WHAT WE KNOW
Goji berries are one of the so-called superfruits that have attracted much attention in recent years. One of the most nutritionally dense fruits in the world, goji berries (also known as wolfberries) have been used in Chinese medicine for over 2,000 years. What’s the appeal? They have been found to make people feel generally more super. And who doesn’t want to feel better?
While goji berries have a very holistic benefit to one’s sense of well-being, they are frequently used to aid with sleep and stress, in particular. That’s because data has shown that goji berries have among the highest concentrations of melatonin among edible plants. In fact, as the authors of one study reported, “The results found that participants experienced significantly increased [...] sleep quality, ease of waking up, ability to focus, mental acuity, calmness and an overall feelings of health, contentment and happiness."
Researchers are also exploring the effect of goji berries on vision with several studies suggesting the fruit has a positive impact on macular health. Goji is also recognized as a good source of antioxidants.
Sleep and stress
In this randomized, double-blind, placebo-controlled study on healthy adults, the researchers set out to examine the general effects of goji berries. Study participants were administered 120 mL Lycium barbaric juice or placebo for 14 days and then asked to subjectively answer a questionnaire about well-being, neurological and psychological traits, gastrointestinal complaints, musculoskeletal complaints and cardiovascular complaints, plus side effects before and after. The results found that participants experienced significantly increased energy, athletic performance, sleep quality, ease of waking up, ability to focus, mental acuity, calmness and an overall sense of feeling healthy, content and happy. They also reported significantly decreased levels of stress and significantly improved GI function. No changes in musculoskeletal or cardiovascular complaints were reported.
Harunobu Amagase and Dwight M. Nance. "A randomized, double-blind, placebo-controlled, clinical study of the general effects of a standardized Lycium barbarum (Goji) Juice, GoChi” The Journal of Alternative and Complementary Medicine. May 2008, 14(4): 403–412.
This study looked at the health benefits of goji fruit juice on older adults. The randomized, double-blind, placebo-controlled study included 60 healthy adults (55 to 72 years old) who were given 120 ml daily (equivalent to 150 g fresh fruit) or placebo for 30 days; measurements taken before and after treatment. Results showed significantly increased lymphocytes, IL-2 (interleukin-2) and immunoglobulin G, all of which are markers of strengthened immunity. Test subjects also reported significantly increased general feelings of well-being such as reduced fatigue and improved sleep, increased short-term memory and focus. No adverse reactions or abnormal symptoms were reported.
Harunobu Amagase, Bixuang Sun, and Dwight M. Nance. “Immunomodulatory Effects of a Standardized Lycium barbarum Fruit Juice in Chinese Older Healthy Human Subjects”Journal of Medicinal Food. October 2009, 12(5): 1159–1165.
This work reviews the available data on melatonin and serotonin levels in edible plants, including goji berries. The data suggests that goji berries have among the highest concentrations of melatonin from the samples reviewed.
There is ongoing research on the effects of goji berries as it relates to the following health concerns:
In this study, the authors investigated the relationship between variables and the optical density of macular pigment (MP) in a group of subjects from a northern European population. The authors concluded that “these findings are consistent with the hypothesis that supplemental lutein and zeaxanthin (found in goji) may delay, avert, or modify the course of this disease.”
Beatty S, Murray IJ, Henson DB, Carden D, Koh H, Boulton ME. “Macular pigment and risk for age-related macular degeneration in subjects from a Northern European population.” Invest Ophthalmol Vis Sci. 2001;42(2): 439–46
The aim of this study, (a single-blind, placebo-controlled, human intervention trial of parallel design) was to provide data on how fasting plasma zeaxanthin concentration changes as a result of dietary supplementation with whole wolfberries (goji berries). The results found “that zeaxanthin in whole wolfberries is bioavailable and that intake of a modest daily amount markedly increases fasting plasma zeaxanthin levels.”
The purpose of this study was to evaluate the effects of daily supplementation with a proprietary milk-based formulation of goji berry, Lacto-Wolfberry (LWB), on macular characteristics and plasma zeaxanthin, and antioxidant capacity levels in elderly subjects. The research found that “overall, daily dietary supplementation with goji berry for 90 days increases plasma zeaxanthin and antioxidant levels, as well as protects from hypopigmentation and soft drusen accumulation in the macula of elderly subjects. However, the mechanism of action is unclear, given the lack of relationship between change in plasma zeaxanthin and change in macular characteristics.”
In this study, researchers used samples from countries worldwide and assayed the samples for their total antioxidant content using a modified version of the FRAP assay. The researchers found that goji berries are high in antioxidant values among this sample.
Carlsen MH, Halvorsen BL, Holte K, Bøhn SK, Dragland S, Sampson L, Willey C, Senoo H, Umezono Y, Sanada C, Barikmo I, Berhe N, Willett WC, Phillips KM, Jacobs DR Jr, Blomhoff R. The total antioxidant content of more than 3,100 foods, beverages, spices, herbs and supplements used worldwide. Nutr J. 2010 Jan 22;9:3.
In this experiment, 29 endophytes were isolated from different organs and tissues of Lycium barbarum of Ningxia by tablet coating method. The experimental results indicated that “endophytic fungi of L. barbarum of Ningxia have a great developing and application prospect for the development of antioxidant agent.”
This study suggests that goji berries hold potential benefit for neuronal diseases due to its effect against oxidative stress, inflammation, apoptosis and cell death with minimal side effects.
This study found that goji has significantly higher total antioxidant activities when compared to other genotypes.