Clinical studies in healthy volunteers
Amagase and Nance26 performed a randomized, double-blind, placebo-controlled, clinical study to investigate the general effects of use of a standardized L. barbarum juice (GoChi) for 14 days in healthy Chinese subjects. GoChi was produced from fresh ripe LBFs grown in the People’s Republic of China. As a finished product, the juice contains 1,632 mg/day serving (120 mL, ie, 13.6 mg/mL) of LBPs. The placebo matched the color, flavor, and taste of GoChi in a formulation of sucralose (10 mg), artificial fruit flavor (30 mg), citric acid (60 mg), and caramel color (12 mg) in 30 mL of purified water. The effects of GoChi were examined by questionnaire subjective ratings (0–5) of general feelings of well-being, neurologic/psychologic traits, gastrointestinal, musculoskeletal, and cardiovascular complaints as well as any adverse effects. Body weight, body mass index, blood pressure, pulse rate, and visual acuity were also measured before and after consuming 120 mL of GoChi/day or placebo control solution.26 Significant differences between day 1 and day 15 were found in the GoChi group (n=16) with increased ratings for energy level, athletic performance, quality of sleep, ease of awakening, ability to focus on activities, mental acuity, calmness, and feelings of health, contentment, and happiness. GoChi also significantly reduced fatigue and stress, and improved regularity of gastrointestinal function. In contrast, the placebo group (n=18) showed only two significant changes (heartburn and happiness).26 No significant changes in musculoskeletal or cardiovascular complaints were observed in either group. All parametric data (body weight, etc) were not significantly different between groups or between day 1 and day 15 for either group. These results clearly indicate that daily consumption of GoChi for 14 days increases subjective feelings of general well-being and improves neurologic/psychologic performance and gastrointestinal functions.
Amagase et al27 further conducted a randomized, double-blind, placebo-controlled clinical study to examine the antioxidant effects of GoChi in healthy Chinese adults living in Hunan province, People’s Republic of China. In the study, 50 Chinese healthy adults aged 55–72 years were recruited and treated with Goji juice containing 13.6 mg/mL LBPs at a dose of 120 mL/day or placebo (n=25 each group).27 In vivo antioxidant markers including serum levels of SOD, GPx, and lipid peroxidation (indicated by the level of MDA) were determined before and after GoChi or placebo consumption for 30 days. The results showed that GoChi consumption significantly increased serum SOD level by 8.4% and GPx by 9.9%, whereas MDA was significantly decreased by 8.7%.27 There were no dropouts during this 30-day trial. After GoChi or placebo consumption, no abnormalities were seen in subjects’ energy, urine, stools, or other examined physical parameters. These data indicate that chronic GoChi is well tolerated in humans and can promote antioxidant capacity in humans via upregulating antioxidative enzymes.
Four randomized, blind, placebo-controlled clinical trials were pooled to identify the general effects of oral consumption of 120 mL/day GoChi.28 A questionnaire consisting of symptoms graded 0–5 was given to the participants. For each question, the score changes in the questionnaire between pre- and post-intervention were summarized by the standardized mean difference and associated standard error of the mean to perform the meta-analysis. The change was also characterized into a binary outcome, improved or not, to derive odds ratio (OR) and associated standard error of the mean derived by a binary outcome using the Mantel–Haenszel method. The meta-analysis and heterogeneity were evaluated with the R program using the rmeta package. In total, 161 participants (18–72 years old) were included in the meta-analysis. Compared with the placebo group (n=80), the GoChi-treated group (n=81) showed significant improvements in weakness, stress, mental acuity, ease of awakening, shortness of breath, focus on activity, sleep quality, daydreaming, and overall feelings of health and well-being under a random effects model.28 A fixed effects model showed additional improvements in fatigue, depression, circulation, and calmness. The OR indicated significantly higher chance to improve fatigue, dizziness, and sleep quality.28 Three studies had statistically significant heterogeneity in procrastination, shoulder stiffness, energy, and calmness. The meta-analysis confirmed the various health-promoting effects of GoChi in humans.