Nobiletin Stimulates Adrenal Hormones and Modulates the Circadian Clock in Mice.

Polymethoxyflavonoids, such as nobiletin (abundant in Citrus depressa), have been reported to have antioxidant, anti-inflammatory, anticancer, and anti-dementia effects, and are also a circadian clock modulator through retinoic acid receptor-related orphan receptor (ROR) α/γ. However, the optimal timing of nobiletin intake has not yet been determined. Here, we explored the time-dependent treatment effects of nobiletin and a possible novel mechanistic idea for nobiletin-induced circadian clock regulation in mice. In vivo imaging showed that the PER2::LUC rhythm in the peripheral organs was altered in accordance with the timing of nobiletin administration (100 mg/kg). Administration at ZT4 (middle of the light period) caused an advance in the peripheral clock, whereas administration at ZT16 (middle of the dark period) caused an increase in amplitude. In addition, the intraperitoneal injection of nobiletin significantly and potently stimulated corticosterone and adrenaline secretion and caused an increase in Per1 expression in the peripheral tissues. Nobiletin inhibited phosphodiesterase (PDE) 4A1A, 4B1, and 10A2. Nobiletin or rolipram (PDE4 inhibitor) injection, but not SR1078 (RORα/γ agonist), caused acute Per1 expression in the peripheral tissues. Thus, the present study demonstrated a novel function of nobiletin and the regulation of the peripheral circadian clock.

Protective Effects of Inulin on Stress-Recurrent Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the digestive tract and is closely associated with the homeostasis of the gut microbiota. Inulin, as a natural prebiotic, displays anti-inflammatory activity and maintains equilibrium of the intestinal microbiota. In this study, our research aimed to explore the potential of inulin in enhancing intestinal immunity and reducing inflammation in stress-recurrent IBD. In this study, a co-culture intestinal epithelium model and a stress-recurrent IBD mouse model was used to examine the protective effects of inulin. It was observed that inulin digesta significantly reduced pro-inflammatory cytokine expression (CXCL8/IL8 and TNFA) and increased MUC2 expression in intestinal epithelial cells. In vivo, our findings showed that Inulin intake significantly prevented IBD symptoms. This was substantiated by a decrease in serum inflammatory markers (IL-6, CALP) and a downregulation of inflammatory cytokine (Il6) in colon samples. Additionally, inulin intake led to an increase in short-chain fatty acids (SCFAs) in cecal contents and a reduction in the expression of endoplasmic reticulum (ER) stress markers (CHOP, BiP). Our results highlight that inulin can improve stress-recurrent IBD symptoms by modulating microbiota composition, reducing inflammation, and alleviating ER stress. These findings suggested the therapeutic potential of inulin as a dietary intervention for ameliorating stress-recurrent IBD.

Effect of breakfast protein intake on muscle mass and strength in adults: a scoping review.

BACKGROUND: The distribution of protein intake throughout the day is frequently skewed, with breakfast having the lowest protein intake across all age groups. There is no review that addresses the association between breakfast protein intake and muscle mass and strength. OBJECTIVE: This scoping review aims to summarize the literature on the relationship between protein intake during breakfast and muscle mass and strength in adults. METHODS: This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. Two independent reviewers screened and appraised the articles identified from 3 electronic databases (Medline, Web of Science, and Scopus) that focused on protein intake per meal and its impact on muscle-related outcomes. RESULTS: A total of 14 763 articles were retrieved from 3 databases, and after the screening process, 15 articles were included for analysis. Approximately 58.8% of findings from 11 studies examining the association between high protein intake during breakfast and muscle mass indicated an increase in muscle mass among participants. Half of 6 studies (50.0%) exploring the relationship between high protein intake at breakfast and muscle strength demonstrated an increase in muscle strength. Consuming high amounts of protein at breakfast or more protein in the morning than in the evening was associated with an increase in the skeletal muscle index and lean body mass. CONCLUSION: Protein consumption at breakfast revealed potential benefits in increasing muscle mass across 5 studies involving an elderly population and 2 studies encompassing middle-aged women and young men in our review. However, the relationship between protein intake at breakfast and muscle strength remains unclear. Further high-quality randomized controlled trials are required to examine whether adults can preserve skeletal muscle health outcomes by consuming higher amounts of protein at breakfast.

Association between disruption of circadian activity rhythms and obesity.

This cross-sectional study aimed to elucidate the association between disruption of circadian activity rhythms and obesity-related indices. This study included 69 older participants (male, n = 36; female, n = 33), and disruption of circadian activity rhythms in daily life was assessed using the cosinor method based on physical activity data. The daily physical activity data were fitted to a cosine curve to estimate the peak phase (acrophase), and the difference in the peak phase (time) for each day was determined. The standard deviation (SD) of the mean peak phase differences over 6 days was obtained. The higher the SD value, the more disturbed the circadian rhythm of activity. Based on the calculated values, the samples were divided into tertiles (small, medium, and large). A significant positive correlation was found between Log SD and body fat percentage on the disruption of circadian activity rhythms and obesity-related indices. In addition, positive associations were observed among body mass, body mass index, and Log SD. However, these associations were not observed in women. These results suggest that disruption of circadian activity rhythms is associated with obesity-related indices and may differ according to sex.

Sleep, light exposure at night, and psychological wellbeing during pregnancy.

BACKGROUND: Psychological wellbeing during pregnancy is imperative for optimal maternal outcomes. The present study aimed to determine the association between sleep quality, light exposure at night, and psychological wellbeing in the 2nd and 3rd trimesters of pregnancy. METHODS: This prospective study was conducted in 9 randomly selected government maternity clinics in Kuala Lumpur, Malaysia. Healthy women aged 20-48 years old with single pregnancy were recruited using convenience sampling (n = 169). Sleep quality, light exposure at night, and psychological wellbeing were self-reported using the Pittsburgh Sleep Quality Index (PSQI), Harvard Light Exposure Assessment (H-LEA), and Depression, Anxiety, and Stress Scale (DASS-21) in the 2nd trimester and followed-up at the 3rd trimester. RESULTS: During the 2nd and 3rd trimesters of pregnancy, mild to severe symptoms of stress (10.7 and 11.3%), anxiety (42 and 44.3%), and depression (9.6 and 16.6%) were observed among the participants. Adjusted multiple linear regression revealed that poor sleep quality and higher light exposure at night were attributed to greater stress and depression symptoms in the 3rd trimester. Higher lux level exposed from 10 pm to < 1 am was associated with increased stress (ß = 0.212, p = 0.037) and depression (ß = 0.228, p = 0.024). Only poor sleep quality was observed to adversely affect anxiety (ß = 0.243, p = 0.002) and depression levels (ß = 0.259, p = 0.001) in the 2nd trimester. CONCLUSIONS: Present study provided preliminary findings on the association between sleep quality, light at night, and psychological wellbeing of pregnant women. As a recommendation, future research could investigate whether public health interventions aimed at decreasing artificial light at night can benefit sleep quality and the psychological health of pregnant women.

Association between circadian clock gene expressions and meal timing in young and older adults.

Ageing is associated with a decline in circadian clock systems, which correlates with the development of ageing-associated diseases. Chrononutrition is a field of chronobiology that examines the relationship between the timing of meal/nutrition and circadian clock systems. Although there is growing evidence regarding the role of chrononutrition in the prevention of lifestyle and ageing-related diseases, the optimal timing of meal intake to regulate the circadian clock in humans remains unknown. In this study, we investigated the relationship between clock gene expression and meal timing in young and older adults. In this cross-sectional study, we enrolled 51 healthy young men and 35 healthy older men (age, mean±standard deviation: 24 ± 4 and 70 ± 4 y, respectively). Under daily living conditions, beard follicle cells were collected at 4-h intervals over a 24-h period to evaluate clock gene expression. Participants were asked to record the timing of habitual sleep and wake-up, breakfast, lunch, and dinner. From these data, we calculated "From bedtime to breakfast time," "From wake up to first meal time," and "From dinner to bed time." NR1D1 and PER3 expressions in older adults at 06:00 h were significantly higher than those in young adults (P = 0.001). There were significant differences in the peak time for NR1D2 (P = 0.003) and PER3 (P = 0.049) expression between young and older adults. "From bedtime to breakfast time" was significantly longer in older adults than in young adults. In contrast, "From dinner to bed time" was significantly shorter in older adults than in young adults. Moreover, higher rhythmicity of NR1D1 correlated with longer "From bedtime to breakfast time" (r = -0.470, P = 0.002) and shorter "From wake up to first meal time" in young adults (r = 0.302, P = 0.032). Higher rhythmicity of PER3 correlated with longer "From bedtime to breakfast time" in older adults (r = -0.342, P = 0.045). These results suggest that the peak time of clock gene expression in older adults may be phase-advanced compared to that in young adults. In addition, a longer fasting duration from bedtime to breakfast in both young and older adults and earlier intake of meals after waking up in young adults may correlate with robust clock gene expression rhythms.

The combined effect of rowing exercise and the intake of functional foods containing inulin on muscle mass and bone mineral density in older Japanese women.

AIM: Aging decreases muscle mass and bone mineral density (BMD), especially in older women. It has been reported that rowing and inulin intake positively affect muscle and bone, respectively. We examined the synergistic effect of rowing and functional food intake, including inulin, on lean body mass, BMD, and physical function parameters in older Japanese women. METHODS: Fifty women aged 65-79 years were divided into four groups with or without inulin intake and rowing. The interventions were carried out for 12 weeks in each group. We assessed lean body mass and BMD using dual-energy X-ray absorptiometry at baseline and after the intervention and examined the changes in the values in each group. RESULTS: Lean body mass in all groups decreased, and the change in lean body mass in the group with rowing and inulin intake was significantly smaller than that in the group without them (-0.05 ± 0.61; -0.83 ± 0.59 kg; P = 0.030). The BMD in the three intervention groups increased after the 12-week intervention. The change in BMD in each of the three intervention groups showed significant differences compared with the control group (Rowing + Inulin: P = 0.03; Rowing + No inulin: P = 0.01; No rowing + Inulin: P < 0.01). CONCLUSIONS: Rowing and the intake of functional foods, including inulin, synergistically prevented a decrease in lean body mass. These factors, individually and additively, might increase BMD in older Japanese women. Geriatr Gerontol Int 2023; 23: 779-787.

Association of Eating Pattern, Chronotype, and Social Jetlag: A Cross-Sectional Study Using Data Accumulated in a Japanese Food-Logging Mobile Health Application.

Chronotype (morningness-eveningness) and social jetlag (SJL; discrepancy in the sleep pattern between the weekday and weekend) are related to eating behavior and health. The association between sleep behavior and the daily macro- and micronutrient eating pattern of each meal (breakfast, lunch, and dinner) have not been discussed well and need more evidence. Here, meal pattern datasets of Japanese participants aged 20-59 years were obtained as averages over 1 month from the data stored in the food-logging app "Asken". We allocated three groups for each chronotype and SJL. Multiple regression analyses revealed that morning chronotype and small SJL were associated with higher total daily intake of potassium, fiber, magnesium, phosphorus, and vitamin K. Breakfast energy intake and consumption of nutrients, including protein, lipid, carbohydrate, and minerals, were higher in the morning chronotype or small SJL. Lunch intake of potassium, cholesterol, fiber, magnesium, and vitamin K was also higher in the morning chronotype or small SJL. Dinner energy intake and nutrient intake of proteins, lipids, carbohydrates, sodium, and saturated fatty acids were lower in the morning chronotype or small SJL. The current data would help to establish a detailed reference for dietary intake which considers eating patterns over a day.

Combined resistant dextrin and low-dose Mg oxide administration increases short-chain fatty acid and lactic acid production by gut microbiota.

The consumption of resistant dextrin improves constipation, while its fermentation and degradation by the intestinal microbiota produce short-chain fatty acids (SCFA) and lactic acid, which have beneficial effects on host metabolism and immunity. Mg oxide (MgO) is an important mineral that is used to treat constipation. Therefore, resistant dextrin and MgO are often administered together to improve constipation. However, limited information is available regarding the effect of this combination on SCFA and lactic acid production. Crl:CD1(ICR) mice were fed a Mg-free diet with 5% resistant dextrin, followed by oral administration of MgO. We collected the cecum contents and measured SCFA and lactic acid levels. Additionally, the human subjects received resistant dextrin and Mg supplements as part of their habitual diet. The results of this study demonstrate that intestinal microbiota cannot promote SCFA and lactic acid production in the absence of Mg. In a mouse model, low doses of MgO promoted the production of SCFA and lactic acid, whereas high doses decreased their production. In humans, the combined consumption of resistant dextrin and Mg supplements increased the production of SCFA and lactic acid. The production of SCFA and lactic acid from dietary fiber may be augmented by the presence of MgO.

Maternal melatonin levels and temporal dietary intake: results from MY-CARE cohort study.

Chrononutrition emerges as a novel approach to promote circadian alignment and metabolic health by means of time-of-the-day dietary intake. However, the relationship between maternal circadian rhythm and temporal dietary intake during pregnancy remains understudied. This study aimed to determine the change in melatonin levels in pregnant women across gestation and its association with temporal energy and macronutrient intake. This was a prospective cohort involving 70 healthy primigravidas. During the second and third trimesters, pregnant women provided salivary samples collected at 9:00, 15:00, 21:00, and 3:00 h over a 24 h day for melatonin assay. Data on chrononutrition characteristics were collected using a 3-day food record. Parameters derived from melatonin measurements including mean, amplitude, maximal level, area under the curve with respect to increase (AUCI), and area under the curve with respect to ground (AUCG) were computed. A rhythmic melatonin secretion over the day that remained stable across trimesters was observed among the pregnant women. There was no significant elevation in salivary melatonin levels as pregnancy advanced. In the second trimester, higher energy intake during 12:00-15:59 h and 19:00-06:59 h predicted a steeper melatonin AUCI (ß=-0.32, p = 0.034) and higher AUCG (ß = 0.26, p = 0.042), respectively. Macronutrient intake within 12:00-15:59 h was negatively associated with mean melatonin (Fat: ß=-0.28, p = 0.041) and AUCG (Carbohydrate: ß=-0.37, p = 0.003; Protein: ß=-0.27, p = 0.036; Fat: ß=-0.32, p = 0.014). As pregnant women progressed from the second to the third trimester, a flatter AUCI was associated with a reduced carbohydrate intake during 12:00-15:59 h (ß=-0.40, p = 0.026). No significant association was detected during the third trimester. Our findings show that higher energy and macronutrient intakes particularly during 12:00-15:59 h and 19:00-06:59 h are associated with the disparities in maternal melatonin levels. Findings suggest the potential of time-based dietary approaches to entrain circadian rhythm in pregnant women.

Association of breakfast styles such as Japanese, Western, and cereals with sleeping habits, eating habits, and lifestyle in preschool and elementary school children.

Introduction: In Japan, breakfast styles are categorized into five groups; Japanese breakfast (JB; rice and miso soup), Western breakfast (WB; bread and milk), Japanese-Western breakfast (J-WB; alternative daily serving), cereal breakfast (CB), and breakfast skipping. In our recent studies, breakfast style was highly associated with the daily sleep-wake phase (chronotype), and healthy eating habits. In contrast with other breakfast style consumers, JB-consumers were positively associated with the morning chronotype and healthy eating habits such as a high consumption of a variety of protein sources, vegetables, and dietary fibers, and low consumption of sweetened juices. These previous studies included only adult participants; hence, in the current study, we investigated whether similar observations can be made in children. Methods: Preschool (aged 3-5 years) and elementary school children (6-8 years) (N = 6,104, 49.87% boys, 50.13% girls, mean body mass index 15.39 ± 0.03 kg/m2 for preschoolers and percentage of overweight -2.73 ± 0.22 for elementary school children) participated in this cross-sectional online survey on lifestyle, including eating and sleep habits, through their mother's responses. Results: The results showed that the morning-evening type index values (chronotype indicator, smaller indicates morning type) were negatively correlated with JB intake (-0.05, p < 0.01) and positively correlated with WB (0.03, p < 0.05) and CB intake (0.06, p < 0.01), suggesting that the JB group exhibited the morning chronotype and the WB and CB groups exhibited the evening chronotype. The JB group consumed a variety of protein sources (mean ± SE; days/week) with more frequency (fish 2.95 ± 0.038 p < 0.001, soy 3.55 ± 0.043 p < 0.001, egg 3.82 ± 0.044 p < 0.001) compared with the WB group (fish 2.58 ± 0.033, soy 3.00 ± 0.038, egg 3.49 ± 0.039). On the other hand, the JB group consumed snacks (5.48 ± 0.042 p < 0.001) and sweetened juice (2.50 ± 0.050 p < 0.001) less frequently than the WB group (snacks; 5.80 ± 0.037 and sweetened juice; 2.74 ± 0.049). Discussion: JB-eating children with a morning chronotype exhibited better sleep and eating habits than WB-eating children with an evening type pattern. The results suggest that JB eating habits may be associated with good eating and sleeping lifestyles, even among preschool and elementary school children.

Effects of Additional Granola in Children's Breakfast on Nutritional Balance, Sleep and Defecation: An Open-Label Randomized Cross-Over Trial.

The contribution of breakfast to daily nutrient intake is low, particularly among children, at only about 20%, and it is difficult to determine whether children are receiving adequate nutrients at breakfast. Although alterations in breakfast content are considered to affect lifestyle habits such as sleep and defecation, there have been few intervention studies in children. The relationship between nutritional balance, dietary intake, and lifestyle habits in children remains unclear. We conducted an intervention study on elementary school children's breakfasts and observed the effects of improving the nutritional balance of breakfast on sleep parameters and defecation status. An intervention study was conducted with 26 elementary school students in Tokyo. The study design was an open-label randomized cross-over trial. Subjects consumed their usual breakfast during the control period and a granola snack containing soy protein in addition to their usual breakfast during the intervention period. Questionnaires regarding breakfast, sleep, and bowel movements were administered during each period. Based on the answers to these questionnaires, we compared the nutritional sufficiency of macronutrients, vitamins, and minerals (29 in total), as well as changes in sleep parameters and defecation status. The additional consumption of granola snacks increased the breakfast intake of 15 nutrients. The changes were particularly significant for iron, vitamin B1, vitamin D, and dietary fiber. During the intervention, sleep duration was decreased and wake-up time became earlier. In terms of defecation, the intervention did not change stool characteristics, but the frequency of defecations per week increased on average by 1.2 per week. These results suggest that the nutritional balance and the amount of breakfast are linked to sleep and defecation and that improving breakfast content can lead to lifestyle improvements in children.

Euglena gracilis-derived ß-glucan paramylon entrains the peripheral circadian clocks in mice.

Paramylon, a ß-1,3-glucan storage polysaccharide derived from Euglena gracilis, has various health benefits, such as anti-obesity effects and modulation of immune function. However, whether paramylon intake affects the circadian clock remains unknown. In this study, we examined the effect of paramylon intake on the circadian clock. The results showed that the paramylon intake regulated peripheral clocks in mice. Furthermore, cecal pH and short-chain fatty acid concentrations after paramylon intake were measured. The correlation between changes in the expression of clock-related genes and alterations in the intestinal environment was confirmed. In addition, peripheral clock entrainment by paramylon intake was not observed in antibiotic-treated mice whose gut microbiota was weakened. These findings suggest that the regulation of the circadian clock by paramylon intake was mediated by changes in gut microbiota. In addition, the entraining effect of paramylon intake was also confirmed in mice bred under conditions mimicking social jetlag, which implies that paramylon intake may contribute to recovery from social jetlag. Thus, the appropriate consumption of paramylon may have a beneficial effect on health from a chrono-nutritional perspective.

Mid-Point of the Active Phase Is Better to Achieve the Natriuretic Effect of Acute Salt Load in Mice.

Excess sodium intake and insufficient potassium intake are a prominent global issue because of their influence on high blood pressure. Supplementation of potassium induces kaliuresis and natriuresis, which partially explains its antihypertensive effect. Balancing of minerals takes place in the kidney and is controlled by the circadian clock; in fact, various renal functions exhibit circadian rhythms. In our previous research, higher intake of potassium at lunch time was negatively associated with blood pressure, suggesting the importance of timing for sodium and potassium intake. However, the effects of intake timing on urinary excretion remain unclear. In this study, we investigated the effect of 24 h urinary sodium and potassium excretion after acute sodium and potassium load with different timings in mice. Compared to other timings, the middle of the active phase resulted in higher urinary sodium and potassium excretion. In Clock mutant mice, in which the circadian clock is genetically disrupted, urinary excretion differences from intake timings were not observed. Restricted feeding during the inactive phase reversed the excretion timing difference, suggesting that a feeding-induced signal may cause this timing difference. Our results indicate that salt intake timing is important for urinary sodium and potassium excretion and provide new perspectives regarding hypertension prevention.

Effect of circadian clock and claudin regulations on inulin-induced calcium absorption in the mouse intestinal tract.

Dietary calcium supplementation has been shown to be an effective adjunct therapy in an inflammatory bowel disease model. Soluble dietary fiber reduces intestinal pH and is known to enhance calcium absorption. Although many circadian clock regulations of nutrient absorption in the intestinal tract have been reported, the effects of clock regulation on calcium absorption have yet to be understood. In this study, we investigated the timing of efficient calcium intake by measuring urinary calcium excretion in mice. The diurnal variations in channel-forming tight junctions (claudins) were detected in both the jejunum and ileum. Following 2 days of feeding with a Ca2+-free diet, Ca2+-containing diets with or without soluble fiber (inulin) were fed at specific timings, and urine was subsequently examined every 4 hr. There was an evident increase in urinary calcium concentration when the inulin diet was fed at the beginning of the resting period. The Claudin 2 (Cldn2) expression level also showed a significant day-night change, which seemed to be a mechanism for the increased calcium excretion after inulin intake. This diurnal rhythm and enhanced Cldn2 expression were abolished by disruption of the suprachiasmatic nucleus, the central clock in the hypothalamus. This study suggests that intestinal calcium absorption might be modulated by the circadian clock and that the intake of inulin is more effective at the beginning of the resting period in mice.

Effects of intake of four types of snack with different timings on postprandial glucose levels after dinner.

PURPOSE: It has been reported that the consumption of fruit granola (FG), mulberry leaves, and barley cookies as an afternoon snack suppresses the postprandial increase in glucose levels at dinner. However, there have been no reports on the second-meal effect of snacking on popular snacks, such as potato chips (PC), roasted sweet potato (SP), and black beans (BB), or on the interval between snacking and dinner. METHOD: The present study was an open-label randomized crossover trial of five study groups (PC, SP, BB, FG, and no snack) regarding the second-meal effects with different intervals between snacks and dinner. The subjects consumed prescribed meals for lunch and dinner at 12:00 and 19:00, and a snack fixed at 838 kJ (= 200 kcal) at 15:00 or 17:00. RESULTS: When the participants snacked at 15:00, the postprandial glucose elevation at dinner was suppressed in the FG and SP groups, and the area under the curve (AUC) was also low. When they snacked at 17:00, the postprandial glucose elevation was suppressed in all the groups. The AUCs for PC, FG, and SP were lower than those for no snacking. On the other hand, carbohydrate intake increased with snacking, but the total AUC of snacks and dinner did not differ in any of the groups. The duration of hyperglycemia decreased with snack intake, as did the glucose amplitude. CONCLUSION: We believe that the intake of carbohydrates and soluble fiber in snacks is an important factor in the second-meal effect at dinner. These results will contribute to the development of snacking and research into the second-meal effect.

Chrono-exercise: Time-of-day-dependent physiological responses to exercise.

Exercise is an effective strategy to prevent and improve obesity and related metabolic diseases. Exercise increases the metabolic demand in the body. Although many of the metabolic health benefits of exercise depend on skeletal muscle adaptations, exercise exerts many of its metabolic effects through the liver, adipose tissue, and pancreas. Therefore, exercise is the physiological state in which inter-organ signaling is most important. By contrast, circadian rhythms in mammals are associated with the regulation of several physiological and biological functions, including body temperature, sleep-wake cycle, physical activity, hormone secretion, and metabolism, which are controlled by clock genes. Glucose and lipid tolerance reportedly exhibit diurnal variations, being lower in the evening than in the morning. Therefore, the effects of exercise on substrate metabolism at different times of the day may differ. In this review, the importance of exercise timing considerations will be outlined, incorporating a chrono-exercise perspective.

Effects of the timing of acute mulberry leaf extract intake on postprandial glucose metabolism in healthy adults: a randomised, placebo-controlled, double-blind study.

BACKGROUND/OBJECTIVES: Glucose tolerance is controlled by the internal clock and is worse in the evening. From a chrononutrition perspective, diabetes prevention requires evaluating the antidiabetic effects of the timing of functional ingredients and nutrient intake. The purpose of this study was to investigate the timing effects of acute mulberry leaf extract (MLE) intake on postprandial glucose levels in young adults. SUBJECTS/METHODS: Twelve young adults underwent four trials. Blood samples were collected in a fasting state and at 30, 60, 120, and 180 min after eating a mixed meal. The study had a randomised, placebo-controlled, double-blind trial design involving: (1) morning placebo trial (08:00 h; MP trial), (2) evening placebo trial (18:00 h; EP trial), (3) morning MLE trial (08:00 h; MM trial), and (4) evening MLE trial (18:00 h; EM trial). RESULTS: The incremental area under the blood glucose curve (iAUC) in the EM trials was significantly lower than that in the EP trials (P = 0.010). The postprandial glucose concentrations 120 min after the meal were significantly lower in the EM trials than those in the EP trials (P = 0.006). The postprandial insulin concentrations at 120 min were significantly lower in the MM trials than those in the MP trials (P = 0.034). Moreover, the postprandial insulin concentrations 180 min after the meal were significantly lower in the EM trials than those in the EP trials (P = 0.034). CONCLUSIONS: MLE intake in the evening, but not in the morning, was effective in improving glucose tolerance. TRIAL REGISTRATION: Clinical trial reference: UMIN 000045301; website of trial registry: https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000051340 .

Effects of Differences of Breakfast Styles, Such as Japanese and Western Breakfasts, on Eating Habits.

A balanced diet and protein source intake are reportedly good for health. However, many people skip breakfast or have a light breakfast. Thus, this study aimed to examine the influence of breakfast styles on eating habits among Japanese workers, including traditional Japanese-style breakfast (JB), a pattern in which Japanese foods are eaten; Japanese-Western-style breakfast (J-W B), a pattern in which Japanese and Western foods are eaten alternately; Western-style breakfast (WB), a pattern in which Western foods are eaten; and cereal-style breakfast (CB), a pattern in which cereal is eaten. We hypothesized that breakfast style may be related to good eating habits. Data from 4274 respondents (67.97% male, 33.03% female, age 48.12 ± 0.19 years), excluding night shift workers and breakfast absentees out of a total of 5535 respondents, were analyzed. The results suggest that Japanese food is linked to the intake of protein sources such as fish, eggs, and soy. Furthermore, it was suggested that Japanese food breakfast is effective for good eating habits, such as not eating irregular amounts of food, not eating snacks, not drinking sweet juices, and having a balanced diet.

Association between blood pressure and circadian timing of physical activity of Japanese workers.

High blood pressure (BP) is reported to be accounted for more than 10 million deaths, and the high prevalence of hypertension is a global issue. Exercise is known to reduce BP and the optimal exercise prescription has been discussed. Furthermore, since the circadian clock plays an important role in BP regulation and its related physiological functions, the time-of-day difference in the effect of exercise on BP is suggested. However, when people should regularly exercise for the prevention of hypertension remains unclear. In this cross-sectional research, we analyzed the association of habitual exercise and BP depending on their performed timing, time length, and frequency for three levels of intensity from an analysis of questionnaire answered by Japanese male workers (N = 2,343, mean age ± SE = 49.2 ± 0.2 years old, date: June 2021). From the subjects who responded, subjects with irregularly high or low BP, no regular physical activity or under the treatment of hypertension were excluded from the analysis. From the comparison of SBP and DBP between those who performed physical activity at each time period, vigorous or moderate physical activity in the evening (18:00-21:00) showed significantly lower average BP. On the other hand, those who walked in early morning (03:00-06:00) showed higher DBP. These time-specific differences were confirmed from multiple regression analysis, eliminating the confounding factors such as age and BMI. When participants were divided into groups according to their BP, compared to normal BP groups, higher BP groups exercised less in the evening. Our findings suggest that when to exercise is important, and that exercising in the evening (18:00-21:00) may be better to achieve the hypotensive effect of exercise.