Ginger supplementation could be an effective adjuvant treatment for chemotherapy-induced nausea (CIN). The aim of this clinical trial was to address significant methodological limitations in previous trials. Patients (N = 51) were randomly allocated to receive either 1.2 g of standardised ginger extract or placebo per day, in addition to standard anti-emetic therapy, during the first three cycles of chemotherapy. The primary outcome was CIN-related quality of life (QoL) measured with the Functional Living Index- Emesis (FLIE) questionnaire. Secondary outcomes included acute and delayed nausea, vomiting, and retching as well as cancer-related fatigue, nutritional status, and CIN and vomiting-specific prognostic factors. Over three consecutive chemotherapy cycles, nausea was more prevalent than vomiting (47% vs. 12%). In chemotherapy Cycle 1, intervention participants reported significantly better QoL related to CIN (p = 0.029), chemotherapy-induced nausea and vomiting (CINV)-related QoL (p = 0.043), global QoL (p = 0.015) and less fatigue (p = 0.006) than placebo participants. There were no significant results in Cycle 2. In Cycle 3, global QoL (p = 0.040) and fatigue (p = 0.013) were significantly better in the intervention group compared to placebo. This trial suggests adjuvant ginger supplementation is associated with better chemotherapy-induced nausea-related quality of life and less cancer-related fatigue, with no difference in adverse effects compared to placebo.

Emerging evidence supports the health benefits of ginger for a range of conditions and symptoms; however, there is a lack of synthesis of literature to determine which health indications are supported by quality evidence. In this umbrella review of systematic reviews we aimed to determine the therapeutic effects and safety of any type of ginger from the Zingiber family administered in oral form compared with any comparator or baseline measures on any health and well-being outcome in humans. Five databases were searched from inception to April 2021. Review selection and quality were assessed in duplicate using the Assessment of Multiple Systematic Reviews–2 (AMSTAR-2) checklist and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) method, with results presented in narrative form. Twenty-four systematic reviews were included with 3% overlap of primary studies. The strongest evidence was found for the antiemetic effects of ginger in pregnant women (effect size: large; GRADE: high), analgesic effects for osteoarthritis (effect size: small; GRADE: high), and glycemic control (effect size: none to very large; GRADE: very low to moderate). Ginger also had a statistically significant positive effect on blood pressure, weight management, dysmenorrhea, postoperative nausea, and chemotherapy-induced vomiting (effect size: moderate to large; GRADE: low to moderate) as well as blood lipid profile (effect size: small; GRADE: very low) and anti-inflammatory and antioxidant biomarkers (effect size: unclear; GRADE: very low to moderate). There was substantial heterogeneity and poor reporting of interventions; however, dosage of 0.5–3 g/d in capsule form administered for up to 3 mo was consistently reported as effective. Dietary consumption of ginger appears safe and may exert beneficial effects on human health and well-being, with greatest confidence in antiemetic effects in pregnant women, analgesic effects in osteoarthritis, and glycemic control. Future randomized controlled and dose-dependent trials with adequate sample sizes and standardized ginger products are warranted to better inform and standardize routine clinical prescription.

Ginger (Zingiber officinale) has been investigated for its potentially therapeutic effect on a range of chronic conditions and symptoms in humans. However, a simplified and easily understandable examination of the mechanisms behind these effects is lacking and, in turn, hinders interpretation and translation to practice, and contributes to overall clinical heterogeneity confounding the results. Therefore, drawing on data from nonhuman trials, the objective for this narrative review was to comprehensively describe the current knowledge on the proposed mechanisms of action of ginger on conferring therapeutic health effects in humans. Mechanistic studies support the findings from human clinical trials that ginger may assist in improving symptoms and biomarkers of pain, metabolic chronic disease, and gastrointestinal conditions. Bioactive ginger compounds reduce inflammation, which contributes to pain; promote vasodilation, which lowers blood pressure; obstruct cholesterol production, which regulates blood lipid profile; translocate glucose transporter type 4 molecules to plasma membranes to assist in glycemic control; stimulate fatty acid breakdown to aid weight management; and inhibit serotonin, muscarinic, and histaminergic receptor activation to reduce nausea and vomiting. Additional human trials are required to confirm the antimicrobial, neuroprotective, antineoplastic, and liver- and kidney-protecting effects of ginger. Interpretation of the mechanisms of action will help clinicians and researchers better understand how and for whom ginger may render therapeutic effects and highlight priority areas for future research.

Trace amines such as p-tyramine, p-octopamine and p-synephrine are found in low concentrations in animals and plants. Consumption of pre-workout supplements containing these plant-derived amines has been associated with cardiovascular side effects. The aim of this study was to determine the mechanisms of action of these trace amines on porcine isolated coronary and mesenteric arteries. Noradrenaline caused contraction of mesenteric arteries and relaxation of coronary arteries. In both tissues, all three trace amines induced contractions with similar potencies and responses were unaffected by the β-adrenoceptor antagonist propranolol (1 µM), the nitric oxide synthase inhibitor L-NNA (100 µM), or the TAAR-1 antagonist, EPPTB (100 nM). However, the contractile responses of mesenteric arteries, but not coronary arteries, were significantly reduced by depletion of endogenous noradrenaline. Mesenteric responses to all three amines were abolished in the presence of prazosin (1 µM) whereas residual contractile responses remained in the coronary artery which were inhibited by a high concentration (100 µM) of EPPTB. The results suggest complex responses of the coronary artery to the trace amines, with activity at α₁-adrenoceptors and potentially TAARs other than TAAR-1. In contrast the actions of the amines on the mesenteric artery appeared to involve indirect sympathomimetic actions and direct actions on α₁-adrenoceptors.