Reviewed: Jaafarpour M, Hatefi M, Najafi F, Khajavikhan J, Khani A. The effect of cinnamon on menstrual bleeding and systemic symptoms with primary dysmenorrhea. Iran Red Crescent Med J. 2015;17(4):e27032. doi: 10.5812/ircmj.17(4)2015.27032.
Primary dysmenorrhea, or painful pelvic cramps occurring just before or during menstruation, can interfere with daily activities and can negatively impact a woman’s quality of life. It is thought to be linked to the production of prostaglandins, especially PGF2α, from the uterine endometrium during menstruation. Pharmaceuticals, nonpharmacological treatments, dietary supplements, and medicinal herbs have been used to treat primary dysmenorrhea. Cinnamon (Cinnamomum spp., Lauraceae)has been used in traditional medicine to treat diarrhea, dyspnea (difficult breathing), impotence, vaginitis, rheumatism, and neuralgia, among other ailments. These authors conducted a randomized, double-blind clinical trial to assess the effects of cinnamon on menstrual bleeding and systemic symptoms in Iranian college students suffering from primary dysmenorrhea.
For the 2013-2014 study conducted at Ilam University of Medical Sciences in Iran, 76 subjects aged 18-30 years with moderate primary dysmenorrhea and regular menstrual cycles were enrolled. The healthy subjects had body mass indices ranging from 19-26 kg/m2. Baseline characteristics of the subjects were similar. Patients were instructed not to use oral contraception or analgesics during the trial.
Thirty-eight subjects received placebo capsules containing starch, and 38 subjects received capsules containing 420 mg dried cinnamon bark powder. They were instructed to take two capsules three times daily during the first three days of their menstrual cycle. No other information was provided regarding the cinnamon capsules (e.g., the species, how the cinnamon was authenticated, or the level of marker compounds such as cinnamaldehyde, which is present in at least four species of Cinnamomum and in other species as well).
A standard visual analogue scale was used to determine the severity of pain and nausea. The number of vomiting episodes was counted daily, and daily menstrual bleeding was measured by the number of saturated pads. Pain severity was recorded at 1, 2, 3, 4, 8, 16, 24, 48, and 72 hours after the study intervention. At 24, 48, and 72 hours after treatment, the mean duration of pain, severity of nausea, number of vomiting episodes, and amount of bleeding were assessed.
The mean pain severity score and the mean duration of pain were less in the cinnamon group than in the placebo group at all measured intervals (P < 0.001 for both) after treatment. Overall, the amount of bleeding decreased significantly at various intervals in the cinnamon group (P < 0.001) but not in the placebo group. The number of subjects experiencing excessive menstrual bleeding (at least four pads per day) in the cinnamon group decreased significantly compared with the placebo group at 24 hours (P = 0.037) and at 48 and 72 hours (P < 0.001 for both). In both the cinnamon group and the placebo group, 12 subjects experienced excessive menstrual bleeding before treatment began. At 72 hours, those numbers decreased to zero in the cinnamon group and three in the placebo group.
The mean severity of nausea significantly decreased in the cinnamon group at 24 hours (P = 0.01) and at 48 and 72 hours (P < 0.001) compared with the placebo group, which also had significant reductions (P < 0.05) at various intervals. The number of vomiting episodes in the cinnamon group was significantly fewer (P < 0.001) than in the placebo group. No adverse side effects were observed, and there were no drop-outs from the study.
Results of this study suggest that cinnamon can significantly reduce pain, menstrual bleeding, nausea, and vomiting associated with primary dysmenorrhea, without any adverse side effects. “Cinnamon can be regarded as a safe and effective treatment for primary dysmenorrhea,” the authors conclude. While the authors provide information regarding the dosage of cinnamon, they do not provide any information as to how the capsules were manufactured, the species of cinnamon, how or if the cinnamon aroma was masked, or if the cinnamon was standardized — a major limitation of this study. More detailed information regarding the cinnamon capsules should have been included.
A peer reviewer of this summary suggested that it may be helpful to compare the results of this study to similar research on valerian (Valeriana officinalis, Caprifoliaceae) and ginger (Zingiber officinale, Zingiberaceae).
— Shari Henson