At
a popular cancer meeting in September I was assailed by sellers of a bottled drink
made from goji. In my ignorance, I had never heard of this drink, but was assured
by a bright-eyed young salesperson that it was more powerful and better tasting
than yesterday's sensation, XanGo. So I tasted the
goji juice blend she offered me, and guess what? It really was delicious! Sweet
and sour. Complex and intriguing. If goji ever filters down to my supermarket,
I definitely intend to buy some.
But
apparently goji is more than just a refreshing beverage. According to one website
it is the "number one-rated, third party tested and validated, patent-pending,
single focus functional health tonic designed to deliver you incredible health
benefits." The very name of the website, www.beyoungnow.com, gives some idea
of the extravagant benefits they are talking about.
The
hype for goji is way over the top. "If You Found The Fountain Of Youth...Would
You Stop To Take A Drink?" asks one website. Dr. Earl Mindell, a pharmacist
who describes himself as "the world's leading nutritionist," wrote a
pamphlet in which he tells the story of Li Qing Yuen, who supposedly lived to
be 252 years old. The source of this longevity? You guessed it: goji. Dr. Mindell
calls his story "a powerful testimony to [this] remarkable berry "
(Mindell 2003).
Dr.
Mindell has formulated his own version of goji that, he says, is nearly identical
to "the original Himalayan goji berries used for centuries by ancient healers!"
Another
website calls its version of goji "the most nutritionally dense nutritional
source on the planet," and calls it "among the most revered of sexual
tonic herbs" in Asia. Echoing the classic movie "Doctor Strangelove,"
it promises to increase "sexual fluids and enhance fertility."
As
with XanGo and noni juice, two earlier "functional juice" fads, the
reason people are willing to pay this much money is not simply because of the
product's exotic taste, but because they believe that these juices may do something
extraordinary for their health. In addition to making you a stud at age 120, the
alleged benefits of the juice include fighting cancer, improving the function
of the immune system, and decreasing the side effects of chemotherapy and radiation.
Effects
on Cancer
Another
website
tells us that in China, "researchers claim that the goji berry is beyond
a prevention for cancer, but reveal [sic] that it is a cure for cancer!"
"Tibetan
Goji berries are now undergoing intense scrutiny as a cancer drug in Mongolia,
China, Japan and Switzerland," says another.
"The
Himalayan Goji Berry can add 20 years to your life, shut down cancer cells, supercharge
your immune system and rev up your love life! Believe it or Not," says yet
another website.
Alas,
such "incredible health benefits" come at a price. In its current incarnation
as a "functional food," goji is still expensive. A self-described "number-one
rated" goji product sells for $44 per liter bottle, plus shipping. (Discounts
are available for those who join a marketing network, and cheaper versions are
available over the Internet.)
What
is Goji?
The
pitches I heard at the cancer meeting certainly promised patients that goji would
impart great health benefits. But is this reasonable to expect?
Goji
(gouqi or gou qi zi) is the Chinese name for a number of different species. It
usually refers to varieties of Lycium, called in English wolfberry,
matrimony vine, or Chinese boxthorn. Lycium is an evergreen shrub that is often
spiny and grows in temperate and subtropical regions. The two species most commonly
used in folk medicine are Lycium chinense or Lycium barbarum, both in the nightshade
(Solanaceae) family.
The
fruit is the main source of medicinal extracts, although the leaves are also sometimes
consumed as food. Traditionally, in various cultures, goji has been used to treat
inflammations, skin irritations, nosebleeds and aches and pains, and has also
been used as a sedative (Dafni 1994). In China, it is often used in combination
with other botanicals to treat poor vision, anemia, and cough (Bensky 1993). In
the test-tube, a polysaccharide (complex sugar) isolated from goji has been shown
to have anti-cancer effects (Gan 2001). It also has some immune enhancing properties
(Gan 2003). Goji seems to be able to increase the therapeutic effects of radiation
(i.e., to act as a radiosensitizer), at least in mice (Lu 1991).
Lycium
chinense originates in Hebei province in China, the area around Beijing. Its berries
are small, orange to light red in color and have many seeds. They are too sour
to eat on their own, and so are added to other foods (Mindell 2003).
The
more commonly utilized goji berry is Lycium barbarum. This plant originates in
Tibet and Inner Mongolia. Apparently, various places compete for the title of
"Goji Capital of the World." Some people say this is Ningxia, situated
in northwest China along the Yellow River. According to Dr. Mindell, "Ningxia
goji berries are a real treat. The fruits are large and plump, with a beautiful
deep red color, few seeds and an exquisitely sweet taste and juicy texture."
According
to Dr. Mindell, however, the best goji berries actually come from Xinjiang, a
huge region at the very Western corner of China, bordering Tibet and Mongolia.
To
view a drawing of goji, from Prof. Dr. OttoWilhelm Thomé's Flora von Deutschland
Österreich und der Schweiz, click
here.
The
Evidence
There
is plenty of charming folklore surrounding the goji berry. But the real question
is whether there is compelling enough evidence to justify spending $44 for a bottle
of fruit juice.
PubMed,
the US government's comprehensive database of 15 million medical journal citations,
lists a total of 102 articles on Lycium species. Fifty of these are on Lycium
barbarum. Most of these concern laboratory tests, and only five articles even
mention cancer. If we restrict our consideration to just clinical trials (structured
studies involving human subjects) there are precisely two. One is irrelevant to
our purposes, since it does not concern cancer (Breithaupt 2004).
A
Single Report
This
leaves a single report of a clinical trial in cancer using a goji extract. It
was carried out by G.W. Cao and colleagues at the Second Military Medical University
in Shanghai and published in a Chinese medical publication, the Chinese
Journal of Oncology. Seventy-nine patients with advanced cancer were enrolled
in a trial in which they were treated with lymphocyte-activated killer (LAK) cells
+ interleukin-2 (IL-2). But some of the patients also received polysaccharides
(complex sugars) derived from Lycium barbarum (abbreviated LBP).
Initial
results of the treatment from 75 evaluable patients indicated that "objective
regression of cancer was achieved in patients with malignant melanoma, renal cell
carcinoma, colorectal carcinoma, lung cancer, nasopharyngeal carcinoma."
It also was supposedly effective in "malignant hydrothorax" (which presumably
refers to pleural effusion, a collection of fluid within the chest cavity which
frequently accompanies thoracic cancers).
According
to this Chinese article, the response rate of patients treated with LAK + IL-2
alone was 16.1 percent. But when goji extract was given to some patients the response
rate jumped to 40.9 percent. The authors also state that the remission in patients
treated with LAK + IL-2 plus goji extract lasted significantly longer and led
to a more marked increase in natural killer (NK) cell activity than LAK + IL-2
alone.
"The
results indicate that LBP can be used as an adjuvant in the biotherapy [i.e.,
immunotherapy] of cancer," the authors concluded.
This
is a potentially important finding. A juice that can double the response rate
to standard cancer treatment would be worth many multiples of $44. However, there
remain numerous questions about this clinical trial that might be difficult to
answer, since all there is to go on is an abstract in PubMed. The full article
is in a Chinese journal that does not maintain an English-language website. Dr.
Gao is the co-author of just seven PubMed articles, none of which gives his contact
information.
If,
however, I could interview Dr. Gao here are some of the questions I would ask:
How many
patients were treated in each group?
What
exactly is your standard for an "objective regression"?
How
much longer did the remissions last in the goji-added group than the control group?
Was
there any effect on disease-free or overall survival?
Have
there been any follow-up studies using goji with drugs in a single form of the
disease?
Additionally,
this Chinese study uses a non-standard therapy for many of these cases, i.e. LAK
+ IL-2. This was a "hot" therapy in the 1980s and early 1990s, primarily
because of the advocacy of Steven Rosenberg, MD, of the National Cancer Institute
(Rosenberg 1993). But is rarely used today. Indeed, the NCI has stated that the
addition of LAK to IL-2 has "not improved response rates or durable remissions
sufficiently to merit the expense and complexity of this therapy" (NCI 2004).
Even
the NCI's clinical trials database
does not list a current clinical trial using these once popular treatments (Kimura
1997). So this small goji trial uses an outdated therapy. It would, however, be
interesting to see what goji extract could do when added to the current treatment
for a group of patients with biopsy-confirmed cancer of a single type.
Therefore,
although I am intrigued by Dr. Gao's findings, I would still recommend that patients
hold onto their $44 until there is better documentation of the drink's purported
effects.
By
comparison to goji, something as simple as green tea looks to have an equal or
even better effect at about one-hundredth of the cost. Over 1,000 articles
on tea and cancer have already been published in the medical literature, of which
19 refer to randomized, controlled trials. A study published in February, 2004,
showed that when heavy smokers drank four cups of green tea per day for four months
there was a significant decrease in a urinary marker of DNA damage (Hakim 2004).
Green tea might also be beneficial for those undergoing conventional treatment
for cancer, although that is far from proven.
The
network marketeers are hoping we will go chasing after goji, in mankind's never
ending quest for a magic potion to cure our most persistent ills. However, we
would be far better off to let science be our guide. There are more effective,
better proven, and certainly less expensive alternatives available to all.
Caution:
Every indication is that goji is safe to drink in moderation. However, there is
one exception to that rule. Like some other natural products, it may have anti-coagulant
activity. While this is generally desirable, it could lead to a dangerous situation
for anyone who is taking the prescription medication Warfarin (coumadin). One
should therefore be careful about taking the two together, as this could lead
to dangerous episodes of bleeding (Lam 2001).
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 goji juice is
the best thing since... well, orange juice. Click
here to read some of their comments.
References:
Breithaupt
DE, Weller P, Wolters M, Hahn A. Comparison of plasma responses in human subjects
after the ingestion of 3R,3R'-zeaxanthin dipalmitate from wolfberry (Lycium barbarum)
and non-esterified 3R,3R'-zeaxanthin using chiral high-performance liquid chromatography.
Br J Nutr. 2004;91:707-13.
Cao
GW, Yang WG, Du P. [Observation of the effects of LAK/IL-2 therapy combining with
Lycium barbarum polysaccharides in the treatment of 75 cancer patients] Zhonghua
Zhong Liu Za Zhi. 1994;16:428-31.
Dafni
A,.Yaniv Z. Solanaceae as medicinal plants in Israel. J Ethnopharmacol. 1994;44:11-8.
Gan
L, Wang J, Zhang S. [Inhibition the growth of human leukemia cells by Lycium barbarum
polysaccharide]. Wei Sheng Yan Jiu. 2001;30:333-5.
Gan
L, Zhang SH, Liu Q, Xu HB. A polysaccharide-protein complex from Lycium barbarum
upregulates cytokine expression in human peripheral blood mononuclear cells. Eur
J Pharmacol. 2003;471:217-22.
Hakim
IA, Harris RB, Chow HH, Dean M, Brown S, Ali IU. Effect of a 4-month tea intervention
on oxidative DNA damage among heavy smokers: role of glutathione S-transferase
genotypes. Cancer Epidemiol Biomarkers Prev. 2004;13:242-9.
Huang
Y, Tan A, Shen Y, Lu J. [Scavenging effect of total flavonoids of lycium barbarum
L on active oxygen radicals and inhibitory effects on heat output from L1210 cells]
Wei Sheng Yan Jiu. 1998;27:109-11, 115.
Kimura
H, Yamaguchi Y. A phase III randomized study of interleukin-2 lymphokine-activated
killer cell immunotherapy combined with chemotherapy or radiotherapy after curative
or noncurative resection of primary lung carcinoma. Cancer. 1997;80:42-9.
Lam
AY, Elmer GW, Mohutsky MA. Possible interaction between warfarin and Lycium barbarum
L. Ann Pharmacother. 2001;35:1199-201.
Liu
XL, Sun JY, Li HY, Zhang L, Qian BC. [Extraction and isolation of active component
for inhibiting PC3 cell proliferation in vitro from the fruit of Lycium barbarum
L.] Zhongguo Zhong Yao Za Zhi. 2000;25:481-3.
Lu
CX, Cheng BQ. [Radiosensitizing effects of Lycium barbarum polysaccharide for
Lewis lung cancer] Zhong Xi Yi Jie He Za Zhi. 1991;11:611-2, 582.
Rosenberg
SA, Lotze MT, Yang JC, et al. Prospective randomized trial of high-dose interleukin-2
alone or in conjunction with lymphokine-activated killer cells for the treatment
of patients with advanced cancer. J Natl Cancer Inst. 1993 ;85:622-32.
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