Effects of flaxseed oil on blood hepcidin and hematologic factors in hemodialysis patients Hadi TABIBI, 1 Maryam MIRFATAHI, 2 Mehdi HEDAYATI, 3 Alireza NASROLLAHI 4 1 Department of Clinical Nutrition & Dietetics, Faculty of Nutrition and Food Technology, National Nutrition and Food Technology Research Institute; 2 Faculty of Nutrition and Food Technology; 3 Cellular and Molecular Research Center, Research Institute for Endocrine Sciences; 4 Department of Nephrology, Taleghani hospital, Shahid Beheshti University of Medical Sciences, Tehran, Islamic Republic of Iran Abstract Introduction In hemodialysis (HD) patients, one of the common complications is renal anemia. Therefore, the present study was designed to investigate the effects of flaxseed oil consumption on blood hepcidin and hematologic factors in HD patients. Methods In this randomized, double- blind, clinical trial, 38 HD patients were randomly assigned to either the flaxseed oil or the control group. The patients in the flaxseed oil group received 6 g/d flaxseed oil for 8 wk, whereas the con- trol group received 6 g/d medium chain triglycerides (MCT) oil. At baseline and the end of week 8, serum hepcidin, and blood hemoglobin, hematocrit, red blood cells (RBCs), mean corpuscular vol- ume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC) were measured after a 12- to 14-h fast. Findings Flaxseed oil consumption significantly reduced serum hepcidin concentration up to 25% during 8 weeks, and the reduction was signifi- cant in comparison with the MCT oil group. In addition, the number of RBCs, blood hemoglobin, hematocrit, MCH and MCHC increased significantly in the flaxseed oil group up to 6%, 10%, 6%, 5%, and 2%, respectively, and these elevations were significant in comparison with the MCT oil group. There was no significant difference between the two groups in mean changes of MCV. Discussion This study indicates that daily consumption of 6 g flaxseed oil reduces serum hepci- din and improves hematologic factors in HD patients. Key words: Flaxseed oil, renal anemia, hemodialysis, hepcidin, hematologic factors INTRODUCTION Renal anemia is a common complication in hemodialysis (HD) patients, and resulting from reduced erythropoietin production. 1,2 Renal anemia can result in reduced exer- cise tolerance, impaired cognition, depression, dyspnea, heart failure and increased mortality in HD patients. 1,2 Erythropoietin therapy is a standard treatment for renal anemia; however, 5–20% of HD patients show erythro- poietin resistance. 1,3,4 The most common cause of erythropoietin resistance is reduced iron availability, including absolute and function- al iron deficiency. 2 Hepcidin, a 25-amino-acid peptide predominantly produced by liver, decreases the release of Correspondence to: Hadi Tabibi, PhD, Department of Clinical Nutrition & Dietetics, Faculty of Nutrition Sciences and Food Technology, National Nutrition and Food Technology Research Institute, 46, West Arghavan St., Farahzadi Blvd., Shahrak Qods, P.O.Box: 19395-4741, Tehran, Islamic Republic of Iran. E-mail: hadtabibi@yahoo. com Conflict of Interest: The authors declare that they have no conflict of interest. Disclosure of grants or other funding: This study was funded by the National Nutrition and Food Technology Research Institute of Iran (grant number 93-5112). VC 2016 International Society for Hemodialysis DOI:10.1111/hdi.12516 1 Hemodialysis International 2016; 00:00–00