Soy Protein Supplementation Research Articles

Effect of Soy Protein Supplementation on Hepatic Lipid Profile in Rats Fed a Cholesterol-Based Diet

The effect of soy protein intake on liver lipid homeostasis in cholesterol-fed rats was investigated. One hundred and five albino Wistar rats divided into five groups (n = 21) were fed 20% soy protein without cholesterol (A), 20% soy protein + 5% cholesterol (B), 20% soy protein + 10% cholesterol (C), 0% soy protein + 20% cholesterol (D), and 5% soy protein + 20% cholesterol (E) for six weeks. Liver total cholesterol, esterified cholesterol, low density lipoprotein cholesterol and triglyceride levels were significantly reduced (p<0.05) in soy protein fed rats (B and C) when compared with those fed cholesterol with no or minimal soy protein (D and E) supplement respectively. It could thus be concluded that soy protein supplementation reduces hepatic lipid load in hypercholesterolemic rats

Effect of soy and milk protein supplementation on serum lipid levels: a randomized controlled trial

Previous clinical trials have documented that soy protein reduces low-density lipoprotein cholesterol and increases high-density lipoprotein (HDL) cholesterol compared with milk protein. However, the effect of soy protein on lipids compared with carbohydrate has not been not well studied. We examined the effect of soy and milk protein supplementation on lipids and lipoproteins compared with carbohydrate among adults without hypercholesterolemia. We conducted a randomized, double-blind, 3-phase crossover trial among 352 US adults with serum total cholesterol level of <240 mg/dl from September 2003 to April 2008. Trial participants were assigned to 40 g/day supplementation of soy protein, milk protein or complex carbohydrate from wheat each for 8 weeks in random order with a 3-week washout period between interventions. Overnight fasting blood samples were collected at the termination of each intervention phase. Compared with carbohydrate, soy protein supplementation was significantly associated with a net change (95% confidence interval (CI)) in total cholesterol and total/HDL cholesterol ratio of -3.97 mg/dl (-7.63 to -0.31, P=0.03) and -0.12 (-0.23 to -0.01, P=0.03), respectively. Compared with milk protein, soy protein supplementation was significantly associated with a net change (95% CI) in HDL and total/HDL cholesterol ratio of 1.54 mg/dl (0.63 to 2.44, P=0.0009) and -0.14 (-0.22 to -0.05, P=0.001), respectively. Compared with carbohydrate, milk protein supplementation was significantly associated with a net change (95% CI) in HDL of -1.13 mg/dl (-2.05 to -0.22, P=0.02). This randomized controlled trial indicates that soy protein, but not milk protein, supplementation improves the lipid profile among healthy individuals.

Isoflavone Soy Protein Supplementation and Atherosclerosis Progression in Healthy Postmenopausal Women

Although epidemiological and experimental studies suggest that dietary intake of soy may be cardioprotective, use of isoflavone soy protein (ISP) supplementation as a primary preventive therapy remains unexplored. We determined whether ISP reduces subclinical atherosclerosis assessed as carotid artery intima-media thickness progression. In a double-blind, placebo-controlled trial, 350 postmenopausal women 45 to 92 years of age without diabetes and cardiovascular disease were randomized to 2 evenly divided daily doses of 25 g soy protein containing 91 mg aglycon isoflavone equivalents or placebo for 2.7 years. Overall, mean (95% CI) carotid artery intima-media thickness progression rate was 4.77 (3.39-6.16) μm/year in the ISP group and 5.68 (4.30-7.06) μm/year in the placebo group. Although carotid artery intima-media thickness progression was reduced on average by 16% in the ISP group relative to the placebo group, this treatment effect was not statistically significant (P=0.36). Among the subgroup of women who were randomized within 5 years of menopause, ISP participants had on average a 68% lower carotid artery intima-media thickness progression rate than placebo participants 2.16 (-1.10 to 5.43) versus 6.79 (3.56-10.01) μm/year (P=0.05). ISP supplementation had a null effect on women who were >5 years beyond menopause when randomized. There were no major adverse events from ISP supplementation. ISP supplementation did not significantly reduce subclinical atherosclerosis progression in postmenopausal women. Subgroup analysis suggests that ISP supplementation may reduce subclinical atherosclerosis in healthy young (median age, 53 years) women at low-risk for cardiovascular disease who were <5 years postmenopausal. These first trial results of their kind warrant further investigation.

Effect of Dietary Protein Supplementation on Blood Pressure

Background— Observational studies have reported an inverse association between dietary protein intake and blood pressure (BP). We compared the effect of soy protein, milk protein, and carbohydrate supplementation on BP among healthy adults. Methods and Results— We conducted a randomized, double-blind crossover trial with 3 intervention phases among 352 adults with prehypertension or stage 1 hypertension in New Orleans, LA, and Jackson, MS, from September 2003 to April 2008. The trial participants were assigned to take 40 g/d soy protein, milk protein, or carbohydrate supplementation each for 8 weeks in a random order. A 3-week washout period was implemented between the interventions. Three BPs were measured at 2 baseline and 2 termination visits during each of 3 intervention phases with a random-zero sphygmomanometer. Compared with carbohydrate controls, soy protein and milk protein supplementations were significantly associated with −2.0 mm Hg (95% confidence interval −3.2 to −0.7 mm Hg, P =0.002) and −2.3 mm Hg (−3.7 to −1.0 mm Hg, P =0.0007) net changes in systolic BP, respectively. Diastolic BP was also reduced, but this change did not reach statistical significance. There was no significant difference in the BP reductions achieved between soy or milk protein supplementation. Conclusions— The results from this randomized, controlled trial indicate that both soy and milk protein intake reduce systolic BP compared with a high-glycemic-index refined carbohydrate among patients with prehypertension and stage 1 hypertension. Furthermore, these findings suggest that partially replacing carbohydrate with soy or milk protein might be an important component of nutrition intervention strategies for the prevention and treatment of hypertension. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00107744.

Whey Protein but Not Soy Protein Supplementation Alters Body Weight and Composition in Free-Living Overweight and Obese Adults ,

AbstractA double-blind, randomized clinical trial was conducted to determine the effect of consumption of supplemental whey protein (WP), soy protein (SP), and an isoenergetic amount of carbohydrate (CHO) on body weight and composition in free-living overweight and obese but otherwise healthy participants. Ninety overweight and obese participants were randomly assigned to 1 of 3 treatment groups for 23 wk: 1) WP; 2) SP (each providing ~56 g/d of protein and 1670 kJ/d); or 3) an isoenergetic amount of CHO. Supplements were consumed as a beverage twice daily. Participants were provided no dietary advice and continued to consume their free-choice diets. Participants' body weight and composition data were obtained monthly. Dietary intake was determined by 24-h dietary recalls collected every 10 d. After 23 wk, body weight and composition did not differ between the groups consuming the SP and WP or between SP and CHO; however, body weight and fat mass of the group consuming the WP were lower by 1.8 kg (P < 0.006) and 2.3 kg (P < 0.005), respectively, than the group consuming CHO. Lean body mass did not differ among any of the groups. Waist circumference was smaller in the participants consuming WP than in the other groups (P < 0.05). Fasting ghrelin was lower in participants consuming WP compared with SP or CHO. Through yet-unknown mechanisms, different sources of dietary protein may differentially facilitate weight loss and affect body composition. Dietary recommendations, especially those that emphasize the role of dietary protein in facilitating weight change, should also address the demonstrated clinical potential of supplemental WP.

Effects of Tomato- and Soy-Rich Diets on the IGF-I Hormonal Network: A Crossover Study of Postmenopausal Women at High Risk for Breast Cancer

To determine whether dietary modifications with tomato products and/or a soy supplement affected circulating levels of insulin-like growth factor (IGF)-1 and other markers of cell signaling in postmenopausal women at risk for developing breast cancer. Eligible and consented postmenopausal women at high risk for developing breast cancer were enrolled in a 26-week, two-arm (tomato and soy, 10 weeks each) longitudinal dietary intervention study in which each woman served as her own control. Changes in biochemical endpoints including IGF-I, IGF-binding protein (IGFBP)-3, estradiol, sex hormone-binding globulin (SHBG), C-peptide, and insulin were measured for each intervention arm. Carotenoid and isoflavone levels were measured to assess adherence. Significant increases in carotenoid and isoflavone levels during the tomato and soy study arms, respectively, suggested that women were adherent to both arms of the intervention. The tomato-rich diet had little effect on cell-signaling biomarkers previously associated with breast cancer risk. However, results of the soy intervention showed that concentrations of IGF-I and IGFBP-3 increased by 21.6 and 154.7 μmol/L, respectively (P = 0.001 for both) and SHBG decreased by 5.4 μmol/L (P < 0.001) after consumption of the soy protein supplement. Increased soy protein intake may lead to small, but significant, increases in IGF-I and IGFBP-3. Soy consumption also led to a significant decrease in SHBG, which has been hypothesized to promote, rather than prevent, cancer growth. Previous epidemiologic studies, however, have confirmed protective effect of soy on breast cancer. Additional investigation about the effect of soy on breast cancer risk and its mechanism of action is warranted.

Effects of soy protein containing isoflavones on women's lipid profile: a meta-analysis

This study evaluated the effects of soy protein containing isoflavones on the lipid profile of women. A meta-analysis including 13 eligible randomized controlled trials was carried out. The literature was systematically searched for randomized controlled trials on the effects of soy protein containing isoflavones on the serum lipids of adult women. The main searched databases were PubMed, Cochrane Library, MedLine, Lilacs and Web of Science. Randomized controlled trials were included if they met the following criteria: published from 1966 to 2005, the study population consisted of women only, had either a crossover or a parallel design and the amounts of soy protein and isoflavones consumed were provided. Weighted mean effect sizes were calculated for net changes in serum lipid concentrations using fixed-effects and random-effects models. Prespecified subgroup analyses were performed to explore the influence of covariates on net lipid change. Soy protein with isoflavones was associated with a significant decrease in total serum cholesterol (by 5.34mg/dL, or 2.4%, p=0.03). No significant associations were detected for low density lipoprotein-cholesterol, triacylglycerols and high density lipoprotein-cholesterol. Amounts of soy protein greater than 40g decreased total cholesterol by 6.56mg/dL (95% CI: -12.35 to -0.39, p=0.04). Soy protein supplementation had small statistically significant effects on the total serum cholesterol of women, but they were clinically insignificant. Furthermore, there were no statistically significant effects on serum low density lipoprotein-cholesterol, high density lipoprotein-cholesterol or triglycerides.

Soy use and vasomotor symptoms: Soy Estrogen Alternative follow-up study

PurposeTo evaluate vasomotor symptoms and soy and hormone therapy use in women who had previously participated in the Soy Estrogen Alternative (SEA) study, a trial conducted to compare the effects of soy protein supplements containing differing levels of isoflavones on menopausal symptoms, chronic disease risk factors, and health-related quality of life in perimenopausal and postmenopausal women.Participants and methodsTwo years after the SEA study ended participants were recontacted to complete questionnaires to quantify their health status, medications, menopausal symptoms, and their use of hormone therapy and soy-based foods and supplements. Participants were also asked to record vasomotor symptoms for seven days.ResultsSurveys were collected from 182 of the 241 participants who had been enrolled in the SEA study (76% response rate). Women were 55 ± 2.8 years of age, well educated (80% more than high school), and 93% reported good to excellent health. All but six reported experiencing at least one menopausal symptom, and 56% reported one or more hot flashes on one or more days. Eighty-one women (45%) continued to use soy for menopausal symptom relief, and 58 (32%) were using hormone therapy. Women taking hormone therapy were experiencing fewer and less severe hot flashes than those who were not taking hormone therapy (P < 0.001); hot flash frequency and severity did not differ significantly between those who did and did not use soy, after controlling for hormone therapy use.ConclusionMost participants reported they were still experiencing menopausal symptoms. Additionally, half of the most symptomatic women (not taking hormone therapy) were still consuming soy products for vasomotor symptoms.

Combination of Sago and Soy-Protein Supplementation During Endurance Cycling Exercise and Subsequent High-Intensity Endurance Capacity

The purpose of the study was to investigate whether a combination of sago and soy protein ingested during moderate-intensity cycling exercise can improve subsequent high-intensity endurance capacity compared with a carbohydrate in the form of sago and with a placebo. The participants were 8 male recreational cyclists with age, weight, and VO2max of 21.5 +/- 1.1 yr, 63.3 +/- 2.4 kg, and 39.9 +/- 1.1 ml . kg(-1) . min(-1), respectively. The design of the study was a randomized, double-blind placebo-controlled crossover comprising 60 min of exercise on a cycle ergometer at 60% VO2max followed by a time-to-exhaustion ride at 90% VO2max. The sago feeding provided 60 g of carbohydrate, and the sago-soy combination provided 52.5 g of carbohydrate and 15 g of protein, both at 20-min intervals during exercise. Times to exhaustion for the placebo, sago, and sago-soy supplementations were 4.09 +/- 1.28, 5.49 +/- 1.20, and 7.53 +/- 2.02 min, respectively. Sago-soy supplementation increased endurance by 84% (44-140%; p < .001) and by 37% (15-63%; p < .05) relative to placebo and sago, respectively. The plasma insulin response was elevated above that with placebo during sago and sago-soy supplementations. The authors conclude that a combination of sago and soy protein can delay fatigue during high-intensity cycling.

One-year soy protein supplementation does not improve lipid profile in postmenopausal women

The risk of heart disease increases significantly in women after menopause mostly because of estrogen deficiency. Soy protein, a good source of isoflavones that are known to bind estrogen receptors, has also been promoted as a dietary means for reducing the risk of heart disease. The aim of this study was to examine the effects of soy protein consumption on heart disease risk in postmenopausal women. Moderately hypercholesterolemic postmenopausal women were randomly assigned to consume soy or control foods daily for 1 year. Serum samples were analyzed for total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, apolipoprotein (Apo) A, and Apo B. Sixty-two women completed the study. There was a trend for total cholesterol and high-density lipoprotein cholesterol levels to increase after 1 year of soy protein supplementation (230.04 +/- 6.1 vs 242.57 +/- 6.2 mg/dL, P < 0.1, and 56.87 +/- 2.5 vs 60.33 +/- 2.5 mg/dL, P < 0.1, respectively). There were no significant differences in low-density lipoprotein cholesterol or triglyceride levels; however, a significant increase in Apo B levels (105.5 +/- 5.9 vs 120.21 +/- 5.9 mg/dL; P = 0.002) and a significant decrease in Apo A levels (189.36 +/- 10 vs 173.21 +/- 10 mg/dL; P = 0.009) were seen. Our data indicate that 1-year soy protein supplementation did not confer cardiovascular benefits, in terms of favorable alterations in the lipid profile, in this cohort of postmenopausal women. These findings, as well as those from other studies, lend credence to the decision of the Food and Drug Administration to reevaluate the soy protein health claim issued a decade ago.

Abstract 2892: Effects of soy protein isolate consumption on serum steroid hormones and biomarkers of angiogenesis, apoptosis, and the IGF axis in men after radical prostatectomy

Abstract Epidemiologic and experimental data suggest that soy may prevent prostate cancer and be beneficial for men with prostate cancer. The mechanisms by which soy may be protective are unclear. Effects of soy constituents on steroid hormones and on angiogenesis, apoptosis, and the insulin growth factor [IGF] axis may be involved. This was examined in a randomized controlled clinical trial testing whether soy reduces biochemical recurrence after radical prostatectomy. Men at high risk for PSA failure after surgery were randomized to a daily soy protein supplement or a casein-based placebo (20 g protein/day) as beverage powders (Solae). The soy and placeboi supplements were identical in composition, except for the protein source. The soy supplement provided 24-26 mg genistein and 40-43 mg total isoflavones daily. The placebo did not contain these or other soy-specific constituents. Self-reported compliance was excellent, serum isoflavones are measured as independent compliance measure, and only few minimal averse effects occurred. Serum samples were taken at baseline, and after 2, 4, 8, 12, and 18 months on intervention. Using ELISA and enzyme immuno-assays, we measured serum indicators of angiogenesis (VEGF and bFGF), global apoptotic activity (soluble Fas [sFas] and Fas ligand [FasL]) and the IGF axis (IGF-1 and IGF binding protein 3 [IGFBP3]) in 8-12 subjects/treatment group, and serum testosterone [T], 17β-estradiol [E2], sex hormone binding globulin [SHBG], and PSA in 12 subjects/group. Generalized Estimating Equations were used to analyze the longitudinal data. FasL increased slightly over time in the placebo group (p=0.05), but sFas did not and there were no differences in change over time between the groups for either. IGF-1 increased slightly over time in placebos (p=0.06), but IGFBP3 did not and there were no differences in change over time between the groups for these endpoints. In contrast, while T levels did not change over time in the placebo group, T levels decreased significantly (p=0.03) from baseline over time by approx. 15% in the soy group. There were no diffrence over time in E2 and SHBG levels in either group. While literature data indicate a lack of soy effects on T and SHBG, this is the first report of soy effects on circulating T and SHBG with repeated serum sampling for up to 1.5 years. This is also the first report of soy effects on serum VEGF, bFGF, sFas, and FasL. The absence of effects on the IGF axis is in line with other studies. Thus, daily consumption of 20 g of soy protein isolate for 18 months slightly reduced serum T levels over time, but did not affect E2, SHBG, and indicators of angiogenesis, apoptosis, and the IGF axis. Despite small sample sizes, several of the group comparisons were close to statistical significance, providing some direction for further studies. (Supported by CA27790 &amp; CA166195 from NIH and the Prevent Cancer Foundation) Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2892.

Abstract A83: Effects on serum testosterone and indicators of apoptosis and the IGF axis of soy protein isolate consumption in a randomized controlled trial with men after radical prostatectomy

Abstract Soy consumption may prevent prostate cancer and be beneficial for men with prostate cancer as suggested by epidemiologic and experimental data. However, the mechanisms by which soy might be protective are not clear, but effects on apoptosis, the insulin growth factor [IGF] axis, and steroid hormones may be involved. We have examined these factors in a randomized controlled clinical trial in which we are testing the hypothesis that soy reduces biochemical recurrence after radical prostatectomy. A standardized soy protein supplement and a casein-based placebo are consumed daily by men at elevated risk for PSA failure during the first 2 years after surgery. The soy protein isolate and placebo (Solae) were made identical in composition, except for the source of protein (20 g protein/day). The soy protein isolate provides 24 to 26 mg genistein and 40 to 43 mg of total isoflavones per day. The placebo is devoid of these and other soy-specific constituents. Self-reported compliance is excellent, serum isoflavones levels are measured as an independent compliance measure, dropout rate is low, and adverse effects minimal to non-existent. In serum samples taken at baseline, and at 2, 4, 8, 12, and 18 months from subsets of subjects we determined indicators of global apoptotic activity (soluble Fas [sFas] and Fas ligand [FasL]) and the IGF axis (IGF-1 and IGF binding protein 3 [IGFBP3]) (7–8 subjects/treatment group), and measures of androgen status, testosterone [T] and sex hormone binding globulin [SHBG] (12 subjects/group) using ELISA and enzyme immuno-assays. Data were analyzed using Generalized Estimating Equations. FasL increased slightly over time (p=0.05), but sFas did not and there were no differences in change over time for sFAs and FasL between the soy and placebo groups. Similarly, IGF-1 increased slightly over time (p=0.06), but IGFBP3 did not and there were no differences in change over time for IGF-1 and IGFBP3 between the soy and placebo groups. In contrast, T levels decreased significantly (p=0.05) from baseline over time by approx. 15% in the soy group compared to placebos, in which T levels did not change over time. SHBG levels were not changed over time or different between the two treatment groups. While data in the literature about soy effects on T and SHBG are mixed, this is the first report of soy effects on circulating T and SHBG with repeated serum sampling over as long as 1.5 years. It is also the first report about soy effects on serum sFas and FasL, while the absence of effects on the IGF axis is in line with other studies that have examined this. Thus, consuming 20 g of soy protein isolate per day for 1.5 years slightly reduced circulating T over time in the absence of changes in SHBG, but did not affect indicators of apoptosis and the IGF axis. (Supported by NIH grants CA27790 &amp; CA166195 and a grant from the Prevent Cancer Foundation.) Citation Information: Cancer Prev Res 2010;3(1 Suppl):A83.

Soy protein supplementation during moderate intensity exercise failed to improve the subsequent 15 min time trial power output in hot environment

Soy protein supplementation during moderate intensity exercise failed to improve the subsequent 15 min time trial power output in hot environment

Evaluation of Isoflavone Rich Soy Protein Supplementation for ostmenopausal Therapy

To examine effects of 6 months supplementation of isoflavone rich soy protein on symptoms, lipid profiles and bone density in postmenopausal women. In this double blind, placebo controlled trial, hundred healthy postmenopausal women not taking Hormone Replacement Therapy, were randomly assigned to consume either 25 g soy protein isolate containing 75 mg isoflavones (study group) or 25 g casein protein (control group) daily. Monthly assessment for acceptability and side effects, 3 monthly for menopausal symptoms (Kupperman Menopausal Index; KMI) and serum lipid-profile, 6 monthly for follicular stimulating hormone, Estradiol levels, vaginal cytology, endometrial thickness and bone density were done. t-test, Analysis of Variance (ANOVA) and chi-square (P ) tests were employed. Significantly higher number of cases 2 reported improvement in hot-flashes, joint-pains and vaginal-dryness on soy treatment (p<0.05). Soy supplement was significantly superior to placebo in reducing KMI (p<0.05). Soy group showed 7.7% decrease in total cholesterol and 14% decrease in LDL-cholesterol (significantly different from control group p<0.05) while no effect was seen on HDL cholesterol, Blood pressure, sex hormones, vaginal cytology, uterine endometrium and bone densitometry. A 25 g soy supplement containing 75 mg of isoflavones may be an effective alternative therapy for menopausal symptoms and may offer a benefit to cardiovascularsystem by altering lipid-profile favorably.

One year soy protein supplementation does not improve lipid profile in postmenopausal women

Based on recent evidence, there is a need to reevaluate the claim that foods containing 25 g of soy protein per serving may reduce cholesterol. The purpose of the present study was to examine if one‐year consumption of soy protein‐containing foods exerts beneficial effects on blood lipids and lipoproteins in postmenopausal women. Eighty‐seven hypercholesterolemic eligible postmenopausal women were randomly assigned to consume soy or control foods daily for one year. Serum samples were analyzed for total cholesterol (TC), LDL, HDL, triglycerides (TG), Apo A and Apo B. Sixty‐two of the 87 women completed the one year study. TC and HDL showed a trend towards increasing from baseline after one year of soy protein supplementation (230.04±6.1 vs. 242.57±6.2 mg/dl P=0.09 and 56.87±2.5 vs. 60.33±2.5 mg/dl, respectively, P=0.08). There were no significant differences in LDL or TG, however a significant increase in Apo B (105.5±5.9 vs. 120.21±5.9 mg/dl P=0.002), and a significant decrease in Apo A (189.36±10 vs. 173.21±10 mg/dl, P=.009) was seen. Our data indicate that one year soy protein supplementation does not confer cardiovascular benefits in postmenopausal women in terms of improving lipid profile. These findings as well as those from other studies lend credence for reevaluating the soy protein health claim issued almost a decade ago.

Resistance training with soy vs whey protein supplements in hyperlipidemic males

BackgroundMost individuals at risk for developing cardiovascular disease (CVD) can reduce risk factors through diet and exercise before resorting to drug treatment. The effect of a combination of resistance training with vegetable-based (soy) versus animal-based (whey) protein supplementation on CVD risk reduction has received little study. The study's purpose was to examine the effects of 12 weeks of resistance exercise training with soy versus whey protein supplementation on strength gains, body composition and serum lipid changes in overweight, hyperlipidemic men.MethodsTwenty-eight overweight, male subjects (BMI 25–30) with serum cholesterol >200 mg/dl were randomly divided into 3 groups (placebo (n = 9), and soy (n = 9) or whey (n = 10) supplementation) and participated in supervised resistance training for 12 weeks. Supplements were provided in a double blind fashion.ResultsAll 3 groups had significant gains in strength, averaging 47% in all major muscle groups and significant increases in fat free mass (2.6%), with no difference among groups. Percent body fat and waist-to-hip ratio decreased significantly in all 3 groups an average of 8% and 2%, respectively, with no difference among groups. Total serum cholesterol decreased significantly, again with no difference among groups.ConclusionParticipation in a 12 week resistance exercise training program significantly increased strength and improved both body composition and serum cholesterol in overweight, hypercholesterolemic men with no added benefit from protein supplementation.

Isoflavone Rich Soy Protein Supplementation For Postmenopausal Therapy

Synopsis: Supplementation of Soy protein isolate containing phytoestrogens in postmenopausal women significantly decreases total and low density cholesterol and improves menopausal symptoms as compared to placebo.Objective: To examine effects of 6 months supplementation of isoflavone rich soy protein on symptoms, lipid profiles and bone density in postmenopausal women. Methods: In this double blind, placebo controlled trial, hundred healthy postmenopausal women not taking Hormone Replacement Therapy, were randomly assigned to consume either 25gm soy protein isolate containing 75 mg isoflavones(study group) or 25 gm casein protein(control group) daily. Monthly assessment for acceptability & side effects, 3 monthly for menopausal symptoms(Kupperman Menopausal Index; KMI) and serum lipid-profile, 6 monthly for Follicular stimulating hormone, Estradiol levels, vaginal cytology, endometrial thickness and bone density were done. T-test, analysis of variance (ANOVA) and chi square tests were employed.Results: Significantly higher number of cases reported improvement in hot- flashes, joint-pains and vaginal-dryness on soy treatment(p<.05). Soy supplement was significantly superior to placebo in reducing KMI(p<.05). Soy group showed 7.7% decrease in total cholesterol and 14% decrease in LDL-cholesterol(significantly different from control group p<.05) while no effect was seen on HDL cholesterol, Blood pressure, sex hormones, vaginal cytology, uterine endometrium & bone densitometry.Conclusion: 25gm soy supplement containing 75mg of isoflavones may be an effective alternative therapy for menopausal symptoms and may offer a benefit to cardiovascular-system by altering lipid- profile favorably.

Soy protein-fortified expanded extrudates: Baseline study using normal corn starch

Soy protein supplementation increases the nutritional value of starch-based expanded snacks. A systematic study was conducted to serve as baseline for optimizing the addition of soy protein concentrate (SPC). Physical and microstructural properties of native corn starch–soy protein concentrate (CS–SPC) extrudates were investigated in relation to the macromolecular changes in starch during extrusion. The effects of extruder screw speed (230 and 330 rpm) and SPC concentration (0%, 5%, 10%, 15%, 20%) on the abovementioned parameters were determined. Increasing screw speed resulted in higher specific mechanical energy (SME) and expansion, and lower mechanical strength. On the other hand, addition of 5–20% SPC led to lower SME and expansion, and higher mechanical strength. X-ray micrographs showed smaller yet more cells, and cell wall thickening with SPC addition. Water absorption index increased and water solubility index decreased with increase in screw speed and SPC level. Increasing screw speed resulted in a slight shift towards smaller molecular weight fractions of starch, as determined by gel permeation chromatography.

Micro‐high‐performance liquid chromatography platform for the depletion of high‐abundance proteins and subsequent on‐line concentration/capturing of medium and low‐abundance proteins from serum. Application to profiling of protein expression in healthy and osteoarthritis sera by 2‐D gel electrophoresis

In this investigation, an integrated microcolumn-based fluidic platform for the simultaneous depletion of high-abundance proteins and the subsequent on-line concentration/capturing of medium- and low-abundance proteins from human serum has been introduced. The platform consists of on-line coupling of tandem affinity micorcolumns to an RP microcolumn to achieve first the depletion of high-abundance proteins by the tandem affinity microcolumns followed by the concentration and capturing of medium- and low-abundance proteins by the RP microcolumn. The tandem affinity microcolumns are based on macroporous monoliths characterized by their relatively high permeability in pressure-driven flow while the RP microcolumn is packed with polymeric particles with an average particle diameter of 20 microm giving rise to a very little back pressure, thus allowing fast flow velocity across the coupled columns format and consequently short processing time of serum samples prior to analysis by 2-DE. The microcolumn-based fluidic platform was applied to serum samples from osteoarthritis (OA) donors before and after soy protein (SP) supplementation, and from healthy donors, and the resulting depleted serum samples from high-abundance proteins were profiled for protein expression by 2-DE. In general, the protein expression was lower in serum of the same OA patient after soy treatment than before soy treatment. Several proteins were down-regulated after soy treatment with transthyretin being the most affected by the SP supplementation. In addition, with respect to serum from healthy donors, the sera from OA patients showed difference in proteins expression.

Determining nitrogen requirements of Aceros and Buceros hornbills

Over 2 months, seven feeding trials were conducted at St. Catherines Island, GA, to quantify protein intake and utilization in captive mature nonreproducing Aceros (n=3 spp.) and Buceros (n=2 spp.) Hornbills were fed homogeneous isocaloric diets. A mixture of Bird of Paradise pellets, grapes, and raisins was offered to the birds as grape-sized balls, supplemented with diced cantaloupe melon to maintain hydration. To vary the protein level (range 10.8-22.6%) within the diets, different amounts of a powdered soy protein supplement were added to the mixture. Test diets were fed for 3 consecutive days. Birds were weighed to test for differences among diets. All excreta and diet samples were collected for nitrogen (N) analysis. Feeding trials were separated by a 4-day period, in which the bird's regular diet was fed. Data were analyzed for N balance, N equilibrium (regression of N intake vs. N excretion) and body mass. Regression analysis of N balances of the nine birds showed that the N equilibriums ranged from 0.081 to 0.595 g N/kg(0.75)/d with an average of 0.387+/-0.298. No differences in N balances were found between Aceros and Buceros hornbills. The methodology of this study suggested a dietary crude protein (CP) requirement of 7.3+/-3.0% dry matter (DM) in a diet containing 4.0 kcal. However, this value was determined by extrapolation and has not been experimentally determined to be adequate. In this study, the hornbills maintained body mass on a diet containing 10.8% CP (with energy at 4.0 kcal/g DM). Zoo Biol 27:282-293, 2008. (c) 2008 Wiley-Liss, Inc.