The effects of extra virgin olive oil or butter on cardiovascular biomarkers in European and Chinese males in the UK: A pilot randomised crossover trial

Purpose: No dietary interventional studies have reported the impact of olive oil on cardiovascular risk markers in groups of different ethnic origins. We report a pilot randomised controlled trial of an intervention supplementing extra virgin olive oil (EVOO) on markers of cardiovascular risk among East Asian Chinese, and European Caucasian individuals. Methods: A cross-over, randomised controlled dietary intervention for 2 weeks was undertaken. Thirty-two adults, healthy, individuals of Chinese and European origin took part in this study. 24-h ambulatory systolic and diastolic blood pressure (SBP, DBP), and blood lipids, were assessed. Results: Positive benefits of EVOO consumption were observed in all participants. Lower 24-h ambulatory SBP (-4.3 mmHg; p = 0.020), and day-time SBP (5.528 mmHg; p = 0.008), night-time DBP (-3.784 mmHg; p = 0.008) and night-time MAP (-3.747 mmHg; p = 0.007) were seen in all participants independently of covariates. In addition, total cholesterol (7.9 mg/dL; p = 0.017) and LDL-cholesterol (6.5 mg/dL; p = 0.028) were increased with butter but not with olive oil. No significant difference in other cardiovascular risk factors were observed. However, differences were observed between Caucasians and East Asian individuals in the absence of significant differences in lifestyle. Conclusion: This pilot study suggests that consumption of EVOO should be advocated as a healthier dietary fat and recommended to replace butter as a dietary strategy to improve cardiovascular health in both Caucasians and East Asian individuals.