Document Type : Original Article(s)


1 Department of Nutrition, Iran University of Medical Sciences, Tehran.

2 Department of Nutrition, Shiraz University of Medical Sciences, Shiraz.

3 Department of Gynaecology, Shiraz University of Medical Sciences.

4 Department of Medical Statistics, Iran University of Medical Sciences, Tehran.


Abstract    BACKGROUND: Cardiovascular disease (CVD) is the leading cause of morbidity and mortality throughout the world. Hyperlipidemia, as one of the main causes of CVD, has been diagnosed in nearly one third of Iranian middle aged women. Menopause manifests wide range of physiologic changes in women, most important of which is hyperlipidemia. Appropriate nutritional interventions can prevent or postpone some cardiovascular events in postmenopausal women. This randomized double blind clinical trial aimed to examine the effect of soy lecithin on serum lipid parameters of hyperlipidemic postmenopausal women.    METHOD AND MATERIALS: Sixty free living postmenopausal women, aged 50-60 years, with mild to moderate hyperlipidemia entered the study. Subjects were randomly assigned in one of three treatments: yogurt; or: yogurt with 16g soy lecithin granules; or: yogurt with 10g sunflower oil, containing equal amount of linoleic acid and energy as the administered lecithin. Strawberry syrup was added to ensure blindness. To assess the effects of confounding factors, BMI and waist circumference were measured. Intake of some dietary factors (energy, macronutrients, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, cholesterol, calcium and fiber) were assessed using 24 hr-food recall and 3-day food record questionnaires. Changes in physical activity level were assessed by seven day-physical activity recall questionnaire. Serum lipid parameters (TC, Non-HDL.C, LDL.C, HDL.C and TG) were measured twice at baseline and 4 weeks of treatment.    RESULTS: There was no significant difference between treatment groups, but a significant decrease was found within the intervention group (lecithin) in the average level of TC (252.33 ± 24.02 vs. 255.22 ± 24.82 mg/dl and P = 0.02), LDL.C/HDL.C (3.99 ± 0.50 vs. 4.17 ± 0.56 mg/dl and P = 0.001) and Non.HDL.C (211.94 ± 23.94 vs. 216.00 ± 23.73 mg/dl and P = 0.005) and accompanying significant increase in serum HDL.C level (40.39 ± 5.21 vs. 39.22 ± 5.58 mg/dl and P = 0.04). Likewise, no significant change was found in serum lipid profile within the control group І (sunflower oil). Decreasing LDL.C/HDL.C level (4.18 ± 0.40 vs. 4.24 ± 0.43 mg/dl and P = 0.03) was the only significant change in serum lipid profile of control group ІІ (yogurt).     CONCLUSION: Soy lecithin treatment had no significant hypocholesterolemic effect on serum lipid profile, in a way that we can not claim any independent effect for lecithin's linoleic acid content.      Keywords: soy lecithin, hyperlipidemic, menopause, linoleic acid, lipid profile.