Comparative efficacy of extra virgin olive oil versus refined olive oil in the treatment of individuals suffering from constipation: A double-blind randomized clinical trial study

Background: Evidence suggested that olive oil may alleviate constipation symptoms. This study compared the effectiveness of two types of extra virgin olive oil and refined olive oil on the treatment of patients experiencing constipation. Methods: This double-blind clinical trial included 140 participants aged 18 years or older who were diagnosed with chronic constipation by a gastroenterologist using the Rome III questionnaire. Block randomization was utilized approach to divide patients into two groups of 70 individuals (Extra virgin olive oil as trial and refined olive oil as control) that consumed two tablespoons per day of olive oil for four weeks. Follow-up assessments were conducted using the Rome III and Bristol Stool Form Scale (BSFS) questionnaires. Results: According to analysis of covariance (ANCOVA), after four weeks of the intervention, the mean score of Rome III decreased significantly from 11.37±2.25 to 7.74±2.53; and from 11.27±2.73 to 3.47±1.73 among refined olive oil and extra virgin olive oil consumers, respectively, (-4.22 (95% CI: 3.63-4.82), (F (1,137) =197.67, p<0.001, η2P=0.591). In week 2,3, and 4, the mean score of BSFS were significantly higher among consumers of extra virgin olive oil than to the consumers of refined olive oil 0.53 (95% CI: 0.38- 0.68), p<0.001, 0.78 (95% CI: 0.60- 0.97), p<0.001 and 1.14 (95% CI: 0.94-1.35), p<0.001, respectively. Conclusion: Extra virgin olive oil was more effective compared refined olive oil at alleviating constipation. These outcomes highlight the importance of extra virgin olive oil as a possible treatment for constipation.