Dietary inflammation, sleep and mental health in the United Kingdom and Japan: A comparative cross-sectional study.

Diet has been repeatedly shown to affect mental and sleep health outcomes. However, it is well known that there are cross-cultural differences in dietary practices as well as the prevalence of mental and sleep health outcomes. Given that the dietary inflammatory potential of diets has been linked to mental and sleep health outcomes, in the current study we sought to assess the inflammatory status of habitual diets and examine its relationship with mental and sleep health outcomes in both the United Kingdom and Japan. Our aim was to determine if the associations between the dietary inflammation index (DII) score and these health outcomes could elucidate any potential cross-cultural differences in health. Online survey data was collected from 602 participants (aged 18-40 years) in the United Kingdom (n = 288) and Japan (n = 314). Participants self-reported their dietary intakes, as well as current mental health and sleep patterns. The DII score was calculated (score range - 2.79 to 3.49) We found that although participants in the United Kingdom reported better overall mental wellbeing, participants in Japan reported less severe depression, anxiety and stress and better subjective sleep quality, less sleep disturbances and daytime dysfunction, despite sleeping shorter, and a better adherence to an anti-inflammatory diet. Moreover, across the United Kingdom and Japan, adherence to more anti-inflammatory diets predicted higher levels of subjective sleep quality, fewer sleep disturbances, less use of sleep medicine and less daytime dysfunction. In conclusion, there are several differences between mental and sleep health outcomes in the United Kingdom and Japan, which could be attributable to the inflammatory potential of respective regional diets. Future studies are warranted to examine the mental and sleep health benefits of adhering to anti-inflammatory traditional Japanese diets in clinical and subclinical cohorts.

The Effect of Nutrients on Subjective Accomplishment at Work: Results from a Health Survey and a Single-Arm Dietary Intervention Study.

In Japan, many workers are exposed to chronic stress, sleep deprivation, and nutritional imbalance. They tend still to go to work when ill, leading to decreased work performance and productivity, which has become a major social problem. We conducted a human entry study with the aim of finding a link between these two factors and proposing an optimized diet, believing that a review of diet may lead to an improvement in labor productivity. In this study, we used subjective accomplishment (SA) as a measure of productivity. First, we compared nutrient intake between groups with high and low SA using data from a health survey of 1564 healthy male and female adults. Significant differences were found in the intake of 13 nutrients in males and 15 nutrients in females, including potassium, vitamin A, insoluble fiber, and biotin. Recommended daily intake of these nutrients was determined from survey data. Next, we designed test meals containing sufficient amounts of 17 nutrients and conducted a single-arm intervention study (registration code UMIN000047054) in Kameyama City, Mie Prefecture, Japan. Healthy working adults (males and females aged 20-79 years) were recruited and supplied with test meals, which were eaten once a day 5 days a week for 8 weeks. SA was significantly higher and daytime sleepiness (DS) was significantly lower after lunch on workdays in younger participants (under 60 years) when they ate the test meals as breakfast or lunch. Our results suggest that SA and DS, which change daily, are strongly influenced by the meal eaten before work, and that taking the 17 nutrients may help prevent presenteeism and improve labor productivity.

The Relationship between Mental and Physical Minor Health Complaints and the Intake of Dietary Nutrients.

Presenteeism is a problem that needs to be solved urgently, both for individual workers and for society overall. In this report, we propose the concept of MHC, which refers to mild mental and physical complaints subjectively perceived by individuals that are not caused by illness. We also planned to examine what kind of physical and mental disorder MHC is and whether food is effective as a method of self-care for MHC. First, we conducted "the comprehensive survey to establish an integrated database of food, gut microbiome, and health information" (the "Sukoyaka Health Survey") and obtained data on psychosomatic disorders and intakes of dietary nutrients. As a result, through factor analysis and item response theory analysis, we found the following specific examples of MHC: lack of vigor, irritability, fatigue, and somatic complaints. In addition, analysis of the relationship between these four MHC levels and the intake dietary nutrients indicated that they are closely related and that MHC levels can be improved by consuming sufficient amounts of multiple nutrients.

Effects of Prebiotic Yeast Mannan on Gut Health and Sleep Quality in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Study.

Human gut health is closely related to sleep. We aimed to evaluate the efficacy of yeast mannan (YM) in improving bowel habits and sleep quality, along with metabolomics in fecal samples. A total of 40 healthy adults (age range, 22-64 years) with discomfort in defecation were enrolled and randomly allocated to receive either YM (n = 20; 1.1 g/day) or placebo (n = 20) for four weeks. Participants recorded their defecation habits throughout the test periods. Sleep electroencephalogram (EEG) recording using an EEG device and fecal sampling were performed pre- and post-treatment. The YM group significantly increased defecation frequency and stool volumes compared to the placebo group. After 4 weeks of treatment, the non-REM sleep stage 3 (N3) duration in the YM group was significantly higher than that in the placebo group. YM ingestion significantly lengthened total time in bed (TIB) and significantly shortened N3 latency compared to placebo intake during the trial. The metabolomics analysis found a total of 20 metabolite differences between the YM and placebo groups. As a result of stepwise linear regression, changes in fecal propionate and gamma-aminobutyric acid (GABA) levels were identified as the primary factors explaining changes in TIB and N3 latency, respectively. Our findings suggest that the prebiotic YM could be beneficial to gut health and sleep quality.

The Impact of Purple-Flesh Potato (Solanum tuberosum L.) cv. "Shadow Queen" on Minor Health Complaints in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Study.

The purple-flesh potato (Solanum tuberosum L.) cultivar "Shadow Queen" (SQ) naturally contains anthocyanins. This randomized, double-blind, placebo-controlled study determines whether ingesting purple potatoes increases the number of mesenchymal stem cells (MSC) and improves stress response, a minor health complaint in healthy adults (registration number: UMIN000038876). A total of 15 healthy subjects (ages: 50-70 years) with minor health complaints were randomly assigned to one of two groups. For 8 weeks, the placebo group received placebo potatoes cv. "Haruka" and the test group received test potato cv. SQ containing 45 mg anthocyanin. The MSC count and several stress responses were analyzed at weeks 0 and 8 of the intake periods. The ingestion of a SQ potato did not affect the MSC count but markedly improved psychological stress response, irritability, and depression as minor health complaints compared with "Haruka". No adverse effects were noted. Hence, an 8-week intake of SQ could improve stress responses.

The effect of 24-week continuous intake of quercetin-rich onion on age-related cognitive decline in healthy elderly people: a randomized, double-blind, placebo-controlled, parallel-group comparative clinical trial.

Quercetin, a type of flavonoid, is believed to reduce age-related cognitive decline. To elucidate its potential function, we carried out a randomized, double-blind, placebo-controlled, parallel-group comparative clinical trial involving 24-week continuous intake of quercetin-rich onion compared to quercetin-free onion as a placebo. Seventy healthy Japanese individuals (aged 60 to 79 years old) were enrolled in this study. We examined the effect of quercetin-rich onion (the active test food) on cognitive function using the Mini-Mental State Examination, Cognitive Assessment for Dementia iPad version, and Neuropsychiatric Inventory Nursing Home version. The Mini-Mental State Examination scores were significantly improved in the active test food group (daily quercetin intake, 50 mg as aglycone equivalent) compared to the placebo food group after 24 weeks. On the Cognitive Assessment for Dementia iPad version for emotional function evaluation, we found that the scores of the active test food group were significantly improved, suggesting that quercetin prevents cognitive decline by improving depressive symptoms and elevating motivation. On the Neuropsychiatric Inventory Nursing Home version, we found significant effects on reducing the burden on study partners. Taking all the data together, we concluded that 24-week continuous intake of quercetin-rich onion reduces age-related cognitive decline, possibly by improving emotional conditions. Clinical trial register and their clinical registration number: This study was registered with UMIN (approval number UMIN000036276, 5 April 2019).

Effects of white rice containing enriched gamma-aminobutyric acid on blood pressure.

Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter with beneficial effects including antihypertension and antistress properties. In this study, we examined the effects of GABA-enriched white rice (GABA rice) on blood pressure (BP) in 39 mildly hypertensive adults in a randomized, double-blind, placebo-controlled study. The participants were divided into a test group (n = 22) who consumed rice with 11.2 mg GABA/100 g of rice and a placebo group (n = 17) who consumed rice with 2.7 mg GABA/100 g of rice. For 8 weeks, the participants took 150 g of either the GABA rice or the placebo rice. Hematological examinations were performed on both groups at 0, 4, and 8 weeks after the start of rice consumption. Home BP was self-measured two times daily, morning and evening, from 1 weeks before to 2 weeks after the intervention. Although the hospital BP and evening BP measurements of the participants showed no significant change, consumption of the GABA rice improved the morning BP compared with the placebo rice after the 1(st) week and during the 6(th) and 8(th) weeks. These results showed the possibility that the GABA rice improves morning hypertension.

Improvement of Blood Pressure, Glucose Metabolism, and Lipid Profile by the Intake of Powdered Asparagus ( Lú Sun) Bottom-stems and Cladophylls.

Asparagus ( Lú Sǔn; Asparagus officinalis L.) is a common vegetable, long used as an herbal medicine. The cladophylls and bottom-stems of asparagus have various pharmacological effects, but they are generally discarded at harvesting. The present open clinical trial was performed to examine the effects of the intake of cladophylls and bottom-stems on the improvement of metabolic syndrome characterized by hypertension, hyperglycemia, and dyslipidemia. Twenty-eight healthy volunteers ingested either cladophyll or bottom-stem powder (6 g/day) daily for 10 weeks. The cladophyll intake resulted in significant reduction in the subjects' diastolic blood pressure and fasting plasma glucose (FPG), and decreased both the left cardio-ankle vascular index score and the total cholesterol level (T-CHO). The bottom-stem intake significantly reduced the subjects' systolic and diastolic blood pressure and FPG as well as T-CHO. These results suggest the possibility that asparagus cladophylls and bottom-stems differentially improve hypertension, hyperglycemia, and dyslipidemia.