METHOD: The Cochrane Central Register of Controlled Trials, MEDLINE, CINAHL, EMBASE, SCOPUS and conference proceedings were searched for relevant trials to June 2019. We included randomized controlled trials comparing pomegranate with placebo. The outcomes examined were effects on lipids level. Two authors screened titles for inclusion, extracted data and assessed the quality of the trials using the revised Cochrane risk of bias tool. We used a random effects model to pool data and stratified trials to examine sources of statistical heterogeneity. To assess the quality of the evidence, we used the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) approach.
RESULTS: Seventeen trials recruiting 763 subjects met the inclusion criteria. These trials varied in terms of the dosage form of pomegranate used, subjects recruited and trials duration. Meta-analyses of data did not show pomegranate produced a significant effect on the lipids level examined. The quality of evidence for all outcomes was low due to the imprecision of the pooled effect and the inconsistency within the included trials. The limited data on safety suggest only mild, transient and infrequent adverse events with the short-term use of pomegranate.
CONCLUSION: Current evidence does not show pomegranate has significant effects on serum lipid levels. The quality of evidence is poor to support the increasing use of pomegranate for hyperlipidaemia.
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.