Survey of Dietary Habits and Physical Activity in Japanese Patients with Non-Obese Non-Alcoholic Fatty Liver Disease

The incidence of non-obese non-alcoholic fatty liver disease (NAFLD), characterized by the presence of a fatty liver in individuals with a normal body mass index, is on the rise globally. Effective management strategies, including lifestyle interventions such as diet and exercise therapy, are urgently needed to address this growing public health concern. The aim of this study was to investigate the association between non-obese NAFLD, dietary habits, and physical activity levels. By elucidating these relationships, this research may contribute to the development of evidence-based recommendations for the management of non-obese NAFLD. The study had a single-center retrospective cross-sectional design and compared clinical data and dietary and physical activity habits between patients with and without non-obese NAFLD. Logistic regression analysis was utilized to investigate the relationship between food intake frequency and the development of NAFLD. Among the 455 patients who visited the clinic during the study period, 169 were selected for analysis, including 74 with non-obese NAFLD and 95 without NAFLD. The non-obese NAFLD group showed a less-frequent consumption of fish and fish products as well as olive oil and canola/rapeseed oil, while they showed more frequent consumption of pastries and cake, snack foods and fried sweets, candy and caramels, salty foods, and pickles compared to the non-NAFLD group. Logistic regression analysis revealed that NAFLD was significantly associated with the consumption of fish, fish products, and pickles at least four times a week. The physical activity level was lower and the exercise frequency was lower in patients with non-obese NAFLD compared to those without NAFLD. The results of this study suggest that a low consumption of fish and fish products and high consumption of pickles may be associated with a higher risk of non-obese NAFLD. Moreover, dietary habits and physical activity status should be taken into consideration for the management of patients with non-obese NAFLD. It is important to develop effective management strategies, such as dietary and exercise interventions, to prevent and treat NAFLD in this patient population.

Association between the dietary inflammatory index and disability in Japanese older people

OBJECTIVES

To examine the demographic and lifestyle characteristics related to the dietary inflammatory index (DII™) score and to evaluate the association between DII score and disability among older people in Japan.

DESIGN

Cross-sectional design. The DII score was calculated from nutrient intake information obtained from a FFQ. Disability was assessed using the Tokyo Metropolitan Institute of Gerontology Index of Competence questionnaire. Overall disability and disability in each component of everyday competence, that is, instrumental activities of daily living (IADL), intellectual activities and social participation, were assessed. Those with a deficit in one or more activities were defined as disabled.

SETTING

Five non-urban areas in Japan.

PARTICIPANTS

A total of 1642 Japanese older people aged 65 years or older.

RESULTS

Women, residents of Oga-shi, and those with a higher education and greater frequency of shopping followed a more anti-inflammatory diet, while those living alone and residents of Minamiawaji-shi had higher dietary inflammation. A pro-inflammatory diet was associated with higher odds of overall disability and disability in each component of competence: overall disability, OR (95 % CI) = 1·26 (1·16, 1·36); IADL disability, OR (95 % CI) = 1·16 (1·07, 1·26); disability in intellectual activities, OR (95 % CI): 1·30 (1·20, 1·40); and disability in social participation, OR (95 % CI) = 1·20 (1·11, 1·29).

CONCLUSIONS

Sex, living alone, education, frequency of shopping and area of residence were shown to be determinants of DII score in Japanese older people. DII score was positively associated with disability.

Dietary Components, Microbial Metabolites and Human Health: Reading between the Lines

Trillions of bacteria reside in the human gut and they metabolize dietary substances to obtain nutrients and energy while producing metabolites. Therefore, different dietary components could affect human health in various ways through microbial metabolism. Many such metabolites have been shown to affect human physiological activities, including short-chain fatty acids metabolized from carbohydrates; indole, kynurenic acid and para-cresol, metabolized from amino acids; conjugated linoleic acid and linoleic acid, metabolized from lipids. Here, we review the features of these metabolites and summarize the possible molecular mechanisms of their metabolisms by gut microbiota. We discuss the potential roles of these metabolites in health and diseases, and the interactions between host metabolism and the gut microbiota. We also show some of the major dietary patterns around the world and hope this review can provide insights into our eating habits and improve consumers' health conditions.

The 1975 type Japanese diet improves the gut microbial flora and inhibits visceral fat accumulation in mice

In this study, the 1975 type Japanese diet was prepared and its effects and related mechanism were examined in mice. Mice were assigned to three experimental groups, the CD group fed a control diet, the MD group fed a modern Japanese diet (MD), and the JD group fed the 1975 type Japanese diet (JD) for 4 weeks. MD and JD were low protein, high fat, and high carbohydrate diets compared to the CD. Total white adipose tissue weights were significantly increased in the MD group compared to those in the CD group and were decreased in the JD group compared to those in the MD group. In the JD group, adipocyte hypertrophy was inhibited and Hsl mRNA expression was enhanced in epididymal adipose tissue and the number of bacteria associated with the production of short chain fatty acids was increased. Therefore, the JD inhibits lipid accumulation in white adipose tissue.

ABBREVIATIONS

Actb: β-actin; ALT: alanine aminotransferase; ANOVA: analyses of variance; AST: aspartate aminotransferase; Fas: fatty acid synthase; G6pdx: glucose 6-phosphate dehydrogenase; HE: hematoxylin and eosin; HOMA-IR: Homeostatic model assessment for insulin resistance; Hsl: hormone-sensitive lipase; JD: 1975 type Japanese diet; Leptin: leptin; MD: modern Japanese diet; Me: malic enzyme; NEFA: non-esterified fatty acids; PL: phospholipids; Pparδ: peroxisome proliferator-activated receptor delta; Pparγ: peroxisome proliferator-activated receptor gamma; qRT-PCR: quantitative reverse transcriptase polymerase chain reaction; SAMP8: senescence-accelerated prone 8; SEM: standard error of the mean; Srebp1c: Sterol regulatory element binding protein 1c; TBARS: thiobarbituric acid reactive substance; TC: total cholesterol; TG: Triacylglycerol; V3: variable regions 3.

Carbohydrate-restricted diet alters the gut microbiota, promotes senescence and shortens the life span in senescence-accelerated prone mice

This study examined the effects of a carbohydrate-restricted diet on aging, brain function, intestinal bacteria and the life span to determine long-term carbohydrate-restriction effects on the aging process in senescence-accelerated prone mice (SAMP8). Three-week-old male SAMP8 were divided into three groups after a week of preliminary feeding. One group was given a controlled diet, while the others fed on high-fat and carbohydrate-restricted diets, respectively. The mice in each group were further divided into two subgroups, of which one was the longevity measurement group. The other groups fed ad libitum until the mice were 50 weeks old. Before the test period termination, passive avoidance test evaluated the learning and memory abilities. Following the test period, serum and various mice organs were obtained and submitted for analysis. The carbohydrate-restricted diet group exhibited significant decrease in the survival rate as compared to the other two diet groups. The passive avoidance test revealed a remarkable decrease in the learning and memory ability of carbohydrate-restricted diet group as compared to the control-diet group. Measurement of lipid peroxide level in tissues displayed a marked increase in the brain and spleen of carbohydrate-restricted diet group than the control-diet and high-fat diet groups. Furthermore, notable serum IL-6 and IL-1β level (inflammation indicators) elevations, decrease in Enterobacteria (with anti-inflammatory action), increase in inflammation-inducing Enterobacteria and lowering of short-chain fatty acids levels in cecum were observed in the carbohydrate-restricted diet group. Hence, carbohydrate-restricted diet was revealed to promote aging and shortening of life in SAMP8.

Abdominal Fat in Individuals with Overweight Reduced by Consumption of a 1975 Japanese Diet: A Randomized Controlled Trial

OBJECTIVE

This study aimed to investigate whether the intake of the 1975 Japanese diet (JD) could reduce the amount of abdominal fat in people with overweight.

METHODS

Using a single-blind randomized controlled trial, the modern diet (MD) was compared with the 1975-type JD, which is based on the MD but includes five characteristics of the 1975 JD in an enhanced form. Overweight people were randomly assigned to an MD group (n = 30) and a JD group (n = 30). The participants consumed test diets that were provided three times a day for 28 days. Body composition measurements and blood biochemical examinations were performed before and after the test diet intake, and the proportions of change were compared.

RESULTS

Those in the JD group had significantly decreased BMI, fat mass, and levels of low-density lipoprotein cholesterol, glycated hemoglobin, and C-reactive protein (P = 0.002, 0.015, 0.014, 0.012, and 0.039, respectively) and significantly increased high-density lipoprotein cholesterol levels compared with those in the MD group (P = 0.020).

CONCLUSIONS

The intake of a diet with the characteristics of the 1975 JD may have beneficial effects on lipid metabolism in people with overweight and reduce the onset risk of metabolism-related disorders, such as obesity and diabetes.

Miso (Fermented Soybean Paste) Suppresses Visceral Fat Accumulation in Mice, Especially in Combination with Exercise

We investigated whether the difference in miso consumption between the Japanese diets of 1975 and 2010 has influenced the observed increase in diet-induced obesity. To recreate the 2010 and 1975 Japanese high-fat diets with the corresponding proportions of miso, freeze-dried miso was added to high-fat mouse feed at 1.6% and 2.6%, respectively. When 5-week-old male Institute of Cancer Research (ICR) mice were provided each of these diets ad libitum for 8 weeks, it was found that the white adipose tissue weight and adipocyte area were lower in mice receiving the 1975 diet than in those receiving the 2010 diet. Therefore, high miso consumption is one reason why the 1975 Japanese diet tended to not lead to obesity. Next, the combined effects of treadmill exercise and miso consumption were investigated. The mice were divided into three groups, which were provided either a high-fat diet (group C), a high-fat diet with exercise (group C + E), or a miso-supplemented high-fat diet with exercise (group M + E) for 8 weeks. In this experiment, the white adipose tissue weight and adipocyte area in group M + E were lower than in group C. When the mRNA expression of lipid metabolism-associated genes in adipose tissue was measured, we found that expression of Hsl (lipase, hormone sensitive), which is involved in lipolysis, and Pparγ (peroxisome proliferator activated receptor gamma), which regulates adipocyte differentiation upstream of Hsl, was increased in group M + E. These results clearly demonstrated that lipid accumulation in the adipose tissues is suppressed by miso consumption in combination with exercise.

Simultaneous Intake of Euglena gracilis and Vegetables Exerts Synergistic Anti-Obesity and Anti-Inflammatory Effects by Modulating the Gut Microbiota in Diet-Induced Obese Mice

We determined whether the anti-obesity effect provided by the consumption of Euglena gracilis (Euglena), which is rich in insoluble dietary fiber, could be enhanced by the co-consumption of vegetables with an abundance of soluble dietary fiber. Nine-week-old male C57BL/6J mice were divided into five groups as follows: group 1 received a normal diet, group 2 received a high-fat diet, and groups 3, 4, and 5 received high fat diets containing 0.3% paramylon, 1.0% Euglena, or 1.0% Euglena plus 0.3% vegetables (barley leaf, kale, and ashitaba), respectively. Mice were fed ad libitum until 18 weeks of age. Euglena intake significantly reduced visceral fat accumulation in obese mice, and co-consumption of vegetables enhanced this effect. Consumption of Euglena with vegetables reduced adipocyte area, suppressed the expression of genes related to fatty acid synthesis, upregulated genes related to adipocyte lipolysis, and suppressed serum markers of inflammation. Notably, we also observed an increase in the fraction of short-chain fatty acid-producing beneficial bacteria, a reduction in harmful bacteria that cause inflammation, and an increase in short-chain fatty acid production. Therefore, the co-consumption of vegetables enhanced the anti-obesity and anti-inflammatory effects of Euglena, likely by modulating the gut microbiota composition.

Koji glycosylceramide commonly contained in Japanese traditional fermented foods alters cholesterol metabolism in obese mice

Koji, which is manufactured by proliferating non-pathogenic fungus Aspergillus oryzae on steamed rice, is the base for Japanese traditional fermented foods. We have revealed that koji and related Japanese fermented foods and drinks such as amazake, shio-koji, unfiltered sake and miso contain abundant glycosylceramide. Here, we report that feeding of koji glycosylceramide to obese mice alters the cholesterol metabolism . Liver cholesterol was significantly decreased in obese mice fed with koji glycosylceramide. We hypothesized that their liver cholesterol was decreased because it was converted to bile acids. Consistent with the hypothesis, many bile acids were increased in the cecum and feces of obese mice fed with koji glycosylceramide. Expressions of CYP7A1 and ABCG8 involved in the metabolism of cholesterol were significantly increased in the liver of mice fed with koji glycosylceramide. Therefore, it was considered that koji glycosylceramide affects the cholesterol metabolism in obese mice.

Simultaneous Intake of Euglena Gracilis and Vegetables Synergistically Exerts an Anti-Inflammatory Effect and Attenuates Visceral Fat Accumulation by Affecting Gut Microbiota in Mice

We determined whether the benefits provided by the consumption of Euglena gracilis (Euglena), which is a unicellular photosynthesizing green alga and rich in insoluble dietary fiber paramylon, can be enhanced by the co-consumption of vegetables that are rich in soluble dietary fiber. Nine-week-old male C57BL/6J mice were divided into four groups: group 1 received normal diet, whereas groups 2, 3 and 4 received normal diet containing 0.3% paramylon, 1.0% Euglena, or 1.0% Euglena plus 0.3% vegetables (barley leaf, kale and ashitaba), respectively. Mice were fed ad libitum until 18 weeks of age. Euglena intake significantly decreased serum markers of inflammation and co-consumption of vegetables enhanced this reduction. Notably, we observed an increase in the fraction of beneficial bacteria producing short-chain fatty acids, a reduction in harmful bacteria that cause inflammation and an increase in short-chain fatty acid production. Visceral fat accumulation was also reduced. Subsequent analyses showed that co-consumption of Euglena with vegetables reduced adipocyte area, suppressed the expression of genes related to fatty acid synthesis and increased the expression of genes related to adipocyte growth and lipolysis. Therefore, co-consumption of Euglena with vegetables enhanced its anti-inflammatory effect and the inhibitory effect on visceral fat accumulation likely by modulating the composition of gut microbiota.

Advances in Understanding the Molecular Basis of the Mediterranean Diet Effect

Increasingly, studies showing the protective effects of the Mediterranean diet (MedDiet) on different diseases (cardiovascular, diabetes, some cancers, and even total mortality and aging indicators) are being published. The scientific evidence level for each outcome is variable, and new studies are needed to better understand the molecular mechanisms whereby the MedDiet may exercise its effects. Here, we present recent advances in understanding the molecular basis of MedDiet effects, mainly focusing on cardiovascular diseases but also discussing other related diseases. There is heterogeneity in defining the MedDiet, and it can, owing to its complexity, be considered as an exposome with thousands of nutrients and phytochemicals. We review MedDiet composition and assessment as well as the latest advances in the genomic, epigenomic (DNA methylation, histone modifications, microRNAs, and other emerging regulators), transcriptomic (selected genes and whole transcriptome), and metabolomic and metagenomic aspects of the MedDiet effects (as a whole and for its most typical food components). We also present a critical review of the limitations of the studies undertaken and propose new analyses and greater bioinformatic integration to better understand the most important molecular mechanisms whereby the MedDiet as a whole, or its main food components, may exercise their protective effects.