Dose-Response Effects of Pecan Consumption on Blood Lipid Profiles in Adults with Excess Body Weight and/or Dyslipidemia: a Randomized Controlled Trial

BACKGROUND: Consuming ≥20% of daily energy from pecans improves blood lipids and reduces dyslipidemia but exceeds dietary recommendations. The benefits of lower doses remain unclear. OBJECTIVES: This study aimed to examine the effects of pecan consumption at doses of 6%, 13%, and 20% of total energy needs on fasting and postprandial blood lipids in adults with excess body weight and/or dyslipidemia, compared with the control (CON). We hypothesized a dose-response relationship, with the 20% group showing the greatest lipid improvements, followed by 13% and 6%, and all would be better than the CON. METHODS: ) or dyslipidemia. Participants were randomly assigned to 6% (n = 26), 13% (n = 26), or 20% (n = 25) pecan-intake groups, or to a CON (n = 25) that maintained a habitual, nut-free diet. Participants completed preintervention and postintervention visits, which included fasting lipid assessments and a high-fat meal challenge (17% of total energy), followed by 4-h postprandial blood draws. RESULTS: Change in total cholesterol (TC), low-density lipoprotein cholesterol, apolipoprotein B, non-HDL cholesterol, and TC/HDL cholesterol ratio all decreased from preintervention to postintervention in the middle (MID) (-13.3 ± 3.4, -12.7 ± 3.3, -9.2 ± 2.3, -13.9 ± 3.2, and -0.3 ± 0.1 mg/dL, respectively; P < 0.05 for all) and HIGH (-12.7 ± 3.6, -11.9 ± 3.4, -7.8 ± 1.9, -13.8 ± 3.6, and -0.3 ± 0.1 mg/dL, respectively; P < 0.05 for all) groups compared with no change in the LOW or CON groups. Change from baseline postprandial nonesterified fatty acids (NEFAs) decreased from preintervention to postintervention in MID (P = 0.01) compared with no changes in CON, HIGH, or LOW (P > 0.05 for all). Fasting triglycerides (TGs), fasting NEFAs, and postprandial TGs did not differ between groups (P > 0.05 for all). CONCLUSIONS: Pecan intake providing 20% and 13%, but not 6%, of daily energy improved fasting blood lipid profiles compared with the control, with postprandial NEFA reductions observed only at 13%. These findings offer the first evidence that moderate doses of daily pecan consumption confer cardioprotective benefits. This trial was registered at clinicaltrials.gov as NCT05949879 and available from: https://clinicaltrials.gov/study/NCT05949879. The date of initial trial registration was 18 July, 2023.