Soy-based renoprotection

Effect of Unfermented Soy Product Consumption on Blood Lipids in Postmenopausal Women: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Clinical studies have reported the beneficial effects of unfermented soy product consumption on blood lipids in various populations. However, contradictory results have been reported regarding the influence of unfermented soy product consumption on blood lipids in postmenopausal women.

OBJECTIVE

The aim of this systematic review and meta-analysis was to evaluate the effects of diets with unfermented soy products compared with diets without unfermented soy products on blood lipids in postmenopausal women.

METHODS

The Cochrane Library, PubMed, Scopus, Web of Science, and Embase electronic databases were searched for eligible randomized controlled trials (RCTs) published up to February 21, 2023. RCTs were included if they were published in English and investigated the effect of unfermented soy product consumption on blood lipids in postmenopausal women who had discontinued hormone replacement therapy at least 3 months before randomization. A random-effects model was used to calculate the overall effect size of the mean difference (MD) and 95% CI. Risk of bias was assessed using the Cochrane Risk-of-Bias Tool for Randomized Trials, version 2.

RESULTS

Twenty-nine RCTs involving 2,457 participants were included. The results showed that, compared with the control group that did not consume unfermented soy products, consumption of unfermented soy products significantly reduced total cholesterol (TC) (MD, -9.46 mg/dL [to convert mg/dL cholesterol to mmol/L, multiply mg/dL by 0.0259; to convert mmol/L cholesterol to mg/dL, multiply by 38.7]; 95% CI -15.04 to -3.89 mg/dL; P = .001) and triglycerides (TGs) (MD, -10.86 mg/dL [to convert mg/dL TGs to mmol/L, multiply mg/dL by 0.0113; to convert mmol/L TGs to mg/dL, multiply mmol/L by 88.6]; 95% CI -19.70 to -2.02 mg/dL; P = .016), while significantly increasing high-density lipoprotein cholesterol (MD, 2.32 mg/dL; 95% CI 0.87 to 3.76 mg/dL; P = .002) in postmenopausal women, but had no significant effect on low-density lipoprotein cholesterol (MD, -4.55 mg/dL; 95% CI -10.90 to 1.80 mg/dL; P = .160). Results of soy preparation subgroup analysis showed that soy isolate protein significantly reduced TC and soy protein-containing isoflavones significantly reduced TC and low-density lipoprotein cholesterol and increased high-density lipoprotein cholesterol. Furthermore, unfermented soy product consumption significantly reduced TC, low-density lipoprotein cholesterol, and TG levels in postmenopausal women with lipid disorders and TGs in healthy postmenopausal women.

CONCLUSIONS

The results showed that unfermented soy product consumption reduced TC and TG levels significantly, and increased high-density lipoprotein cholesterol levels in postmenopausal women. The findings of this review contribute to the evidence-base for dietary management of blood lipids in postmenopausal women.

The association between the amount and timing of coffee consumption with chronic kidney disease in diabetic patients

Previous studies have suggested that diabetic patients should align their food and nutrient intake with their biological metabolic rhythm. However, the optimal timing of coffee consumption to prevent the development of chronic kidney disease (CKD) in diabetic patients remains unknown. This study aims to examine the association between the amount and timing of coffee consumption and CKD prevalence in diabetic patients. We recruited a nationally representative sample of 8564 diabetes patients from NHANES (National Health and Nutrition Examination Survey) from 2003 to 2018. Coffee intake was assessed using a 24 hour dietary recall and categorized into different time periods throughout the day: dawn-to-forenoon (5:00 a.m. to 8:00 a.m.), forenoon-to-noon (8:00 a.m. to 12:00 p.m.), noon-to-evening (12:00 p.m. to 6:00 p.m.), and evening-to-dawn (6:00 p.m. to 5:00 a.m.). Logistic regression models were used to assess the association between the amount and timing of coffee consumption and the prevalence of CKD in diabetic patients. After adjusting for potential confounders, diabetic patients who had the status of coffee consumption throughout the day had a lower prevalence of CKD compared to those who did not (OR: 0.89, 95% CI: 0.80-0.99). In terms of the timing of coffee consumption, diabetic patients who consumed coffee or had higher levels of coffee consumption from dawn-to-forenoon had a lower incidence risk of CKD (OR: 0.87, 95% CI: 0.77-0.98; OR: 0.83, 95% CI: 0.70-0.98). Conversely, diabetic patients who consumed higher levels of coffee during the noon-to-evening and evening-to-dawn periods had an increased incidence risk of CKD (OR: 1.35, 95% CI: 1.07-1.71 and OR: 1.28, 95% CI: 1.01-1.64, respectively). These observations remained robust across different participant subtypes. Our results indicated that diabetic patients who consumed coffee from dawn-to-forenoon had a lower risk of developing CKD, while those who consumed coffee from noon-to-evening or evening-to-dawn had an increased risk.

A Tripeptide (Ser-Arg-Pro, SRP) from Sipunculus nudus L. Improves Cadmium-Induced Acute Kidney Injury by Targeting the MAPK, Inflammatory, and Apoptosis Pathways in Mice

Cadmium (Cd) is a toxic heavy metal that causes nephrosis, including acute kidney injury. To prevent and treat acute kidney injury (AKI) following Cd exposure, a tripeptide, Ser-Arg-Pro (SRP), from Sipunculus nudus L. was employed, and its potential efficacy in AKI was assessed. Oral administration of SRP significantly alleviated Cd-induced kidney damage, leading to improved renal function and the attenuation of structural abnormalities. A network pharmacology analysis revealed the potential of SRP in renal protection by targeting various pathways, including mitogen-activated protein kinase (MAPK) signaling, inflammatory response, and apoptosis pathways. Mechanistic studies indicated that SRP achieves renal protection by inhibiting the activation of MAPK pathways (phosphorylation of p38, p56, ERK, and JNK) in the oxidative stress cascade, suppressing inflammatory responses (iNOS, Arg1, Cox2, TNF-α, IL-1β, and IL-6), and restoring altered apoptosis factors (caspase-9, caspase-3, Bax, and Bcl-2). Hence, SRP has the potential to be used as a therapeutic agent for the treatment of Cd-induced nephrotoxicity.

The realm of plant proteins with focus on their application in developing new bakery products

Plant proteins are spreading due to growing environmental, health and ethical concerns related to animal proteins. Proteins deriving from cereals, oilseeds, and pulses are witnessing a sharp growth showing a wide spectrum of applications from meat and fish analogues to infant formulations. Bakery products are one of the biggest markets of alternative protein applications for functional and nutritional motives. Fortifying bakery products with proteins can secure a better amino-acids profile and a higher protein intake. Conventional plant proteins (i.e., wheat and soy) dominate the bakery industry, but emerging sources (i.e., pea, chickpea, and faba) are also gaining traction. Each protein brings specific functional properties and nutritional value. Therefore, this chapter gives an overview of the main features of plant proteins and discusses their impact on the quality of bakery products.

Soy Phospholipids Exert a Renoprotective Effect by Inhibiting the Nuclear Factor Kappa B Pathway in Macrophages

Complications associated with chronic kidney disease (CKD), which involves kidney inflammation, are a major health problem. Soy protein isolate (SPI) reportedly inhibits CKD exacerbation; however, its detailed action mechanism remains obscure. Therefore, the role of the polar lipid component of SPI in suppressing inflammation was investigated. Zucker fatty rats were divided into three groups and fed a diet containing casein, SPI, or casein + SPI ethanol extract (SPIEE) for 16 weeks. The isoflavones and phospholipids of SPIEE were evaluated for their anti-inflammatory effects. Rats in the SPI and casein + SPIEE groups showed reduced levels of the urinary N-acetyl-β-d-glucosaminidase and renal IL-1β mRNA (an inflammatory marker) compared with those in the casein group. In proximal tubular cells, genistein significantly inhibited monocyte chemoattractant protein-1 (MCP-1) expression induced by an IL-1β stimulus. In macrophages, soybean phospholipids suppressed lipopolysaccharide-induced IL-1β gene expression by inhibiting the phosphorylation of inhibitor κB and p65. Phosphatidylinositol (PI) was found to be essential for inhibition of IL-1β expression. SPIEE inhibited the exacerbation of kidney disease. Genistein and soybean phospholipids, especially soybean-specific phospholipids containing PI, effectively inhibited the inflammatory spiral in vitro. Hence, daily soybean intake may be effective for inhibiting chronic inflammation and slowing kidney disease progression.

Nephroprotective Plants: A Review on the Use in Pre-Renal and Post-Renal Diseases

Kidney diseases are expected to become the fifth leading cause of death by 2040. Several physiological failures classified as pre-, intra-, and post-renal factors induce kidney damage. Diabetes, liver pathologies, rhabdomyolysis, and intestinal microbiota have been identified as pre-renal factors, and lithiasis or blood clots in the ureters, prostate cancer, urethral obstructions, prostate elongation, and urinary tract infections are post-renal factors. Additionally, the nephrotoxicity of drugs has been highlighted as a crucial factor inducing kidney injuries. Due to the adverse effects of drugs, it is necessary to point to other alternatives to complement the treatment of these diseases, such as nephroprotective agents. Plants are a wide source of nephroprotective substances and can have beneficial effects in different levels of the physiological pathways which lead to kidney damage. In traditional medicines, plants are used as antioxidants, anti-inflammatories, diuretics, and anticancer agents, among other benefits. However, the mechanism of action of some plants empirically used remains unknown and scientific data are required to support their nephroprotective effects. The present work reviewed the plants with a beneficial effect on kidney diseases. The classification of nephroprotective plants according to the clinical definition of pre-renal, intrinsic, and post-renal factors is proposed to orient their use as complementary treatments.

A Survey Study on Soy Food Consumption in Patients with Chronic Kidney Diseases

Chronic kidney disease (CKD) is one of the major and exacerbating global health burdens, which is characterized by no curative treatments and high morbidity and mortality. Since malnutrition has become an important factor determining the final clinical outcomes of CKD, soy products, high-quality plant-based sources of proteins and other nutrients, are recommended by many physicians for CKD patients. However, it has been reported that adherence to this dietary advice among those patients is low. In order to dissect the potential reasons behind this phenomenon and to subsequently develop target intervention to improve the current situation, we designed and conducted a self-administered questionnaire survey in 3 medical centers in China. Total 570 patients responded to our survey and data analysis reveals that 85.6% of the respondents were aware of the necessaries of high-quality protein diets for CKD patients, but only 41.9% of patients knew that soy foods provide high-quality proteins needed. In contrast, up to 90.4% of patients were affected by the notion that patients with CKD should avoid soy products. Besides, comparing with other groups, higher percentage of patients undergoing peritoneal dialysis recognized soy products as foods with high-quality proteins, however, as many as 68.8% of them did not consume any soy foods due to the concerns of adverse effects on the progress of CKD. Our data suggest that a significant portion of patients with CKD do not consume soy foods, which could be mainly resulted from their misconception towards soy products delivered by medical workers or social media. Evidence-based updated education of patients and medical workers on soy foods would be a necessary strategy for improving nutrition status of CKD patients and their clinical outcomes.

Effects of different sources of dietary protein on markers of kidney function in individuals with diabetes: a systematic review and meta-analysis of randomized controlled trials

CONTEXT

The type of dietary protein may modulate markers of diabetic kidney disease; however, no attempt to summarize the evidence from randomized controlled trials (RCTs) has been performed to date.

OBJECTIVE

To assess the effects of different types of dietary protein on urinary albumin excretion and glomerular filtration rate in individuals with diabetes.

DATA SOURCES

MEDLINE, EMBASE, and Scopus were searched for all published RCTs, with no language restriction, up to July 2020.

DATA EXTRACTION

Study selection and data extraction were performed independently by 3 authors. Risk of bias was assessed independently by 2 authors, and the GRADE approach was used to assess the quality of the evidence.

RESULTS

Twelve RCTs were included, of which 11 (involving 228 participants) were compiled in meta-analyses of random-effects models. Interventions consisted of diets emphasizing plant or white meat protein, with reduced intake of animal or red meat protein. Pooled data from crossover trials (n = 8) favored intervention diets for urinary albumin excretion (ratio of means, 0.86; 95% confidence interval 0.80 to 0.94; I2 = 4%) and glomerular filtration rate (ratio of means, 0.90; 95% confidence interval 0.87 to 0.94; I2 = 45%), compared with control diets. Results from parallel-design studies (n = 3), however, were not statistically significant for any outcome. The quality of the evidence ranged from very low to moderate, and most studies were judged with at least some concerns in terms of risk of bias.

CONCLUSION

This meta-analysis found weak evidence for small to moderate improvements in markers of kidney function in favor of interventions with lower animal protein (or red meat protein) compared with usual diets in short-term crossover trials. These findings require confirmation in well-designed randomized controlled trials.

Do Bioactive Food Compound with Avena sativa L., Linum usitatissimum L. and Glycine max L. Supplementation with Moringa oleifera Lam. Have a Role against Nutritional Disorders? An Overview of the In Vitro and In Vivo Evidence

Functional clinical nutrition is an integrative science; it uses dietary strategies, functional foods and medicinal plants, as well as combinations thereof. Both functional foods and medicinal plants, whether associated or not, form nutraceuticals, which can bring benefits to health, in addition to being included in the prevention and treatment of diseases. Some functional food effects from Avena sativa L. (oats), Linum usitatissimum L. (brown flaxseed), Glycine max L. (soya) and Moringa oleifera have been proposed for nutritional disorders through in vitro and in vivo tests. A formulation called a bioactive food compound (BFC) showed efficiency in the association of oats, flaxseed and soy for dyslipidemia and obesity. In this review, we discuss the effects of BFC in other nutritional disorders, as well as the beneficial effects of M. oleifera in obesity, cardiovascular disease, diabetes mellitus type 2, metabolic syndrome, intestinal inflammatory diseases/colorectal carcinogenesis and malnutrition. In addition, we hypothesized that a BFC enriched with M. oleifera could present a synergistic effect and play a potential benefit in nutritional disorders. The traditional consumption of M. oleifera preparations can allow associations with other formulations, such as BFC. These nutraceutical formulations can be easily accepted and can be used in sweet preparations (fruit and/or vegetable juices, fruit and/or vegetable vitamins, porridges, yogurt, cream, mousses or fruit salads, cakes and cookies) or savory (vegetable purees, soups, broths and various sauces), cooked or not. These formulations can be low-cost and easy-to-use. The association of bioactive food substances in dietary formulations can facilitate adherence to consumption and, thus, contribute to the planning of future nutritional interventions for the prevention and adjuvant treatment of the clinical conditions presented in this study. This can be extended to the general population. However, an investigation through clinical studies is needed to prove applicability in humans.

Non-animal proteins as cutting-edge ingredients to reformulate animal-free foodstuffs: Present status and future perspectives

Consumer interest in protein rich diets is increasing, with more attention being paid to the protein source. Despite the occurrence of animal proteins in the human diet, non-animal proteins are gaining popularity around the world due to their health benefits, environmental sustainability, and ethical merit. These sources of protein qualify for vegan, vegetarian, and flexitarian diets. Non-animal proteins are versatile, derived mainly from cereals, vegetables, pulses, algae (seaweed and microalgae), fungi, and bacteria. This review's intent is to analyze the current and future direction of research and innovation in non-animal proteins, and to elucidate the extent (limitations and opportunities) of their applications in food and beverage industries. Prior knowledge provided relevant information on protein features (processing, structure, and techno-functionality) with particular focus on those derived from soy and wheat. In the current food landscape, beyond conventionally used plant sources, other plant proteins are gaining traction as alternative ingredients to formulate animal-free foodstuffs (e.g., meat alternatives, beverages, baked products, snack foods, and others). Microbial proteins derived from fungi and algae are also food ingredients of interest due to their high protein quantity and quality, however there is no commercial food application for bacterial protein yet. In the future, key points to consider are the importance of strain/variety selection, advances in extraction technologies, toxicity assessment, and how this source can be used to create food products for personalized nutrition.

Nephroprotection by SGLT2i in CKD Patients: May It Be Modulated by Low-Protein Plant-Based Diets?

Sodium-glucose-transporter 2 inhibitors (SGLT2i) are a new class of anti-diabetic drugs that in large trials such as CREDENCE have shown also a reduction of glomerular hyperfiltration and albuminuria in type 2 diabetic patients. Hence, the interest toward SGLT2i is focused toward this potential nephroprotective effect, in order to reduce the progression to overt nephropathy, and it seems to be confirmed in the most recent DAPA-CKD trial. This is the reason why the indication for SGLT2i treatment has been extended to chronic kidney disease (CKD) patients with eGFR up to 30 ml/min, namely with CKD stage 1-3. In patients with CKD stage 3 to 5, the most recent KDIGO guidelines recommend low-protein diet and plant-based regimens to delay end-stage kidney disease (ESKD) and improve quality of life. Similarly to SGLT2i, low-protein diets exert renal-protective effects by reducing single nephron hyperfiltration and urinary protein excretion. Beyond the glomerular hemodynamic effects, both protein restriction and SGLT2i are able to restore autophagy and, through these mechanisms, they may exert protective effects on diabetic kidney disease. In this perspective, it is likely that diet may modulate the effect of SGLT2i in CKD patients. Unfortunately, no data are available on the outcomes of the association of SGLT2i and low-protein and/or vegan diets. It is therefore reasonable to investigate whether CKD patients receiving SGLT2i may have further advantages in terms of nephroprotection from the implementation of a low-protein and/or plant-based diet or whether this association does not result in an additive effect, especially in vascular nephropathies.

Plant Proteins: Assessing Their Nutritional Quality and Effects on Health and Physical Function

Consumer demand for plant protein-based products is high and expected to grow considerably in the next decade. Factors contributing to the rise in popularity of plant proteins include: (1) potential health benefits associated with increased intake of plant-based diets; (2) consumer concerns regarding adverse health effects of consuming diets high in animal protein (e.g., increased saturated fat); (3) increased consumer recognition of the need to improve the environmental sustainability of food production; (4) ethical issues regarding the treatment of animals; and (5) general consumer view of protein as a "positive" nutrient (more is better). While there are health and physical function benefits of diets higher in plant-based protein, the nutritional quality of plant proteins may be inferior in some respects relative to animal proteins. This review highlights the nutritional quality of plant proteins and strategies for wisely using them to meet amino acid requirements. In addition, a summary of studies evaluating the potential benefits of plant proteins for both health and physical function is provided. Finally, potential safety issues associated with increased intake of plant proteins are addressed.

Effect of Added Dietary Betaine and Soluble Fiber on Metabolites and Fecal Microbiome in Dogs with Early Renal Disease

Renal diets are recommended for dogs with chronic kidney disease (CKD). This study examined the effects of foods with added betaine and fiber on the plasma and fecal metabolome and fecal microbiome in dogs with early stage CKD. At baseline, several metabolites differed between healthy dogs and those with CKD. Dogs with CKD (n = 28) received a control food, low soluble fiber plus betaine food (0.5% betaine, 0.39% oat beta-glucan, and 0.27% short-chain fructooligosaccharides (scFOS)), or high soluble fiber plus betaine food (0.5% betaine, 0.59% oat beta-glucan, and 0.41% scFOS) each for 10 weeks in different sequences. Consumption of test foods led to several favorable, significant changes in the plasma metabolome, including decreases of several uremic toxins and other deleterious metabolites, and increases in favorable metabolites compared with the control food. Only 7 fecal metabolites significantly changed with consumption of the test foods compared with the control food, largely increases in polyphenols and lignans. Few changes were seen in the fecal microbiome, though some taxa that significantly changed in response to the test foods have beneficial effects on health, with some negatively correlating with uremic toxins. Overall, foods with added betaine and soluble fiber showed positive effects on the plasma and fecal metabolomes.

The effect of soy intervention on insulin-like growth factor 1 levels: A meta-analysis of clinical trials

A low insulin-like growth factor 1 (IGF-1) level is known to be associated with many disorders. Several studies have shown that soy consumption may influence IGF-1, but the findings remain inconclusive. In this work, we conducted a systematic review and meta-analysis to provide a more accurate estimation of the effect of soy consumption on plasma IGF-1. A comprehensive systematic search was performed in Scopus, Embase, Web of Science, and PubMed/MEDLINE databases from inception until October 2019. Eight studies fulfilled the eligibility criteria. The pooled weighted mean difference (WMD) of the eligible studies was calculated with random-effects approach. Overall, a significant increment in plasma IGF-1 was observed following soy intervention (WMD: 13.5 ng/ml, 95% CI: 5.2, 21.8, I2 = 97%). Subgroup analyses demonstrated a significantly greater increase in IGF-1, when soy was administered at a dosage of ≤40 g/day (WMD: 11.7 ng/ml, 95% CI: 10.9 to 12.6, I2 = 98%), and when the intervention duration was <12 weeks (WMD: 26.6 ng/ml, 95% CI: 9.1 to 44.1, I2 = 0.0%). In addition, soy intervention resulted in a greater increase in IGF-1 among non-healthy subjects (WMD: 36 ng/ml, 95% CI: 32.7 to 39.4, I2 = 84%) than healthy subjects (WMD: 9.8 ng/ml, 95% CI: 8.9 to 10.7, I2 = 90%). In conclusion, this study provided the first meta-analytical evidence that soy intake may increase IGF-1 levels, but the magnitude of the increase is dependent on the intervention dosage, duration, and health status of the participants.

Beneficial Effects of Isoflavones in the Kidney of Obese Rats Are Mediated by PPAR-Gamma Expression

Several studies have demonstrated an important association between altered lipid metabolism and the development of kidney injury because of a high-fat diet. Fructose is also closely associated with renal injury. We opted for a combination of fructose and saturated fats in a diet (DH) that is a model known to induce renal damage in order to evaluate whether soy isoflavones could have promising use in the treatment of renal alterations. After two months of ingestion, there was an expansion of visceral fat, which was associated with long-term metabolic disorders, such as sustained hyperglycemia, insulin resistance, polyuria, dyslipidemia, and hypertension. Additionally, we found a decrease in renal blood flow and an increase in renal vascular resistance. Biochemical markers of chronic kidney disease were detected; there was an infiltration of inflammatory cells with an elevated expression of proinflammatory cytokines (tumor necrosis factor-α, interleukin (IL)-6, and IL-1β), the activation of the renin–angiotensin system, and oxidative/nitrosative stress. Notably, in rats exposed to the DH diet for 120 days, the concomitant treatment with isoflavones after 60 days was able to revert metabolic parameters, renal alterations, and oxidative/nitrosative stress. The beneficial effects of isoflavones in the kidney of the obese rats were found to be mediated by expression of peroxisome proliferator-activated receptor gamma (PPAR-γ).

Protective effect of genistein in a rat model of ischemic acute kidney injury

BACKGROUND

This study determined the possible anti-inflammatory and antioxidant renal protective effect of genistein, a soy isoflavone, against kidney damage and functional disorders following renal ischemia/reperfusion (I/R) in male rats.

MATERIALS AND METHODS

The animals were dedicated to five groups (n = 7 per group): Sham, Sham + Geni (genistein, 15 mg/kg in 1 ml 1% DMSO, i.p.), Sham + DMSO (1 ml 1% DMSO, i.p.), I/R (bilateral renal ischemia for 45 min followed by 24 h reperfusion), I/R + Geni (genistein, 15 mg/kg). 24-h urine samples, blood and tissue samples of the kidney were collected at the end of 24 h reperfusion period.

RESULTS

Compared to sham, sham + Geni and sham + DMSO groups, IR injury (IRI) ended in kidney dysfunction (decreased creatinine clearance, and increased fractional excretion of sodium), increased levels of malondialdehyde, decreased activities of antioxidant enzymes (superoxide dismutase, gluthatione peroxidase, and catalase), increased gene expression levels of TLR4 (Toll-like receptor 4) and TNF-α (tumor necrosis factor-alpha), as well as histological damages in kidney tissue. Genistein administration decreased all the changes. Therefore, genistein apparently protects the kidney against IRI by mitigating both oxidative stress and inflammation. The antioxidant and anti-inflammatory properties of genistein probably exert important roles in improving functional disorders and offer renal protection against IRI.

Ameliorating Chronic Kidney Disease Using a Whole Food Plant-Based Diet

Novel approaches to ameliorating chronic kidney disease (CKD) are warranted as most patients are undiagnosed until they begin displaying symptoms of kidney failure. There is increasing evidence that a whole food plant-based (WFPB) diet may offer benefits that slow the progression of CKD, decrease the incidence cardiovascular disease, decrease rates of diabetes and obesity, and reduce inflammation and cholesterol, which in turn can delay kidney failure and the initiation of dialysis. While animal-based protein ingestion promotes an acidic environment, inflammation and renal hyperfiltration, study authors report plant-based protein can be alkaline-producing and anti-inflammatory and can contain renoprotective properties. Although there may be benefits to adopting a WFPB diet, macronutrient and micronutrient content should be carefully considered and adjusted to avoid malnutrition in CKD patients. Further research needs to be done in order to establish the biological plausibility and feasibility of a WFPB in individuals with diagnosed CKD.

Aureobasidium pullulans produced β-glucan is effective to enhance Kurosengoku soybean extract induced Thrombospondin-1 expression

Black yeast, Aureobasidium pullulans is extracellularly produced β-(1,3), (1,6)-D-glucan (β-glucan) under certain conditions. In this study, using Glycine max cv. Kurosengoku (Kurosengoku soybeans), the production of β-glucan through fermentation of A. pullulans was evaluated, and the effects of A. pullulans cultured fluid (AP-CF) containing β-glucan made with Kurosengoku soybeans (kAP-CF) on a human monocyte derived cell line, Mono Mac 6 cells were investigated. Concentration of β-glucan in kAP-CF reached the same level as normal AP-CF. An anti-angiogenic protein, Thrombospondin-1 (THBS1) was effectively induced after the stimulation with kAP-CF for comparison with AP-CF. The THBS1 is also induced after stimulation with hot water extract of Kurosengoku soybeans (KS-E), while the combined stimulation of β-glucan with KS-E more effectively induced THBS1 than that with KS-E alone. These results suggest effects of A. pullulans-produced β-glucan on the enhancement of Kurosengoku soybean-induced THBS1 expression.

Does soy protein affect circulating levels of unbound IGF-1?

INTRODUCTION

Despite the enormous amount of research that has been conducted on the role of soyfoods in the prevention and treatment of chronic disease, the mechanisms by which soy exerts its physiological effects are not fully understood. The clinical data show that neither soyfoods nor soy protein nor isoflavones affect circulating levels of reproductive hormones in men or women. However, some research suggests that soy protein, but not isoflavones, affects insulin-like growth factor I (IGF-1).

METHODS

Since IGF-1 may have wide-ranging physiological effects, we sought to determine the effect of soy protein on IGF-1 and its major binding protein insulin-like growth factor-binding protein (IGFBP-3). Six clinical studies were identified that compared soy protein with a control protein, albeit only two studies measured IGFBP-3 in addition to IGF-1.

RESULTS

Although the data are difficult to interpret because of the different experimental designs employed, there is some evidence that large amounts of soy protein (>25 g/day) modestly increase IGF-1 levels above levels observed with the control protein.

CONCLUSION

The clinical data suggest that a decision to incorporate soy into the diet should not be based on its possible effects on IGF-1.

Beyond the Cholesterol-Lowering Effect of Soy Protein: A Review of the Effects of Dietary Soy and Its Constituents on Risk Factors for Cardiovascular Disease

The hypocholesterolemic effect of soy is well-documented and this has led to the regulatory approval of a health claim relating soy protein to a reduced risk of cardiovascular disease (CVD). However, soybeans contain additional components, such as isoflavones, lecithins, saponins and fiber that may improve cardiovascular health through independent mechanisms. This review summarizes the evidence on the cardiovascular benefits of non-protein soy components in relation to known CVD risk factors such as hypertension, hyperglycemia, inflammation, and obesity beyond cholesterol lowering. Overall, the available evidence suggests non-protein soy constituents improve markers of cardiovascular health; however, additional carefully designed studies are required to independently elucidate these effects. Further, work is also needed to clarify the role of isoflavone-metabolizing phenotype and gut microbiota composition on biological effect.

Diet and Diabetic Kidney Disease: Plant Versus Animal Protein

PURPOSE OF REVIEW

The goal of this review is to present an overview of the evidence on the effectiveness of plant-based diets in delaying progression of diabetic kidney disease (DKD).

RECENT FINDINGS

The ideal quantity of dietary protein has been a controversial topic for patients with DKD. Smaller studies have focused on protein source, plant versus animal, for preventing progression. Limited evidence suggests that dietary patterns that focus on plant-based foods, those that are lower in processed foods, or those that are lower in advanced glycation end products (AGE) may be useful in prevention of DKD progression. Increasing plant-based foods, incorporating diet patterns that limit processed foods, or potentially lowering AGE contents in diets may be beneficial for dietary management of DKD. However, dietary studies specifically targeted at DKD treatment are sparse. Further, large trials powered to assess outcomes including changes in kidney function, end-stage kidney disease, and mortality are needed to provide more substantial evidence for these diets.

Soy and Health Update: Evaluation of the Clinical and Epidemiologic Literature

Soyfoods have long been recognized as sources of high-quality protein and healthful fat, but over the past 25 years these foods have been rigorously investigated for their role in chronic disease prevention and treatment. There is evidence, for example, that they reduce risk of coronary heart disease and breast and prostate cancer. In addition, soy alleviates hot flashes and may favorably affect renal function, alleviate depressive symptoms and improve skin health. Much of the focus on soyfoods is because they are uniquely-rich sources of isoflavones. Isoflavones are classified as both phytoestrogens and selective estrogen receptor modulators. Despite the many proposed benefits, the presence of isoflavones has led to concerns that soy may exert untoward effects in some individuals. However, these concerns are based primarily on animal studies, whereas the human research supports the safety and benefits of soyfoods. In support of safety is the recent conclusion of the European Food Safety Authority that isoflavones do not adversely affect the breast, thyroid or uterus of postmenopausal women. This review covers each of the major research areas involving soy focusing primarily on the clinical and epidemiologic research. Background information on Asian soy intake, isoflavones, and nutrient content is also provided.