Rapeseed Oil — A Polish Treasure or an Industrial Product Pretending to Be Healthy?

Aim of the study: To systematically evaluate the evidence on the effects of foods on LDL cholesterol levels and compare the findings with current guidelines.

Results: Several foods clearly change LDL cholesterol levels. The results may help shape future guidelines and dietary advice for hypercholesterolemia.

Aim of the study: Canola oil (CO) is a plant-based oil that may improve several cardiometabolic risk factors. We systematically reviewed controlled clinical trials in adults that investigated the effects of CO on lipid profiles, apolipoproteins, blood sugar measures, inflammation, and blood pressure compared with other edible oils.

Results: Online databases were searched for articles published up to January 2020. Forty-two articles met the inclusion criteria. Compared with other edible oils, CO significantly reduced total cholesterol (TC, -0.27 mmol/l, n = 37), low-density lipoprotein cholesterol (LDL-C, -0.23 mmol/l, n = 35), the 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) (P < 0.05). Compared with olive oil, CO reduced 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 with sunflower oil, CO improved LDL-C (-0.14 mmol/l, n = 11) and LDL/HDL (-0.30, n = 3) (P < 0.05). Compared 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).

Aim of the study: Several randomized clinical trials have investigated the effects of canola oil (CO) compared with olive oil (OO) on blood lipid profiles in adults. However, their findings are inconsistent. This study therefore aimed to compare the effects of consuming CO and OO on blood lipid components in adults.

Results: The following online databases were searched up to February 4th, 2022: PubMed/Medline, Scopus, Clarivate Analytics Web of Science, Cochrane Central Register of Controlled Trials, and Google Scholar. Effect sizes were reported as weighted mean differences (WMD) with 95% confidence intervals (CI). A total of 13 eligible trials were included in this meta-analysis. The results showed that CO consumption significantly reduced serum LDL-c (WMD: -6.13 mg/dl, 95% CI: -9.79, -2.46, p = 0.001), TC (WMD: -8.92 mg/dl, 95% CI: -13.52, -4.33, P < 0.001), and the LDL-c/HDL-c ratio (WMD: -0.30; 95% CI, -0.53, -0.06, p = 0.01) compared with OO. There were no significant changes in the other blood lipid components. The findings of this review suggest that CO consumption has beneficial effects on LDL-c, TC, and the LDL-c/HDL-c ratio compared with OO. Therefore, replacing OO with CO may have cardioprotective effects.

Aim of the study: Hyperlipidemia is a well-known risk factor for cardiovascular disease. A healthy diet containing vegetable oils such as canola oil (CO) may help lower blood lipid levels.

Results: Key teaching points: CO consumption may lower serum TC and LDL, although it does not affect other blood lipids. Overall, canola oil had a significant effect on TC and LDL compared with sunflower oil and saturated fats. CO may benefit serum TC and LDL only when consumed for more than 30 days. CO consumption improved lipid profiles in participants over 50 years of age.

Aim of the study: Vegetable oils, derived from various sources such as seeds, nuts, and some fruits, play an important role in dietary health. However, the current evidence on the health effects of consuming different types of vegetable oils remains controversial.

Results: Evidence of moderate to very low certainty suggested that consuming canola oil and sesame oil reduced body weight. Vegetable oil consumption appears to offer various health benefits, with summary estimates indicating beneficial effects on lipid levels, especially when oils rich in monounsaturated and polyunsaturated fats are consumed in recommended amounts. Future research should focus on long-term studies and comprehensive dietary assessments to better understand the health effects of vegetable oils and provide a basis for informed dietary recommendations. This study was registered with PROSPERO as CRD42021239210.

Aim of the study: Diets based on canola oil have been shown to lower blood cholesterol levels compared with diets containing higher amounts of saturated fatty acids. Canola oil consumption also affects biological functions that influence various other markers of disease risk.

Results: The objective here is to address the health effects of whole canola oil, as this has direct practical importance for consumers, nutritionists, and others deciding which oil to consume or recommend. A literature search examined the effects of canola oil consumption on coronary heart disease, insulin sensitivity, lipid peroxidation, inflammation, energy metabolism, and cancer cell growth. The data show substantial reductions in total and low-density lipoprotein cholesterol, as well as other positive effects, including increased tocopherol levels and improved insulin sensitivity, compared with other dietary fat sources. In summary, growing scientific evidence supports using canola oil as a health-promoting part of the diet, beyond its beneficial effects on blood lipid levels.

Aim of the study: Background: Oxidative stress plays a critical role in the development of chronic diseases.

Results: Oxidative stress markers, including malondialdehyde (MDA), total antioxidant capacity (TAC), and total oxidant status (TOS), were measured at baseline and at the end of each intervention period. Results: A total of 92 participants completed all phases of the trial. After CO and SCO consumption, serum TAC was significantly lower in the adjusted models (p < 0.05), while the treatment oils had no significant effect on other oxidative stress markers in all participants. In analyses by sex, significant reductions in MDA levels with SO and CO were observed only in women (p < 0.05). The intervention oils did not differ in their effects on oxidative stress markers among all participants or among males and females. Conclusions: Except for the significant reducing effect of CO on TAC, the oils studied did not significantly affect MDA and TOS in all participants.