|Home||Introduction||History and folklore||Enjoying the mangosteen|
|Science, non-science and nonsense||Photo gallery||The early years||Flowers, developing mangosteens|
|Fruit pictures page one||Fruit pictures page two||Acknowledgements||Contact and FAQ|
Science, non-science and nonsense
I first reserved the domain name mangosteen.com back in the 1990's. I did it for a very simple and straightforward reason. I have a farm in the tropics where I am growing this exquisite fruit for commercial production and sales. Most people would be seeing the fruit for the first time in the years to come and want to know more. I knew I would need to educate the consumer about this exotic fruit, at least exotic to people in the USA, and where better to look for information than mangosteen.com. That was then.
Today, the mangosteen when processed with the rind as well as the edible portion is the subject of thousands, maybe tens of thousands of web sites because of its alleged health benefits. I can only guess how many products there are out there with untold numbers of formulations as beverages, lotions, teas, pills, powders, extracts, and so on. I can not say if some are better or worse than others with regards to alleged health benefits. For simplicity and convenience (and because I don't type!) I do not want to have to refer in writing over and over to any specific formulation or any specific company's product each and every time on this web site; I have chosen instead to lump together all of the whole mangosteen-containing processed products and refer to them as "PMP." Think of this as "Processed whole Mangosteen Products". When fresh mangosteen is simply pressed for the fresh juice, this is not what I am referring to. I am hopeful that someday the fresh juice will become available as it is quite superb. Read on.
For the last several years, I have received weekly requests from people wanting to know if the domain name mangosteen.com is for sale, lease, rent, banner placement, partnership or available for any other type of PMP promotion using this domain. It is not.
I have been emailed and phoned generally by courteous people but not always. I have been insulted and harassed by a few and some have thought they could wear me down or make higher and higher offers until I finally gave in. Please stop. It is not about the money, it is about the ethics and mine don't have a price. People have also attempted to simply take this domain and try to get it hosted without owning it! And it is spoofed by a few individuals as well but I am sure their intent is, well, obvious.
I decided to add this page to the mangosteen.com web site to address the increasing number of questions being raised by the tidal wave of PMP hitting the market today. I would emphasize before I go on that I have no financial involvement with any PMP company by choice. I would also add that no one has more to gain from the scientific proof of any benefit attached to consuming mangosteens in any form or in any formulation, fresh or processed, than I do...because I grow them for fresh sales. On the other hand, if the mangosteen were to end up tainted by problems relating to the consumption of any of its numerous processed products, then it might spill over and affect my ability to market the fresh fruit. Thus this page on the web site. I am not stating that any problems have arisen with PMP anywhere in this web site. I know of none to date.
The botany of the mangosteen is as follows. The Latin name of the mangosteen is Garcinia mangostana L. The genus Garcinia is named in honor of Laurent Garcin, a French 18th century explorer and plant collector. Linnaeus, the "L" after the species name mangostana, honored his work by naming the genus Garcinia after him. Besides the mangosteen, there are numerous other species within the genus, many of which produce edible fruit but none as exquisite as the mangosteen. Some produce valuable gums, waxes and dyes. I will say that although the word "mango" is contained in the word "mangosteen" there is no relationship botanically. Mangos and mangosteens are not at all related at the genus or family levels, only share several of the same letters.
Going up the scale or hierarchy, the genus Garcinia falls in the plant family Clusiaceae. This is the new name for the family and the replacement for the former family name, Guttiferae. This change was made several years ago by the international botanical nomenclature organization. Further botanical descriptions are available online as well as in botany texts and I will leave it to those who seek more of the technical description to go to those sources directly. An excellent text and source for vast amounts of technical information on numerous tropical fruits and nuts can be found in "Plant Resources of South-East Asia No. 2. Edible fruit and nuts." (1992). This book, by E. W. M. Verheij and R. E. Coronel, is a wonderful resource that provides details for all levels of scholarship.
Some traits of the mangosteen bear further discussion because they have played a major role in limiting the extent to which mangosteens have been planted around the globe. For example, the seeds of the mangosteen are considered "recalcitrant."
This means that they are very short-lived and must be kept moist or they die almost as soon as they dry out. Mangosteen seeds can be kept alive in moist peat moss for weeks and this is how they are usually shipped to distant locations. Holding the mangosteen seeds in a moist medium to keep them alive also causes them to immediately begin trying to sprout.
Mangosteen trees are dioecious, meaning that there are male trees and female trees. The only problem with this is that to date, no one has been able to find a male tree anywhere in the world so if they exist, they are quite rare. Globally, it is possible that there have never been any male mangosteen trees. This places the entire burden on the female tree to perpetuate the species. No males means no pollen, even though the female flower contains rudimentary sterile anthers where pollen would normally be found. Without pollen, there is no way to fertilize the female flower and create true seeds with variable genetic traits. Instead, the female mangosteen trees succeed in perpetuating the species by a process known as apomixis or agamospermy. The wall lining the ovary of the female flower, the nucellus, supplies the material that will then develop within the fruit segments and becomes what is effectively an asexually produced seed. As a result of this, it produces a clone of the mother tree.
In a manner reminiscent of a potato tuber, the seed does not have the normal internal structure found in most plant species' seeds and it can be planted in any orientation, sprouting a new shoot from the highest point underground. There also appears to be no root hair development in mangosteen which may negatively affect nutrient uptake. The involvement with mycorrhizal organisms plays a major role in the mangosteen's ability to get what it needs from the soil. Further impeding the chances of survival, the seed size corresponds to seedling size and vigor and small seeds are not worth planting as they retard the initial development.
And then there is the last problem with growth in the early months. The tap root that forms appears to be adapted to little more than water uptake and during the first 6 months or more, the seedling lives almost exclusively off the contents of the seed's initial nutrient supply. It is only after overcoming all of these hurdles that the mangosteen plant can then continue its already challenged existence. And it proceeds in a similar vein over the next few years before reaching maturity and producing fruit. This is because the mangosteen seedling goes through what is known as a juvenile period with stringent requirements as to light levels and water supply. Many tropical trees have this juvenile period where they slowly grow upwards from the heavily shaded forest floor, gradually reaching for the brighter canopy above. This is often accompanied by a leaf structure that is quite different from that of the mature tree's leaves and is more efficient for light absorption. In many cases, this is a survival strategy; it enables seedlings that happen to land and sprout in a low-light location to bide their time, hoping for a chance at better light levels later. In the case of the mangosteen, this period can go on for decades. In part, this has given the mangosteen the mistaken reputation of requiring 10 or more years to reach maturity and fruit production. Simply not true. Under ideal conditions (plant nursery), the first fruit can be as soon as 6 years after the seed sprouts but the initial low light period is still essential for about the first two years.
Since there is no pollen source and therefore no sexual fertilization, there is no crossing and mixing of the genes that would provide a means for variety development and selection. It can take place but will require lab techniques to manipulate the movement of genetic material within the nucleus and other structures of the cell. This feature in plants is not all that rare. Lawn grass seeds results from this kind of 'seed' production and it is a benefit where uniformity is desired.
Because the seed does not arise from fertilization, genetic variation was thought to be almost nonexistent. Most written resources make mention of this lack of variation or attribute any distinct phenotypes (visually observable expression of the genes) to subtle differences in the environment in which the trees are planted. In other words, amongst one hundred trees in a field together, the small differences in soil structure or chemistry or water retention from one spot to the next might account for any visual differences in the appearance of the trees or their fruit. In large part it could but it turns out there is much more going on at the genetic level.
Since the seed arises from the cell wall of the female tree's flower and is effectively a clone of the mother tree, the seedling has her genes intact and unchanged for generation after generation. This has led many to conclude that all of the mangosteen trees in the world are genetically identical but this is most definitely not so (2, 3). Several experiments have been conducted taking advantage of the most current DNA and RNA analysis techniques and it turns out that there is significant variation globally amongst the different populations of the mangosteen. There is a large proportion that have essentially the same genetic make-up (genotype) but there are significant numbers that do not.
This brings me to a discussion of the chromosomes of the mangosteen. I will say that work is being done now to try and further our understanding of the genetics of the mangosteen because it has such great potential as a fruit tree crop. To date, no one has published a paper that can state the number of chromosomes in the mangosteen with any certainty but this could change any day. Known as a karyotype, the chromosome count has been reported with such a wide variation in number as to be considered an unknown. The key question being looked at is, did the mangosteen arise as a result of a rare cross between two different Garcinia species (1)? And if it did, does this relatively rare event, the crossing of two species, explain in part the difficulty in producing progeny of both genders of trees, having viable pollen or exhibiting a very slow initial growth rate?
These questions when answered will go a long way in helping researchers to develop new cultivars (cultivated varieties) of this wonderful fruit. It is possible that the mangosteen is a result of a cross between two Garcinia species that had double their usual chromosome count (polyploidy), enabling them to interbreed and produce sterile offspring. During cell division, each double set of chromosomes (homologous pair) would be able to find the comparable other chromosome to pair up with and then enable cell division to proceed to completion. As unlikely as this series of events might seem, it has happened many times in the plant kingdom. It is possible with the mangosteen that it has happened more than once and at different locales. In addition to mutation and genetic drift, this could help to explain some of the variation found in genetic samples. This could also help researchers to create new mangosteen lines by determining which are the parent species. One could then manipulate their chromosome count, enabling the crossing of the two species to create new varieties.
The mangosteen has historically been praised (see History and Folklore) for countless centuries by all who encountered it. The edible interior is renown for its indescribable sweet-sour melting rush of flavors. But apart from the edible treasure inside the hull, the rind (technically a pericarp) has also been part of Ayurvedic medicine and has been valued throughout its native range for its medicinal qualities. The rind possesses a great diversity of complex organic chemicals (see Duke below), amongst which are tannic acid and xanthones. Xanthones comprise much of the promotional claims but it may well be the tannic acid which explains why it has been used almost exclusively as an astringent and aid in controlling dysentery, diarrhea and so on. For the last several centuries, the primary medicinal use of the rinds of the mangosteen has been for a disease, dysentery, that rarely ever appears anymore in present day America or most of Europe. In fact, the rind contains so much tannic acid, it was suggested by someone in the 19th century (New York Times, October 27, 1881) that they be sent bulk to the US to aid in the tanning of leather. According to this article, it made sense because the mangosteen rinds contained more tannin than was found in oak bark!
This raises a question as to the palatability of a mangosteen product that claims to be a whole fruit formulation. It would be much too bitter to consume unless the extract was chemically modified or was so dilute it could be masked by sweeteners. Imagine the flavor if you placed an entire grapefruit in a blender, bitter rind and all. As to making a juice out of just the edible interior portion, you might lose out on most or all of the complex xanthones found in the rind. Thus the need for the whole fruit. And since the USDA does not permit the import of fresh mangosteens from anywhere in Southeast Asia as of this writing, the fruit if processed in the US would have to be frozen before it could gain entry.
The table below comprises nutrition results performed at a US food testing lab that is fully certified and accredited. The fruit used were selected from the 2006 crop which was small and from young trees. The results may shift some as the trees mature but probably not much. The analysis below is from a batch of 32 fruits in total. The weight of each fruit was, on average, approximately 4 ounces or 113.4 grams. With the seeds included, the total of the edible part was 32.3% but I do not consider the seeds to be very palatable. Without the seeds, the total weight of just the edible portion of the mangosteen fruit was about 29% of the total whole fruit weight.
See the values in the table marked below with an asterisk
The mangosteen pH is quite low. On its own this would make for an intensely sour fruit were it not for the offsetting effect of the high sugar content. This is at the heart of the popularity of the mangosteen and explains why the fresh fruit is so intense in flavor.
This number was calculated using a refractometer in the field. The value is high and reflects the significant concentration of sugars. This in combination with strong acidity makes the fresh mangosteen such a memorable tasting experience.
This is one of the nutrients that helps to make the fresh mangosteen fruit an excellent source of this important element. Potassium in the diet plays a vital role in energy levels and heart health.
|Fiber, total dietary||1.35%|
|Riboflavin (Vitamin B2)||<0.08% mg/100g|
|Thiamin Vitamin B1)||0.08 mg/100g|
|Vitamin A/B-carotene||<50 IU/100g|
|Vitamin C||7.2 mg/100g|
|Vitamin E||0.6 IU/100g|
Non-Science... and nonsense!
The history and folklore of the mangosteen are dealt with on another page within this site. The page before you is about the scientific research currently being conducted on the mangosteen, Garcinia mangostana L. The science of the mangosteen means research experiments that can and have been repeated at independent laboratories, that use controls and double blinds, have chemical analyses performed by independent labs with national certification and no financial connection to or partnership with the company paying for the results. Science is not when the results of the experiments are from 'in house' tests or uncertified labs or "unpublished results" or from a friend of yours who knows organic chemistry.
Before I continue, I would like to draw your attention to the internationally renown Memorial Sloan-Kettering Cancer Center and the relevant page on their web site, as follows;
Below are some of the examples currently on line on different PMP sites of what I mean by non-science;
1) Anecdotes and testimonials of amazing benefits, ailments that seem to fade away with regular (purchases) use
2) References to fictitious medicinal uses from history
3) Unverified and untested recommendations of doctors, nutritional authorities, people with Ph. D's
4) References to scientific studies with the word mangosteen in them somewhere, anywhere
5) References to "therapeutic doses" of mangosteen extracts or ORAC or xanthones
6) Statements that God created the mangosteen, has higher authority than the FDA ( I kid you not!)
7) References to the big pharmaceutical conspiracy keeping the secrets of the mangosteen from you
8) Citing the Jim Duke USDA paper (4)
Let me start with #1.
Anecdotal evidence requires a leap of faith. You must choose to believe it if you want to believe it, not because you know it to be true. Who was the person who said it? How do you know it was ever said and not made up for promotional purposes? Was it actually a person using the product? Was it a person paid to say it or someone who sells the product? Was it the placebo effect? Did the person have a financial involvement with the firm? This is not to say that anecdotal or testimonial comments are worthless. But they are not scientifically obtained or verified and as such are not a good basis for making health decisions. As everyone knows, sometimes folkloric knowledge or tales passed along hold up under scientific scrutiny, leading to further research. They then become the basis for verified knowledge. But most of the time, anecdotes and testimonials are baseless and the result of ignorance or simple coincidence. They should be taken with a grain of salt at best if there is no scientific substantiation of the claims made.
Going back several centuries, one can only find a very limited amount of information regarding the medicinal uses of the mangosteen. Medical knowledge being what it was, there may have been benefits that were unknown to the user which were working in the background without their awareness. That said, the most common recurring historical reference of medicinal use is related to the astringence of and therefore diuretic effects of the rind of the mangosteen. Pretty much, it was for dysentery. I must add that numerous vendors of the PMP like to give their blurbs a classy touch and throw in words that seem sophisticated to add gravitas or significance to their presentation. My favorite is the frequent reference to "scribes" as it is relatively rarely seen word in the present day. Looking it up, an exercise not often used by the dimwits who write this drivel, one sees that this word actually refers to;
1 : a member of a learned class in ancient Israel through New
Testament times studying the Scriptures and serving as copyists, editors,
teachers, and jurists
2 a : an official or public secretary or clerk b : a copier of manuscripts
3 : WRITER; specifically : JOURNALIST
Basically, a "scribe" is someone who owns a pen and copies other people's writings; they 'transcribe.' Scribes of yesteryear were 1) in Israel and never saw or heard of a mangosteen or 2) were secretaries or people who 'transcribe' other people's work or 3) own a writing instrument and write about stuff. The recurring reference to "scribes" is the result of each of the marketers stealing each other's lamebrain ad copy. A proud moment for all of you. Maybe sometimes scribe means plagiarism.
The use of trained professionals to substantiate product claims is an admirable one. Who better to rely on! And they should be comfortable fully disclosing their education, schools, degrees and the years they completed the programs they received their degrees in. To prevent any conflicts of interest, these experts should always fully disclose their financial involvement with any company whose product they endorse or their comments are potentially prejudiced and compromised. If they are involved financially, they should say so. There is nothing wrong potentially with a financial involvement and in fact it could be a testimonial to their faith in the product in question. Once their involvement is out in the open, then their presentation with genuine verifiable reproducible results should be examined and appraised with an open mind. And they, the experts, should be willing to invite scrutiny and retesting of their claims.
This is probably the most offensive of all the PMP marketing claims out there. Legitimate scientists from accredited universities and pharmaceutical companies are constantly testing different chemicals from plants to try and isolate any substance that might provide a benefit to prolonging and enhancing life. I will not cite their work here as it could be misconstrued as a promotional tool but all one needs to do is go to www.scirus.com and enter the search term "mangosteen." Actual science and actual independent papers by real scientists will appear.
The chemicals primarily in the rind of the mangosteen are complex and in some cases unique to this fruit. They are isolated by simple ethanol extraction and or by more sophisticated means when a particular substance is being sought for a very specific test. The difference is important. The former is crude, yielding a soup of dozens or more chemicals. The latter method is finely tuned and the product yielded must be assayed to verify its chemical composition. Either way, the work done to date shows that some chemicals in the rind of the mangosteen may show some benefits against breast cancer, leukemia, pathogenic bacteria, colon cancer and so on... in test tube-maintained cancer cell lines and in rats. Not in living people. There are very promising hints of possible benefits down the road. We are not down that road yet.
Note that the above studies referred to were isolating and using specific substances extracted from the rind or whole fruit of the mangosteen. In order for a company to promote the benefits of PMP, they should prove that their product contains the same chemicals as those used in the scientific studies they highlight on their web sites. Proof that the specific chemical in the science article is also in the PMP seems to make perfect sense to me. Or what is the relevance of the cited article in the first place?
And one more item for #4. Many foods offer cancer-protective potential; broccoli, tomato, and brightly colored fruits and vegetables, etc. Do any of them cure cancer? No. Do any of them prevent cancer? No. Would you stop taking a cancer medication prescribed by an M.D. and switch to these foods or any other health food store item instead? I hope not! And if PMP is a powerful anticancer mix, do you feel comfortable ingesting an anti-cancer blend of unknown make-up in lieu of seeing an M.D.? Your call.
What exactly is a therapeutic dose of a substance that is not currently prescribed or part of any therapy recognized by any M.D. or pharmaceutical company in the USA? There is no prescription mangosteen extract in the pharmacy or powder from the rind that has been quantified to enable accurate dosing. Saying that the PMP contains, for example, 500 mg of a mangosteen extract or powdered rind or powder of the whole fruit tells us what exactly? Herbalists know that chemical composition and concentration varies from year to year, crop to crop and season to season. All cause wide variation in the amount of active ingredient in many botanicals. Who is quantifying this and what is it that is being quantified? You can not go by weight alone, either. Testing to quantify and qualify are required or one is just gambling with one's health.
ORAC stands for oxygen radical absorbance capacity. Radicals are the substances that naturally form in your tissue and blood as a result of normal cellular activities such as digestion, respiration, strenuous exertion and injury or unnaturally as a result of exposure to pollutants, poisons, cigarette smoke, radiation and so on. They are, as a group, considered a problem if they linger long enough in your system to attach themselves to cellular components and blood vessels because they are damaging to the health of these tissues. They oxidize them or adversely alter them at the cellular level. ORAC is a valuable indicator of how much antioxidant activity there is in a particular foodstuff. Research is active in this area because of the assumed benefit of the scavenging effects of antioxidant foods such as those mentioned above but also wine, beer, vitamin C, vitamin E and many other substances. Xanthones also show a high antioxidant activity but little is known about their effect in people. Are xanthones the best antioxidants? Totally unknown at this time.
What is also not known yet is how much antioxidant is needed or how well a particular ORAC source is absorbed. Does the body have limits as to how much can be used at a given time? If ORAC values are extremely high, can they cause damage by overdoing it or be a waste of money as the excess gets flushed from the system? All unknown at this time. Too little or too much of anything is a hazard. Even Vitamin C and the others can be consumed in excess with very bad results from toxicity. ORAC, therefore, is a quantifier but not qualifier of antioxidant benefits.
This line of reasoning would have people eating anything "natural" without concern for it's chemical content. The shark's liver, a rich natural source of vitamin A, can kill you from an overdose of vitamin A. And who in their right mind would eat a poison arrow frog because it is one of God's creatures??? If you want an eye-opener, look up sassafras tea, a nice folksy tea that delivers carcinogens. Natural?
Much as I hate to say it, there is some truth to this, in a way. Pharmaceutical companies can only exist if they make money. If a particular substance is very cheap or easily available and not able to be patented, then their ability to profit from that substance would be unlikely. But if there is a chemical in the rind of the mangosteen which could make it through clinical trials and then be patented or protected or synthesized, then it would make sense for a pharmaceutical firm to pursue the research. However, when a PMP site lists the scientific articles that contain the word mangosteen or xanthone and then goes on to state that big drug companies are keeping the secrets away from you, I would ask you who you think supplied the funding for the science papers the PMP company cited? Drug companies follow the money. As do the PMP companies.
Jim Duke assembled a list of chemicals in the rind and edible portion of the mangosteen. At the time, he was an employee of the ARS, the Agricultural Research Service. This is part of the U.S.D.A. He was not endorsing any of the components. He was listing them. There are many and they have a very wide range of potential activities. Those activities are still largely unknown. Any claims of benefits are those of the PMP companies and not Jim Duke (personal communication). He just listed them. There may be some hidden gems in the list and there may be some phytochemicals with as yet unknown toxicity at certain levels... Feel like gambling with the unknown?
Science, as opposed to non-science, means certified testing and quantifying of the contents of any product where marketers make health claims. If the PMP company cites a specific researchers' work, then the company should be willing to submit product samples for testing to see if the substances in the paper cited are in their formulation as well and at effective levels. By citing scientific research not directly related to the company's product, it gives the false impression that the PMP company's product will provide the benefits of conclusions made by others studying different substances. For example, if a PMP company cites a study in which beta mangostin was used on a particular cancer, then quantify how much beta mangostin is in the product being sold. In fact, all that really has been accomplished is the appearance of legitimacy by associating their product with citations of actual science done by actual scientists. Proof must be supplied that there is actual relevance.
This really applies to any and all claims that the benefits 'might' include anti-cancer protection (leukemia, breast cancer) or antibiotic or dermatological benefits. The PMP company should be willing to submit product samples to independent labs and universities for in vivo experimentation. Not in vitro i.e. test tubes. To truly test a product's efficacy, it has to be tested in a manner consistent with the formulation presented to the consumer, not to a lab rat or petri dish. Or it needs to be viewed as nothing more or less than a recreational beverage or product. When actual science is being conducted by scientists around the world on the extracts of the mangosteen rind, they are rarely if ever using the extracts on real people. And if they did, the chemicals in question that they have extracted for their work are what exactly? Whatever they are, how does the consumer know for a fact that they are the same as the contents of the PMP you are considering??? Please read (5) the following;
Medicinal Uses: Dried fruits are shipped from Singapore to Calcutta and to China for medicinal use. 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 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.
Julia F. Morton in her "Fruits of warm climates" book. See below for citation.
I ask you, what does the rind of a mangosteen have in it that you think you need? It may provide untold numbers of benefits. It may provide none. Go forward with your eyes open.
I would like to add one final comment on this topic. Much of the promotional content is the basis for the consumption of these products. But if deeper analysis of the promotional claims shows that most if not all of the claims are lies or intentional distortions of the facts, then why would one conclude that the product works? Any person or organization who must use lies to promote their product is really telling you that their product is a fake.
November 24, 2010
The need to add this update is long overdue and I thank those people who
patiently asked me for this over the last
year or two. As we head into the end of 2010, I find myself struck by how little has changed with regard to significant
mangosteen research in the now almost 5 years since I launched www.mangosteen.com. Pretty much, nothing has
changed. The direct scientifically proven health benefits connecting the consumption of processed mangosteen juice
or mangosteen juice with the rind and/or with other fruit juices simply does not exist at this time. There is no
connection that holds up to the scrutiny of science or the FDA.
I do not have the credentials to weigh in on the nutritional or physiological contributions to health that result from
consuming mangosteen beverages or mangosteen cocktails with other fruits. I do not have a degree in organic
chemistry, medicine or human physiology; I am just a grower of exotic fruit. What is evident, however, is that ongoing
work in labs is showing that if your lab rat has acne or certain cancers or inflammation or Alzheimer's, there may (or
may not) be something worth examining regarding certain phytochemicals found in the rind of the mangosteen... if
you inject it or apply it to a cancer cell line in a test tube or put it directly on the rat's skin in a purified form. But not if
you are human and not if you drink it. Work on humans is underway and may bear fruit in the years to come, just not
I may not have the credentials but Dr. Paul M. Gross does. Over the last 4 years I have been in contact with and
become friends with Paul Gross, author of the book "Superfruits" (2009, McGraw Hill) as well as other publications.
Paul has a very impressive curriculum vitae and a great web site at www.berrydoctor.com. And Paul seemed the
perfect person to ask if he would be willing to do a literature search to update where mangosteen research is today.
Is there a future potential for the medicinal contribution of chemicals found in the rind of the mangosteen? Possibly.
But all these years later, it is still on the horizon, still unknown, still impossible to say based on the degree to which
the field of research has progressed. Facts are still playing catch-up with claims. Science is still way behind the
hyperbole of current marketing claims. If this situation changes, I will do my best to post it online as soon as I can
verify it. Hopefully, this won't require waiting another 5 years!
Mangosteen literature update, Sept. 2010. Paul Gross, PhD, author of Superfruits, http://bit.ly/cf69Zf
Introduction and literature review.
This is an update on the state of biomedical literature on mangosteen, as assessed by published reports cataloged by
the US National Library of Medicine and published on PubMed.gov.
In the 4 years since the phytochemical literature of mangosteen was reviewed (1,2), it has continued to grow only at a
modest rate, with 68 total reports accumulating through September, 2010.
The publication rate calculates as an average of 17 per year. For reference, the annual publication rate on intensively
studied fruits like grapes and strawberries is several hundred reports each.
Remarkable among mangosteen publications is the research interest of Asian scientists who published 39 or 57% of
total. Although most of these were by Thai research groups, other Asian sources include China, Malaysia, Japan, Korea
Slowly over the past 4 years, US, western European and Mexican scientists were beginning to adopt mangosteen as a
research topic, publishing 13 papers or 19% of the total. However, by comparison to other fruits under the scrutiny of
American and European research, this attention on mangosteen remains negligible.
The edible mangosteen fruit itself attracted no research attention over the past 4 years.
Pericarp polyphenols, xanthones. 55 or 81% of all reports since 2007 dealt with biochemical characterization of
pericarp polyphenols, particularly the xanthone class and its major constituent, alpha-mangostin.
The mangosteen xanthone research activity can be further divided into major categories as
a) identification and biochemical characterization (8 studies),
b) description of in vitro antioxidant properties (5 studies),
c) use in disease model systems in vitro or in laboratory animals; anti-inflammatory mechanisms, neuroprotection,
cardiovascular diseases and cancer (27 studies),
d) development of insecticides, a long-duration interest in using pericarp extracts (4 studies),
e) anti-fungal and anti-bacterial activities (7 studies),
f) properties tested in humans for possible use for mouthwash and periodontal disease, acne and inflammation (4
Human studies. Although a few human studies were published over the 4 years, insufficient information about the
composition of mangosteen product used discourages science-based conclusions about the role or mechanisms
specifically of mangosteen components. For example, a commonly known juice blend of 8 different fruits and other
additives (undisclosed proportions) prevents any conclusion about specific mangosteen effects.
Reported in 2008, a clinical case study discussed the possible acidosis of a patient who had consumed mangosteen
juice excessively for dietary supplementation – http://bit.ly/ZxtL4
Notable, however, was the beginning in July 2009 of an NIH-registered clinical trial on mangosteen juice
(composition undefined) at the Mayo Clinic – http://bit.ly/9PLeOK
Entitled Mangosteen Effects on Inflammatory Markers in Atrial Fibrillation Trial, this clinical trial is currently
enrolling up to its target of 250 adult patients divided into 4 groups, two of whom will receive mangosteen juice twice
daily over 6 months. All patients will have existing atrial fibrillation requiring anticoagulant therapy. Outcome
measures include determination of blood levels of inflammatory biomarkers, such as interleukin 1, interleukin 6, C-
reactive protein (CRP), and tumor necrosis factor alpha. The study is scheduled to conclude in December, 2011.
The hypotheses being tested are 1) whether the addition of mangosteen juice to standard medical care will reduce the
further risk of atrial fibrillation and also 2) whether the effects of mangosteen juice reduce biomarkers of
Summary and conclusions.
Although the above review demonstrates continuing basic research interest in mangosteen, particularly for its
xanthones, no acceptable conclusions can be made yet about possible health benefits of mangosteen xanthones in
humans. This is the same conclusion reached in a review 4 years ago (1) and in a subsequent commentary (2).
As clinical research requires demonstration of safety, efficacy and specificity of ill-defined natural compounds before
they are applied to treat diseases in humans, it is therefore reasonable to conclude that comprehensive human studies
on mangosteen xanthones are at least a decade away.
Analysis to date shows that mangosteen is a low-nutrient fruit (1) and is not widely distributed to many markets as a
whole food, but certainly is a fruit to be enjoyed simply for its eating pleasure.
Among superfruits, mangosteen research activity is among the lowest (3), indicating that mangosteen has not met
nutritive, market or research standards to be included among true superfruits.
1) Is mangosteen a superfruit? Nutrient and antioxidant properties, Feb. 2007, http://bit.ly/9g9pNV
2) The mangosteen controversy, May 2009, http://bit.ly/b16aTi
3) Superfruits have signatures, Aug. 2008, http://bit.ly/d8hmmt
October 5, 2006
I guess it was just a matter of time. The best way to fully understand anything is to approach it with an open mind; no opinion, no prejudice, no agenda. If you have a conviction that precedes the facts, then you must provide proof that stands up to testing again and again and again. This is the basis of science.
I routinely check the internet for actual (as opposed to paid for) news about the mangosteen. I have been doing this for years and have marveled at the explosion of web sites that claim to be releasing breaking "news" or "discoveries" to the public when in fact they are really just running glorified advertisements. Infomercials. Presumably paid for by someone in need of this kind of exposure. So it was with some relief when I stumbled upon the following articles with titles that you should search for on your own so you can see the sources with your own eyes. Try Google or Yahoo or MSN, enter the word "mangosteen" and then search "news." Which see;
UPDATE 1-XanGo juice drink maker gets US FDA warning
Tue Oct 3, 2006 2:41pm ET
FDA Warns XanGo Juice Maker
XanGo and the FDA
This is by Linda Fantin and Robert Gehrke with
The Salt Lake Tribune
Coincidentally, a very interesting article by Jeffrey Ressner showed up at about the same time. His affiliation is with Time magazine. Check out the MLM or multilevel marketing commentary while the link is still live. For some people reading about processed mangosteen products and contemplating how involved they want to be with them, it will help to put the supplement industry in a light this industry may not appreciate.
(1) Richards, A. J. Studies in Garcinia, dioecious tropical forest trees: the origin of the mangosteen G. mangostana L.). Botanical Journal of the Linnean Society (1990). 103: 301-308
(2) Carl M. Ramage, Lillian Sando, Cameron P. Peace, Bernard J. Carroll & Roderick A. Drew. Genetic diversity revealed in the apomictic fruit species Garcinia mangostana L. (mangosteen). Euphytica 136: 1-10. 2004
(3) Chinawat Yapwattanaphun and Suranant Subhadrabandhu. Phylogenetic relationship of mangosteen (Garcinia mangostana) and several wild relatives (Garcinia spp.) revealed by ITS sequence data. J. Amer. Soc. Hort. Sci. 129 (3): 368-373. 2004.
(4) Dukes, James. http://www.ars-grin.gov/duke/ and http://www.ars-grin.gov/duke/warning.html
(5) Morton, Julia F. Fruits of warm climates. Published by Julia F. Morton. 1987.
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