Dose-Response Effects of Coconut Oil on Glycemic Control: An Updated Meta-Analysis of Randomized Trials

Document Type : Review Article

Authors

1 Nutrition and Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran

2 Department of Clinical Nutrition and Dietetics, Faculty of Nutrition and Food Technology, National Nutrition and Food Technology Research Institute, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Abstract

Background: Previous meta-analyses have not examined intake thresholds for coconut oil’s effect on glycemic markers. This study addressed that gap by investigating the non-linear relationship between coconut oil consumption and fasting glucose and insulin levels.
Methods: PubMed, Scopus, Embase, CENTRAL, ISI Web of Science, and Google Scholar were systematically searched for randomized controlled trials (RCTs) published through August 2025. Eligible studies examined coconut oil’s effect on glycemic markers in adults over at least two weeks. Pooled effect sizes were calculated using a random-effects model, followed by subgroup and sensitivity analyses. Distinct from prior reviews, a restricted cubic spline model was applied to evaluate dose-response patterns.
Results: Twelve RCTs with 518 participants were included. Coconut oil intake showed a modest but significant increase in fasting plasma glucose [mean difference (MD): 3.18 mg/dL; 95%CI: 0.22-6.13; I²=90.8%; n=11]. No significant effect was observed on serum insulin (MD: 0.17 µIU/mL; 95%CI: −2.28-2.63; I²=89.1%; n=5). The dose-response analysis revealed a non-linear trend, indicating that moderate consumption of 30-50 grams per day may attenuate glucose elevations compared to lower doses, a novel finding highlighting the need for dosage-specific guidelines (p for non-linearity=0.533).
Conclusion: Coconut oil appears to exert a modest effect on fasting glucose, with minimal impact on insulin. The observed non-linear dose-response suggests that moderate intake may offer a more favorable glycemic profile. Further high-quality trials are needed to clarify optimal dosing and clinical relevance.

Highlights

Hanieh Malmir (Google Scholar)

Parvin Mirmiran (Google Scholar)

Keywords

References

  1. Guariguata L, Whiting DR, Hambleton I, et al. Global estimates of diabetes prevalence for 2013 and projections for 2035. Diabetes Res Clin Pract. 2014;103:137-49. DOI: 10.1016/j.diabres.2013.11.002. PMID: 24630390.
  2. Masoumi SJ, Nekooeian AA, Tanideh N, et al. Effect of allium porrum on streptozotocin-induced diabetes mellitus hyperglycemia and insulin resistance in male Sprague Dawley rats. Onl J Vet Res. 2020;24:573-577.
  3. Sugandh F, Chandio M, Raveena F, et al. Advances in the Management of Diabetes Mellitus: A Focus on Personalized Medicine. Cureus. 2023;15:e43697. DOI: 10.7759/cureus.43697. PMID: 37724233.
  4. Hosseini SE, Mehrabani D, Rezaei E. Effects of pomegranate juice on liver enzymes (ALT, ALP, AST) in diabetic and non-diabetic rats. J Anim Physiol Develop. 2014;24:59-64.
  5. Hosseini SE, Mehrabani D, Ghaedi HR. The effect of pomegranate juice on hemogram and weight profile in streptozotocin-induced diabetic adult male rats. Damghan J Zool. 2013;6:1-8.
  6. Hosseini SE, Rezaei E, Mehrabani D, et al. Effect of pomegranate juice on lipid profile in streptozotocin-induced diabetic adult male rats. J Exp Anim Biol. 2013;2:13-20.
  7. Malaeb S, Spoke C. The Glucose-Lowering Effects of Coconut Oil: A Case Report and Review of the Literature. Case Rep Endocrinol. 2020;2020:8841781. DOI: 10.1155/2020/8841781. PMID: 33425401.
  8. Setyawati A, Sangkala MS, Malasari S, et al. Virgin Coconut Oil: A Dietary Intervention for Dyslipidaemia in Patients with Diabetes Mellitus. Nutrients. 2023;15. DOI: 10.3390/nu15030564. PMID: 36771272.
  9. Boateng L, Ansong R, Owusu WB, et al. Coconut oil and palm oil's role in nutrition, health and national development: A review. Ghana Med J. 2016;50:189-96. PMID: 27752194.
  10. Eyres L, Eyres MF, Chisholm A, et al. Coconut oil consumption and cardiovascular risk factors in humans. Nutr Rev. 2016;74:267-80. DOI: 10.1093/nutrit/nuw002. PMID: 26946252.
  11. Jayawardena R, Swarnamali H, Lanerolle P, et al. Effect of coconut oil on cardio-metabolic risk: A systematic review and meta-analysis of interventional studies. Diabetes Metab Syndr. 2020;14:2007-20. DOI: 10.1016/j.dsx.2020.09.033. PMID: 33096510.
  12. Neelakantan N, Seah JYH, van Dam RM. The Effect of Coconut Oil Consumption on Cardiovascular Risk Factors: A Systematic Review and Meta-Analysis of Clinical Trials. Circulation. 2020;141:803-14. DOI: 10.1161/CIRCULATIONAHA.119.043052. PMID: 31928080.
  13. Duarte AC, Spiazzi BF, Zingano CP, et al. The effects of coconut oil on the cardiometabolic profile: a systematic review and meta-analysis of randomized clinical trials. Lipids Health Dis. 2022;21:83. DOI: 10.1186/s12944-022-01685-z. PMID: 36045407.
  14. Teng M, Zhao YJ, Khoo AL, et al. Impact of coconut oil consumption on cardiovascular health: a systematic review and meta-analysis. Nutr Rev. 2020;78:249-59. DOI: 10.1093/nutrit/nuz074. PMID: 31769848.
  15. Dhanasekara CS, Nelson A, Spradley M, et al. Effects of consumption of coconut oil or coconut on glycemic control and insulin sensitivity: A systematic review and meta-analysis of interventional trials. Nutr Metab Cardiovasc Dis. 2022;32:53-68. DOI: 10.1016/j.numecd.2021.09.014. PMID: 34802850.
  16. Moher D, Shamseer L, Clarke M, et al. Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015 statement. Syst Rev. 2015;4:1. DOI: 10.1186/2046-4053-4-1. PMID: 25554246.
  17. Higgins JPT, Altman DG, Gøtzsche PC, et al. The Cochrane Collaboration’s tool for assessing risk of bias in randomised trials. BMJ. 2011;343:d5928. DOI: 10.1136/bmj.d5928. PMID: 22008217.
  18. Meral Koc B, Yilmaz Akyuz E, Ozlu T. The effect of coconut oil on anthropometric measurements and irisin levels in overweight individuals. Int J Obes (Lond). 2022;46:1735-41. DOI: 10.1038/s41366-022-01177-1. PMID: 35778479.
  19. Mansouri E, Asghari S, Nikooei P, et al. Effects of virgin coconut oil consumption on serum brain-derived neurotrophic factor levels and oxidative stress biomarkers in adults with metabolic syndrome: a randomized clinical trial. Nutr Neurosci. 2024;27:487-98. DOI: 10.1080/1028415X.2023.2223390. PMID: 37409587.
  20. Nikooei P, Hosseinzadeh-Attar MJ, Asghari S, et al. Effects of virgin coconut oil consumption on metabolic syndrome components and asymmetric dimethylarginine: A randomized controlled clinical trial. Nutr Metab Cardiovasc Dis. 2021;31:939-49. DOI: 10.1016/j.numecd.2020.11.020. PMID: 33549429.
  21. Korrapati D, Jeyakumar SM, Putcha UK, et al. Coconut oil consumption improves fat-free mass, plasma HDL-cholesterol and insulin sensitivity in healthy men with normal BMI compared to peanut oil. Clin Nutr. 2019;38:2889-99. DOI: 10.1016/j.clnu.2018.12.026. PMID: 30630708.
  22. Mitra A. Study on the Benefits of Sesame Oil Over Coconut Oil in Patients of Insulin Resistance Syndrome, Notably Type 2 Diabetes and Dyslipidaemia. J Hum Ecol. 2007;22:61-6.
  23. Jeyakumar SM, Damayanti K, Rajkumar Ponday L, et al. Assessment of virgin coconut oil in a balanced diet on indicators of cardiovascular health in non-obese volunteers: A human metabolic study. Diabetes Metab Syndr. 2023;17:102844. DOI: 10.1016/j.dsx.2023.102844. PMID: 37591045.
  24. Assunção ML, Ferreira HS, dos Santos AF, et al. Effects of dietary coconut oil on the biochemical and anthropometric profiles of women presenting abdominal obesity. Lipids. 2009;44:593-601. DOI: 10.1007/s11745-009-3306-6. PMID: 19437058.
  25. Cardoso DA, Moreira AS, de Oliveira GM, et al. A coconut extra virgin oil-rich diet increases hdl cholesterol and decreases waist circumference and body mass in coronary artery disease patients. Nutr Hosp. 2015;32:2144-52. DOI: 10.3305/nh.2015.32.5.9642. PMID: 26545671.
  26. Vogel C, Crovesy L, Rosado EL, Soares-Mota M. Effect of coconut oil on weight loss and metabolic parameters in men with obesity: a randomized controlled clinical trial. Food Funct. 2020;11:6588-94. DOI: 10.1039/d0fo00872a. PMID: 32648861.
  27. Johansson AK, Korte H, Yang B, Stanley JC, Kallio HP. Sea buckthorn berry oil inhibits platelet aggregation. J Nutr Biochem. 2000;11:491-5. DOI: 10.1016/s0955-2863(00)00105-4. PMID: 11120446.
  28. Khaw KT, Sharp SJ, Finikarides L, et al. Randomised trial of coconut oil, olive oil or butter on blood lipids and other cardiovascular risk factors in healthy men and women. BMJ Open. 2018;8:e020167. DOI: 10.1136/bmjopen-2017-020167. PMID: 29511019.
  29. Heber D, Ashley JM, Solares ME, et al. The effects of a palm-oil enriched diet on plasma lipids and lipoproteins in healthy young men. Nutr Res. 1992;12:S53-S9. DOI:10.1016/S0271-5317(05)80450-6.
  30. Maki KC, Hasse W, Dicklin MR, Bell M, Buggia MA, Cassens ME, et al. Corn Oil Lowers Plasma Cholesterol Compared with Coconut Oil in Adults with Above-Desirable Levels of Cholesterol in a Randomized Crossover Trial. J Nutr. 2018;148:1556-63. DOI: 10.1093/jn/nxy156. PMID: 30204921.
  31. Vijayakumar V, Shankar N, Nanjundaiah R, et al. Diet enriched with fresh coconut decreases blood glucose levels and body weight in normal adults. J Complement Integr Med. 2018;15:/j/jcim.2018.15.issue-3/jcim-2017-0097/jcim-2017-0097.xml. DOI: 10.1515/jcim-2017-0097. PMID: 29461972.
  1. Rezaei E, Hosseini SE, Mehrabani D. Effects of pomegranate juice on insulin and glucose in diabetic and non-diabetic male rats. J Birjand Univ Med Sci. 2013;20:1-8.
  2. Lundsgaard AM, Fritzen AM, Sjøberg KA, et al. Small Amounts of Dietary Medium-Chain Fatty Acids Protect Against Insulin Resistance During Caloric Excess in Humans. Diabetes. 2020;70:91-8. DOI: 10.2337/db20-0582. PMID: 33122393.
  3. Vandenberghe C, St-Pierre V, Pierotti T, et al. Tricaprylin Alone Increases Plasma Ketone Response More Than Coconut Oil or Other Medium-Chain Triglycerides: An Acute Crossover Study in Healthy Adults. Curr Dev Nutr . 2017;1:e000257. DOI: 10.3945/cdn.116.000257. PMID: 29955698.
  4. Schönfeld P, Wojtczak L. Short- and medium-chain fatty acids in energy metabolism: the cellular perspective. J Lipid Res. 2016;57:943-54. DOI: 10.1194/jlr.R067629. PMID: 27080715.
  5. Mehrabani D, Masoumi SJ, Masoumi AS, et al. Role of diet in mesenchymal stem cells’ function: a review. Int J Nutr Sci. 2023;8:9-19. DOI: 10.30476/IJNS.2023.97788.1221.
  6. Mehrabani D, Vahedi M, Eftekhari MH, et al. Food avoidance in patients with ulcerative colitis: a review. Int J Nutr Sci. 2018;2:189-95.

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