The effects of Canola oil on cardiovascular risk factors: A systematic review and meta-analysis with dose-response analysis of controlled clinical trials

Background and aims: Canola oil (CO) is a plant-based oil with the potential to improve several cardiometabolic risk factors. We systematically reviewed controlled clinical trials investigating the effects of CO on lipid profiles, apo-lipoproteins, glycemic indices, inflammation, and blood pressure compared to other edible oils in adults. Methods and results: Online databases were searched for articles up to January 2020. Forty-two articles met the inclusion criteria. CO significantly reduced total cholesterol (TC, −0.27 mmol/l, n = 37), low-density lipoprotein cholesterol (LDL-C, −0.23 mmol/l, n = 35), LDL-C to high-density lipoprotein cholesterol ratio (LDL/HDL, −0.21, n = 10), TC/HDL (−0.13, n = 15), apolipoprotein B (Apo B, −0.03 g/l, n = 14), and Apo B/Apo A-1 (−0.02, n = 6) compared to other edible oils (P < 0.05). Compared to olive oil, CO decreased TC (−0.23 mmol/l, n = 9), LDL-C (−0.17 mmol/l, n = 9), LDL/HDL (−0.39, n = 2), and triglycerides in VLDL (VLDL-TG, −0.10 mmol/l, n = 2) (P < 0.05). Compared to sunflower oil, CO improved LDL-C (−0.14 mmol/l, n = 11), and LDL/HDL (−0.30, n = 3) (P < 0.05). In comparison with saturated fats, CO improved TC (−0.59 mmol/l, n = 11), TG (−0.08 mmol/l, n = 11), LDL-C (−0.49 mmol/l, n = 10), TC/HDL (−0.29, n = 5), and Apo B (−0.09 g/l, n = 4) (P < 0.05). Based on the nonlinear dose–response curve, replacing CO with ~15% of total caloric intake provided the greatest benefits. Conclusion: CO significantly improved different cardiometabolic risk factors compared to other edible oils. Further well-designed clinical trials are warranted to confirm the dose–response associations.