A Non-Probiotic Fermented Soy Product Reduces Total and LDL Cholesterol: A Randomized Controlled Crossover Trial

Abstract

Traditional Asian fermented soy food products are associated with reduced cardiovascular disease risk in prospective studies, but few randomized controlled trials have been conducted in at-risk populations. The aim of this study was to investigate the effect of a commercial non-probiotic fermented soy product on blood lipids in adults with cardiovascular risk biomarkers. In a randomized, crossover, intervention study, 27 men and women (aged 29–75 y) exhibiting at least two risk factors, consumed two packets (12.5 g each) daily of a fermented powdered soy product, or an isoenergic control powder made from germinated brown rice for 12 weeks each. The consumption of the fermented soy product resulted in a significantly greater mean change from baseline (compared to the germinated rice, all p < 0.05) in total cholesterol of −0.23 mmol/L (CI: −0.40, −0.06) compared with 0.14 mmol/L (CI: −0.03, 0.31), respectively; and low density lipoprotein (LDL) cholesterol −0.18 mmol/L (CI: −0.32, −0.04) compared with 0.04 mmol/L (CI: −0.01, 0.018) respectively. This was accompanied by an increase in high density lipoprotein (HDL) cholesterol in the germinated rice group, a decrease in apolipoprotein B (ApoB) in the fermented soy group, and a between-treatment effect in apolipoprotein A1 (ApoA1); however, the ratio of the LDL:HDL and of Apo B:ApoA1 did not differ between the groups. The ratio of total cholesterol:LDL decreased in men in the fermented soy group (p < 0.001). Twenty-four-hour urine collection at the end of each treatment period resulted in an increased excretion expressed as a ratio in μmol/d between treatments of 10.93 (CI: 5.07, 23.54) for daidzein; 1.24 (CI: 1.14, 4.43) for genistein; and, 8.48 (CI: 4.28, 16.80) for glycitein, all p < 0.05. The fermented soy powder consumed by participants in this study without implementing other changes in their typical diets, decreased the total and LDL cholesterol, and may serve as a dietary strategy to manage blood lipids. The trial was registered at ClinicalTrials.gov as NCT03429920.

The impact of botanical fermented foods on obesity, metabolic syndrome and type 2 diabetes: a systematic review of randomised controlled trials

“…Meta-analyses of red yeast rice identified significant improvements in LDL-C, TC and TG compared to placebo in dyslipidaemic patients. [36,37,95] Our review also found that some lactofermented foods, [53,63,76] jangs, [67,72,74] tempeh, [58][59][60] brown rice lees [64] and fermented soy powder [69] significantly improved lipid parameters compared to controls.…”

“…Notably, 21 out of 26 included studies were conducted in East Asian populations (South Korea, Japan, Indonesia) with one from Western Asia [63] (Iran) using traditional BFFs from these regions, which reflects the importance of these products in their diets. The other studies from Italy, [76] the USA, [69] Iran [75] and Mauritius [61] used nontraditional fermented interventions. East Asians may be at higher risk of poor cardiometabolic outcomes at a lower BMI than Caucasians.…”

“…[53,60,64,65] Akamine et al [62] also reported no dropouts, but only analysed 88% of participants for plasma SCFA, and 85% of participants for faecal microbiota composition, due to missing or uncollected samples. Analysis of over 90% of randomised participants (91 to 96%) was conducted in ten studies; [55,[57][58][59]63,[66][67][68][69][70] all of these studies used per-protocol analysis. Between 80 to 90% of participant data was analysed in five studies, [71][72][73][74][75] with only Cha et al [72] and Oh et al [73] using intention-to-treat analysis for missing data.…”

“…Overall, we judged 14 of the included RCTs to have a low risk of bias. [63][64][65][66][67][68][69][71][72][73][74][75][76][77] Eight of the ten studies assessed to be of some concern [53][54][55][56][57][58][59][60] would likely be upgraded to low risk if more information regarding randomisation and allocation concealment was provided. Han et al [70] likely engaged in selective non-reporting of between-group analysis; more information from authors may change the level of risk assigned.…”

“…RCTs by An et al [54] and Lee et al [56] were only described in abstracts. There were seven crossover studies, [53][54][55][56]69,75,77] with the rest being of parallel design; 15 were double-blinded or more, [64][65][66][67][68][69][70][71][72][73][74][75][76][77][78] whilst 11 were open-label studies.…”