The Short-Term Effects of Olive Oil and Flaxseed Oil for the Treatment of Constipation in Hemodialysis Patients

J Ren Nutr. 2015 Jan;25(1):50-6. doi: 10.1053/j.jrn.2014.07.009. Epub 2014 Sep 17.


Objectives: To evaluate the effects of olive oil and flaxseed oil compared with mineral oil for the treatment of constipation in patients undergoing hemodialysis.

Methods: A 4-week, double-blind, randomized, and controlled trial was conducted. Fifty constipated patients (29% male, 51 ± 12 years) diagnosed by the Rome III criteria were randomly assigned to receive mineral oil (control group; n = 17), olive oil (n = 16), or flaxseed oil (n = 17). The initial oil dose was 4 mL/day, and adjustments during the follow-up could be made as needed. The impact of the intervention was assessed by the Rome III criteria scores.

Results: The most frequent symptoms of constipation evaluated by the Roma III criteria at baseline were comparable among the groups and included "incomplete evacuation" (92%), "lumpy or hard stools," (72%) and "anorectal obstruction" (70%). The Rome III score improved significantly in patients receiving mineral oil (10.5 ± 5.0 to 4.1 ± 4.0; P < .01), olive oil (10.3 ± 4.2 to 3.2 ± 3.8; P = .01), and flaxseed oil (9.6 ± 4.2 to 6.0 ± 5.1; P < .01), with no significant group-by-time interaction (P = .15). The scores of 5 from 6 constipation symptoms reduced similarly in the mineral oil and olive oil groups, whereas only the frequency of evacuation and the consistency of stools improved in the flaxseed oil group.

Conclusions: We demonstrated that the daily use of olive oil or flaxseed oil was as effective as mineral oil in the treatment of constipation in patients undergoing hemodialysis.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Body Mass Index
  • Constipation / drug therapy*
  • Double-Blind Method
  • Female
  • Follow-Up Studies
  • Humans
  • Linseed Oil / administration & dosage*
  • Male
  • Middle Aged
  • Olive Oil
  • Plant Oils / administration & dosage*
  • Renal Dialysis*
  • Surveys and Questionnaires


  • Olive Oil
  • Plant Oils
  • Linseed Oil