4. Discussion
TNF-α, inflammation, cardiometabolic disease, Q-CAN, renal and vascular injury, overweight
OBESE, CVD, INFLAMMATION, CHRONIC INFLAMMATION, OXIDATIVE STRESS
The current study examined the effect of a daily supplement of a commercial fermented soy powder Q-CANSince low-grade chronic inflammation is often a feature of cardiometabolic disease, much research has focused on the anti-inflammatory effect of soy foods and their bioactive components on various cytokines and oxidation markers [In the current study, no fermented soy effects were found with respect to the pro-inflammatory cytokines hsCRP, IL-1β, or TNF-α; however, an increase in within-treatment IL-6 levels was noted with the fermented soy intervention and the increase approached statistical significance in between-treatment comparisons. Findings from previous randomized controlled trials with soy foods and isoflavone supplements are inconsistent reporting increased [Since participants in the current study included a higher proportion of females and obese individuals, stratification analysis was applied to determine whether the results of the trial were confounded by sex or BMI. With regards to sex, TNF-α levels decreased with the fermented soy supplement only in females, and although both males and females on fermented soy showed increased TAS, a relatively greater increase occurred in males. Gender differences due to soy foods are likely due to their content of isoflavones. It is well-known that isoflavones as estrogens mimetics may exert pseudo-hormonal activity by binding to estrogen receptors in females [Stratification as a function of BMI showed an association with haptoglobin levels. Haptoglobin is an acute phase α-glycoprotein secreted mainly by the liver whose major biologic function is to strongly bind free hemoglobin, thus preventing renal and vascular injury, loss of iron, and heme-initiated oxidation of proteins and membrane lipids [As indicated above, we previously reported on the primary outcomes of the trial and the effect of the fermented soy product in lowering total- and LDL-C [In Asian countries, commercially fermented soy products such as Q-CAN and traditional fermented soybean foods, such as natto, tempeh, doenjang, and miso are commonly consumed and are postulated to be more effective than unfermented soy foods in mitigating lipids [Although the functional properties associated with inflammation and oxidative stress of fermented soy foods have been tested in numerous cell culture and animal studies [The exact mechanisms by which fermented soy foods exert their actions are unknown and underlying mechanisms can vary due to the diversity of fermented foods and products available and which are formulated with an array of microorganisms producing a multiplicity of bioactive constituents. Fermented soy benefits have been attributed to bioactive peptides and amino acids, isoflavones both glycosylated and as aglycones, saponins, anthocyanins, and to atypical bacterial metabolites and breakdown products of sugars or fatty acids as summarized in recent reviews [The strength of this study derives from the rigorous crossover design that allowed participants to act as their own control and, thereby, minimize the influence of between-subject variability when analyzing treatment effects. The study focused on participants with at least two known CVD risk factors, and most were overweight or obese but had inflammatory marker concentrations within normal ranges. However, the study had limitations. The number of subjects was determined based on the primary objective which was the effect of the supplement on blood lipids and may have been underpowered for assessing differences in inflammation and antioxidant outcomes. Several of our findings were exploratory which limits their validity and In conclusion, the current crossover intervention trial showed a 12% increase in the anti-inflammatory factor IL-1 Ra with the fermented soy product Q-CAN