Fennel (Foeniculum vulgare) and Menstrual cramps: evidence and sources

Background One of the most common complaints for women is dysmenorrhea. Several studies investigated the treatment effects of medicinal plants on primary dysmenorrhea. Objectives This systematic review and meta-analysis investigates the effect of Foeniculum vulgare (Fennel) on pain in primary dysmenorrhea in comparison to non-steroidal anti-inflammatory drugs such as mefenamic acid. Methods PubMed, EMBASE, EBSCO Web of Science, Scopus, Cochrane library, Cochrane Central Register of Controlled Trials (CENTRAL), Science Direct, ProQuest, ISI Web of Science, Google Scholar, Magiran, SID, Iran Medex, and Irandoc were searched up to January 2019. Quality assessment of clinical trials was conducted using Jadad scoring system. Totally, 12 studies were entered in the meta-analysis. I 2 was calculated to determine heterogeneity. Fixed effects and/or random effects models were applied. Results Meta-analysis of these trials showed that F. vulgare intake decreased significantly the intensity of dysmenorrhea compared to the placebo (SMD -0.632; CI: -0.827 to -0.436; p I 2 =0%; fixed effect model; seven articles). However, the effect of Mefenamic acid with F. vulgare was not different from each other (SMD=-0.214; CI: -0.446 to 0.017; p=0.07; heterogeneity p=0.58; I 2 =0%; fixed effect model; six trials). Conclusion The F. vulgare alleviates dysmenorrhea. Regarding the same effect of F. vulgare with NSAIDs, it is highly recommend to the women suffered from dysmenorrhea specifically the ones who have high tendency toward herbal medicine.

Objective To assess the efficacy of herbal medicine (cinnamon/fennel/ginger) for treating primary dysmenorrhea. Methods Relevant studies were searched in multiple databases. The weighted mean difference (WMD) was used as the effect indicator for measurement data, and each effect size was given estimates and 95% confidence intervals (CIs). Results Nine studies with 647 patients were selected. Compared with the results in the control group, pain intensity was significantly relieved in the trial group when assessed by the intervention (cinnamon vs. placebo: WMD = 1.815, 95% CI = 1.330-2.301; fennel vs. placebo: WMD = 0.528, 95% CI = 0.119-6.829; ginger vs. placebo: WMD = 2.902, 95% CI = 2.039-3.765), observation period (one cycle: WMD = 2.061, 95% CI = 0.815-3.307; one cycles: WMD = 1.831, 95% CI = 0.973-2.690), and study quality (high quality: WMD = 2.224, 95% CI = 1.488-2.960). Pain duration was significantly shorter in the trial group (cinnamon vs. placebo: WMD = 16.200, 95% CI = 15.271-17.129). No publication bias was observed for either outcome. Conclusions For primary dysmenorrhea, cinnamon/fennel/ginger effectively reduced pain intensity, and cinnamon shortened the duration of pain. Further studies are needed to confirm our results.

Background Dysmenorrhoea refers to painful menstrual cramps and is a common gynaecological complaint. Conventional treatments include non-steroidal anti-inflammatory drugs (NSAIDs) and oral contraceptive pills (OCPs), which both reduce myometrial activity (contractions of the uterus). A suggested alternative approach is dietary supplements. We used the term 'dietary supplement' to include herbs or other botanical, vitamins, minerals, enzymes, and amino acids. We excluded traditional Chinese medicines. Objectives To determine the efficacy and safety of dietary supplements for treating dysmenorrhoea. Search methods We searched sources including the Cochrane Gynaecology and Fertility Group Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, AMED, PsycINFO (all from inception to 23 March 2015), trial registries, and the reference lists of relevant articles. Selection criteria We included randomised controlled trials (RCTs) of dietary supplements for moderate or severe primary or secondary dysmenorrhoea. We excluded studies of women with an intrauterine device. Eligible comparators were other dietary supplements, placebo, no treatment, or conventional analgesia. Data collection and analysis Two review authors independently performed study selection, performed data extraction and assessed the risk of bias in the included trials. The primary outcomes were pain intensity and adverse effects. We used a fixed-effect model to calculate odds ratios (ORs) for dichotomous data, and mean differences (MDs) or standardised mean differences (SMDs) for continuous data, with 95% confidence intervals (CIs). We presented data that were unsuitable for analysis either descriptively or in additional tables. We assessed the quality of the evidence using Grading of Recommendations Assessment, Development and Evaluation (GRADE) methods. Main results We included 27 RCTs (3101 women). Most included studies were conducted amongst cohorts of students with primary dysmenorrhoea in their late teens or early twenties. Twenty-two studies were conducted in Iran and the rest were performed in other middle-income countries. Only one study addressed secondary dysmenorrhoea. Interventions included 12 different herbal medicines (German chamomile (Matricaria chamomilla, M recutita, Chamomilla recutita), cinnamon (Cinnamomum zeylanicum, C. verum), Damask rose (Rosa damascena), dill (Anethum graveolens), fennel (Foeniculum vulgare), fenugreek (Trigonella foenum-graecum), ginger (Zingiber officinale), guava (Psidium guajava), rhubarb (Rheum emodi), uzara (Xysmalobium undulatum), valerian (Valeriana officinalis), and zataria (Zataria multiflora)) and five non-herbal supplements (fish oil, melatonin, vitamins B1 and E, and zinc sulphate) in a variety of formulations and doses. Comparators included other supplements, placebo, no treatment, and NSAIDs.We judged all the evidence to be of low or very low quality. The main limitations were imprecision due to very small sample sizes, failure to report study methods, and inconsistency. For most comparisons there was only one included study, and very few studies reported adverse effects. Effectiveness of supplements for primary dysmenorrhoea We have presented pain scores (all on a visual analogue scale (VAS) 0 to 10 point scale) or rates of pain relief, or both, at the first post-treatment follow-up. Supplements versus placebo or no treatmentThere was no evidence of effectiveness for vitamin E (MD 0.00 points, 95% CI -0.34 to 0.34; two RCTs, 135 women).There was no consistent evidence of effectiveness for dill (MD -1.15 points, 95% CI -2.22 to -0.08, one RCT, 46 women), guava (MD 0.59, 95% CI -0.13 to 1.31; one RCT, 151 women); one RCT, 73 women), or fennel (MD -0.34 points, 95% CI -0.74 to 0.06; one RCT, 43 women).There was very limited evidence of effectiveness for fenugreek (MD -1.71 points, 95% CI -2.35 to -1.07; one RCT, 101 women), fish oil (MD 1.11 points, 95% CI 0.45 to 1.77; one RCT, 120 women), fish oil plus vitamin B1 (MD -1.21 points, 95% CI -1.79 to -0.63; one RCT, 120 women), ginger (MD -1.55 points, 95% CI -2.43 to -0.68; three RCTs, 266 women; OR 5.44, 95% CI 1.80 to 16.46; one RCT, 69 women), valerian (MD -0.76 points, 95% CI -1.44 to -0.08; one RCT, 100 women), vitamin B1 alone (MD -2.70 points, 95% CI -3.32 to -2.08; one RCT, 120 women), zataria (OR 6.66, 95% CI 2.66 to 16.72; one RCT, 99 women), and zinc sulphate (MD -0.95 points, 95% CI -1.54 to -0.36; one RCT, 99 women).Data on chamomile and cinnamon versus placebo were unsuitable for analysis. Supplements versus NSAIDSThere was no evidence of any difference between NSAIDs and dill (MD 0.13 points, 95% CI -1.01 to 1.27; one RCT, 47 women), fennel (MD -0.70 points, 95% CI -1.81 to 0.41; one RCT, 59 women), guava (MD 1.19, 95% CI 0.42 to 1.96; one RCT, 155 women), rhubarb (MD -0.20 points, 95% CI -0.44 to 0.04; one RCT, 45 women), or valerian (MD points 0.62 , 95% CI 0.03 to 1.21; one RCT, 99 women),There was no consistent evidence of a difference between Damask rose and NSAIDs (MD -0.15 points, 95% CI -0.55 to 0.25; one RCT, 92 women).There was very limited evidence that chamomile was more effective than NSAIDs (MD -1.42 points, 95% CI -1.69 to -1.15; one RCT, 160 women). Supplements versus other supplementsThere was no evidence of a difference in effectiveness between ginger and zinc sulphate (MD 0.02 points, 95% CI -0.58 to 0.62; one RCT, 101 women). Vitamin B1 may be more effective than fish oil (MD -1.59 points, 95% CI -2.25 to -0.93; one RCT, 120 women). Effectiveness of supplements for secondary dysmenorrhoea There was no strong evidence of benefit for melatonin compared to placebo for dysmenorrhoea secondary to endometriosis (data were unsuitable for analysis). Safety of supplements Only four of the 27 included studies reported adverse effects in both treatment groups. There was no evidence of a difference between the groups but data were too scanty to reach any conclusions about safety. Authors' conclusions There is no high quality evidence to support the effectiveness of any dietary supplement for dysmenorrhoea, and evidence of safety is lacking. However for several supplements there was some low quality evidence of effectiveness and more research is justified.