| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Original Research Communications |
1 From the Division of Nutritional Sciences, the Department of Veterinary Pathobiology and Community Health, and the Functional Foods for Health Program, University of Illinois at Urbana-Champaign, Urbana, and Protein Technologies International, St Louis.
2 Presented in part at Experimental Biology ‘99 in Washington, DC. FASEB J 1999;13:A208(abstr).
3 Supported by the Illinois Council on Food and Agricultural Research and Protein Technologies International. SRT was supported by the Fulbright Program (fellowship no. 15965032) and Fundação para a Ciência e a Tecnologia, Portugal.
4 Address reprint requests to JW Erdman Jr, 449 Bevier Hall, 905 South Goodwin Avenue, Urbana, IL 61801. E-mail: j-erdman{at}uiuc.edu.
 |
ABSTRACT |
|---|
 TOP ABSTRACT INTRODUCTIONSUBJECTS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
Objective: We evaluated the amount of soy protein needed to reduce blood lipids in moderately hypercholesterolemic men.
Design: Eighty-one men with moderate hypercholesterolemia (total cholesterol concentration between 5.70 and 7.70 mmol/L) were studied. After a 3-wk lead-in on a Step I diet, total cholesterol was measured and subjects were randomly divided into 5 groups. For 6 wk, each group received 50 g protein/d, which included isolated soy protein (ISP) and casein, respectively, in the following amounts: 50:0, 40:10, 30:20, 20:30, and 0:50 (control group) g. Blood was collected at baseline and weeks 3 and 6 of the intervention.
Results: At week 6, significant reductions (P < 0.05) from baseline compared with the control group were found for non-HDL and total cholesterol and apolipoprotein (apo) B for all ISP groups (except total cholesterol with 40 g ISP). At week 3, significant reductions (P < 0.05) were found in apo B for the groups that consumed 
30 g ISP and in non-HDL cholesterol for the groups that consumed 40 g ISP. HDL-cholesterol, apo A-I, lipoprotein(a), and triacylglycerol concentrations were not significantly affected by dietary treatment.
Conclusion: Our findings show that consuming as little as 20 g soy protein/d instead of animal protein for 6 wk reduces concentrations of non-HDL cholesterol and apo B by 
2.6% and 2.2%, respectively. 2000;71:–84.
Key Words: Men • soy protein • diet • apolipoproteins • hypercholesterolemia • blood lipids • total cholesterol • apolipoprotein B • low-density-lipoprotein cholesterol • LDL cholesterol • non-HDL cholesterol • hyperlipidemia
|
INTRODUCTION |
|---|
|
TOPABSTRACTINTRODUCTIONSUBJECTS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
Numerous studies have shown, in both animals and humans, that blood cholesterol concentrations may be reduced by consuming soy protein in place of animal protein (4, 5). Although several clinical trials have confirmed the hypocholesterolemic effects of high amounts of soy protein, the minimum amount required for a biologically significant reduction of blood cholesterol concentrations remains to be defined. Therefore, this dose-response study was designed to determine the effects of graded amounts of dietary soy protein on plasma cholesterol concentrations in moderately hypercholesterolemic men.
|
SUBJECTS AND METHODS |
|---|
|
TOPABSTRACTINTRODUCTIONSUBJECTS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
23 y, total cholesterol (TC) concentration at screening between 5.69 and 7.76 mmol/L (220–300 mg/dL), and a body mass index (BMI; in kg/m2) between 20 and 33. Exclusion criteria included the presence of diabetes mellitus, thyroid disease, or any other chronic illness that could affect blood lipid concentrations or limit the individual's ability to participate in the study, and the use of any medication known to affect lipid concentrations. Subjects who failed to comply with the diet or had a weight variation 3 kg during the study were excluded from the final analysis. Subject characteristics at baseline are shown in Table 1
and Table 2.
|
|
Diet and study design
During a 3-wk lead-in period, all subjects followed a National Cholesterol Education Program Step I diet (<30% of energy from fat, <10% of energy from saturated fat, and <300 mg cholesterol/d). A registered dietitian instructed the subjects on this diet and counseled them about their individual needs for protein, fat, and energy. The subjects were also told to maintain a consistent level of activity throughout the study. After this 3-wk lead-in period, all subjects continued on the Step I diet and were randomly assigned to 1 of 5 experimental groups. For 6 wk, each group received 50 g protein/d, which included 1) isolated soy protein (ISP; Supro Plus 675HG; Protein Technologies International, St Louis) with 1.9 mg total isoflavone aglycone units/g protein, 2) casein in the form of calcium caseinate (Alanate 391; New Zealand Milk Products, Wellington, New Zealand), or 3) both ISP and casein. The 5 groups received 50, 40, 30, 20, and 0 g (control) ISP with 0, 10, 20, 30, and 50 g casein, respectively.
The test proteins were incorporated into a variety of baked products and ready-to-mix beverages (Protein Technologies International), which the subjects received at breakfast 5 d/wk on-site. Subjects were given enough study products for the remainder of the day and for weekends. Their consumption of study foods was monitored 5 times/wk to track compliance and acceptance of the foods. Subjects kept 3-d food records during alternate weeks. The registered dietitian used these food records to determine the average daily nutrient intake with a computerized nutrient database, NUTRITIONIST IV (version 4.1; N-Squared Computing, Salem Park, OR) as soon as the food records were received. When noncompliance was noted, the subjects were counseled on how to modify their diets to achieve the prescribed nutrient intake.
Blood lipid and apolipoprotein analyses
After the subjects fasted for 12 h, blood samples were collected on 2 consecutive days at 3 time points during the study: at the end of the 3-wk lead-in period (baseline) and at weeks 3 and 6 during the study. The results from the 2 consecutive days were averaged and that value was used for statistical analysis. The blood was collected in tubes with and without EDTA and was centrifuged at 800 x g for 15 min at 18°C to obtain plasma or serum, which was stored at -70°C until analyzed.
Concentrations of TC (6), HDL cholesterol (7), and triacylglycerol were analyzed enzymatically with a Hitachi 917 system (Hitachi Inc, Indianapolis) by the Core Laboratory for Clinical Studies, Washington University School of Medicine, St Louis. Interassay CVs were <1.5% for TC, <2.5% for HDL cholesterol, and <2.0% for triacylglycerol. Non-HDL cholesterol (VLDL cholesterol + LDL cholesterol) was calculated by subtracting HDL cholesterol from TC. Lipoprotein(a) concentrations were measured as described by Taddei-Peters et al (8) with a commercial, enzyme-linked immunosorbent assay kit (PerImmune Inc, Rockville, MD). Lipoprotein(a) concentrations [nmol/L apolipoprotein(a)] were obtained by nonlinear regression with a 4-parameter, logistic equation that approximated the shape of the standard curve. The intraassay CV was <10%, as recommended by the manufacturer of the assay kit. Apolipoprotein (apo) A-I and B concentrations were measured in the second-day blood sample by immunoturbidimetric assays, as described by Rifai and King (9), with commercial kits (Raichem, San Diego). Apo A-I and B concentrations were determined from a calibration curve constructed by a second-order polynomial curve fit to measurements of the assay standards; the intraassay CV was <4%.
Other measurements
Body weight was monitored twice weekly (Deteco Physician's Scale; Deteco Scale Company, Webb City, MO) and BMI was calculated. The daily activity level was assessed by using 3-d activity records that were completed concurrently with the dietary intake records. An activity score was calculated from the information provided on the activity records, as described by Bouchard et al (10).
Blood isoflavone concentrations were measured in the second-day plasma samples collected at baseline and at weeks 3 and 6. The isoflavones daidzein, equol, dihydrodaidzein, o-desmethyl angolentin, genistein, 4-ethyl phenol, and glycitein were measured by HPLC coulometric array detection (model 5600 CoulArray 8-channel detector; Ralston Analytic Laboratories, Ralston Purina Co, St Louis). Basic steps in this procedure were performed as described by Coward et al (11). The total isoflavone concentrations were determined by summing the concentrations of all the individual isoflavones.
Statistical analysis
We used multiple linear regression to analyze the effects of different amounts of soy protein on the concentrations of 9 blood indexes: TC, HDL cholesterol, non-HDL cholesterol, TC:HDL cholesterol, triacylglycerol, apo B, apo A-I, lipoprotein(a), and isoflavones. The outcome measure was the change from baseline for each subject, with treatment effects represented as each group contrasted with the control group (dummy coding). For each subject, the baseline value of each outcome variable was included in the model as a covariate, coded as the deviation from the baseline mean. In this model, the intercept term represents the change from baseline in the control group (12). Individual treatment effects were examined only if the multiple R2 for the model was significant (P < 0.05). The treatment effect for each outcome variable was tested first for the week 6 results. Those variables with significant results were further tested for the week 3 results. This was done to reduce experiment-wise type-I error.
Between-group differences in nutrient intake, physical activity, BMI (at baseline and weeks 3 and 6), and baseline subject characteristics were identified by using the Kruskal-Wallis test. Protein and energy intakes were analyzed separately for each group to compare baseline and week 6 values by using the Wilcoxon paired-sample test.
All statistical analyses were conducted with SAS (version 6; SAS Institute, Cary, NC) with an 
level of 0.05. For concentrations of TC, non-HDL cholesterol, and apo B, and TC:HDL cholesterol, it was predicted that treatment with soy protein at all doses would result in a decrease relative to the control group; for isoflavone concentrations, an increase relative to the control group was predicted. For these outcomes with directional predictions, one-tailed P values were calculated in evaluating the treatment effects. For concentrations of HDL cholesterol, apo A-I, triacylglycerol, and lipoprotein(a), we made no specific prediction about the direction of treatment effects and therefore two-tailed P values were used.
|
RESULTS |
|---|
|
TOPABSTRACTINTRODUCTIONSUBJECTS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
No significant differences were found among the different groups for the nutrient intakes that we analyzed, except for cholesterol intake at week 3 (P = 0.049, Kruskal-Wallis test). Although the average intake of total dietary cholesterol was <300 mg/d in all groups (230.9, 116.7, 136.1, 199.5, and 223.4 mg/d for the groups consuming 0, 20, 30, 40, and 50 g ISP, respectively), some subjects had higher intakes occasionally.
Protein intake increased in all the groups between baseline and both weeks 3 and 6, because most of the subjects did not completely substitute the 50 g study protein for their usual dietary protein. Differences between baseline and week 6 were statistically significant in all the groups (P < 0.01, Wilcoxon paired-sample test). Energy intake also increased in all the groups from baseline to weeks 3 and 6, but significant differences between baseline and week 6 were found in only the groups that consumed 0, 20, and 40 g ISP (P < 0.01, Wilcoxon paired-sample test). Between-group differences were not found at baseline, week 3, or week 6 for either protein or energy intake (Kruskal-Wallis test). The intakes of remaining nutrients did not differ among the groups during the entire study. Statistical tests were not performed on other dietary constituents to reduce the number of statistical tests and the corresponding experiment-wise type-I error rate.
On average, subjects from all the groups consumed 20% of total energy from protein and 57% from carbohydrates. Fat consumption was <23% of total energy intake, with <6% as saturated fat. No significant differences were found between groups for BMI or physical activity.
At baseline, no significant differences in plasma total isoflavone concentrations were found between groups (Kruskal-Wallis test) (Figure 1). As determined by multiple linear regression, plasma total isoflavone concentrations were significantly higher than those of the control group at week 6 for all groups that received ISP (P = 0.04 for 20 g ISP, P = 0.005 for 30 g ISP, and P < 0.0001 for 40 and 50 g ISP). These effects were also seen at week 3 for the groups that consumed 30, 40, and 50 g ISP (P = 0.0136, P < 0.0001, and P < 0.0001, respectively). At week 6, the average plasma total isoflavone concentrations ranged from 244 nmol/L (control group) to 1141 nmol/L (40-g-ISP group).
|
. Non-HDL-cholesterol concentrations were significantly reduced at week 6 in all groups that received ISP (Figure 2 and Table 3). Adjusted mean changes of -0.139, -0.163, -0.095, and -0.182 mmol/L were found for the groups that received 20, 30, 40, and 50 g ISP, respectively. At week 3, significant reductions were found only when 40 and 50 g ISP were consumed, with adjusted mean changes of -0.236 and -0.278 mmol/L, respectively.
|
|
and Table 3) was significant at week 6 for the groups that consumed 20, 30, and 50 g ISP (adjusted mean changes of -0.126, -0.115, and -0.167 mmol/L, respectively). For the 40-g-ISP group, a nonsignificant reduction of 0.053 mmol/L was found. At week 3, the multiple R2 for the multiple linear regression was not significant (P = 0.059; Figure 3). However, there were identifiable trends when 40 g ISP was consumed. The adjusted mean changes were -0.230 and -0.240 mmol/L (P = 0.01 for both; Figure 3) for the 40- and 50-g-ISP groups, respectively. This suggests that the effects identified at week 6 were also apparent at week 3 for the 40- and 50-g-ISP groups.
|
and Table 4) were significantly reduced at week 6 in all groups that consumed ISP. Adjusted mean changes of -0.055, -0.113, -0.055, and -0.063 g/L were found for the 20-, 30-, 40-, and 50-g-ISP groups, respectively. At week 3, significant reductions were found when 30 g ISP was consumed. The adjusted mean changes were -0.059, -0.116, and -0.087 g/L for the 30-, 40-, and 50-g-ISP groups, respectively. At week 6, no significant changes were found for concentrations of HDL cholesterol, triacylglycerol, apo A-I, or lipoprotein(a) or TC:HDL cholesterol in any group that received ISP (Tables 3 and 4).
|
|
|
DISCUSSION |
|---|
|
TOPABSTRACTINTRODUCTIONSUBJECTS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
2.6%) and TC (1.8%) concentrations in moderately hypercholesterolemic men. Replacement of animal protein with 30, 40, and 50 g soy protein resulted in significant reductions in non-HDL-cholesterol concentrations of 3.0%, 1.5%, and 4.5%, respectively. At week 3, only 40 and 50 g soy protein produced significant reductions (4.64% and 5.84%, respectively). Most earlier studies used much higher amounts of soy protein, which is not a practical approach in many individuals. Twenty grams of soy protein can be incorporated quite easily into a typical American diet, thus enabling the use of this dietary means of lowering blood cholesterol. Further, our findings show that replacement of animal protein with soy protein improved the cholesterol-lowering effect of a Step I diet without lowering HDL-cholesterol concentrations or increasing triacylglycerol concentrations. Finally, this amount of ISP (20 g) is similar to the qualifying amount of soy protein (25 g) proposed in a health claim petition that was approved by the Food and Drug Administration (13).
Other studies have confirmed that similar amounts of soy protein produce significant decreases in blood lipid concentrations. Bakhit et al (14) reported decreases in TC concentrations in men (baseline TC 5.7 mmol/L) who consumed 25 g soy protein/d. Furthermore, in a recent study by Crouse et al (15), the effects of 25 g soy protein with different amounts of isoflavones were examined in moderately hyperlipidemic men and women. The authors found that 25 g of the soy protein with the highest isoflavone content (62 mg aglycone units/d) significantly reduced TC and LDL-cholesterol concentrations. Among the subjects who received soy protein with 37 mg aglycone units/d, significant reductions were found only in subjects with the highest initial TC and LDL-cholesterol concentrations. In the present study, 20 g of the ISP that contained a similar amount of isoflavones (37.5 mg aglycone units/d) significantly decreased non-HDL-cholesterol and TC concentrations by week 6.
Apo B concentrations have been proposed as an indicator of CHD risk (16). Previous studies conducted with soy protein at the University of Illinois by Bakhit et al (14), Potter et al (17), and Baum et al (18) showed varied effects of soy on apo B concentrations. Bakhit et al (14) and Baum et al (18) did not observe significant alterations in the concentrations of this apolipoprotein in moderately hypercholesterolemic men and postmenopausal women, respectively. However, Potter et al (17) observed significant reductions in apo B concentrations in moderately hypercholesterolemic men who consumed ISP. In the current study, we also found significant decreases at week 6 in all the groups that consumed ISP. The different results found in these studies may be explained by different populations, sample sizes, or both.
No change in HDL-cholesterol concentration was detected in any of the ISP treatment groups. This finding agrees with many other studies in men (5), which also did not detect significant increases in HDL-cholesterol concentrations when animal protein was replaced with soy protein. However, in women, Baum et al (18) reported a significant increase in HDL-cholesterol concentrations with consumption of soy.
In a meta-analysis by Anderson et al (5), triacylglycerol concentrations decreased with the substitution of soy protein for animal protein. However, there were no significant alterations in the concentrations of triacylglycerol in the studies by Potter et al (17), Bakhit et al (14), and Baum et al (18), or in the present study. The intra- and interindividual variation in triacylglycerol concentrations is large, and thus a greater number of subjects may be needed to find statistically significant changes in this lipid.
Lipoprotein(a) concentrations have been shown to be a valuable indicator of CHD risk (19). Although no dietary factors have been found to influence the concentration of this lipid so far, studies with hormones showed that estrogens may decrease lipoprotein(a) concentrations by as much as 35% (20). In the present study, we found no significant changes in lipoprotein(a) concentrations. These results agree with those of Crouse et al (15), who also did not report significant changes when ISP was consumed.
An unexpected finding in this study was that the 40-g-ISP group did not show a significant reduction in TC at week 6, whereas all the other ISP groups did. Dietary noncompliance for the 40-g-ISP group was unlikely because dietary intake patterns of subjects were carefully monitored for 3 d/wk every 2 wk, and those few subjects with poor compliance were eliminated from the final statistical analysis. Blood total isoflavone concentrations were also measured and no obvious changes occurred in this group between weeks 3 and 6 (Figure 1). In fact, although the 0.053-mmol/L reduction in TC when 40 g ISP was consumed was not significant at week 6, the P value of 0.07 indicated a nearly significant change. Thus, the results for the 40-g-ISP group are consistent with those of the groups consuming different amounts of ISP in indicating a decrease in TC concentrations relative to the control. We also noted increases in non-HDL-cholesterol, TC, and apo B concentrations in the control group (0 g ISP and 50 g casein; Table 2), but these changes were not significant at week 6.
In conclusion, the data from this study indicate that in moderately hypercholesterolemic men, the consumption of as little as 20 g soy protein in place of animal protein (casein) for 6 wk is effective in reducing non-HDL-cholesterol (2.6%), TC (1.8%), and apo B (2.2%) concentrations. The consumption of 40 or 50 g ISP had similar, beneficial effects on non-HDL-cholesterol and apo B concentrations at week 3, and these effects were maintained at week 6. Apparently, with lower amounts of soy protein, a longer duration of dietary treatment was needed to achieve the metabolic effects that resulted in altered plasma cholesterol. The reductions in non-HDL-cholesterol, TC, and apo B concentrations were observed in addition to the reductions achieved with a National Cholesterol Education Program Step I diet. These reductions were not accompanied by significant changes in HDL-cholesterol, apo A-I, or triacylglycerol concentrations.
|
ACKNOWLEDGMENTS |
|---|
|
REFERENCES |
|---|
|
TOPABSTRACTINTRODUCTIONSUBJECTS AND METHODSRESULTSDISCUSSIONREFERENCES |
|---|
This article has been cited by other articles:
|
|
 |
|
  C. D. Gardner, M. Messina, A. Kiazand, J. L. Morris, and A. A. Franke Effect of Two Types of Soy Milk and Dairy Milk on Plasma Lipids in Hypercholesterolemic Adults: A Randomized Trial J. Am. Coll. Nutr., December 1, 2007; 26(6): 669 - 677. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. Sosic-Jurjevic, B. Filipovic, V. Ajdzanovic, D. Brkic, N. Ristic, M. M. Stojanoski, N. Nestorovic, S. Trifunovic, and M. Sekulic A BRIEF COMMUNICATION: Subcutaneously Administrated Genistein and Daidzein Decrease Serum Cholesterol and Increase Triglyceride Levels in Male Middle-Aged Rats Experimental Biology and Medicine, October 1, 2007; 232(9): 1222 - 1227. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. R Matthan, S. M Jalbert, L. M Ausman, J. T Kuvin, R. H Karas, and A. H Lichtenstein Effect of soy protein from differently processed products on cardiovascular disease risk factors and vascular endothelial function in hypercholesterolemic subjects Am. J. Clinical Nutrition, April 1, 2007; 85(4): 960 - 966. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. M. Sacks, A. Lichtenstein, L. Van Horn, W. Harris, P. Kris-Etherton, M. Winston, and for the AHA Nutrition Committee Soy protein, isoflavones, and cardiovascular health: a summary of a statement for professionals from the american heart association nutrition committee. Arterioscler. Thromb. Vasc. Biol., August 1, 2006; 26(8): 1689 - 1692. [Full Text] [PDF]
|
|
|
|
 |
|
 C. N. Bairey Merz, B. D. Johnson, G. D. Braunstein, C. J. Pepine, S. E. Reis, M. Paul-Labrador, G. Hale, B. L. Sharaf, V. Bittner, G. Sopko, et al. Phytoestrogens and Lipoproteins in Women J. Clin. Endocrinol. Metab., June 1, 2006; 91(6): 2209 - 2213. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Dewell, P. L. W. Hollenbeck, and C. B. Hollenbeck A Critical Evaluation of the Role of Soy Protein and Isoflavone Supplementation in the Control of Plasma Cholesterol Concentrations J. Clin. Endocrinol. Metab., March 1, 2006; 91(3): 772 - 780. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. M. Sacks, A. Lichtenstein, L. Van Horn, W. Harris, P. Kris-Etherton, M. Winston, and for the American Heart Association Nutrition Commi Soy Protein, Isoflavones, and Cardiovascular Health: An American Heart Association Science Advisory for Professionals From the Nutrition Committee Circulation, February 21, 2006; 113(7): 1034 - 1044. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. L McVeigh, B. L Dillingham, J. W Lampe, and A. M Duncan Effect of soy protein varying in isoflavone content on serum lipids in healthy young men Am. J. Clinical Nutrition, February 1, 2006; 83(2): 244 - 251. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Ma, D. Chiriboga, B. C. Olendzki, R. Nicolosi, P. A. Merriam, and I. S. Ockene Effect of Soy Protein Containing Isoflavones on Blood Lipids in Moderately Hypercholesterolemic Adults: A Randomized Controlled Trial J. Am. Coll. Nutr., August 1, 2005; 24(4): 275 - 285. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. H Wu, F. Z Stanczyk, C. Martinez, C.-C. Tseng, S. Hendrich, P. Murphy, S. Chaikittisilpa, D. O Stram, and M. C Pike A controlled 2-mo dietary fat reduction and soy food supplementation study in postmenopausal women Am. J. Clinical Nutrition, May 1, 2005; 81(5): 1133 - 1141. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Messina and J. W Erdman Jr Need to establish threshold soy protein intake for cholesterol reduction Am. J. Clinical Nutrition, April 1, 2005; 81(4): 942 - 943. [Full Text] [PDF]
|
|
|
|
|
|
S. Zhan and S. C Ho Meta-analysis of the effects of soy protein containing isoflavones on the lipid profile Am. J. Clinical Nutrition, February 1, 2005; 81(2): 397 - 408. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Vega-Lopez, K.-J. Yeum, J. L Lecker, L. M Ausman, E. J Johnson, S. Devaraj, I. Jialal, and A. H Lichtenstein Plasma antioxidant capacity in response to diets high in soy or animal protein with or without isoflavones Am. J. Clinical Nutrition, January 1, 2005; 81(1): 43 - 49. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. A. Greany, J. A. Nettleton, K. E. Wangen, W. Thomas, and M. S. Kurzer Probiotic Consumption Does Not Enhance the Cholesterol-Lowering Effect of Soy in Postmenopausal Women J. Nutr., December 1, 2004; 134(12): 3277 - 3283. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X.-G. Zhuo, M. K. Melby, and S. Watanabe Soy Isoflavone Intake Lowers Serum LDL Cholesterol: A Meta-Analysis of 8 Randomized Controlled Trials in Humans J. Nutr., September 1, 2004; 134(9): 2395 - 2400. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. R. Teixeira, K. A. Tappenden, L. Carson, R. Jones, M. Prabhudesai, W. P. Marshall, and J. W. Erdman Jr. Isolated Soy Protein Consumption Reduces Urinary Albumin Excretion and Improves the Serum Lipid Profile in Men with Type 2 Diabetes Mellitus and Nephropathy J. Nutr., August 1, 2004; 134(8): 1874 - 1880. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Tholstrup, C.-E. Hoy, L. N. Andersen, R. D.K. Christensen, and B. Sandstrom Does Fat in Milk, Butter and Cheese Affect Blood Lipids and Cholesterol Differently? J. Am. Coll. Nutr., April 1, 2004; 23(2): 169 - 176. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Desroches, J.-F. Mauger, L. M. Ausman, A. H. Lichtenstein, and B. Lamarche Soy Protein Favorably Affects LDL Size Independently of Isoflavones in Hypercholesterolemic Men and Women J. Nutr., March 1, 2004; 134(3): 574 - 579. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Sagara, T. Kanda, M. NJelekera, T. Teramoto, L. Armitage, N. Birt, C. Birt, and Y. Yamori Effects of Dietary Intake of Soy Protein and Isoflavones on Cardiovascular Disease Risk Factors in High Risk, Middle-Aged Men in Scotland J. Am. Coll. Nutr., February 1, 2004; 23(1): 85 - 91. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Lin, G. W. Meijer, M. A. Vermeer, and E. A. Trautwein Soy Protein Enhances the Cholesterol-Lowering Effect of Plant Sterol Esters in Cholesterol-Fed Hamsters J. Nutr., January 1, 2004; 134(1): 143 - 148. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Song, S.-O. Lee, P. A. Murphy, and S. Hendrich Soy Protein With or Without Isoflavones, Soy Germ and Soy Germ Extract, and Daidzein Lessen Plasma Cholesterol Levels in Golden Syrian Hamsters Experimental Biology and Medicine, October 1, 2003; 228(9): 1063 - 1068. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. J. Bhathena, A. A. Ali, C. Haudenschild, P. Latham, T. Ranich, A. I. Mohamed, C. T. Hansen, and M. T. Velasquez Dietary Flaxseed Meal is More Protective Than Soy Protein Concentrate Against Hypertriglyceridemia and Steatosis of the Liver in an Animal Model of Obesity J. Am. Coll. Nutr., April 1, 2003; 22(2): 157 - 164. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Nestel Role of Soy Protein in Cholesterol-Lowering: How Good Is It? Arterioscler. Thromb. Vasc. Biol., November 1, 2002; 22(11): 1743 - 1744. [Full Text] [PDF]
|
|
|
|
|
|
A. H. Lichtenstein, S. M. Jalbert, H. Adlercreutz, B. R. Goldin, H. Rasmussen, E. J. Schaefer, and L. M. Ausman Lipoprotein Response to Diets High in Soy or Animal Protein With and Without Isoflavones in Moderately Hypercholesterolemic Subjects Arterioscler. Thromb. Vasc. Biol., November 1, 2002; 22(11): 1852 - 1858. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. A.J.M. Kerckhoffs, F. Brouns, G. Hornstra, and R. P. Mensink Effects on the Human Serum Lipoprotein Profile of {beta}-Glucan, Soy Protein and Isoflavones, Plant Sterols and Stanols, Garlic and Tocotrienols J. Nutr., September 1, 2002; 132(9): 2494 - 2505. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Tonstad, K. Smerud, and L. Hoie A comparison of the effects of 2 doses of soy protein or casein on serum lipids, serum lipoproteins, and plasma total homocysteine in hypercholesterolemic subjects Am. J. Clinical Nutrition, July 1, 2002; 76(1): 78 - 84. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Dewell, C. B. Hollenbeck, and B. Bruce The Effects of Soy-Derived Phytoestrogens on Serum Lipids and Lipoproteins in Moderately Hypercholesterolemic Postmenopausal Women J. Clin. Endocrinol. Metab., January 1, 2002; 87(1): 118 - 121. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. H Lichtenstein Got soy? Am. J. Clinical Nutrition, April 1, 2001; 73(4): 667 - 668. [Full Text] [PDF]
|
|
|
|
|
|
R. M. Krauss, R. H. Eckel, B. Howard, L. J. Appel, S. R. Daniels, R. J. Deckelbaum, J. W. Erdman Jr, P. Kris-Etherton, I. J. Goldberg, T. A. Kotchen, et al. AHA Scientific Statement: AHA Dietary Guidelines: Revision 2000 |
