(LB02-15-25) Comparison of Blood Lipid Responses to High PUFA vs. High MUFA Dietary Interventions: A Meta-Analysis

Objectives: Blood lipid concentrations are standard clinical biomarkers of cardiovascular disease risk. It is well accepted that replacing dietary saturated fat for unsaturated fat is expected to lower blood lipids. However, meta-analyses are lacking regarding a quantifiable difference in blood lipid response between comparable diets rich in mono- (MUFA) and poly-unsaturated fat (PUFA) with consideration for food source, intervention length, and health status.

Methods: PubMed and Web of Science were searched through January 2025 for randomized clinical trials comparing high PUFA (≥10% of energy intake from PUFAs) and high MUFA (≥15% of energy intake from MUFAs) diets for ≥5 days in adults. Fasting total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c) and triglycerides (TG) data were extracted by two reviewers. Eligible studies were pooled using random-effects models, including additional subgroups analyses for food source, length, and health status, and expressed as mean differences (MDs) with 95% CI.

Results: Fifty-three trials representing 1,690 individuals met inclusion criteria. High PUFA dietary interventions lowered TC (-5.80; 95% CI -8.02, -3.59 mg/d; p< 0.01), LDL-c (-3.49; 95% CI -5.45, -1.53 mg/dL; p< 0.01), HDL-c (-0.69; 95% CI -1.24, -0.15 mg/dL; p=0.01) and TG (-7.10; 95% CI -9.20, -4.99 mg/dL; p< 0.01)) compared to high MUFA interventions. Dietary interventions utilizing oils had larger MDs for TC (p=0.04) and LDL-c (p=0.01) while mixed diet interventions had larger MDs for TG (p=0.03), all showing greater reduction in blood lipids with high PUFA vs. high MUFA interventions. Interventions longer than 4 weeks did not show a difference in HDL-c (p=0.13); length of intervention did not modify other relationships. There were no differences in MDs based on health status (healthy vs. hypercholesterolemia vs. ‘other’).

Conclusions: Diets providing ≥10% of energy intake from PUFAs are more effective for blood lipid control than diets providing ≥15% of energy intake from MUFAs. This effect is greater when cooking oils or high PUFA foods are used to deliver unsaturated fats and is maintained in longer interventions.

Funding Sources: NIDDK T32 (salary support)