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1.
Dietary Inflammatory Index, Sleep Duration, and Sleep Quality: A Systematic Review.
Coxon, C, Nishihira, J, Hepsomali, P
Nutrients. 2024;(6)
Abstract
The inflammatory potential of the diet, as measured by the Dietary Inflammatory Index (DII®), has been repeatedly shown to be associated with various inflammatory markers and mental and physical health outcomes. Of specific importance, several cross-sectional studies revealed mixed results regarding the correlations between the DII and sleep outcomes. Hence, in the current paper, a systematic review that examines the associations between the DII, sleep duration, and sleep quality was performed. The PubMed database was systematically searched for studies published up to November 2023 following PRISMA guidelines. Only cross-sectional studies that assessed the DII, sleep duration, and sleep quality across healthy and unhealthy cohorts were included. Eleven and seven studies were included in the systematic review for sleep quality and duration, respectively. The results of the present systematic review show that pro-inflammatory diets may be associated with poor sleep outcomes (duration and quality); however, as the current literature is inconsistent and limited, further cross-sectional studies in larger cohorts are necessary to (i) explore this relationship to address this heterogeneity and (ii) explore populations that are more sensitive to diet-induced inflammation.
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2.
Effects of Prebiotic Yeast Mannan on Gut Health and Sleep Quality in Healthy Adults: A Randomized, Double-Blind, Placebo-Controlled Study.
Tanihiro, R, Yuki, M, Sasai, M, Haseda, A, Kagami-Katsuyama, H, Hirota, T, Honma, N, Nishihira, J
Nutrients. 2023;(1)
Abstract
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.
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3.
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.
Maeda-Yamamoto, M, Honmou, O, Sasaki, M, Haseda, A, Kagami-Katsuyama, H, Shoji, T, Namioka, A, Namioka, T, Magota, H, Oka, S, et al
Nutrients. 2022;(12)
Abstract
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.
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4.
Continuous partially hydrolyzed guar gum intake reduces cold-like symptoms: a randomized, placebo-controlled, double-blinded trial in healthy adults.
Sakai, S, Kamada, Y, Takano, H, Ichikawa, M, Kurimoto, M, Katsuyama, HK, Nishihira, J, Sasaki, M
European review for medical and pharmacological sciences. 2022;(14):5154-5163
Abstract
OBJECTIVE Partially hydrolyzed guar gum (PHGG), a water-soluble dietary fiber produced by the controlled partial enzymatic hydrolysis of guar gum beans, has various physiological roles. PHGG is expected to influence the immune function and prevent infections. The objective of this study was to examine the effect of continuous ingestion of PHGG for 12 weeks on the development of cold-like symptoms. PATIENTS AND METHODS A placebo-controlled, double blind, randomized, parallel-group comparative study was conducted. 96 healthy Japanese adults received 5.2 g PHGG or placebo daily for 12 weeks. Cold-like symptoms were assessed based on patient diary, and the levels of short-chain fatty acids (SCFAs) in stool and blood immune markers at baseline and at weeks 6 and 12. RESULTS The cumulative number of "no symptoms" days for all symptoms was significantly larger in the PHGG than in the placebo group. The result of the analysis by severity of cold-like symptoms also showed significant differences, with the PHGG group having a lower severity of cold-like symptoms. Propionic acid at weeks 6 and 12 and n-butyric acid and total SCFAs at week 12 were significantly higher in the PHGG than in the placebo group. The Interferon-γ level was significantly lower at week 6 in the PHGG than in the placebo group. CONCLUSIONS PHGG intake may affect immune function and suppress cold-like symptoms through the production of SCFAs in healthy adults.
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5.
[A literature review on the relationship between questionnaires for assessing minor health complaints and health status indices among Japanese people].
Tousen, Y, Mizushima, R, Koitaya, N, Kurotani, K, Nishihira, J, Maeda-Yamamoto, M, Takimoto, H
[Nihon koshu eisei zasshi] Japanese journal of public health. 2022;(5):368-382
Abstract
Objectives Minor health complaints related to stress, mental health, sleep, and fatigue are closely associated with each other, and their deterioration may cause lifestyle diseases. The health status of people can be predicted through a questionnaire by exploring the relationship between their state of minor health complaints and objective health status indices. Therefore, we conducted a systematic review of the relationship between a questionnaire on the state of minor health complaints and health status indices among Japanese people who have a high level of stress, which they experience on a daily basis, using epidemiological literature. Additionally, we considered items for the questionnaire which were necessary for an index development.Methods The PubMed database was searched for papers on "autonomic nervous system," "sleep disorders," "mental health and stress," and "fatigue," using keywords mentioned in previous studies on minor health complaints. The extracted research papers were screened according to the following inclusion criteria: 1) the participants were healthy Japanese people; 2) descriptions included characteristics of the target population; 3) use of analytic epidemiological study design, intervention studies, and systematic reviews; 4) minor health complaints assessed by a questionnaire; 5) evaluation of the relationship between the questionnaires for minor health complaints and the health index; and 6) written in Japanese or English. Based on this, ten papers were adopted.Results Of the 10 papers collected, one was a cohort study, three were case-control studies, and six were cross-sectional studies. The participants in five of them were working adults. Reports on three out of six questionnaires on stress, four out of seven on sleep, and all two on comprehensive health status showed significant associations between minor health complaints assessed by the questionnaires and the index for health status. The increase in responses about work-related stress from the questionnaire was associated with an increase in the "risk of developing depression" [odds ratio 2.96 (confidence interval: 1.04-8.42)]. Poor sleep quality was associated with an increase in "changes in autonomic index," "number of comorbidities and the rate of depression," and the "risk of work-related injuries." Moreover, the health score was associated with the "autonomic nervous system index".Conclusion These results suggest that a questionnaire evaluating minor health complaints should include questions about "stress," "sleep quality," and "comprehensive health status." Since studies that appropriately adopted for risk of bias were limited, it is necessary to further examine these relationships by applying prospective studies such as cohort studies and intervention studies.
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6.
The Role of Micronutrients in Ageing Asia: What Can Be Implemented with the Existing Insights.
Inui, T, Hanley, B, Tee, ES, Nishihira, J, Tontisirin, K, Van Dael, P, Eggersdorfer, M
Nutrients. 2021;(7)
Abstract
Life expectancy as a measure of population health does not reflect years of healthy life. The average life expectancy in the Asia-Pacific region has more than doubled since 1900 and is now above 70 years. In the Asia-Pacific region, the proportion of aged people in the population is expected to double between 2017 and 2050. Increased life expectancy leads to an increase in non-communicable diseases, which consequently affects quality of life. Suboptimal nutritional status is a contributing factor to the prevalence and severity of non-communicable diseases, including cardiovascular, cognitive, musculoskeletal, immune, metabolic and ophthalmological functions. We have reviewed the published literature on nutrition and healthy ageing as it applies to the Asia-Pacific region, focusing on vitamins, minerals/trace elements and omega-3 fatty acids. Optimal nutritional status needs to start before a senior age is reached and before the consequences of the disease process are irreversible. Based on the nutritional status and health issues in the senior age in the region, micronutrients of particular importance are vitamins A, D, E, C, B-12, zinc and omega-3 fatty acids. The present paper substantiates the creation of micronutrient guidelines and proposes actions to support the achievement of optimal nutritional status as contribution to healthy ageing for Asia-Pacific populations.
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7.
The combined effect of green tea and α-glucosyl hesperidin in preventing obesity: a randomized placebo-controlled clinical trial.
Yoshitomi, R, Yamamoto, M, Kumazoe, M, Fujimura, Y, Yonekura, M, Shimamoto, Y, Nakasone, A, Kondo, S, Hattori, H, Haseda, A, et al
Scientific reports. 2021;(1):19067
Abstract
Green tea, a widely consumed beverage in Asia, contains green tea catechins effective against obesity, especially epigallocatechin-3-O-gallate (EGCG), but must be consumed in an impractically huge amount daily to elicit its biological effect. Meanwhile, citrus polyphenols have various physiological effects that could enhance EGCG functionality. Here we investigated the antiobesity effect of a combination of EGCG and α-glucosyl hesperidin, a citrus polyphenol, at doses that have not been previously reported to exert antiobesity effects by themselves in any clinical trial. In a randomized, placebo-controlled, double-blinded, and parallel-group-designed clinical trial, 60 healthy Japanese males and females aged 30-75 years consumed green tea combined with α-glucosyl hesperidin (GT-gH), which contained 178 mg α-glucosyl hesperidin and 146 mg EGCG, for 12 weeks. Physical, hematological, blood biochemical, and urine examinations showed that GT-gH is safe to use. At week 12, GT-gH prevented weight gain and reduced body mass index (BMI) compared with the placebo. Especially in those aged < 50 years, triglyceride and body fat percentage decreased at week 6, visceral fat level and body fat percentage decreased at week 12; body weight, BMI, and blood LDL/HDL ratio also decreased. In conclusion, taking GT-gH prevents weight gain, and the antiobesity effect of GT-gH was more pronounced in people aged < 50 years.
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8.
Highly Bioavailable Curcumin Derivative Ameliorates Crohn's Disease Symptoms: A Randomized, Double-Blind, Multicenter Study.
Sugimoto, K, Ikeya, K, Bamba, S, Andoh, A, Yamasaki, H, Mitsuyama, K, Nasuno, M, Tanaka, H, Matsuura, A, Kato, M, et al
Journal of Crohn's & colitis. 2020;(12):1693-1701
Abstract
BACKGROUND & AIMS The new curcumin derivative Theracurmin® has a 27-fold higher absorption rate than natural curcumin powder. Theracurmin® is an inhibitor of nuclear factor-κB, which mediates the expression of inflammatory cytokines. The effect of Theracurmin® on inflammatory bowel disease in humans has not been explored; therefore, we investigated the efficacy and safety of Theracurmin® in patients with Crohn's disease. METHODS In this randomized, double-blinded study performed at 5 independent medical centers in Japan, Theracurmin® (360 mg/day, n = 20) or placebo (n = 10) was administered to patients with active mild-to-moderate Crohn's disease for 12 weeks. The agent's efficacy was assessed by evaluating clinical and endoscopic remission, healing of anal lesions, and blood levels of inflammatory markers. RESULTS In the Theracurmin® group, a significant reduction in clinical disease activity was observed in week 12 relative to that in week 0 (p = 0.005). On intention-to-treat analysis, clinical remission rates were 35%, 40%, and 40% at weeks 4, 8, and 12, respectively, which were significantly higher than those in the placebo group (all 0%; p = 0.033, p = 0.020, and p = 0.020, respectively). Furthermore, reduction in endoscopic Crohn's disease severity (p = 0.032) was observed at week 12 in the Theracurmin® group. The endoscopic remission rates were 15% and 0% in the Theracurmin® and placebo groups, respectively. Significant healing of anal lesions (p = 0.017) was observed at week 8 in the Theracurmin® group. No serious adverse events were observed in either group throughout the study. CONCLUSIONS Theracurmin® shows significant clinical and endoscopic efficacy together with a favorable safety profile in patients with active mild-to-moderate Crohn's disease. CLINICAL TRIAL UMIN REGISTRATION ID UMIN000015770.
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9.
Effect of Increased Daily Water Intake and Hydration on Health in Japanese Adults.
Nakamura, Y, Watanabe, H, Tanaka, A, Yasui, M, Nishihira, J, Murayama, N
Nutrients. 2020;(4)
Abstract
Increased hydration is recommended as healthy habit with several merits. However, supportive data are sparse. To assess the efficacy of increased daily water intake, we tested the effect of water supplementation on biomarkers in blood, urine, and saliva. Twenty-four healthy Japanese men and 31 healthy Japanese women with fasting blood glucose levels ranging from 90-125 mg/dL were included. An open-label, two-arm, randomized controlled trial was conducted for 12 weeks. Two additional 550 mL bottles of water on top of habitual fluid intake were consumed in the intervention group. The subjects drank one bottle of water (550 mL) within 2 h of waking, and one bottle (550 mL) 2 h before bedtime. Subjects increased mean fluid intake from 1.3 L/day to 2.0 L/day, without changes in total energy intake. Total body water rate increased with associated water supplementation. There were no significant changes in fasting blood glucose and arginine vasopressin levels, but systolic blood pressure was significantly decreased in the intervention group. Furthermore, water supplementation increased body temperature, reduced blood urea nitrogen concentration, and suppressed estimated glomerular filtration rate reduction. Additionally, existence of an intestinal microbiome correlated with decreased systolic blood pressure and increased body temperature. Habitual water supplementation after waking up and before bedtime in healthy subjects with slightly elevated fasting blood glucose levels is not effective in lowering these levels. However, it represents a safe and promising intervention with the potential for lowering blood pressure, increasing body temperature, diluting blood waste materials, and protecting kidney function. Thus, increasing daily water intake could provide several health benefits.
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10.
Effects of Oral Gamma-Aminobutyric Acid (GABA) Administration on Stress and Sleep in Humans: A Systematic Review.
Hepsomali, P, Groeger, JA, Nishihira, J, Scholey, A
Frontiers in neuroscience. 2020;:923
Abstract
Gamma-aminobutyric acid (GABA) is a non-proteinogenic amino acid and is the main inhibitory neurotransmitter in the mammalian brain. GABA's stress-reducing, and sleep enhancing effects have been established. However, although several human clinical trials have been conducted, results regarding the role of natural and/or biosynthetic oral GABA intake on stress and sleep are mixed. We performed a systematic review to examine whether natural and/or biosynthetic oral GABA intake has an effect on stress and sleep. We systematically searched on PubMed database for studies published up to February 2020 following PRISMA guidelines. Only placebo-controlled human trials that assessed stress, sleep, and related psychophysiological outcomes as a response to natural GABA (i.e., GABA that is present naturally in foods) or biosynthetic GABA (i.e., GABA that is produced via fermentation) intake were included. Fourteen studies met the criteria and were included in the systematic review. Although more studies are needed before any inferences can be made about the efficacy of oral GABA consumption on stress and sleep, results show that there is limited evidence for stress and very limited evidence for sleep benefits of oral GABA intake.