The effects of palm oil on serum lipid profiles: A systematic review and meta-analysis

Background and Objectives: Current guidelines recommend reducing intake of diets rich in saturated fats and replacing it with diets rich in unsaturated fats. Palm oil contains a high amount of saturated fatty acids, but its effect on serum lipid levels is unclear. The study aimed to compare the effects of palm oil consumption with other edible oils rich in monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) on serum lipid profiles. Methods and Study Design: We searched Medline, Embase, Cochrane Central Registry of Controlled Trials and CINAHL. Clinical trials were eligible if they compared palm oil-rich diets with diets rich in MUFAs or PUFAs. We pooled results of included studies using a random effects model and assessed the quality of the evidence and certainty of conclusions using the GRADE approach. Results: Intake of palm oil intake compared to oils rich in MUFA was associated with increased levels of total cholesterol (TC) [mean difference (MD)=0.27 mmol/L; 95% CI 0.08 to 0.45], LDL-C (MD=0.20 mmol/L; 95% CI 0.02 to 0.37) and HDL-C (MD=0.06 mmol/L; 95% CI 0.02 to 0.10). Similarly, for comparison with oils rich in PUFAs, palm oil showed increased in TC (MD=0.38 mmol/L; 95% CI 0.14 to 0.62), LDL-C (MD= 0.44 mmol/L; 95% CI 0.01 to 0.88) and HDL-C (MD=0.08 mmol/L; 95% CI 0.03 to 0.13). For both comparisons, there were no significant effects on triglycerides. Conclusions: Even though palm oil increases marginally the level of serum lipids, the evidence is mostly of low to moderate quality.