Zingiber officinale
Evidence: Moderate
Containing gingerols and shogaols, ginger exhibits potent anti-emetic and prokinetic effects. Recent reviews indicate it stimulates gastric emptying and reduces nausea via action on serotonin receptors. Its notable anti-inflammatory properties further contribute to overall digestive comfort and gut homeostasis.
There are 6,749 peer-reviewed scientific studies on this ingredient.
Selected Study:
Anh, N. H., Kim, S. J., Long, N. P., Min, J. E., Yoon, Y. C., Lee, E. G., Kim, M., Kim, T. J., Yang, Y. Y., Son, E. Y., Yoon, S. J., Diem, N. C., Kim, H. M., & Kwon, S. W. (2019). Ginger on Human Health: A Comprehensive Systematic Review of 109 Randomized Controlled Trials. Nutrients, 12(1), 157. https://doi.org/10.3390/nu12010157
Study summary:
Study type: PRISMA-guided systematic review of 109 randomized, placebo- or drug-controlled human trials; quality rated with Cochrane risk-of-bias tool (only 43 studies—39 %—deemed “high quality”). Trials collectively enrolled several thousand volunteers, but most had <60 participants per arm and came from Iran or the USA; only 5 studies exceeded 100 subjects.
Consistently supported benefits:
- Nausea & vomiting: Reliable relief during pregnancy, some chemotherapy-induced and postoperative nausea.
- Metabolic markers: Modest improvements in fasting glucose, HbA1c, LDL-C and CRP in type-2-diabetes or metabolic-syndrome trials.
- Anti-inflammatory / pain: Symptom easing in osteoarthritis, dysmenorrhea and migraine in several small but positive RCTs.
- Digestive & colorectal health: Faster gastric emptying and favorable changes in colorectal-cancer risk biomarkers.  
Mechanisms discussed: Gingerols, shogaols and related phenolics (a) block 5-HT₃ and substance-P pathways that trigger nausea; (b) inhibit NF-κB and COX-2, reducing inflammatory cytokines; (c) enhance insulin sensitivity and lipid metabolism, potentially via AMPK activation; and (d) accelerate gastric motility while scavenging reactive oxygen species.
Side-effect profile: Across 17 randomized controlled trials (RCTs) reporting safety, no serious events occurred. The most frequent complaints were mild to moderate gastrointestinal issues—heartburn (16 studies), transient nausea, bloating, gas or diarrhea. Rare cardio-respiratory symptoms were noted after laparoscopic surgery. 
Evidence strength: Benefits for pregnancy nausea and some metabolic or inflammatory endpoints are supported by multiple RCTs, but most studies are small, short (≤12 weeks) and heterogeneous in dose (0.5–4 g/day) and outcome measures. The data suggest good safety and modest efficacy for targeted issues, yet larger, well-standardized trials are still needed to confirm long-term benefits and optimal dosing.
