Pomegranate (Punica granatum) peel is well known for its effects on gut health and dysbiosis, thanks to its antimicrobial and prebiotic effects. However its benefits extend far beyond the gut. Pomegranate and Pomegranate constituents have demonstrated antioxidant, anti-inflammatory, anticancer, antidiabetic, antihyperlipidaemic, vasculoprotective, hepatoprotective, neuroprotective, cardioprotective, and immunomodulatory activity. Preliminary in vitro and in vivo studies have shown benefits in a wide range of conditions, including diabetes, hepatitis, arthritis, dermatitis, inflammatory lung conditions, viral infections, malaria, various types of cancer, and cardiovascular disease.1,2 Human clinical trials are confirming some of these benefits.
Cardio-metabolic health
Pomegranate peel has shown promising effects for improving cardiometabolic health. In a randomised, controlled trial, 37 patients diagnosed with type 2 diabetes who were treated with metformin were given Pomegranate peel extract 250 mg (equivalent to 2 g dry peel) twice daily for eight weeks, or placebo. By the end of the study, the Pomegranate peel group had clinically significant reductions in waist circumference (-2.46 cm), and systolic (-6.06 mmHg) and diastolic (-2.1 mmHg) blood pressure. They also had statistically significant improvements in high density lipoprotein (HDL) cholesterol (p<0.001), serum triglycerides (p<0.01), low density lipoprotein (LDL) cholesterol (p<0.001), glycated haemoglobin (HbA1c) (p<0.05), lipid peroxidation markers (p<0.001) and fatty acid profile compared to placebo.3 In another randomised controlled trial by the same group, 60 overweight patients with type 2 diabetes took the same dose of Pomegranate peel extract or placebo for eight weeks, and their body composition was monitored. By the end of the trial, the Pomegranate peel group had significant reductions in waist circumference (-2.17 cm, p<0.001), and a trend towards reduced visceral fat and fat mass percentage compared with placebo.4 In a similar study involving 60 diabetic patients, Pomegranate peel supplementation significantly reduced levels of the inflammatory markers interleukin-6, tumour necrosis factor α (TNF-α), and high-sensitivity C-reactive protein (hs-CRP), oxidative stress biomarkers, and homocysteine, while significantly improving total antioxidant capacity and lipid profiles compared to placebo.5 A fourth study confirmed these results, finding that eight weeks of Pomegranate peel supplementation significantly improved anthropometric measurements, and glycaemic and lipid parameters in diabetic patients.6 Pomegranate peel supplementation has also significantly improved lipid parameters in non-diabetic obese women with dyslipidaemia, in two randomised controlled trials.7,8
Pomegranate supplementation has also improved metabolic and hepatic measures in patients with non-alcoholic fatty liver disease (NAFLD). In this randomised controlled trial, 78 patients with NAFLD received Pomegranate peel extract or placebo daily for eight weeks, in combination with a low-calorie diet. The Pomegranate peel group had significant reductions in anthropometric measures, blood pressure, lipid profile, and blood sugar levels compared to placebo. They also experienced significant improvements in measures of liver steatosis and stiffness compared to placebo.9
Pomegranate may also reduce the cardiovascular complications associated with chronic kidneydisease. Supplementation with Pomegranate peel plus vitamin E significantly improved inflammatory markers and endothelial function in patients undergoing haemodialysis.10 Another study found a significant improvement in oxidative stress markers and antioxidant capacity in patients taking Pomegranate peel plus vitamin E versus placebo.11
Female reproductive health
Pomegranate peel is traditionally used for menstrual disorders in traditional Persian medicine.12 A randomised controlled trial has confirmed its benefit in women with menorrhagia. In this study, 56 women with menorrhagia received either Pomegranate peel extract (250 mg) or mefenamic acid three times daily during menstruation, for three menstrual cycles. The results found a significant reduction in menstrual blood loss, and a significant improvement in serum haemoglobin levels and quality of life scores in both groups, with no significant differences between them. This indicates that Pomegranate peel was equally as effective as the drug mefenamic acid in relieving menorrhagia.12
Oral health
Pomegranate peel may improve oral health when used topically. A randomised controlled trial found that application of a topical Pomegranate peel gel significantly reduced ulcer size, pain, and duration to healing over seven days in patients with recurrent aphthous stomatitis, when compared to placebo.13 Pomegranate peel gel has also shown benefit on treating oral lichen planus, with patients experiencing significant decreases in sign scoring scales, pain scales and oral health impact profile scores over four weeks, compared to baseline.14 This herb may also protect against dental caries and gingivitis, with clinical trials demonstrating a significant reduction in oral pathogenic bacteria when Pomegranate peel is used as a mouthwash in patients at high risk of dental caries;15 and significant reductions in plaque index, gingival index, and interleukin-1β levels when used as an oral irrigation in patients with gingivitis.16
Conclusion
Pomegranate peel is a valuable herb with a diverse range of indications. From gut health and far beyond, Pomegranate peel is a valuable addition to any herbal dispensary.
References
1 Fahmy HA, Farag MA. Ongoing and potential novel trends of pomegranate fruit peel; a comprehensive review of its health benefits and future perspectives as nutraceutical. Journal of Food Biochemistry. 2022 Jan;46(1):e14024. https://doi.org/10.1111/jfbc.14024
2 Ismail T, Sestili P, Akhtar S. Pomegranate peel and fruit extracts: A review of potential anti-inflammatory and anti-infective effects. Journal of Ethnopharmacology. 2012 Sep;143(2):397-405. http://dx.doi.org/10.1016/j.jep.2012.07.004
3 Grabež M, Škrbić R, Stojiljković MP, Rudić-Grujić V, Paunović M, Arsić A, et al. Beneficial effects of pomegranate peel extract on plasma lipid profile, fatty acids levels and blood pressure in patients with diabetes mellitus type-2: A randomized, double-blind, placebo-controlled study. Journal of Functional Foods. 2020 Jan;64:103692. https://doi.org/10.1016/j.jff.2019.103692
4 Grabež M, Škrbić R, Stojiljković M, Rudić-Grujić V, Šavikin K, Menković N, et al. Beneficial effects of pomegranate peel extract treatment on anthropometry and body composition of overweight patients with diabetes mellitus type-2: A randomised clinical trial. Scripta Medica. 2020;51(1):21-7. DOI:10.5937/scriptamed51-25763
5 Grabež M, Škrbić R, Stojiljković MP, Vučić V, Rudić Grujić V, Jakovljević V, et al. A prospective, randomized, double-blind, placebo-controlled trial of polyphenols on the outcomes of inflammatory factors and oxidative stress in patients with type 2 diabetes mellitus. Rev Cardiovasc Med. 2022 Feb 11;23(2):057. http://doi.org/10.31083/j.rcm2302057
6 Özpak Akkuş Ö, Metin U, Çamlık Z. The effects of pomegranate peel added bread on anthropometric measurements, metabolic and oxidative parameters in individuals with type 2 diabetes: a double-blind, randomized, placebo-controlled study. Nutr Res Pract. 2023;17(4):698. https://doi.org/10.4162/nrp.2023.17.4.698
7 Haghighian MK, Rafraf M, Hemmati S, Haghravan S, Asghari-Jafarabadi M. Effects of pomegranate (Punica granatum L.) peel extract supplementation on serum lipid profile and oxidative stress in obese women with knee osteoarthritis: A double blind, randomized, placebo controlled study. Advances in Integrative Medicine. 2021 May;8(2):107-13. https://doi.org/10.1016/j.aimed.2020.05.001
8 Haghighian MK, Rafraf M, Moghaddam A, Hemmati S, Jafarabadi MA, Gargari BP. Pomegranate (Punica granatum L.) peel hydro alcoholic extract ameliorates cardiovascular risk factors in obese women with dyslipidemia: A double blind, randomized, placebo controlled pilot study. European Journal of Integrative Medicine. 2016 Oct;8(5):676-82. https://doi.org/10.1016/j.eujim.2016.06.010
9 Barghchi H, Milkarizi N, Belyani S, Norouzian Ostad A, Askari VR, Rajabzadeh F, et al. Pomegranate (Punica granatum L.) peel extract ameliorates metabolic syndrome risk factors in patients with non-alcoholic fatty liver disease: a randomized double-blind clinical trial. Nutr J. 2023 Aug 22;22(40):. https://doi.org/10.1186/s12937-023-00869-2
10 Jafari T, Fallah AA, Reyhanian A, Sarmast E. Effects of pomegranate peel extract and vitamin E on the inflammatory status and endothelial function in hemodialysis patients: a randomized controlled clinical trial. Food Funct. 2020;11(9):7987-93. https://doi.org/10.1039/D0FO01012J
11 Jafari T, Fallah AA, Bahrami M, Lorigooini Z. Effects of pomegranate peel extract and vitamin E on oxidative stress and antioxidative capacity of hemodialysis patients: A randomized controlled clinical trial. Journal of Functional Foods. 2020 Sep;72:104069. https://doi.org/10.1016/j.jff.2020.104069
12 Salsali G, Emadi F, Saber SS, Fesharaki MG, Zafarghandi N. Comparison of effects of pomegranate peel and mefenamic acid consumption on the treatment of menorrhagia: a triple-blind randomized controlled trial. Med Sci. 2019 Dec 2;23(100):885-92.
13 Darakhshan S, Malmir M, Bagheri F, Safaei M, Sharifi R, Sadeghi M, et al. The effects of pomegranate peel extract on recurrent aphthous stomatitis. Current Issues in Pharmacy and Medical Sciences. 2019 Sep 1;32(3):115-20. DOI: 10.2478/cipms-2019-0021
14 Zakaria M, Said A, Abd EL-Kader A, Mostafa B. Evaluation of Topical Pomegranate Extracts in Management of Oral Lichen Planus: A randomized clinical trial. Advanced Dental Journal. 2020 Jan 1;2(1):1-11. https://doi.org/10.21608/adjc.2020.22381.1047
15 Jacob B, Malli Sureshbabu N, Ranjan M, Ranganath A, Siddique R. The Antimicrobial Effect of Pomegranate Peel Extract versus Chlorhexidine in High Caries Risk Individuals Using Quantitative Real-Time Polymerase Chain Reaction: A Randomized Triple-Blind Controlled Clinical Trial. International Journal of Dentistry. 2021 Aug 30;2021:1-14. https://doi.org/10.1155/2021/5563945
16 Eltay EG, Gismalla BG, Mukhtar MM, Awadelkarim MO. Punica granatum peel extract as adjunct irrigation to nonsurgical treatment of chronic gingivitis. Complementary Therapies in Clinical Practice. 2021 May;43:101383. https://doi.org/10.1016/j.ctcp.2021.101383
