The Dilemma With the Soy Protein Health Claim

Mass Yields, Antioxidant and Anti-DU145 Prostate Cancer Cell Proliferation Properties of ProSoy Soymilk as Affected by Extraction Methods and Cooking

Both the soybean variety and processing method affect the end soybean product's characteristics. This study's objective was to characterize the effects of four extraction methods (variations of soaking and grinding) combined with cooking on the content and composition of phenolic substances and the antioxidant and anti-DU145 prostate cancer cell proliferation properties of soymilks prepared from a yellow soybean of the ProSoy variety, which is a high-protein variety. The results showed that the soymilk processing yield was the greatest using method 4, although method 2 gave the highest solid and protein yields by about 14 and 12%, respectively. Method 4, a two-step grinding method, also gave increased yields (8 and 7% for solids and proteins, respectively), and in all but one instance produced higher total phenolic content (TPC), total flavonoid content (TFC), condensed tannin content (CTC), and total isoflavone content values in both raw and cooked soymilks as compared to method 1. Cooking the soymilks reduced 14-17% of their total phenolic substances. Cooking reduced the anti-cancer capacity of the phenolic extracts from the soymilk prepared using method 4 by increasing the IC50 value from about 4.9 mg/mL to 6.8 mg/mL. The increases in phenolic compounds and antioxidants produced in the Prosoy soymilks using methods 2 and 4, with simultaneous increases in product and solid yields, are of significant benefit to the soymilk industry and consumer health.

Fermented natto powder alleviates obesity by regulating LXR pathway and gut microbiota in obesity rats

AIM

This study aimed to investigate the positive effect of natto powder on obese rats fed with a high-fat diet (HFD).

METHODS AND RESULTS

Sprague-Dawley rats were fed with a HFD for 8 weeks continuously and gavaged with natto powder, respectively, for 8 weeks starting from the ninth week. The results showed that natto powder significantly reduced the body weight of rats and maintained the balance of cholesterol metabolism in the body by inhibiting the activity of liver X receptors (LXR) target genes, increasing the active expression of cholesterol 7 alpha-hydroxylase, and reducing the active expression of sterol-regulatory element-binding protein and 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR). Furthermore, natto powder increased the relative abundance of potentially beneficial microbiota in gut and decreased the relative abundance of obesity-related harmful bacteria, and also increased the Bacteroidetes/Firmicutes ratio and improved the composition of gut microbiota.

CONCLUSIONS

Natto powder maintains the balance of cholesterol metabolism by inhibiting the LXR pathway and regulating the gut microbiota.

Supplements for Lipid Lowering: What Does the Evidence Show?

PURPOSE

In this review, the regulation, proposed hypolipidemic mechanism, and efficacy of common dietary supplements (DSs) marketed for cardiovascular health are discussed.

RECENT FINDINGS

Data demonstrate modest but inconsistent lipid-lowering effects with common DSs such as probiotics, soluble fibers, plant sterols, green tea, berberine, guggul, niacin, and garlic. Furthermore, data is limited regarding turmeric, hawthorn, and cinnamon. Red yeast rice has shown to be a beneficial DS, but its safety and efficacy are dependent upon its production quality and monacolin K content, respectively. Finally, soy proteins and omega-3 fatty acid-rich foods can have significant health benefits if used to displace other animal products as part of a healthier diet. Despite the rising use of DSs, data demonstrate unpredictable results. Patients should be educated on the difference between these DSs and evidence-based lipid-lowering medications proven to improve cardiovascular outcomes.

Preparation, Characterization and In Vitro Stability of a Novel ACE-Inhibitory Peptide from Soybean Protein

A soy protein isolate was hydrolyzed with Alcalase®, Flavourzyme® and their combination, and the resulting hydrolysates (A, F and A + F) were ultrafiltered and analyzed through SDS-PAGE. Fractions with MW < 1 kDa were investigated for their ACE-inhibitory activity, and the most active one (A < 1 kDa) was purified by semi-preparative RP-HPLC, affording three further subfractions. NMR analysis and Edman degradation of the most active subfraction (A1) enabled the identification of four putative sequences (ALKPDNR, VVPD, NDRP and NDTP), which were prepared by solid-phase synthesis. The comparison of their ACE-inhibitory activities suggested that the novel peptide NDRP might be the main agent responsible for A1 fraction ACE inhibition (ACE inhibition = 87.75 ± 0.61%; IC50 = 148.28 ± 9.83 μg mL−1). NDRP acts as a non-competitive inhibitor and is stable towards gastrointestinal simulated digestion. The Multiple Reaction Monitoring (MRM) analysis confirmed the presence of NDRP in A < 1 kDa.

Maximizing the Estrogenic Potential of Soy Isoflavones through the Gut Microbiome: Implication for Cardiometabolic Health in Postmenopausal Women

Soy isoflavones have been suggested as an alternative treatment for managing postmenopausal symptoms and promoting long-term health due to their structural similarity to mammalian estrogen and ability to bind to estrogen receptors. Among all soy isoflavones and their metabolites, (S)-equol is known for having the strongest estrogenic activity. Equol is a metabolite of the soy isoflavone daidzein produced through intestinal bacterial metabolism. However, more than half of the human population is not able to produce equol due to the lack of equol-producing bacteria in their gastrointestinal tract. The interpersonal variations in the gut microbiome complicate the interpretation of data collected from humans. Furthermore, because rodents are efficient equol-producers, translatability between rodent models and humans is challenging. Herein, we first summarized the current knowledge of the microbial conversion of daidzein to equol, its relation to health, and proposed the need for developing model systems by which equol production can be manipulated while controlling other known confounding factors. Determining the necessity of equol-producing capacity within a gut microbial community when consuming soy as a functional ingredient, and identifying strategies to maximize equol production by modulating the gut microbiome, may provide future therapeutic approaches to improve the health of postmenopausal women.

Comparison of requirements for using health claims on foods in the European Union, the USA, Canada, and Australia/New Zealand

Nutrition is recognized as one of the leading factors influencing the growing incidence of noncommunicable diseases. Despite society experiencing a global rise in obesity, specific populations remain at risk of nutrient deficiencies. The food industry can use health claims to inform consumers about the health benefits of foods through labeling and the broader promotion of specific food products. As health claims are carefully regulated in many countries, their use is limited due to considerable investments required to fulfill the regulatory requirement. Although health claims represent a driving force for innovation in the food industry, the risk of misleading of consumers need to be avoided. The health claim scientific substantiation process must be efficient and transparent in order to meet the needs of companies in the global market, but should be based on strong scientific evidence and plausible mechanisms of actions, to ensure highest level of consumer protection. The objective of this review is to compare the possibilities for using health claims on foods in the European Union, the USA, Canada, and Australia and New Zealand. In particular, we focused on differences in the classification of claims, on the scientific substantiation processes and requirements for health claims use on foods in the selected regions. Reduction of disease risk (RDR) claims are associated with relatively similar procedures and conditions for use, whereas several notable differences were identified for other types of claims. In all cases, RDR claims must be approved prior their introduction to the market, and only a few such claims have been authorized. Much greater differences were observed concerning other types of claims.

Isoflavone Intake and the Risk of Coronary Heart Disease in US Men and Women: Results From 3 Prospective Cohort Studies

BACKGROUND

Whether soy products confer health benefits related to coronary heart disease (CHD) remains controversial because of inconsistent evidence.

METHODS

A total of 74 241 women from the NHS (Nurses' Health Study; 1984-2012), 94 233 women from the NHSII (Nurses' Health Study II; 1991-2013), and 42 226 men from the Health Professionals Follow-Up Study (1986-2012), who were free of cardiovascular disease and cancer at baseline, were included in the present analysis. Dietary data were updated every 2 to 4 years using a validated food frequency questionnaire. Nonfatal myocardial infarction and CHD deaths were adjudicated through reviewing medical records, death certificates, and other medical documents.

RESULTS

In these cohorts, 8359 incident CHD cases were documented during 4 826 122 person-years of follow-up. In multivariable-adjusted analyses, isoflavone intake was inversely associated with CHD (pooled hazard ratio [HR] comparing the extreme quintiles: 0.87 [95% CI, 0.81-0.94]; P=0.008). Consumption of tofu, but not soy milk, was inversely associated with the risk of CHD, with pooled HRs (95% CIs) of 0.82 (0.70-0.95; P=0.005) and 0.87 (0.69-1.10; P=0.41), respectively, comparing ≥1 serving/week with <1 serving/month. Further analyses showed that, in women, the favorable association of tofu was primarily driven by stronger inverse association of tofu intake observed in younger women before menopause and postmenopausal women without hormone use (P_interaction=0.002).

CONCLUSIONS

Higher intake of isoflavones and tofu was associated with a moderately lower risk of developing CHD, and in women the favorable association of tofu were more pronounced in young women or postmenopausal women without hormone use.

The Dilemma With the Soy Protein Health Claim

See Article Jenkins et al.