Am J Clin Nutr. 2026 Jan;123(1):101086. doi: 10.1016/j.ajcnut.2025.10.003. Epub 2025 Dec 9.
ABSTRACT
BACKGROUND: Blood lipid concentrations are standard clinical biomarkers of cardiovascular disease risk. Replacing dietary saturated fat with unsaturated fat is expected to lower blood lipids. However, meta-analyses are lacking regarding quantifiable differences in blood lipid response between comparable diets rich in mono-(MUFA) and polyunsaturated fat (PUFA), considering food sources and dose-response.
OBJECTIVES: The objective was to compare the effects of "high PUFA" compared with "high MUFA" diets on fasting blood lipids.
METHODS: PubMed and Web of Science were searched through February 2025 for randomized clinical trials comparing "high PUFA" (≥10% of energy intake from PUFAs) and "high MUFA" (≥15% of energy intake from MUFAs) diets in adults. Reviewers extracted fasting total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and triglycerides (TG). Eligible studies were pooled using random-effects models and expressed as mean differences with 95% confidence interval.
RESULTS: Fifty-three records were included, representing 1690 adult participants. "High PUFA" diets reduced TC [-5.71 (-8.02, -3.40) mg/dL], LDL cholesterol [-3.31 (-5.39, -1.24) mg/dL], HDL cholesterol [-0.77 (-1.27, -0.26) mg/dL], and TG [-6.59 (-8.77, -4.42) mg/dL] compared with "high MUFA" diets. Subgroup analyses showed that the effects of LDL cholesterol (P = 0.03), and TG (P = 0.03) were stronger with oil compared with nut or diet interventions. Metaregressions revealed that the benefit of consuming a "high PUFA" compared with a "high MUFA" diet increases with total fat intake, with a ∼0.5 mg/dL greater reduction in TC (P = 0.01) and LDL cholesterol (P = 0.01) for every 1% increase in energy intake from fat. Cochrane Risk of Bias tool identified some concerns in most of the included records.
CONCLUSIONS: High PUFA diets have a small, but significant, advantage for lowering blood lipids compared with high MUFA diets and may be a valuable strategy for improving blood lipids in some populations. This trial was registered at PROSPERO as CRD42023474301 (https://www.crd.york.ac.uk/PROSPERO/view/CRD42023474301).
PMID:41485873 | DOI:10.1016/j.ajcnut.2025.10.003