Pecans Lower Low Density Lipoprotein Cholesterol in People with Normal Lipid Levels

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Abstract

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 Eightweek, 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 selfselected diets. The pecans contributed 459 kcal and 44 g fat daily. The control group avoided nuts and consumed selfselected diets.

Main outcome measures Total serum cholesterol, lowdensity lipoprotein cholesterol (LDL-C), highdensity 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: 1.3710.23 vs 1.4710.34 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. J Am Diet Assoc. 2000;100:312 318.

Section snippets

Study Design

An 8week randomized, controlled study was conducted in adults with normal lipid levels. Subjects were randomly assigned to either a treatment group who consumed 68 g pecans (approximately 34cup of large halves) daily during the 8 weeks of the study or to a control group who avoided nut consumption. Because of the 8week treatment period, the design of a pecan treatment group vs control group was selected rather than a crossover design.

Subjects

To investigate the possible effects of ingestion of pecan nut

Subject Characteristics and Dietary Intakes

Nineteen subjects (9 in the control group and 10 in the pecan treatment group) completed the study. Four subjects did not complete the study because they were not able to conform to the study protocols; their data were not included in the statistical analyses. The control group consisted of 8 women and 1 man; mean age±standard deviation (SD) was 45± 10 years. The pecan treatment group consisted of 7 women and 3 men; mean age+SD was 37±12 years. Body weights for the subjects were standardized by

Discussion

This study compared the serum lipid levels and dietary intakes of subjects with normal lipid levels who consumed selfselected diets plus 68 g pecans per day for 8 weeks with subjects who consumed selfselected diets but avoided nuts. Previous studies (11), (22), (23), (24), (25) of the effects of almonds and walnuts on blood lipid levels used strict dietary regimens to control nutrient intake in addition to nut supplementation. In this study,subjects consumed selfselected diets except for

Applications/Conclusions

A growing body of scientific evidence suggests potential beneficial effects from the ingestion of tree nuts such as pecans, walnuts, and almonds. A possible mechanism for the action of pecans and other tree nuts is their high content of monounsaturated fat in the form of oleic acid. Although fiber and vitamin E intake were not consistently higher in the pecan treatment group in our study, other investigators have postulated that the presence of these nutrients in nuts might have a protective

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