Effects of canola or olive oil on plasma lipids, lipoprotein-associated phospholipase A(2) and inflammatory cytokines in patients referred for coronary angiography

BACKGROUND: The potential cardioprotective benefits of olive oil (OO) and canola oil (CO) consumption have been shown in some studies. The present study compared the effects of CO and OO on plasma lipids, some inflammatory cytokines, and lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) mass and activity in patients undergoing coronary angiography. METHODS: The current randomized, controlled, parallel-arm, clinical trial involved 48 patients (44 men and 4 women, aged 57.63 ± 6.34 years) with at least one classic cardiovascular risk factor (hypertension, dyslipidemia, or diabetes) who referred for coronary angiography. Patients were randomly divided into two groups and received 25 mL/day refined olive oil (n = 24) or canola oil (n = 24) for 6 weeks. Plasma lipids, some selected inflammatory markers, and Lp-PLA(2) levels were measured at baseline and after the intervention. RESULTS: CO consumption produced a significant reduction in plasma Lp-PLA(2) mass (− 0.97 ± 1.84 vs. 0.34 ± 1.57 ng/mL, p = 0.008 for CO and OO, respectively), whereas the mean changes in interleukine-6 concentration were significantly lower after OO consumption compared with CO (− 9.46 ± 9.46 vs. -0.90 ± 6.80 pg/mL, p = 0.008 for OO and CO, respectively). After 6 weeks of intervention, no significant changes were observed in plasma Lp-PLA(2) activity, complement C3, C4, or lipid profiles in the two intervention groups. CONCLUSIONS: Comparing the two vegetable oils in subjects with cardiovascular risk factors showed that the consumption of olive oil is more effective in reducing the level of inflammatory cytokine interleukine-6, whereas canola oil was more effective in lowering Lp-PLA(2) levels; however, this finding should be interpreted with caution, because Lp-PLA(2) activity did not change significantly. TRIAL REGISTRATION: IRCT20160702028742N5 at www.irct.ir (04/19/2019).