Cancer-related fatigue is the most common unmanaged symptom in patients who are undergoing chemotherapy, radiation therapy, biologic therapy, or have completed cancer therapy. The patients describe cancer-related fatigue as a feeling of being overwhelmingly tired and fatigued, which cannot be relieved by sleep. The purpose of this study was to investigate the potential of 3 doses of American ginseng root for alleviating cancer-related fatigue and to examine the potential toxicity of American ginseng. The only adverse side effect traditionally attributed to American ginseng (Panax quinquefolius, Araliaceae) is insomnia.
Patients (n = 290) with cancer-related fatigue, determined by a score of 4 or more on a screening questionnaire (with 10 being “as bad as you can imagine”), were included in this randomized, double-blind, placebo-controlled multicenter study (medical centers throughout the United States participated). Patients had to have cancer-related fatigue for at least 1 month and a life expectancy of at least 6 months. For 8 weeks, patients (n = 39 to 48 per group) received placebo or 750, 1000, or 2000 mg/day of American ginseng (4-year-old powdered root of Wisconsin-grown ginseng, encapsulated by Beehive Botanicals, Hayward, WI, and total ginsenoside content measured by Covance Labs, Madison, WI, at the start of the study to ensure at least 5% total ginsenosides).
Randomization was computer generated, but participants were stratified according to stage of disease, gender, baseline fatigue score (4–7 vs 8–10), and current treatment. The primary outcome measure was the Brief Fatigue Inventory. Secondary outcome measures included other validated questionnaires: the vitality subscale of the Medical Outcome Scale Short Form-36, the Pittsburgh Sleep Quality Index, the Global Impression of Change, and the Linear Analogue Self Assessment Scale. Patients reported toxicities (adverse effects) in a diary, and researchers also graded toxicities using the National Cancer Institute Common Toxicity Criteria. Baseline characteristics were similar among groups. Dropout rates were also similar.
There were no statistical differences between the placebo and ginseng groups on the primary or secondary endpoints. However, for the primary efficacy endpoint, there was a trend for greater positive effects with the highest dose of ginseng compared with placebo (P = 0.08). Also, the highest dose (2000 mg/day) was more effective than the other doses and more effective than placebo at improving vitality and quality of life.
Compared with the placebo group, more than twice as many patients in the 1000 and 2000 mg/day ginseng groups perceived a “moderate” to “very much better” improvement in fatigue at study end (placebo: 17% vs ginseng: 40%). In addition, more patients treated with 1000 and 2000 mg/day of American ginseng were satisfied with their treatment for fatigue than those treated with placebo. These data were obtained while patients were still blinded to their treatment group.
There were no significant differences among groups in the quantity, severity, or types of adverse effects, including sleep-related side effects. Patients in all groups reported various adverse effects: nausea, dizziness, nervousness, headache, trouble falling asleep, and trouble staying asleep.
The authors conclude that 1000 and 2000 mg/day of Wisconsin ginseng decreased fatigue more than placebo. They state that the most compelling evidence is the patient-reported improvement. Further, it is also compelling that there were no significant toxicities in the ginseng groups compared with the placebo group, despite the fact that the patients were undergoing cancer treatment and many had advanced disease. Based on in vivo studies referenced by this trial’s authors, American ginseng may be producing its effect by modulating the neurotransmitters dopamine, norepinephrine, serotonin, and GABA.
The authors have started recruiting patients in the North Central Cancer Treatment Group to enable them to conduct a larger, more definitive trial. The trial will be funded by the National Cancer Institute and supported by the Mayo Clinic, Rochester, MN. One thing that would be important to include in the next study/analysis is whether ginseng might have any adverse effects on cancer treatment outcome. None is expected, but this is an important variable that should not be overlooked.
—Heather S. Oliff, PhD