Poster Topical Area: Aging and Chronic Disease
Poster Board Number: 115
Objective: To determine if replacement of SFA with walnut-derived PUFA and bioactives confers greater cardioprotective effects compared to a high PUFA diet devoid of walnuts or a low-alpha-linolenic acid (ALA), high-MUFA diet.
Methods: 46 adults with overweight or obesity with elevated low-density lipoprotein-cholesterol (LDL-C; mean±SD = 119.2±30.7 mg/dL) and/or elevated brachial blood pressure (BP; 118±11.3/80±7.3 mmHg) were enrolled in this crossover, isocaloric, controlled-feeding study. Following a 2-week Standard Western Diet run-in (12% SFA, 7% PUFA, 12% MUFA), 45 participants were randomized to three, 6-week treatments: Walnut diet (WD; 7% SFA, 16% PUFA, 3% ALA, 9% MUFA), an ALA-matched high-PUFA diet with no walnuts (AMD; 7% SFA, 16% PUFA, 3% ALA, 9% MUFA), and a low-ALA diet (LAD; 7% SFA, 14% PUFA, 0.5% ALA, 12% MUFA). Outcomes were assessed after each treatment, using the SphygmoCor XCEL System for vascular tests. 36 subjects completed the trial, but all 45 were included in the analysis.
Results: Central systolic BP (mean±SE; -1.6±1.1, WD; -0.5±1.1, AMD; -0.7±0.9 mmHg, LAD; P=0.60), central diastolic BP (-1.8±1.0, WD; -0.2±0.8, AMD; 0.1±0.1 mmHg, LAD; P=0.08), brachial systolic BP (-2.1±1.2, WD; -1.2±1.4, AMD; -1.2±1.1 mmHg, LAD; P=0.41), and brachial diastolic BP (-1.4±1.0, WD; 0.5±1.0, AMD; 0.4±0.7 mmHg, LAD; P=0.12) showed improvements from baseline in all groups, but did not reach statistical significance. Total cholesterol (-15.8±3.1, WD; -14.6±2.9, AMD; -11.2±2.7 mg/dL, LAD; P < 0.0001; TC), LDL-C (-13.4±2.9, WD; -11.1±2.3, AMD; -9.2±2.3 mg/dL, LAD; P < 0.0001), and non-HDL-C (-14.0±2.9, WD; -12.5±2.5, AMD; -11.0±2.2 mg/dL, LAD; P < 0.0001) improved from baseline in all groups. Direct comparisons of WD, LAD, and AMD demonstrated greater reductions in TC (P=0.01) and LDL-C (P=0.02) after WD compared to LAD, with similar changes following WD and AMD.
Conclusions: Replacing SFA with either PUFA or MUFA lowered lipids and lipoproteins in adults at risk for cardiovascular disease (CVD). This agrees with previous findings that replacing SFA with unsaturated fat improves the lipid profile and reduces CVD risk. Furthermore, the greater TC and LDL-C reductions following the WD suggests that substituting SFA with whole walnuts versus MUFA confer additional benefits.
The Pennsylvania State University
University Park, Pennsylvania