determined marketers who aggressively
sell their product, often to their own friends, relatives and neighbors.
The more people they can recruit into the growing network the more
money they themselves make. A sophisticated marketing blitz, including
books and pamphlets, seemingly objective newsletters, press releases
and chattering websites, inflate the importance of a product, creating
a buzz that only dies away when the huge supply of potential customers
and salespeople is finally exhausted. Or when, as it has on occasion,
the government finally steps in. But the essential requirement for
a successful MLM operation of this sort is a kernel of promising-sounding
scientific evidence, coupled with a credible and compelling story,
a compliant doctor willing to underwrite the concept, and finally
some patients (who may themselves be distributors) willing to testify
that the product led to astounding cures.
Aloe
vera, colloidal minerals, gingko biloba and ginseng were all popularized
in this way. But perhaps the most memorable example of a network
marketing stampede is noni juice, a once totally obscure Polynesian
fruit that became the basis of a huge industry. Tahitian Noni International,
formerly called Morinda, last year claimed to have passed the two
billion dollar sales mark! This is the sort of performance that
makes get-rich-quick artists drool.
The
techniques of network marketing, honed through decades of trial
and error, are now being used by a Utah-based company to position
mangosteen as the latest "miracle cure" craze. The price
of their XanGo mangosteen juice is currently $37 per bottle (or
four for $100). You have to ask yourself: who on earth would pay
that much for a bottle of fruit juice, no matter how delicious it
might be? The reason the marketers can succeed in selling juice
at this price is obvious: when people are suffering from medical
conditions for which there does not appear to be much hope, or for
which the orthodox medical recommendations are too toxic or expensive,
they will actively seek alternatives. And then someone, oftentimes
someone they trust, such as a friend or neighbor, convinces them
to give some new product a try. Products such as mangosteen exploit
humanity's understandable desire to discover simple and painless
solutions to intractable problems.
Now
that the commercial ball is rolling an increasing number of mangosteen
brands are reaching the market. But for the time being the market
leader is XanGo (www.myxango.com). A visit to their website
triggers an audio webcast from a very pleasant sounding young lady,
who assures us that "by integrating the Internet, teamwork,
and personal mentoring, MyXanGo.com provides you a vehicle to improve
the areas of your life that are most important to you, and we do
it for FREE."
I listened
in amazement to her polished spiel and the brazen intrusiveness
of this message. I was particularly amused when she said, "You
should know that this message is not about selling." Right.
"It's not about false claims and outlandish statements."
Sure. "It's about sharing facts to help you decide if now is
the right time in your life to consider XanGo." Really.
The
rhetoric gets even more effusive. A March 2004 press release from
one seller proclaims: "Mangosteen is now on an unstoppable
march to conquer the world" (Goss 2004). Put this way it sounds
rather ominous…almost like a cross between Osama bin Laden and the
Attack of the Killer Tomatoes.
Xanthones
As
stated, one requirement for a successful network promotion is that
there be at least a kernel of scientific truth around which exaggerated
claims can be assembled. As with noni juice, mangosteen is not entirely
without scientific documentation. The problem, as usual, is that
the claims for mangosteen are inflated till they far outpace what
has been established through careful experimentation.
Some
mangosteen promoters have mined James Duke's famous ethnobotanical
database for confirmation of their product's value. And, indeed,
Dr. Duke confirms that the plant contains several interesting components.
But so do thousands of other plants in his voluminous database.
For most of the chemicals contained in this fruit (such as beta-mangostin,
catechins, cis-hex-3-enyl-acetate, gamma-mangostin, gartanin, garcinones)
the database lists NO particular biochemical activities. Only the
compound called "mangostin" seems to have some scientific
backing for its antibacterial, antiseptic and fungicidal properties
(Recio 1989). Yet scores of mangosteen websites now cite Duke's
database as scientific justification for this product. In reality,
Dr. Duke has absolutely nothing to do with any mangosteen distributor
and is not particularly enthusiastic about the product.
Much
is made of the xanthone connection. According to the MyXanGo.com
website: "There are over 200 xanthones in nature. Each xanthone
can have specific effects on the body. What's remarkable about the
mangosteen is that there are over 40 xanthones identified in the
pericarp, or rind, making it the single most xanthone-rich source
in the world….Only six of the xanthones have been studied in depth.
While we don't know fully why the mangosteen works on such a wide
variety of physical conditions, we know it has to do with being
the world's most potent source of xanthones. Each xanthone has its
own effect, and when combined, they take on a synergistic quality
that supports the health of the entire body."
But
all of this is speculative. It is undoubtedly true that there are
many xanthones (a kind of antioxidant) in mangosteen. In fact, according
to the Merck Index (11th Ed., p. 5613) the first scientifically
defined substance to be derived from mangosteen was the xanthone
mangostin. This was isolated by a German scientist named Schmid
in 1855. In 1979, mangostin was found to have significant anti-inflammatory
and anti-ulcer effects in rats (Shankaranarayan 1979). Yet although
mangosteen's xanthones have been known for almost 150 years, there
are still only 19 PubMed articles on these xanthones and none of
these articles concerns the use of xanthones in the actual clinical
treatment of human disease. So I would say the jury is still out
on their effectiveness in treating anything.
The
main XanGo website also claims that the antioxidant ORAC (oxygen
radical absorbance capacity) value of mangosteen is the highest
of all edible plants. "It is so potent that literally I know
of nothing else in the supplement market that can possibly come
even close to it," says J. Frederic Templeman, MD, a Georgia
family practitioner who is interviewed at the MyXanGo website. Many
other XanGo-promoting websites repeat the claim that while the previous
champion, prunes, have an ORAC value of 7,000 per ounce, mangosteen
has an ORAC value of 17,000 to 24,000.
Yet
XanGo sites claim that "a new champion" has been born
in the worldwide contest for ORAC supremacy. But where in the scientific
literature is the ORAC value of XanGo published? The source of these
numbers is hard to track down. For instance, the Sunsweet prune
website states that 100 grams (3.5 ounces) of prunes have an ORAC
value of 5,770. While the ORAC values for most fruits and vegetables
have been determined by standard laboratories and published in scientific
journals, this is not so for mangosteen. I have not seen independent
confirmation of these confidently promulgated claims. However, even
if we assume for the sake of argument that the figures cited are
indeed accurate, it must be pointed out that merely having an astronomically
high ORAC value does not in and of itself confer any particular
advantage. Not all antioxidants that are confirmed as present in
the laboratory can be absorbed by human beings. And there is a limit
to how much we can benefit from an increased intake of antioxidants.
According
to Dr. Ronald Prior of the US Department of Agriculture Research
Service at Tufts University, Boston, Massachusetts, "a
significant increase in antioxidants of 15 to 20 percent is possible
by increasing consumption of fruits and vegetables, particularly
those high in ORAC value." However, in order to have a significant
impact on plasma and tissue antioxidant capacity one can only meaningfully
increase one's daily intake by 3,000 to 5,000 ORAC units. Any greater
amount is probably redundant. That is because the antioxidant capacity
of the blood is tightly regulated, says Dr. Prior. Thus there is
an upper limit to the benefit that can be derived from antioxidants.
Taking in 25,000 ORAC units at one time (as reputedly occurs with
mangosteen) would be no more beneficial than taking in a fifth of
that amount: the excess is simply excreted by the kidneys.
Marketers
of the drink have widely claimed that XanGo has exceptional health-giving
properties based on its very high ORAC score. (ORAC stands for oxygen
radical absorbance capacity - a measure of the antioxidant value
of a substance.) But having a high ORAC value does not necessarily
confer any health advantage.
According
to Dr. J. Frederic Templeman, a Georgia family practitioner who
has written a small book on mangosteen, and who is widely quoted
by XanGo marketers, if you take these antioxidants "you aren't
going to probably have a heart attack as fast as someone who doesn't
take them" and consuming them could therefore constitute "literally
the difference between life and death." Although I myself have
written a book on the subject of the benefit of antioxidants (Antioxidants
Against Cancer), I would say it is a tremendous stretch
to claim that antioxidants are predictably going to save anyone's
life. Good health is achieved through a combination of many factors,
hereditary as well as environmental.
Effects
on Cancer
At
the XanGo website, a company spokesperson interviews Dr Templeman
on the subject of mangosteen's beneficial effect on cancer. They
both agree that a single test tube experiment is proof of the anticancer
value of the juice:
Dr.
Templeman: "That's striking."
XanGo
spokesperson: "It's incredible."
At
various other websites devoted to XanGo (and there are now over
21,000 of them!) we read in glowing terms about both the supposed
quantity and quality of scientific research on this previously obscure
fruit.
Reality
Check
So
it is high time for a reality check. Has mangosteen really been
thoroughly studied in terms of its effect on cancer and a host of
other diseases? Or is this simply a wild extrapolation driven by
strong commercial motives?
Dr.
Templeman refers to 44 scientific publications on this topic but
there are just 29 articles on the topic of Garcinia mangostana in
PubMed, the US National Library of Medicine database of 14+ million
citations. A total of four of these studies relate to cancer. In
one test tube experiment it was shown that a xanthone found in mangosteen
kills cancer cells as effectively as many chemotherapeutic drugs.
It also appears (on the basis of limited data) that compounds found
abundantly in mangosteen can inhibit the harmful Cox 1 and Cox 2
enzymes, and can also induce programmed cell death (apoptosis) in
aberrant cells (Ho 2002). Mangosteen thus joins a fairly long list
of naturally derived compounds that might potentially have some
anticancer activity.
These
29 articles do not constitute a wealth of data. For example, by
contrast, PubMed lists over 2,300 articles on the topic of vitamin
C and cancer, 125 of which refer to clinical trials. There are a
similar number of studies on vitamin E and cancer. There are 835
studies of melatonin and cancer, and a truly impressive 16,000 on
polysaccharides and cancer, including 536 clinical trials and 277
randomized controlled trials (RCTs).
Yet,
we're to believe that four test-tube experiments constitute - to
quote the aforementioned Dr. Templeman - "mountains of evidence"
on the benefits of XanGo.
According
to the promotional website of one of XanGo's many "independent
distributors" at http://bjsbytes.com/Xango/Questions.htm:
"...much
of the science behind xanthones is predominantly available to
those in the medical community until recently. Many of the clinical
studies on xanthones have been done in universities and testing
facilities throughout Asia and have recently started to catch
the attention of Western researchers."
But
is this true? Reputable researchers the world over, including those
in Asia, publish in PubMed-listed journals. For example
there are over 63,000 articles on cancer in PubMed
in the Japanese language. Yet despite the website's misleading talk
about "clinical studies," PubMed does not
contain a single clinical trial of mangosteen in the treatment of
cancer, or any other disease. Perhaps these promoters don't realize
that a clinical study is not something done in a laboratory, but
a study that by definition is carried out on living patients. Laboratory
studies on cell lines or even animals do not qualify for the title
'clinical study'.
Thus,
despite what you may read at any one of those 21,000 promotional
websites, very little scientific evidence exists concerning mangosteen's
anticancer activity in humans.
In
my opinion, what we have here is simply an overpriced fruit drink.
Fruit drinks are often healthful beverages. But the only reason
I can see that the promoters of mangosteen can get away with charging
$37 for this product is that they are playing on patients' hopes
and fears in a cynical way. Without the health claims, open or implied,
the product could only be sold for at most $5 or $6 (which, for
example, is the cost of antioxidant-rich pomegranate juice).
The
mangosteen phenomenon is a reprise of the aloe vera, gingko biloba,
and especially the noni juice story, complete with exaggerated claims
for the health benefits of an exotic fruit. It should come as no
surprise that both the President and the Chief Financial Officer
of Xango once worked for Morinda (now called Tahitian Noni International).
Compounds
found in plants have long been of great interest to cancer researchers.
We must never forget that about one-fifth of all chemotherapeutic
agents (including Vincristine, Vinblastine, Etoposide, Teniposide,
and Taxol) are ultimately derived from plant sources. Many of these
took a long time to pass through the regulatory process, since serious
research into botanical medicine often goes begging for financial
and intellectual support. Starved of funds in this way, the riches
of the natural world are often neglected by mainstream science,
only to be plundered by less scrupulous organizations. The patient
loses twice - by not having the fruits of serious research and by
being deceived by slick operators posing as friends and benefactors.
Some may even opt for unproven miracle juices in lieu of more certain
therapies that might save their lives.
When
it comes to cancer, we truly live in a topsy-turvy world.
CancerDecisions.com
is directed by Ralph W. Moss, Ph.D. Dr. Moss is the author of eleven
acclaimed books including Antioxidants Against Cancer, Herbs Against
Cancer, Questioning Chemotherapy, and Cancer Therapy. He consults
for thousands of clients through his Moss Reports service. The
Moss Reports specializes in educating cancer patients about
the most promising alternative treatments for their condition.
Note
from Chet: Be sure to sign up for Dr. Moss's excellent
newsletter at his website.
Another
Note from Chet: We get a lot of email from people who
think mangosteen is the best thing since sliced bread. Click
here to read some of their comments.
References:
Campin,
Jac. Guide to Plant Relationships (for food allergy and intolerance
identification),Version 12 (14 April 2004. Retrieved April 27, 2004
from: http://www.purr.demon.co.uk/Food/RelatedPlantList.html
Duke,
James, ed. Dr. Duke's Phytochemical and Ethnobotanical Databases.
United States Department of Agriculture, Agricultural Research Service,
Accessed April 27, 2004 from: http://www.ars-grin.gov/cgi-bin/duke/farmacy2.pl?1228
Hedrick,
U.P. (ed.) 1972. Sturtevant's Edible Plants of the World. NY, NY:
Dover Publications, Inc., 1972. Downloaded from: www.swsbm.com/
Ho
CK, Huang YL, Chen CC. Garcinone E, a xanthone derivative, has potent
cytotoxic effect against hepatocellular carcinoma cell lines. Planta
Med. 2002 Nov;68(11):975-9.
Matsumoto
K, Akao Y, Kobayashi E, Ohguchi K, Ito T, Tanaka T, Iinuma M, Nozawa
Y. Induction of apoptosis by xanthones from mangosteen in human
leukemia cell lines. J Nat Prod. 2003 Aug;66(8):1124-7.
Moongkarndi
P, Kosem N, Kaslungka S, Luanratana O, Pongpan N, Neungton N. Antiproliferation,
antioxidation and induction of apoptosis by Garcinia mangostana
(mangosteen) on SKBR3 human breast cancer cell line. J Ethnopharmacol.
2004 Jan;90(1):161-6.
Morton,
Julia F. Mangosteen. In: Fruits of Warm Climates. Self-published.
Miami, FL, 1987, pp. 301-304. ISBN: 0-9610184-1-0
Nakatani
K, Nakahata N, Arakawa T, Yasuda H, Ohizumi Y. Inhibition of cyclooxygenase
and prostaglandin E2 synthesis by gamma-mangostin, a xanthone derivative
in mangosteen, in C6 rat glioma cells. Biochem Pharmacol. 2002 Jan
1;63(1):73-9.
ORAC
value of Sunsweet prunes: http://www.sunsweetdryers.com/Sunsweet.htm
Recio,
M. C., Rios, J. L., and Villar, A., A review of some antimicrobial
compounds isolated from medicinal plants reported in the literature
1978-1988, Phytotherapy Research. 1989:3(4)117-125.
Shankaranarayan
D, Gopalakrishnan C, Kameswaran L. Pharmacological profile of mangostin
and its derivatives. Arch Int Pharmacodyn Ther. 1979 Jun;239(2):257-69.
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