A Friendly Skeptic Looks at Goji Juice
By Dr. Ralph Moss
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 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).
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."
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.
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).
