The Effects of the Habitual Consumption of Miso Soup on the Blood Pressure and Heart Rate of Japanese Adults: A Cross-sectional Study of a Health Examination

Relationship between maternal consumption of fermented foods and the development of the offspring at the age of 3 years: The Japan Environment and Children's Study

BACKGROUND

It is well known that maternal diet affects the development of offspring. Herein, the relationship between maternal intake of fermented foods during pregnancy and offspring development was investigated.

METHODS

The diet of 103,060 pregnant women at >4 months of gestation who were enrolled in the Japan Environment and Children's Study was analyzed. Their intake levels of fermented soybeans (miso and natto), yogurt, and cheese were investigated. The developmental status of the offspring at 3 years of age was assessed using the Ages and Stages Questionnaires (ASQ-3). Multivariable logistic regression analysis was performed to determine the risk of maternal intake levels of the fermented foods associated with subsequent developmental delay in the offspring.

RESULTS

Intake of cheese was associated with a reduced risk of child developmental delay in all intake level groups from the second quartile onward. Intakes of miso and yogurt were associated with a reduced risk of developmental delay in communication skills in the fourth quartile. There was no association between intake of natto and developmental delay.

CONCLUSION

Maternal consumption of fermented foods during pregnancy may reduce the risk of later developmental delay in offspring. It is therefore important to review the mother's diet for fermented foods during pregnancy. However, further studies are warranted to evaluate the factors influencing the association between diet and offspring development.

Healthy Eating in Population Models of Nutrition: Asian Diet Style Summary

The population of Japan and Okinawa is known for the longest life expectancy, which many researchers rightly associate with the nature of nutrition existing in these territories. The Japanese diet and Okinawan diet, along with other traditional diets, are real examples of historically established sustainable patterns of healthy eating. Asian eating styles have marked differences from European eating patterns, not only in differences in food sources, but also in eating habits. The article presents the historical, climatic and cultural features of these diets; the issues of food composition, energy and nutritional value of these models of nutrition are considered in detail with an analysis of the differences existing between them; highlights the benefits of products grown mainly in Japan, which are ration-forming for the population of this country; as well as the results of scientific studies on the protective effect of the Japanese and Okinawan diets on human health and disease prevention.

The apparent inverse association between dietary carotene intake and risk of cardiovascular mortality disappeared after adjustment for other cardioprotective dietary intakes: The Japan collaborative cohort study

BACKGROUND AND PURPOSE

An effect of dietary carotenes on risk of cardiovascular disease (CVD) is uncertain. We aimed to investigate whether the association between dietary carotenes intake and risk of CVD mortality will persist after controlling for the intakes of potential cardioprotective dietary factors that correlate with dietary alpha- and/or beta-carotenes.

METHODS AND RESULTS

We followed up a total of 58,646 Japanese between 1988 and 1990 and 2009. We used a food frequency questionnaire (FFQ) to determine the dietary intakes of carotenes, and estimated the hazard ratios (HRs) and 95% confidence intervals (CIs) of CVD mortality in relation to carotene intake by the proportional hazard regression developed by David Cox. During 965,970 person-years of follow-up (median 19.3 years), we identified 3388 total CVD deaths. After adjusting for demographic and lifestyle factors, dietary intakes of alpha-carotene were significantly associated with the reduced risk of mortality from coronary heart disease (CHD); adjusted HR (95% CI) in the highest versus lowest quintiles of intake was 0.75 (0.58-0.96; P-trend = 0.02) and dietary intakes of beta-carotene were significantly associated with the reduced risk of mortality from CVD, CHD, and other CVD; adjusted HRs (95% CIs) were 0.88 (0.79-0.98; P-trend = 0.04), 0.78 (0.61-0.99; P-trend = 0.01), and 0.81 (0.67-0.98; P-trend = 0.04), respectively. However, after further adjusting for the dietary intakes of potassium, calcium, vitamins C, E, or K, these associations disappeared.

CONCLUSIONS

-Dietary alpha- and beta-carotene intakes were not associated with risk of CVD mortality after controlling for intakes of other potential cardioprotective nutrients.

Assessment of Foods Associated with Sodium and Potassium Intake in Japanese Youths Using the Brief-Type Self-Administered Diet History Questionnaire

The identification of sodium and potassium intake in youths is an important step to preventing the increase of blood pressure in childhood. We examined food intake and estimated mineral intake using a brief-type self-administered diet history questionnaire (BDHQ) to test its validity as a comparison with urinary excretion in Japanese youths. The subjects were 5th and 8th graders (n = 2377), who completed the BDHQ and permitted the use of their overnight urine specimens. Sodium intake was poorly associated with sodium excretion (Rho = 0.048), and the coefficients of dietary potassium and a sodium-to-potassium molar ratio were 0.091–0.130. Higher soybean paste (miso) intake and pickles were significantly associated with higher sodium excretion (p ≤ 0.005). However, these foods were positively associated with potassium excretion (p = 0.002–0.012), and not associated with an excreted sodium-to-potassium ratio. Fruits and dairy products were positively associated (p ≤ 0.048), whereas beverages were negatively associated with potassium excretion (p ≤ 0.004). The association of the sodium-to-potassium ratio was opposite to that of potassium (p ≤ 0.001). The choice of foods, potassium, and the sodium-to-potassium ratio assessed using the BDHQ are available as part of health education for youths, but the assessment of sodium intake in population levels should be carefully conducted.

Fermentation and the microbial community of Japanese koji and miso: A review

Miso is a well-known traditional Japanese fermented food, with a characteristic savory flavor and aroma, known predominately as the seasoning in miso soup. Miso production involves a two-stage fermentation, where first a mold, such as Aspergillus oryzae, is inoculated onto a substrate to make koji. A subsequent fermentation, this time by bacteria and yeast, occurs when the koji is added to a salt and soybean mash, with the miso left to ferment for up to 2 years. The microbial community of miso is considered essential to the development of the unique taste, texture, and nutritional profile of miso. Despite the importance of microorganisms in the production of miso, very little research has been undertaken to characterize and describe the microbial process. In this review, we provide an overview of the two-stage fermentation process, describe what is currently known about the microbial communities involved and consider any potential health benefits associated with the consumption of miso, along with food safety concerns. As the popularity of miso continues to expand globally and is produced under new environmental conditions, understanding the microbiological processes involved will assist to ensure that global production of miso is safe as well as delicious.

Habitual Miso (Fermented Soybean Paste) Consumption Is Associated with Glycemic Variability in Patients with Type 2 Diabetes: A Cross-Sectional Study

Glycemic control, including glycemic variability, is important for the prevention of diabetic vascular complications in patients with type 2 diabetes mellitus (T2DM). There was an association between miso soup intake and insulin resistance. However, the relationship between habitual miso consumption and glycemic control, including glycemic variability, in patients with T2DM remains unknown. We defined people without habitual miso consumption if they did not consume miso soup at all in a day. The average, standard deviation (SD), and coefficient of variation (CV), calculated as CV = (SD/average HbA1c) × 100 (%), of hemoglobin (Hb) A1c levels were evaluated. The proportions of habitual miso consumption of male and female were 88.1% and 82.3%, respectively. The average (7.0 [6.4-7.5] vs. 7.3 [6.8-8.4] %, p = 0.009), SD (0.21 [0.12-0.32] vs. 0.37 [0.20-0.72], p = 0.004), and CV (0.03 [0.02-0.04] vs. 0.05 [0.03-0.09], p = 0.005) of HbA1c levels in female with habitual miso consumption were lower than those of female without. Moreover, habitual miso consumption correlated with average (β = -0.251, p = 0.009), SD (β = -0.175, p = 0.016), and CV (β = -0.185, p = 0.022) of HbA1c levels after adjusting for covariates. However, no association between habitual miso consumption and any glycemic parameters was shown among male. This study clarified the association between habitual miso consumption and good glycemic control, including glycemic variability, in female, but not in male.

Chinese Traditional Fermented Soy Sauce Exerts Protective Effects against High-Fat and High-Salt Diet-Induced Hypertension in Sprague-Dawley Rats by Improving Adipogenesis and Renin-Angiotensin-Aldosterone System Activity

Although high-fat and high-salt diets are considered risk factors for hypertension, the intake of salty soybean-based fermented foods has beneficial effects. This study explored the potential of Chinese traditional fermented soy sauce (CTFSS) in preventing hypertension by analyzing its effects on adipogenesis and the renin-angiotensin-aldosterone system (RAAS). Male Sprague-Dawley (SD) rats were divided into four groups (n = 6): normal diet (ND), high-fat diet (HD), high-fat diet with saline (HDS, NaCl-8%), and high-fat diet with Chinese traditional soy sauce (HDCTS, NaCl-8%). Each group is administrated 12 weeks by oral gavage as 10 mL/kg dose, respectively. CTFSS supplementation resulted in significantly lower body weight, epididymal fat weight, and systolic blood pressure. Additionally, it decreased the serum total cholesterol (TC), triglyceride (TG), alanine aminotransferase (ALT), aspartate aminotransferase (AST), renin, angiotensin II (Ang II), angiotensin-converting enzyme (ACE), and aldosterone levels. It also increased the urinary volume and improved sodium and potassium ion balance. The gene levels showed significant enhancements in the mRNA levels of renin-angiotensin-aldosterone system-related and adipogenesis-related genes. In addition, CTFSS may prevent hypertension-associated kidney injury. Therefore, this study demonstrates that CTFSS has no harmful effects on hypertension. In contrast, the beneficial effects of CTFSS intake in ameliorating hypertension were shown.

Association between the Intake of Fermented Soy Products and Hypertension Risk in Postmenopausal Women and Men Aged 50 Years or Older: The Korea National Health and Nutrition Examination Survey 2013-2018

Sodium intake is positively associated with hypertension risk; however, it is not clear whether there is an association between the intake of fermented soy products, a major source of salt, and blood pressure (BP). This study aimed to investigate the hypothesis that hypertension risk and BP were negatively associated with the intake of fermented soy products but not with the intake of sodium from fermented soy products. This cross-sectional study was performed using data from the Korea National Health and Nutrition Examination Survey (2013–2018). In total, 11,566 men and postmenopausal women aged ≥50 years were divided according to quintiles of sodium or fermented soy product intake. The intake of fermented soy products was negatively associated with hypertension risk (odds ratio: 0.81, 95% confidence interval: 0.66–0.98; p-trend = 0.023) and systolic BP (SBP; p-trend = 0.043) in postmenopausal women. Mediation analysis showed that the intake of fermented soy products had total and direct effects on SBP; however, there was no indirect effect because soy nutrients, such as protein, fiber, calcium, and potassium, had no significant effects on SBP. Among men, fermented soy product intake was not associated with hypertension risk and BP. Additionally, the intake of sodium from fermented soy products was not significantly associated with hypertension risk and BP in both postmenopausal women and men. This study suggests that hypertension risk and BP were not associated with the intake of sodium from fermented soy products; further, hypertension risk and BP were inversely associated with fermented soy product intake in postmenopausal women. Further clinical studies are needed to confirm the effect of fermented soy product intake on hypertension risk and BP.

Review of the health benefits of habitual consumption of miso soup: focus on the effects on sympathetic nerve activity, blood pressure, and heart rate

High salt intake increases blood pressure, and dietary salt intake has been clearly demonstrated to be associated with hypertension incidence. Japanese people consume higher amounts of salt than Westerners. It has been reported that miso soup was one of the major sources of daily salt intake in Japanese people. Adding salt is indispensable to make miso, and therefore, in some cases, refraining from miso soup is recommended to reduce dietary salt intake. However, recent studies using salt-sensitive hypertensive models have revealed that miso lessens the effects of salt on blood pressure. In other word, the intake of miso dose not increase the blood pressure compared to the equivalent intake of salt. In addition, many clinical observational studies have demonstrated the absence of a relationship between the frequency of miso soup intake and blood pressure levels or hypertension incidence. The mechanism of this phenomenon seen in the subjects with miso soup intake has not been fully elucidated yet. However, in basic studies, it was found that the ingredients of miso attenuate sympathetic nerve activity, resulting in lowered blood pressure and heart rate. Therefore, this review focused on the differences between the effects of miso intake and those of the equivalent salt intake on sympathetic nerve activity, blood pressure, and heart rate.

Isolation of food-derived bacteria inducing interleukin-22 in B cells

Recently, we found a novel function of the lactic acid bacterium Tetragenococcus halophilus derived from miso, a fermented soy paste, that induces interleukin (IL)-22 production in B cells preferentially. IL-22 plays a critical role in barrier functions in the gut and skin. We further screened other bacteria species, namely, Enterococcus, Lactobacillus, Lactococcus, Leuconostoc, Weissella, Pediococcus, and Bacillus, in addition to Tetragenococcus and found that some of them possessed robust IL-22-inducible function in B cells in vitro. This process resulted in the augmented expression of activation markers CD86 and CD69 on B and T cells, respectively. However, these observations were not correlated with IL-22 production. We isolated Bacillus coagulans sc-09 from miso and determined it to be the best strain to induce robust IL-22 production in B cells. Furthermore, feeding B. coagulans sc-09 to mice augmented the barrier function of the skin regardless of gut microbiota.

Household dietary salt consumption and mortality from cardiovascular diseases: an ecological panel analysis in Japan

Background

Epidemiological evidence has shown that lower salt intake reduces hypertension-related disease mortality. Japan has experienced a drastic decrease in cardiovascular mortality, although this varies across regions. This regional variation does not necessarily match the local patterns of reported average salt intake. In this study, we examined population-level risk factors for hypertension-related disease mortality, focussing on the average household dietary consumption of salt intake sources.

Methods

We prepared an ecological panel dataset, with prefecture as the unit of analysis, by referring to public statistics and market research data from 2012 to 2015. We collected prefectural averages of household dietary consumption related to salt intake and other nutrients that may affect hypertension control. We used demographic characteristics, medical care availability and local economy indices as covariates. Panel data analysis with fixed-effects modelling was performed, regressing prefectural-level mortality from ischaemic heart diseases, subarachnoid and intracerebral haemorrhage and cerebral infarction on dietary consumption and the selected covariates.

Results

We confirmed the average household consumption of salt equivalents of discretional salt intake sources to be positively but only weakly associated with mortality from ischaemic heart diseases and cerebral infarction. Household expenditure on processed foods was positively associated with ischaemic heart disease mortality.

Conclusions

These findings may suggest that the reduction of salt in processed foods, in addition to individual behavioural change, could be useful for decreasing mortality from ischaemic heart diseases in the Japanese population. Ecological factors related to decreasing cerebrovascular disease mortality in the context of the ageing Japanese population require further investigation.

Association between the Portion Sizes of Traditional Japanese Seasonings-Soy Sauce and Miso-and Blood Pressure: Cross-Sectional Study Using National Health and Nutrition Survey, 2012⁻2016 Data

While previous studies have reported the association between food portion size and health outcomes, the association between food seasonings and blood pressure (BP) has not been clarified. This study aimed to investigate the association between the portion sizes of traditional Japanese seasonings and BP. Data on 25,738 Japanese participants (10,154 men and 15,584 women) aged ≥20 years registered in the 2012–2016 National Health and Nutrition Survey (NHNS) were used for this cross-sectional study. The portion sizes of soy sauce or miso were calculated from the reported weight of soy sauce or miso, and the number of dishes. Regression models were used to estimate BP and prevalence of hypertension, and their 95% confidence intervals according to the portion size of soy sauce or miso. We did not observe an association between the portion sizes of soy sauce or miso and BP. A larger portion size of soy sauce or miso was associated with a higher prevalence of hypertension in the crude model among women, but no significant associations were observed in the multivariate model in both sexes. Our findings suggest that the portion sizes of soy sauce or miso are not associated with BP among Japanese adults.

Inhibitory effect of Japanese rice-koji miso extracts on hepatitis A virus replication in association with the elevation of glucose-regulated protein 78 expression

Hepatitis A virus (HAV) infection is one of the major causes of acute hepatitis and acute liver failure in developing and developed countries. Although effective vaccines for HAV infection are available, outbreaks of HAV infection still cause deaths, even in developed countries. One approach to control HAV infection is prevention through diet, which can inhibit HAV propagation and replication. Glucose-regulated protein 78 (GRP78) is a member of the heat shock protein 70 family of molecular chaperone required for endoplasmic reticulum stress and stress-induced autophagy. We previously showed that the elevation of GRP78 expression inhibits HAV replication. It has been reported that Japanese miso extracts, which was made from rice-koji, enhance GRP78 expression. In the present study, we used human hepatoma Huh7 cells and human hepatocyte PXB cells to examine the efficacy of Japanese miso extracts as antiviral agents against HAV. Japanese miso extracts enhanced GRP78 expression and inhibited HAV replication in human hepatocytes. Together, these results demonstrate that Japanese miso extracts may partly modulate GRP78 expression and additively or synergistically work as antivirals against HAV infection. Japanese miso extracts can be used as effective dietary supplements for severe hepatitis A.