Goji berry is a small red fruit resembling an elongated cherry. Of Tibetan origin, it has been cultivated for more than 2,000 years in south eastern China, where it has traditionally been used to prepare many medicines.
History of goji berries
Over the past years, the dried berries and goji berries juice became very popular in the West, particularly because of their antioxidant content. This popularity is strongly driven by allegations pertaining to marketing rather than well-documented data. How can we not be perplexed by reading the following allegations “Miraculous berries”, “The secret of youth of Tibet”, “Berries of the smile”, etc.
In China, goji berries are eaten for at least 2,000 years. According to traditional Chinese medicine, the fruit has the property to “feed the kidneys and the liver”, “wet the lung” and “supplement the Yin”. Chinese herbalists use it, along with several other plants, to treat male infertility and respiratory disorders, and to fight against fatigue. For prevention, they use it to protect the liver and kidneys, to stimulate the immune system, preserve the integrity of the neurological functions and vision organs against aging effects.
Research on the goji berries
Although some manufacturers or distributors of goji berries claim the latter has been the subject of multiple studies, no recent and reliable clinical trial confirmed the effectiveness of berries when they are used alone. Recent research has studied especially the antioxidants they contain. They identified four polysaccharides specific to this plant. These substances, according to in vitro and on animal’s tests, have antioxidant properties, stimulatory, anti-diabetic, antihypertensive, anti-infertility and hypolipidemia.
A preliminary double-blind placebo trial with low methodological quality was published in May 2008. It was conducted in the United States by the manufacturer of the product GoChi (FreeLife International LLC) alongside 34 adults in good health. The results indicate that consumption of 120 ml (½ cup) of goji berry juice in two weeks improved the general well-being (energy level, sleep, mood, etc), compared to the control group. However, as participants were already consuming goji berries for several months prior to the test; they were able to recognize if they were drinking a goji juice or a placebo. In this case, it is more than a blind test, much limiting the validity of the results obtained, as the small number of subjects, short duration and the subjectivity of the questionnaire completed by the participants.
A comparative clinical trial published in 1994 was conducted in China including 75 patients with various cancers at an advanced stage (skin, renal, colorectal, lung, etc.). The results indicate that the addition of purified compounds (polysaccharides) goji to a classical immunotherapy treatment (lymphocytes LAK) had beneficial effects. These results do not conclude the effectiveness of juice or berries in the treatment of cancer.
A case study published in 1989 was conducted in China including 35 asthmatics in recovery. They took during 10 weeks a mixture containing seven plants, including goji berries: this traditional remedy (Invigorating Kidney) reduced the patient’s airway obstruction.
Tests on animals or in vitro
Asian researchers were interested in the compounds of the goji berries. The results of their tests in vitro indicate that compounds isolated from the bark of the root of goji berries have antimicrobial and antifungal properties, and the berries have an antiviral action. These data tend toward the validation of goji berries use in traditional Chinese medicine to treat viral respiratory infections.
Other tests were done on animals or cells with purified goji berries compounds, mainly its polysaccharides, also giving interesting results in several health issues, such as infertility and aging. It can however be concluded that the juice or pulp of the fruit, eaten raw, would have the same effect.
Pregnancy and breastfeeding. Data are insufficient to establish the safety of the goji berries during pregnancy and breastfeeding. It is possible that the goji berries stimulates the uterus.
Allergy or intolerance. Some people may suffer from allergy or intolerance of the goji berries or other foods of the family of Solanaceae (potato, apple, tomato, eggplant, pepper, chili, etc.)