What is Mangosteen?
Mangosteen is Garcinia mangostana, a fruit-bearing tree native to Southeast Asia. The fruit has been dubbed the “Queen of Fruits,” thanks to its delicately-flavored white pulp, although it’s the surrounding—and inedible—pericarp (i.e., the outer layer) that attracts the most interest from researchers and health-conscious consumers in the West.
What’s So Interesting about It?
As it turns out, it’s rich in a range of phytochemicals, including a class known as xanthones.
Although xanthones are not unique to mangosteen, it contains several, including α-, β- and γ-mangostins, garcinone and gartanin, that appear to have therapeutic potential. Pericarp extracts have been shown to have antioxidant, anti-cancer, anti-inflammatory, analgesic, anti-microbial and aromatase-inhibiting activities in cell cultures and animal models.
Thus, it’s fair to say that the phytochemicals in mangosteen are biologically active and potentially healthful. But the key word here is “potentially.”
What Does the Science Say about Mangosteen?
Unfortunately, most of these results have not been confirmed by human studies, so it’s difficult to predict how applicable they are to you and me.
Digestion and first-pass metabolism don’t happen in cell cultures. Likewise, there are going to be differences between the results you get from swallowing a poorly-characterized juice product, vs. injecting defined amounts of semi-purified xanthones into implanted mouse tumors.
In other words, you can’t make specific claims about preventing or treating human disease, in the absence of well-controlled, human clinical trials to back them up. This isn’t just about good science; it’s also the law (at least here in the US).
This is an important distinction to keep in mind, as irresponsible marketers have suggested that mangosteen and/or its xanthones can prevent or treat diseases such as cancer. However, as the Memorial Sloan-Kettering Cancer Center states:
“There are no clinical data available to support the beneficial effects of mangosteen in humans.”
Indeed.
Peer Reviewed Human Data?
The only peer-reviewed human studies I could find were tests of specific commercial products: “Mangosteen Plus with Essential Minerals” and “XanGo.” Needless to state, none of these studies do much to bolster mangosteen’s claim to “superfruit” status.
The company behind Mangosteen Plus, Vemma, sponsored two product studies: the first demonstrated that there was a modest, but statistically significant rise in subjects’ plasma antioxidant status after consuming the product.
The second determined that Mangosteen Plus reduced test subjects’ C-reactive protein (CRP) levels and improved some markers of immune function. More of the test group also reported improvements in their (self-evaluated) health status, although the authors state this was “a relatively subjective indicator.”
The single XanGo study covered similar territory: the authors looked at antioxidant levels, CRP and other markers of inflammation in subjects consuming 6 oz.–18 oz. of juice per day for 8 weeks. A significant reduction in CRP was seen, but only in the group consuming the highest amount of juice (18 oz.) (Considering that the recommended dose of XanGo is 1–3 ounces per day, however, this could be considered a major FAIL).
Although the companies involved should be commended for their willingness to put their products to the test, there are some problems with these studies. For starters, neither product is pure mangosteen: Mangosteen Plus contains a range of vitamins and minerals, in addition to aloe vera and green tea extracts.
XanGo, on the other hand, is a blend of mangosteen puree with other fruit juices.
Thus, it is difficult to attribute the results (such as they are) solely to their mangosteen contents.
Underwhelming…
Secondly, although the results of each study are positive, they’re also a tad… underwhelming. They offer exactly zero support to claims that mangosteen can prevent/treat serious diseases.
In addition, the studies offer little perspective on the merits of the products tested, relative to less expensive, more readily available alternatives.
And alternatives do exist: for example, tomato juice, orange and blackcurrant juices, tart cherry juice and a commercial, sterol-fortified orange juice drink have been found to reduce oxidative stress and markers of inflammation (including CRP), too.
To be blunt, it’s not enough to demonstrate that a product is “good” in some way. If a premium price is being charged, it should be demonstrably superior to more ordinary products.
Lastly, these studies were quite brief… so they tell us nothing about the long-term benefits (if any) of the products on users’ overall health and longevity.
This takes us back to the evidence discussed at the top. Certainly the results of in-vitro tests on tumor cells and animal experiments are interesting and worth noting. But that’s all they are, at this point in time.
This point was also stressed by “The Berry Doctor,” Paul Gross, Ph.D., and a co-author, mangosteen farmer Ian Crown. In their article, “The Mangosteen Controversy,” they stated:
“Research interest for mangosteen is increasing, however, as 75% of the total number of mangosteen publications have occurred since 2000 on topics such as antioxidant characteristics of xanthones and in vitro disease models. Still, this level of research places mangosteen phytochemicals at the earliest stages of investigation, many years from building sufficient scientific substantiation to justify human studies that may validate a health benefit (8).
There is no scientific evidence xanthones or any other mangosteen extracts have significance in human biology (9-12).
No health authority supports consumption of processed mangosteen products to gain health benefits or treatment of any human disease condition…”
The Center for Science in the Public Interest (CSPI) affirmed this assessment in its own publication, “Squeezing Cold Cash Out of Three ‘Hot’ Juices.”
So does this mean mangosteen is “bad,” or is not worth buying?
Warning: Over-hyped and Unproven
Not necessarily… right now, it’s just over-hyped and unproven. Time (and more research) will tell if mangosteen (as well as some other exotic “superfruits”) are truly as “hot” as promoters insist they are.
For the record, though, mangosteen supplements and juices appear to be non-toxic (although prescription drug interactions are possible—when in doubt, check with your doctor or pharmacist).
In addition, affordable, standardized products are available. So if you’re interested in experimenting, do some comparison shopping first. Large online retailers such as iHerb.com, Swanson, Vitamin Shoppe or Vitacost are good places to search, and offer a range of alternatives to pricey multi-level marketing (MLM) products.
You can buy mangosteen products online at iHerb.com, one of our recommended online retailers.
