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.
METHODS AND STUDY DESIGN: Eating behaviors namely Cognitive Restraint, Uncontrolled Eating and Emotional Eating scores were assessed by the Three Factor Eating Questionnaire-R18. The preference/intake frequency/craving of 26 common high-fat Malaysian foods was assessed using a 7-point hedonic scale. Anthropometric measurements were taken and Taq1 gene polymorphisms were genotyped by PCR-Restriction Fragment Length Polymorphism using DNA extracted from mouthwash samples.
RESULTS: The overall minor allele frequencies of Taq1A, Taq1B and Taq1D according to ethnicities (Chinese/Indian) were 0.37/0.29, 0.39/0.28, 0.06/0.30, respectively; genotype and allele distributions of Taq1B and Taq1D were significantly different between ethnicities. Eating behaviorscores were not significantly different between gender and ethnicities. Those with A1 or B1 allele had lower Cognitive Restraint score and higher Uncontrolled Eating score, while those with A1/A1 or B1/B1 genotype had higher fast food preference. D1 allele was associated with increased starchy food craving and mamak (Malaysian Indian-Muslim) food preference, but not eating behavior scores. All three gene variants were not associated with obesity and adiposity.
CONCLUSION: Taken together, we posit that three DRD2 Taq1 gene polymorphisms influence the eating behavior and preference/intake frequency/craving of certain high-fat foods in Malaysian adults, but their role in obesity and adiposity is still inconclusive and needs further investigation.