Soy Protein Supplementation Research Articles

Effects of high-quality protein supplementation on cardiovascular risk factors in individuals with metabolic diseases: A systematic review and meta-analysis of randomized controlled trials

BackgroundUncertainties still existed about the effect of high-quality protein supplementation on cardiovascular disease (CVD) risk factors, although high-quality proteins such as soy and milk proteins have proposed to be beneficial for cardiometabolic health. MethodsA systematic search in PubMed, Web of Science, Cochrane Library, Scopus, and Embase was conducted to quantify the impact of high-quality protein on CVD risk factors. Results63 RCTs on 4 types of high-quality protein including soy protein, milk protein, whey, and casein were evaluated. Soy protein supplementation decreased systolic blood pressure (SBP, -1.42 [-2.68, -0.17] mmHg), total cholesterol (TC, -0.18 [-0.30, -0.07] mmol/L), and low-density lipoprotein cholesterol (LDL-C, -0.16 [-0.27, -0.05] mmol/L). Milk protein supplementation decreased SBP (-2.30 [-3.45, -1.15] mmHg) and total cholesterol (-0.27 [-0.51, -0.03] mmol/L). Whey supplementation decreased SBP (-2.20 [-3.89, -0.51] mmHg), diastolic blood pressure (DBP, -1.07 [-1.98, -0.16] mmHg), triglycerides (-0.10 [-0.17, -0.03] mmol/L), TC (-0.18 [-0.35, -0.01] mmol/L), LDL-C (-0.09 [-0.16, -0.01] mmol/L) and fasting blood insulin (FBI, -2.02 [-3.75, -0.29] pmol/L). Casein supplementation decreased SBP (-4.10 [-8.05, -0.14] mmHg). In the pooled analysis of four high-quality proteins, differential effects were seen in individuals with different health status. In hypertensive individuals, high-quality proteins decreased both SBP (-2.69 [-3.50, -1.87] mmHg) and DBP (-1.34 [-2.09, -0.60] mmHg). In overweight/obese individuals, high-quality proteins improved SBP (-1.40 [-2.22, -0.59] mmHg), DBP (-2.59 [-3.20, -1.98] mmHg), triglycerides (-0.09 [-0.15, -0.02] mmol/L), TC (-0.14 [-0.22, -0.05] mmol/L), LDL-C (-0.12 [-0.16, -0.07] mmol/L), and HDL-C levels (0.02 [0.01, 0.04] mmol/L). According to the benefits on CVD risks factors, whey ranked top for improving cardiometabolic health in hypertensive or overweight/obese individuals. ConclusionOur study supports a beneficial role of high-quality protein supplementation to reduce CVD risk factors. Further studies are still warranted to investigate the effects of different high-quality proteins on CVD risks in individuals with cardiometabolic disorders.

Abstract MP78: A Comprehensive Investigation of the Effect of Dietary Intervention on Perfluorooctanoic Acid and Perfluorooctane Sulfonate

Introduction: The US Environment Protection Agency has proposed National Primary Drinking Water Regulation for six per- and polyfluoroalkyl substances including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). The health effects of the two chemicals need to be thoroughly evaluated. In addition, few studies have investigated interventions that can help clear the two chemicals from the human body. Hypothesis: We hypothesize that the plasma metabolome reflects reactions of the human body to PFOA/PFOS exposures and dietary supplements can reduce PFOA/PFOS. Methods: In the Protein and Blood Pressure (ProBP) trial, 80 participants were randomly assigned to take 40 grams/day of soy protein, milk protein, or carbohydrate supplementation each for 8 weeks in a cross-over design. Plasma PFOA and PFOS levels were tracked from baseline to each of the three intervention phases. We analyzed the associations of serum PFOS and PFOA with a total of 964 known metabolites at baseline and each dietary intervention, respectively. Age, sex, and race were adjusted in all analyses. ProBP findings were evaluated for replication among 1261 participants of the Bogalusa Heart Study (BHS). Results: PFOA and PFOS were significantly reduced after phase I and were decreased further with intervention phases. Soy protein showed the strongest reduction on both PFOA (net change: -0.13, p=1.13х10 -5 ) and PFOS (net change: -0.18, p=4.32х10 -5 ) compared with carbohydrate and milk protein. After Bonferroni correction for 77 independent metabolite clusters (p<6.49х10 -4 ), PFOS was positively associated with 54 metabolites (47 at baseline, 9 at soy protein, 8 at milk protein, and 6 at carbohydrate, respectively). Of which, 20 associations were replicated in BHS ( Table ). PFOA was positively associated with 3-methyladipate at soy protein and bilirubin (E,E) at milk protein. Conclusions: Dietary intervention reduced serum PFOA and PFOS. Several metabolites may play important roles in PFOA/PFOS related health effects.

Impact of Soy Enrichment on Physico-Chemical, In-Vitro Protein and Starch Digestibility, Vitamin, Antioxidant and Sensory Properties of “Lafun” Flour

The study evaluated the physico-chemical, in-vitro protein and starch digestibility, vitamin and antioxidant properties of soy-enriched “lafun” flours as well as the quality acceptability of the reconstituted dough meal from the flours through sensory evaluation. “Lafun”’ was enriched with soy protein supplements (curd or residue at 10%) during the mashing before drying (wet-mix method) followed by thorough mixing to ensure uniform distribution of the soy curd and residue. The total titratable acidity of the flours ranged from 0.65 – 0.86% and pH ranged from 3.43 – 4.07. While enrichment increased the in-vitro protein digestibility from 8.70 to 71.20%, an inversely correlated observation was obtained for the in-vitro starch digestibility which ranged between 45.55 and 71.20. Enrichment also increased the vitamin (B-vitamins) as well as the antioxidant properties of the flour. While this study showed the possibility of enriching cassava flour (“Lafun”) with soy curd or residue, the quality acceptability result revealed higher preference for the non-enriched samples.

Examination of Serum Metabolome Altered by Dietary Carbohydrate, Milk Protein, and Soy Protein Interventions Identified Novel Metabolites Associated with Blood Pressure: The ProBP Trial.

This study aims to discover metabolites of dietary carbohydrate, soy and milk protein supplements and evaluate their roles in blood pressure (BP) regulation in the protein and blood pressure (ProBP), a cross-over trial. Plasma metabolites are profiled at pre-trial baseline and after 8 weeks of supplementation with carbohydrate, soy protein, and milk protein, respectively, among 80 ProBP participants. After Bonferroni correction (α = 6.49 × 10-4 ), dietary interventions significantly changed 40 metabolites. Changes of erucate (22:1n9), an omega-9 fatty acid, are positively associated with systolic BP changes (Beta = 1.90, p = 6·27 × 10-4 ). This metabolite is also associated with higher odds of hypertension among 1261 participants of an independent cohort (odds ratio per unit increase = 1.34; 95% confidence interval: 1.07-1.68). High levels of acylcholines dihomo-linolenoyl-choline (p = 4.71E-04) and oleoylcholine (p = 3.48E-04) at baseline predicted larger BP lowering effects of soy protein. Increasing cheese intake during the trial, as reflected by isobutyrylglycine and isovalerylglycine, reduces the BP lowering effect of soy protein. The study identifies molecular signatures of dietary interventions. Erucate (22:1n9) increases systolic BP. Acylcholine enhances and cheese intake reduces the BP lowering effect of soy protein supplement.

The Effect of Soy and Whey Protein Supplementation on Glucose Homeostasis in Healthy Normal Weight Asian Indians.

Milk and legumes are good source of protein foods used to sustain muscle mass, but their effects on postprandial glucose homeostasis and energy metabolism may be different. This is relevant, for example, in the dietetic response to obesity or diabetes, where the intake of high-quality protein is often increased significantly. The objective of this study was to characterize the acute effect of whey and soy protein (15% vs. 30%) on glucose homeostasis, energy metabolism, and satiety. Healthy, normal body mass index (BMI) Indian adult males aged 20-35 years (n = 15) received 4 test meals (2 proteins (soy vs. whey) and 2 doses (15% vs. 30% protein: energy ratio)). Blood samples were collected serially after the meal to calculate the incremental area under the curve for plasma glucose and insulin. Energy expenditure and substrate oxidation were measured after the meal. Satiety was measured with a visual analogue scale. The insulin response, represented by the incremental area under the curve, was significantly higher for the 30% whey compared to the 30% soy protein meal (p < 0.01) but was not significantly different between the 15% protein doses. There were no differences in the plasma glucose response across protein sources or doses. The mean peak fat and carbohydrate oxidation, satiety, and energy expenditure did not differ between the protein sources and doses. In conclusion, at higher doses, whey protein has a greater insulinogenic response, compared to soy protein, and exhibits a dose-response effect. However, at lower doses, whey and soy protein elicit similar insulinogenic responses, making them equally effective protein sources in relation to glucose homoeostasis.

Comparative effects of soy protein concentrate, enzyme-treated soybean meal, and fermented soybean meal replacing animal protein supplements in feeds on growth performance and intestinal health of nursery pigs

BackgroundSoy protein supplements, with high crude protein and less antinutritional factors, are produced from soybean meal by different processes. This study evaluated the comparative effects of various soy protein supplements replacing animal protein supplements in feeds on the intestinal immune status, intestinal oxidative stress, mucosa-associated microbiota, and growth performance of nursery pigs.MethodsSixty nursery pigs (6.6 ± 0.5 kg BW) were allotted to five treatments in a randomized complete block design with initial BW and sex as blocks. Pigs were fed for 39 d in 3 phases (P1, P2, and P3). Treatments were: Control (CON), basal diet with fish meal 4%, 2%, and 1%, poultry meal 10%, 8%, and 4%, and blood plasma 4%, 2%, and 1% for P1, P2, and P3, respectively; basal diet with soy protein concentrate (SPC), enzyme-treated soybean meal (ESB), fermented soybean meal with Lactobacillus (FSBL), and fermented soybean meal with Bacillus (FSBB), replacing 1/3, 2/3, and 3/3 of animal protein supplements for P1, P2, and P3, respectively. Data were analyzed using the MIXED procedure in SAS 9.4.ResultsThe SPC did not affect the BW, ADG, and G:F, whereas it tended to reduce (P = 0.094) the ADFI and tended to increase (P = 0.091) crypt cell proliferation. The ESM did not affect BW, ADG, ADFI, and G:F, whereas tended to decrease (P = 0.098) protein carbonyl in jejunal mucosa. The FSBL decreased (P < 0.05) BW and ADG, increased (P < 0.05) TNF-α, and Klebsiella and tended to increase MDA (P = 0.065) and IgG (P = 0.089) in jejunal mucosa. The FSBB tended to increase (P = 0.073) TNF-α, increased (P < 0.05) Clostridium and decreased (P < 0.05) Achromobacter and alpha diversity of microbiota in jejunal mucosa.ConclusionsSoy protein concentrate, enzyme-treated soybean meal, and fermented soybean meal with Bacillus could reduce the use of animal protein supplements up to 33% until 7 kg body weight, up to 67% from 7 to 11 kg body weight, and entirely from 11 kg body weight without affecting the intestinal health and the growth performance of nursery pigs. Fermented soybean meal with Lactobacillus, however, increased the immune reaction and oxidative stress in the intestine consequently reducing the growth performance.

A Soy Protein Isolate Rich in Genistein and Daidzein and Its Effects on Plasma Isoflavone Concentrations, Platelet Aggregation, Blood Lipids and Fatty Acid Composition of Plasma Phospholipid in Normal Men

The effects of consuming a soy protein isolate beverage powder (60 g/d for 28 d) vs. a casein supplement was evaluated in 20 male subjects who were randomly allocated into the two groups. A dramatic rise in plasma isoflavone concentrations was observed after supplementation in the soy protein group, the levels reaching 907 ± 245 nmol/L for genistein (a 110-fold increase) and 498 ± 102 nmol/L for daidzein (a 150-fold increase) as measured by isotope dilution gas chromatography - mass spectrometry. These concentrations are higher than previously reported for the plasma of Japanese subjects consuming a traditional diet (276 nmol/L and 107 nmol/L, respectively). No significant differences in collagen- or 9,11-dideoxy-11α, 9α-epoxymethanoprostaglandin F2α (U46619)-induced platelet aggregation were observed in platelet-rich plasma from the two groups; the increase in plasma isoflavonoids from soy protein supplementation is not sufficient to significantly inhibit platelet aggregation ex vivo. Similarly, plasma total and HDL-cholesterol were not affected by protein supplementation, possibly because the men were normo-cholesterolemic at entry. Analysis of plasma phospholipid polyunsaturated fatty acid composition showed no differences between soy protein and casein supplementation. Previous investigations reported a significant alteration in fatty acid status in animals fed soy protein relative to those fed casein. The present studies indicate that although soy protein supplementation to a typical Western diet can increase plasma concentrations of isoflavones, this may not necessarily be sufficient to counter heart disease risk factors such as high plasma cholesterol and platelet aggregation.

Soy protein compared with whey protein ameliorates insulin resistance by regulating lipid metabolism, AMPK/mTOR pathway and gut microbiota in high-fat diet-fed mice.

The findings of soy protein versus whey protein supplementation on glycemic regulation are inconsistent. The aim of the present study was to investigate the preventive effect of soy protein isolate (SPI) and whey protein isolate (WPI) on a high-fat diet (HFD) induced insulin resistance and its potential molecular mechanisms. Male C57BL/6J mice were randomly divided into seven groups (n = 12): normal control, HFD plus 10% SPI, HFD plus 20% SPI, HFD plus 30% SPI, HFD plus 10% WPI, HFD plus 20% WPI, and HFD plus 30% WPI. After 12 weeks of feeding, compared with the WPI groups, serum concentration of insulin, homeostasis model assessment of insulin resistance (HOMA-IR) and liver weight were significantly lower in the SPI groups. Compared with the WPI groups, the mRNA levels of CD36, SLC27A1, PPARγ and AMPKα were significantly higher, and those of LPL, SREBP1c, FASN and ACC1 were significantly lower in the liver in the SPI groups. In the liver or gastrocnemius muscle, compared with the WPI groups, the mRNA levels of GLUT4, IRS-1, PI3K and AKT were significantly higher, and those of mTOR and S6K1 were significantly lower, and the protein levels of GLUT4, p-AMPKα/AMPKα, p-PI3K/PI3K and p-AKT/AKT were significantly higher, and those of p-IRS-1Ser307/IRS-1, p-mTOR/mTOR and p-S6K1/S6K1 were significantly lower in the SPI groups. The Chao1 and ACE indices were higher, and the relative abundance of Staphylococcus and Weissella was lower in the SPI groups than those in the WPI groups. In conclusion, soy protein was more effective than whey protein in preventing IR in HFD-fed mice by regulating lipid metabolism, the AMPK/mTOR pathway, and gut microbiota.

Abstract 14096: Examination of the Serum Metabolome After Dietary Carbohydrate, Milk Protein, and Soy Protein Interventions Identified Novel Metabolites for Blood Pressure: The ProBP Trial

Introduction: In the Protein and Blood Pressure (ProBP) trial, milk and soy protein supplements reduced blood pressure (BP) compared to carbohydrate intervention. We investigated the underlying mechanisms influencing the effects. Methods: Serum metabolites were profiled at pre-trial baseline and after supplementation with carbohydrate, soy protein, and milk protein, respectively, among 80 ProBP participants. We tested the mediating and modifying effects of metabolites on BP-lowering effects of soy and milk protein interventions. Results: Dietary interventions significantly ( P &lt;6.49х10 -4 ) changed 40 metabolites, of which 29 had reduced levels. Two clusters of metabolites mediated 45.5% and 100% of the effects of soy and milk protein interventions, respectively. Within the clusters, lipid 4-cholesten-3-one had the largest effect and mediated 12.7% ( P =0.03) and 16.3% ( P =0.045) of the effects of soy and milk protein interventions, respectively. At baseline, amino acids 5-oxoproline and taurine, lysophospholipid 1-arachidonoyl-GPA(20:4) , and acylcholines oleoylcholine , dihomo-linolenoyl-choline , and arachidonoylcholine predicted BP increase during carbohydrate intervention; while lipids N-stearoyl-sphinganine(d18:0/18:0) and isoursodeoxycholate and peptide gamma-glutamylserine predicted less reduction of BP during soy protein and milk protein supplements ( P &lt;6.49х10 -4 ). Finally, effects of soy and milk protein interventions on systolic and diastolic BP were influenced by changes of isobutyrylglycine ( P for interaction=0.02 and 9.12х10 -5 , respectively). In the bottom tertile of isobutyrylglycine changes, soy and milk protein reduced 5.10 ( P =0.03) and 4.43 ( P =0.01) mmHg systolic BP and 3.22 ( P =0.03) and 3.12 ( P =0.04) mmHg diastolic BP, respectively; while in the top tertile, the two interventions had no or increasing effects on systolic (β soy protein =-0.04, P =0.98; β milk protein =-2.34, P =0.25) and diastolic BP (β soy protein =3.19, P =0.02; β milk protein =1.08, P =0.43). Conclusions: We documented serum metabolites altered by dietary carbohydrate, milk protein, and soy protein interventions, and identified important metabolites mediating or modifying the BP-lowering effect of milk and soy protein interventions.

Effects of Enrichment on Amino Acid Profile, Mineral Composition and Anti-Nutritional Factors of Lafun Powder

‘Lafun” was enriched with soy protein supplements (curd or residue) during the mashing before drying at 10%. The amino acid result indicated that enrichment improved the amino acids contents as well as the protein quality of the products. While enrichment generally improved the mineral element composition, enrichment with the residue significantly improved the mineral composition when compared to enrichment curd. That the products were hygienically produced was confirmed by the non-detection of heavy metals which may suggest it safety for human consumption. Condensed tannins, phytate, oxalate, hydrogen cyanide and trypsin inhibitor were tested as possible anti-nutritional factors in the product and the values obtained were within safe level and correlated with those reported in previous or similar studies. It was concluded that enrichment with soy curd/residue is a safe and viable means to improve the nutritional benefits derivable from “Lafun” especially for those that ‘Lafun” is a major staple.

Abstract 035: Novel Metabolites Associated With Blood Pressure During Dietary Protein And Carbohydrate Interventions

Introduction: Dietary protein and carbohydrate intake have been associated with blood pressure (BP). However, molecular mechanisms for these associations are not well studied. Hypothesis: We hypothesize that novel metabolites – intermediate products of metabolic reactions of diet or genetic factors, may play a role in BP regulation during dietary protein and carbohydrate interventions. Methods: In the Protein and Blood Pressure (ProBP) trial, 80 participants were randomly assigned to take 40 grams/day of soy protein, milk protein, or carbohydrate supplementation each for 8 weeks in a cross-over design. We analyzed the associations of serum metabolites with BP at baseline and each dietary intervention, respectively. Age, sex, race, education, smoking, drinking, and body mass index were adjusted in all analyses. ProBP findings were evaluated for replication among 1206 participants of the Bogalusa Heart Study. Results: After Bonferroni correction for 77 independent metabolite clusters, we identified 17 metabolites (1 at baseline, 8 at carbohydrate diet, 4 at milk protein diet, and 5 at soy protein diet) positively associated with BP (P&lt;6.49E-4). Furthermore, 12 of these metabolite-BP associations identified at dietary interventions were replicated in the BHS (P&lt;0.05, Table ). Of the 12 metabolites, glycerol and hexadecadienoate (16:2n6) were associated with BP in previous studies, and all other metabolite-BP associations were novel. Conclusions: Several novel metabolites may play an important role in BP regulation during dietary protein and carbohydrate intake.

Effects of whey and soy protein supplementation on inflammatory cytokines in older adults: a systematic review and meta-analysis.

Low-grade inflammation is a mediator of muscle proteostasis. This study aimed to investigate the effects of isolated whey and soy proteins on inflammatory markers. We conducted a systematic literature search of randomised controlled trials (RCT) through MEDLINE, Web of Science, Scopus and Cochrane Library databases from inception until September 2021. To determine the effectiveness of isolated proteins on circulating levels of C-reactive protein (CRP), IL-6 and TNF-α, a meta-analysis using a random-effects model was used to calculate the pooled effects (CRD42021252603). Thirty-one RCT met the inclusion criteria and were included in the systematic review and meta-analysis. A significant reduction of circulating IL-6 levels following whey protein [Mean Difference (MD): -0·79, 95 % CI: -1·15, -0·42, I2 = 96 %] and TNF-α levels following soy protein supplementation (MD: -0·16, 95 % CI: -0·26, -0·05, I2 = 68 %) was observed. The addition of soy isoflavones exerted a further decline in circulating TNF-α levels (MD: -0·20, 95 % CI: -0·31, -0·08, I2 = 34 %). According to subgroup analysis, whey protein led to a statistically significant decrease in circulating IL-6 levels in individuals with sarcopenia and pre-frailty (MD: -0·98, 95 % CI: -1·56, -0·39, I2 = 0 %). These findings may be dependent on participant characteristics and treatment duration. These data support that whey and soy protein supplementation elicit anti-inflammatory effects by reducing circulating IL-6 and TNF-α levels, respectively. This effect may be enhanced by soy isoflavones and may be more prominent in individuals with sarcopenia.

Isolated Soy Protein Supplementation Combined With Resistance Training Improves Muscle Strength, Mass, and Physical Performance of Aging Female Mice.

Background/Purpose: In recent years, the aging population has gradually increased, and the aging process is accompanied by health-associated problems, such as loss of muscle mass and weakness. Therefore, it is important to explore alternative strategies for improving the health status and physical fitness of the aged population. In this study, we investigated the effect of soy protein supplementation combined with resistance training on changes in the muscle mass, muscle strength, and functional activity performance of aging mice. Methods: Female Institute of Cancer Research (ICR) mice were divided into four groups (n = 8 per group): sedentary control (SC), isolated soy protein (ISP) supplementation, resistance training (RT), and a combination of ISP and RT (ISP + RT). The mice in designated groups received oral ISP supplementation (0.123 g/kg/day), RT (5 days/week for a period of 4 weeks), or a combination of both ISP plus RT for 4 weeks. Afterward, we assessed muscle strength, endurance, and anaerobic endurance performance and analyzed blood biochemical and pathological tissue sections to investigate whether there were adverse effects or not in mice. Results: ISP supplementation effectively improved the muscle mass, muscle endurance, and endurance performance of aging female mice. The RT group not only showed similar results with ISP but also increased muscle strength and glycogen content. Nevertheless, the combination of ISP supplementation and RT had greater beneficial effects on muscle strength, physical performance, and glycogen levels (p < 0.05). In addition, the combination of ISP supplementation and RT had significantly increased type II muscle percentage and cross-sectional area (p < 0.05). Conclusion: Although ISP or RT alone improved muscle mass and performance, the combination of ISP with RT showed greater beneficial effects in aging mice. Our findings suggest that regular exercise along with protein supplementation could be an effective strategy to improve overall health and physical fitness among the elderly.

PSVI-17 Supplemental Effects of Soy Protein Supplements Replacing Animal Protein Supplements on Growth Performance and Intestinal Health of Nursery Pigs

Abstract This study evaluated the effects of soy protein supplements replacing animal protein on growth performance and intestinal health of nursery pigs. Soy protein supplements included processed soybean meal processed after ethanol extraction, enzyme hydrolysis, and fermentation. Forty-eight newly weaned pigs (6.6 ± 0.3 kg BW) were allotted to 4 treatments in a RCBD with initial BW and sex as blocks. Pigs were fed for 39 d in 3 phases (P1/2/3 for 7/13/19 d, respectively). Dietary treatments were CON (basal diet with fish meal 4/2/1%, poultry meal 10/8/4%, and blood plasma 4/2/1% for P1/2/3, respectively), SPC, ESBM, and FSBM (basal diets with soy protein concentrate (SPC), enzyme treated soybean meal (ESBM), and fermented soybean meal (FSBM), replacing 1/3, 2/3, 3/3 animal protein supplements in P1, P2, P3, respectively). Titanium dioxide (0.4%) was added to diets as indigestible marker from d 32. Growth performance was recorded by phase. Pigs were euthanized on d 39 to collect samples to measure intestinal health and apparent ileal digestibility (AID) of nutrients. Data were analyzed using SAS 9.4. The SPC tended to increase (P = 0.060) Ki-67+ crypt cells (26.7 to 29.0%), and decreased (P &amp;lt; 0.05) AID of EE (66.2 to 52.2%) without affecting growth performance and fecal scores. The ESBM tended to decrease (P = 0.098) protein carbonyls (1.93 to 1.38 nmol/mg of protein) in the jejunal mucosa without affecting growth performance. The FSBM increased (P &amp;lt; 0.05) TNF-α (0.39 to 0.72 pg/mg of protein) in the jejunal mucosa without affecting growth performance. Collectively, soy protein supplements obtained from soybean meal by ethanol extraction, enzyme hydrolysis, and fermentation can partly replace animal protein supplements without affecting the growth performance with minor impacts on intestinal health of nursery pigs.

Effects of Isolated Soy Protein Supplementation Combined with Aerobic Exercise Training on Improving Body Composition, Anthropometric Characteristics and Cardiopulmonary Endurance in Women: A Pilot Study.

Today, women are concerned with health promotion but also with improvements in body weight and shape. The purpose of this study was to investigate the effects of aerobic exercise training (AET) combined with isolated soy protein (ISP) supplementation on the body composition, anthropometric characteristics, and cardiopulmonary endurance of women. The qualified subjects were randomly assigned to AET or AET + ISP groups. Women in the AET + ISP group were given an ISP-rich supplement (40 g/day) 5 days a week for 8 weeks; those in the AET group were given the same amount of water in an identical manner. All women received 60 min of AET twice a week for 8 weeks at an intensity of 40–65% heart rate reserve (HRR) and their body composition, anthropometric characteristics, and physical fitness were measured one week before and after the 8-week AET class. A total of 16 subjects (age: 36.13 ± 5.76 years) completed the study and were included in the dataset. The results of this study show that the AET + ISP group obtained greater reductions in body weight (effect size = 0.99), body mass index (BMI, effect size = 1.04), percentage body fat (PBF, effect size = 1.18), circumferences (waist and hip, all effect sizes > 0.8), and greater gains in the percentage lean body mass (PLBM, effect size = 0.89), compared with the AET group, without significant differences in 20 m multi-stage shuttle run test (20 m MST). We conclude that there is a trend for the consumption of ISP following AET to improve the body composition and anthropometric characteristics in women, compared with those who received the same AET without ISP supplementation.

Soy protein supplementation in men following radical prostatectomy: a 2-year randomized, placebo-controlled clinical trial

Many studies have addressed effects of dietary supplementation with soy protein, but most have been inconsistent and few have been long-term studies in men. This study was a secondary analysis of body weight, blood pressure, thyroid hormones, iron status, and clinical chemistry in a 2-y trial of soy protein supplementation in middle-aged to older men. Data were analyzed as secondary outcomes of a randomized controlled trial of dietary supplementation with 20 g/d soy protein isolate, providing 41 mg/d total isoflavones and 23 mg/d genistein, in 44- to 75-y-old men who were at risk of cancer recurrence following prostatectomy randomized to soy (n=50) or a casein-based placebo (n=43). Weight, blood pressure, and blood samples were collected at baseline, every 2 mo in year 1, and every 3 mo in year 2. Compared with casein, soy supplementation did not affect body weight, blood pressure, serum total cholesterol, calcium, phosphorus, and thyroid hormones. Serum ferritin concentrations doubled over 2 y in both groups (117-129%), whereas hemoglobin and hematocrit increased slightly. In an exploratory subgroup analysis of soy group data, weight increased in subjects producing equol but not in nonproducers. Blood pressure was reduced in nonequol producers but not in producers. Other endpoints were not affected by equol production status. Soy protein supplementation for 2 y compared with a casein-based placebo did not affect body weight, blood pressure, serum total cholesterol, iron status parameters, calcium, phosphorus, and thyroid hormones. Exploratory analysis suggests that equol production status of subjects on soy may modify effects of soy on body weight and possibly blood pressure. This trial was registered at clinicaltrials.gov as NCT00765479.

Randomized, Placebo-Controlled Six-Month Intervention Study of Soy Protein Isolate in Men with Biochemical Recurrence after Radical Prostatectomy: A Pilot Study

There is evidence to suggest that soy may be beneficial for prostate cancer patients, but few randomized trials have addressed this. We examined the effect of 6–8 mo soy protein supplementation on prostate specific antigen (PSA) serum levels in men who recurred (PSA > 0.1 ng/ml) within three years of prostatectomy. Sixteen men were randomized to 20 g soy protein (∼24–26/day genistein; ∼40–43/day total isoflavones) or casein placebo. PSA was measured at base line and at 1, 2, 4, and 6–8 mo. Serum genistein levels greatly increased from baseline and cholesterol decreased in the soy group. In both treatment arms PSA increased similarly and PSA doubling times were not different over the 6–8 mo study duration. Two subjects in each group had stable PSA. A literature search for clinical studies of soy, isoflavones, and PSA revealed that supplementation with soy or isoflavones did not affect PSA in virtually all clinical studies identified. Although this study is too small to draw a definitive conclusion on the effect of soy protein on PSA in men with biochemical failure, the null finding in this study is consistent with the results of virtually all reports of soy and soy isoflavones in the literature.

Daily Supplementation With Whey, Soy, or Whey-Soy Blended Protein for 6 Months Maintained Lean Muscle Mass and Physical Performance in Older Adults With Low Lean Mass

BackgroundFew studies have investigated the effect of long-term protein supplementation alone on muscle health in older adults with low lean mass. ObjectiveTo determine the effect of whey, soy or whey-soy blended protein supplementation on lean muscle mass and physical performance in older adults with low lean mass. DesignA 4-arm randomized controlled trial. Participants/settingChinese older adults (n = 123, 65-79 years) with low lean mass (appendicular skeletal muscle index < 7.0 kg/m2 in men and < 5.4 kg/m2 in women) living in the urban area of Guangzhou participated between October 2015 and June 2016. InterventionParticipants were randomly assigned to receive approximately 16 g/d of whey, soy, or whey-soy blend protein or maintained habitual diets in control group for 6 months. Main outcome measuresLean mass, handgrip strength, and physical performance (gait speed, chair stand test, and Short Physical Performance Battery) were assessed at baseline and 6 months. Statistical analysesTwo-way analysis of variance with the main effects of treatment and time and treatment × time interaction and analysis of covariance was used to determine differences in outcomes. ResultsAppendicular skeletal muscle index, lean mass, percent lean mass in legs and appendicular areas, gait speed, and Short Physical Performance Battery score were maintained in the treatment groups and decreased in the control group, resulting in significant reduction in these variables from baseline in the control compared with treatment groups (all P < .01; percent differences between treatment and control groups ranged from 80% to 156%). The chair stand test time at month 6 decreased from baseline in the treatment groups and increased in the control group, resulting in a significant increase in the control compared with treatment groups (all P < .01; percent differences between treatment and control groups ranged from 132% to 155%). Handgrip strength remained unchanged. There were no significant differences in outcomes among treatment groups. ConclusionsSupplementation with whey, soy, or whey-soy blended protein for 6 months equally maintained lean muscle mass and physical performance in older adults with low lean mass.

Impact of 18-Month Soy Protein Supplementation on Steroid Hormones and Serum Biomarkers of Angiogenesis, Apoptosis, and the Growth Hormone/IGF-1 Axis: Results of a Randomized, Placebo-Controlled Trial in Males Following Prostatectomy

Many studies have addressed the effects of dietary supplementation with soy protein on cancer risk and mortality, but there are only few randomized studies with soy in males. We used serum samples from a two-year trial of soy protein isolate supplementation in middle-aged to older males at risk of recurrence of prostate cancer after radical prostatectomy to determine soy effects on steroid hormones involved in prostate cancer (testosterone, SHBG, and estradiol) and explore the effects on biomarkers of the growth hormone/IGF-1 axis, apoptosis, and angiogenesis. Compared with a casein-based placebo, 18 mo, of consumption of 19.2 g/day of whole soy protein isolate containing 24 mg genistein-reduced circulating testosterone and SHBG, but not free testosterone, and did not affect serum concentrations of estradiol, VEGF, IGF-1, IGFBP-3, IGF-1/IGFBP-3 ratio, soluble Fas, Fas-ligand, and sFas/Fas-ligand ratio. Thus, soy protein supplementation for 18 mo, affected the androgen axis, but the effects on other cancer biomarkers remain to be more definitively determined. The study was registered at clinicaltrials.gov (NCT00765479).

Effect of whey vs. soy protein supplementation on recovery kinetics following speed endurance training in competitive male soccer players: a randomized controlled trial

BackgroundSoccer-specific speed-endurance training induces short-term neuromuscular fatigue and performance deterioration over a 72-h recovery period, associated with elevated markers of exercise-induced muscle damage. We compared the effects of whey vs. soy protein supplementation on field activity, performance, muscle damage and redox responses following speed-endurance training in soccer players.MethodsTen well-trained, male soccer players completed three speed-endurance training trials, receiving whey protein (WP), soy protein (SP) or an isoenergetic placebo (PL; maltodextrin) according to a randomized, double-blind, crossover, repeated-measures design. A pre-loading period was applied in each trial during which protein supplementation was individually adjusted to reach a total protein intake of 1.5 g/kg/day, whereas in PL protein intake was adjusted at 0.8–1 g/kg/day. Following pre-loading, two speed-endurance training sessions (1 and 2) were performed 1 day apart, over a 3-day experimental period. During each session, field activity and heart rate were continuously monitored using global positioning system and heart rate monitors, respectively. Performance (isokinetic strength of knee extensors and flexors, maximal voluntary isometric contraction, speed, repeated sprint ability, countermovement jump), muscle damage (delayed-onset of muscle soreness, creatine kinase activity) and redox status (glutathione, total antioxidant capacity, protein carbonyls) were evaluated at baseline (pre), following pre-loading (post-load), and during recovery from speed-endurance training.ResultsHigh-intensity and high-speed running decreased (P ≤ 0.05) during speed-endurance training in all trials, but WP and SP mitigated this response. Isokinetic strength, maximal voluntary isometric contraction, 30-m speed, repeated sprint ability and countermovement jump performance were similarly deteriorated during recovery following speed-endurance training in all trials (P ≤ 0.05). 10 m speed was impaired at 24 h only in PL. Delayed-onset of muscle soreness, creatine kinase, total antioxidant capacity and protein carbonyls increased and glutathione decreased equally among trials following speed-endurance training (P ≤ 0.05), with SP inducing a faster recovery of protein carbonyls only at 48 h (P ≤ 0.05) compared to WP and PL.ConclusionsIn conclusion, increasing daily protein intake to 1.5 g/kg through ingestion of either whey or soy protein supplements mitigates field performance deterioration during successive speed-endurance training sessions without affecting exercise-induced muscle damage and redox status markers.Trial registrationName of the registry: clinicaltrials.gov. Trial registration: NCT03753321. Date of registration: 12/10/2018.