Replacement of saturated with unsaturated fats had no impact on vascular function but beneficial effects on lipid biomarkers, E-selectin, and blood pressure: results from the randomized, controlled Dietary Intervention and VAScular function (DIVAS) study.
Level 2 - randomized trial
Individual randomized controlled trial
PubMed 26016869 · doi:10.3945/ajcn.114.097089
What was done
A single-blind, parallel-group randomized controlled trial in the UK evaluated 195 men and women aged 21–60 years with moderate CVD risk (≥50% above the population mean). Participants followed one of three 16-week isoenergetic diets (% total energy target total fat:SFA:MUFA:n-6 PUFA): SFA-rich (36:17:11:4, n = 65), MUFA-rich (36:9:19:4, n = 64), or n-6 PUFA-rich (36:9:13:10, n = 66), substituting 9.5–9.6% of energy from SFAs. The primary endpoint was flow-mediated dilatation; secondary outcomes included fasting serum lipids, microvascular reactivity, arterial stiffness, ambulatory blood pressure, and markers of insulin resistance, inflammation, and endothelial activation.
What was found
Replacing SFAs with MUFAs or n-6 PUFAs did not significantly affect percentage flow-mediated dilatation or other vascular reactivity measures. For secondary outcomes, MUFA substitution reduced night systolic blood pressure (-4.9 mm Hg, P = 0.019) and E-selectin (-7.8%, P = 0.012). Both MUFAs and n-6 PUFAs lowered total cholesterol (-8.4% and -9.2%, respectively), LDL cholesterol (-11.3% and -13.6%), and total-to-HDL cholesterol ratios (-5.6% and -8.5%, all P ≤ 0.001).
Why it matters
Exchanging dietary saturated fats for unsaturated fats does not noticeably alter conduit artery endothelial function over 16 weeks, but it produces clinically meaningful improvements in atherogenic lipids, blood pressure, and endothelial activation markers.
Limits
The intervention lasted only 16 weeks and measured intermediate cardiovascular biomarkers rather than hard clinical cardiovascular events. Findings reflect a UK population with moderate baseline CVD risk and tested n-6 PUFAs rather than n-3 PUFAs.
Cited by
- supports Replacing saturated fat with polyunsaturated fat in the diet is neutral or beneficial for cardiovascular risk and inflammation.