Objective: To compare serum lipid profiles and dietary intakes of people with normal lipid levels who consumed pecans and those who did not consume nuts.
Design: Eight-week, randomized, controlled study of pecan treatment group vs control group.
Subject: Nineteen people with normal lipid levels completed the study; 10 had been randomly assigned to the pecan treatment group (7 women, 3 men, mean age = 45 +/- 10 years) and 9 to the control group (8 women, 1 man, mean age = 37 +/- 12 years).
Intervention: The pecan treatment group consumed 68 g pecans per day for 8 weeks plus self-selected diets. The pecans contributed 459 kcal and 44 g fat daily. The control group avoided nuts and consumed self-selected diets.
Main outcome measures: Total serum cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and total triglyceride levels were measured at the time of entrance to the study (baseline), week 4, and week 8. Computer analyses were done on five 3-day food records.
Statistical analysis: Comparisons were made using analysis of variance or paired t test.
Results: LDL-C was lowered in the pecan treatment group from 2.61 +/- 0.49 mmol/L at baseline to 2.35 +/- 0.49 at week 4 (P < .05) and to 2.46 +/- 0.59 at week 8 (P < .05). At week 8, total cholesterol and HDL-C in the pecan treatment group were significantly lower (P < .05) than in the control group (total cholesterol: 4.22 +/- 0.83 vs 5.02 +/- 0.54 mmol/L; HDL-C: 1.37 +/- 0.23 vs 1.47 +/- 0.34 mmol/L). Dietary fat, monounsaturated fat, polyunsaturated fat, insoluble fiber, magnesium, and energy were significantly higher in the pecan treatment group than in the control group. Body mass indexes and body weights were unchanged in both groups.
Applications: Pecans can be included in a healthful diet when energy intake and potential weight gain are addressed.