Curriculum Vitaes

Narumi Nagai

  (永井 成美)

Profile Information

Affiliation
University of Hyogo
Degree
Ph.D.(Kyoto University)

J-GLOBAL ID
200901082455764526
researchmap Member ID
1000327043

External link

In education, I am responsible for lectures and practical training in the theory of nutrition education in the registered dietitian and nutrition teacher’s courses. In my research I conduct experimental and observational studies using nutritional physiology and epidemiological methods on humans at life stages from foetal (pregnancy) to old age individuals. Findings from the above research are used in nutrition education research and nutrition education activities (Syokuiku), and information is disseminated to our society. I am also conducting research in the new field of ‘chrono-nutrition research’, which examines nutritional intake in terms of timing. In Japan, generally, dietary counseling and nutrition education have been provided mainly to health-conscious persons or self-directed groups. However, these approaches have an aspect of increasing the knowledge level of those who are interested in health, while the apathetic group does not respond and the ‘health gap’ may expand. I therefore decided that there was a need for nutrition education that could involve people who were not concerned about their health, so I started an intervention study in the workplace (company canteen and vending machines) as a new research field.


Research History

 4

Papers

 110
  • KayoYoshitani, Yukina Yumen, Yumi Takayama, Miyoko Okuzono, Fuminori Hanzawa, Narumi Nagai
    The Japanese Journal of Sports Nutrition (Early Online Release), Jan, 2025  Peer-reviewedLast author
  • Yukina Yumen, Yumi takayama, Kayo Yoshitani, Miyoko Okuzono, Fumiaki Hanzawa, Naoki Sakane, Narumi Nagai
    Journal of Japan Society for the Study of Obesity, 30(3), Dec, 2024  Peer-reviewedLast authorCorresponding author
  • Narumi Nagai, Fumiaki Hanzawa, Miyoko Okuzono, Kayo Yoshitani
    The journal of Clinical Sports Medicine, 41(6) 608-612, Jun, 2024  InvitedLead authorCorresponding author
  • Yosuke Isoyama, Sayaka Nose-Ogura, Mariko Jana Ijitsu, João Gabriel Segato Kruse, Narumi Nagai, Momoko Kayaba, Hitomi Ogata, Madhur Mangalam, Ken Kiyono
    Frontiers in Public Health, 12 1-14, Apr 24, 2024  Peer-reviewed
    Background Precision in evaluating underweight and overweight status among children and adolescents is paramount for averting health and developmental issues. Existing standards for these assessments have faced scrutiny regarding their validity. This study investigates the age and height dependencies within the international standards set by the International Obesity Task Force (IOTF), relying on body mass index (BMI), and contrasts them with Japanese standards utilizing the percentage of overweight (POW). Method We scrutinized a comprehensive database comprising 7,863,520 children aged 5–17 years, sourced from the School Health Statistics Research initiative conducted by Japan's Ministry of Education, Culture, Sports, Science, and Technology. Employing the quantile regression method, we dissected the structure of weight-for-height distributions across different ages and sexes, quantifying the potentially biased assessments of underweight and overweight status by conventional criteria. Results Applying IOFT criteria for underweight assessment revealed pronounced height dependence in males aged 11–13 and females aged 10–11. Notably, a discernible bias emerged, wherein children in the lower 25th percentile were classified as underweight five times more frequently than those in the upper 25th percentile. Similarly, the overweight assessment displayed robust height dependence in males aged 8–11 and females aged 7–10, with children in the lower 25th percentile for height deemed obese four or five times more frequently than their counterparts in the upper 25th percentile. Furthermore, using the Japanese POW criteria for assessment revealed significant age dependence in addition to considerably underestimating the percentage of underweight and overweight cases under the age of seven. However, the height dependence for the POW criterion was smaller than the BMI criterion, and the difference between height classes was less than 3-fold. Conclusion Our findings underscore the intricacies of age-dependent changes in body composition during the growth process in children, emphasizing the absence of gold standards for assessing underweight and overweight. Careful judgment is crucial in cases of short or tall stature at the same age, surpassing sole reliance on conventional criteria results.
  • 永井成美, 湯面百希奈
    栄養-Trends of Nutrition-, 39(2) 77-82, 2024  InvitedLead authorCorresponding author
  • Okuzono M, Hanzawa F, Nakano T, Koizumi T, Morioto A, Nagai N
    Journal of Japan Society for the Study of Obesity, 29(3) 107-114, Dec, 2023  Peer-reviewedLast author
  • Morimoto A, Gonda M, Hashimoto A, Yumen Y, Takayama Y, Okuzono M, Hanzawa F, Nagai N
    J Jp Soc Psychosom Obstet Gynecol, 28(2) 211-221, Nov, 2023  Peer-reviewedCorresponding author
  • Yumi Takayama, Yukina Yumen, Takamasa Kitajima, Noritsugu Honda, Naoki Sakane, Motonari Fukui, Narumi Nagai
    PLOS ONE, 18(8) e0290277-e0290277, Aug 22, 2023  Peer-reviewedLast author
    Background We have previously reported that female patients with nontuberculous mycobacterial lung disease (NTM-LD) are thinner and eat less than healthy controls. Therefore, we hypothesized that their thinness is associated with body size misperception. The aim of this study was to clarify whether patients’ body size perception (BSP) is associated with body mass index (BMI) independent of potential confounders. Methods In this cross-sectional study, we assessed 81 outpatients for BSP using the Japanese version of Body Image Scale, body composition, dietary intake, and biochemical markers. As a control, we used BSP and self-reported anthropometric data from 111 healthy women collected via a web survey. First, BSP and BMI were compared between the patients and the controls. Second, patient data was compared between patients who overestimated their body size (OE, n = 31) and a control who did not (Non-OE, n = 50). Multiple regression analysis was performed to clarify the association between BSP (independent variable) and BMI (dependent variable), adjusting for potential confounders, such as age, disease duration, and nutritional factors. Results There was a negative correlation between body size distortion and BMI in both patients and controls (p < 0.001, both). In interpatient comparisons, the OE group had significantly lower BMI and body fat percentage (p < 0.001, both), normalized energy (p = 0.037), and protein (p = 0.013) intakes, and significantly greater weight loss from age 20 (p = 0.003) than the Non-OE group. Multiple regression analysis revealed that overestimation of body size was associated with lower BMI independent of confounders, such as longer disease history, longitudinal weight loss, and nutritional factors. Conclusion These findings suggest that body size distortion is an etiological factor for lower BMI in female patients with NTM-LD. Thus, it may be important to understand the patient’s body image when providing dietary advice.
  • Ikuyo Hayashi, Naoki Sakane, Akiko Suganuma, Narumi Nagai
    Nutrition Research, 115 38-46, Jul, 2023  Peer-reviewedLast author
  • Akio Iida, Yukina Yumen, Yumi Takayama, Arata Suzuki, Fumiaki Hanzawa, Narumi Nagai
    Jpn. J. Nutr. Diet, 81(2) 84-92, May, 2023  Peer-reviewedLast authorCorresponding author
  • Yukina Yumen, Yumi Takayama, Fumiaki Hanzawa, Naoki Sakane, Narumi Nagai
    Nutrients, 15(7) 1589, Mar, 2023  Peer-reviewedLast author
    Recent reports have associated the use of social networking sites (SNS) with the drive for thinness in young women; however, its influence on their actual body shape and eating behaviors (EB) remains unclear. We aimed to examine the effect of SNS use on body mass index (BMI), body image (BI), and EB in young women. Participants included 196 healthy women (20-29 years) who answered questions about their SNS use, height, weight, BI and EB via a web-based survey. First, the correlation between time spent on SNS and each variable was determined. Participants were then divided into quartiles according to the duration of daily SNS use as long (≥3 h, n = 52) and short (<1 h, n = 54), and the data were then compared between the groups. Correlation analysis showed that the longer the duration of daily SNS use, the significantly lower the BMI, the use of nutrition labels, and the frequency of consumption of milk and dairy products. The long group had significantly lower BMI and ideal BI than the short group. The results suggest that spending more time on SNS in young women may be associated with thinner actual and ideal body shapes and poorer access to health information and healthy foods.
  • Yumi Takayama, Takamasa Kitajima, Noritsugu Honda, Naoki Sakane, Yukina Yumen, Motonari Fukui, Narumi Nagai
    BMC Pulmonary Medicine, 22(1) 315-315, Aug 15, 2022  Peer-reviewedLast author
    Abstract Background In women, slender body habitus has been reported to be one of the predisposing factors underlying the development and poor prognosis of non-tuberculous mycobacterial lung disease (NTM-LD). Given the lack of nutritional data contributing to treatment strategies, we aimed to clarify the nutritional status of female patients with NTM-LD and its association with disease severity. Methods In this single-center observational study, we enrolled 81 female outpatients with NTM-LD. Data on healthy women of similar ages were selected from our previous survey data and categorized as controls. First, we compared anthropometric and dietary survey data between patients and controls. Second, after the patients were categorized into relatively mild (mild, n = 40) and relatively severe groups (severe, n = 41) based on pulmonary X-ray-image finding scores, body composition, nutritional intake, and biochemical markers were compared between the groups. To identify nutritional factors associated with disease severity, logistic regression analyses were performed. Results Compared with controls, patients with NTM-LD had significantly lower energy intake, body mass index, body fat, and skeletal muscle mass (all p &lt; 0.001). Compared with the mild group, the severe group had significantly lower skeletal muscle mass (p = 0.037), albumin (p = 0.029), transthyretin (prealbumin) (p = 0.002), retinol-binding protein (p = 0.011), and hemoglobin (p = 0.001); however, no between-group differences were observed in energy or nutrient intake. Logistic analyses revealed that transthyretin (p = 0.025) and hemoglobin (p = 0.003) levels were independent factors associated with disease severity. Conclusions This is the first study to comprehensively report the association between NTM-LD severity and nutritional status, including body composition, nutrient intake, and biomarkers. The results suggest that initiating nutritional therapy from the mild stage of the disease to prevent undernutrition is warranted.
  • Yukina Yumen, Haruna Doi, Yumi Takayama, Yoko Nose, Narumi Nagai
    The Japanese Journal of Nutrition and Dietetics, 80(4) 246-255, Aug 1, 2022  Peer-reviewedLast authorCorresponding author
  • Miyoko Okuzono, Yoko Nose, Yumi Takayama, Yukina Yumen, Arata Suzuki, Akio Iida, Ippei Murata, Narumi Nagai
    The Japanese Journal of Nutrition and Dietetics, 80(2) 139-148, Apr 1, 2022  Peer-reviewedLast authorCorresponding author
  • Yoko Nose, Chiyori Hiromatsu, Fumiaki Hanzawa, Yukina Yumen, Kazuhiko Kotani, Narumi Nagai
    Chronobiology international, 39(6) 1-10, Feb 21, 2022  Peer-reviewedLast authorCorresponding author
    For athletes, it is important to acquire lean body mass (LBM) involving the skeletal muscle mass during their growth periods; however, the influence of chronotype on LBM gain remains unclear. We therefore aimed to investigate whether chronotype, sleep-wake cycle on weekdays (SWC-W), and their interaction contribute to LBM gain among adolescent male athletes in a 4-month intervention study. The participants were 45 male high-school baseball players. The intervention, including exercise menu (running and muscle strength training) and nutritional education, was conducted during a 4-month period of season-off training. The chronotype, body composition, lifestyle, and dietary intake were investigated before intervention (baseline) and after 4 months. Among the participants [Morningness (n = 14), Eveningness (n = 15), Intermediate (n = 16); ME score based on the Morningness/Eveningness Scale for Children (MES-C)], the midpoint of sleep on weekdays (MSW) was calculated in the "Morningness" and "Eveningness" participants, respectively. They were divided into 4 groups based on a match/mismatch with the chronotype: Type M-match (n = 8), Type M-mismatch (n = 6), Type E-match (n = 7), and Type E-mismatch (n = 8) groups. The data were compared among the 4 groups. Moreover, multiple regression analysis was conducted using an increase (kg) LBM gain as a response variable. When comparing the data between the "Morningness" and "Eveningness" participants, there were no differences in nutrient intake, the duration of training, or each parameter of body composition (per body weight) at baseline or after 4 months. There were also no differences in the rates of change in the body weight or each parameter of body composition. In groups in which the chronotype was consistent with the SWC-W (the Type M-match and Type E-match groups), the LBM gain were slightly greater than in the Type M-mismatch and Type E-mismatch groups (Type M-match: 3.5 ± 2.0 kg, Type M-mismatch: 1.6 ± 1.7 kg, Type E-match: 3.4 ± 2.2 kg, and Type E-mismatch: 1.2 ± 1.8 kg, p = .057). Multiple regression analysis revealed that an extent of the LBM gain was associated with a match between the chronotype and SWC-W (ß = 0.37, p = .030), independent of a long duration of training (ß = 0.52, p = .004). The results suggested that training-related LBM gain is associated with interactions between the chronotype and SWC-W in adolescent male athletes.Abbreviations: LBM: Lean body mass; SWC-W: Sleep-wake cycle on weekdays; ME score: Morningness-eveningness score; MES-C: Morningness/Eveningness Scale for Children; MSW: Midpoint of sleep on weekdays; MSF: Midpoint of sleep on free days; MSFsc: Midpoint of sleep on free days corrected for sleep debt accumulated through weekdays.
  • Yumen Y, Takayama Y, Arata S, Yuji W, Sakane N, Narumi N
    J Jap Soc Study Obes, 27(3) 140-148, Dec, 2021  Peer-reviewedLast authorCorresponding author
  • Maki Suzuki, Kotomi Miyata, Yuji Wada, Takako Muto, Kazuhiko Kotani, Narumi Nagai
    The Japanese Journal of Nutrition and Dietetics, 78(5) 223-231, Oct, 2020  Peer-reviewedLast authorCorresponding author
  • Yumen Y, Korekane Y, Takagi A, Shinya N, Ochiai N, Nose Y, Nagai N
    78(4) 152-162, Aug, 2020  Peer-reviewedLast authorCorresponding author
  • Hayashi I, Yamaguchi K, sumitomo K, Minato S, Suzuki M, Nose Y, Takakura K, Sakane N, nagai N
    Pediatric Health Research, 79(3) 267-278, May, 2020  Peer-reviewedLast authorCorresponding author
  • Ikuyo Hayashi, Ken Yamaguchi, Masahiro Sumitomo, Kenji Takakura, Narumi Nagai, Naoki Sakane
    BMC research notes, 13(1) 199-199, Apr 3, 2020  Peer-reviewed
    OBJECTIVE: Low birth weight (LBW) is a major public health issue as it increases the risk of noncommunicable diseases throughout life. However, the genome-wide DNA methylation patterns of full-term LBW infants (FT-LBWs) are still unclear. This exploratory study aimed to analyze the DNA methylation differences in FT-LBWs compared with those in full-term normal birth weight infants (FT-NBWs) whose mothers were nonsmokers and had no complications. Initially, 702 Japanese women with singleton pregnancies were recruited. Of these, four FT-LBWs and five FT-NBWs were selected as references for DNA methylation analysis, and 862,260 CpGs were assessed using Illumina Infinium MethylationEPIC BeadChip. Gene ontology enrichment analysis was performed using DAVID v6.8 software to identify the biological functions of hyper- and hypomethylated DNA in FT-LBWs. RESULTS: 483 hyper-differentially methylated genes (DMGs) and 35 hypo-DMGs were identified in FT-LBW promoter regions. Hyper-DMGs were annotated to 11 biological processes; "macrophage differentiation" (e.g., CASP8), "apoptotic mitochondrial changes" (e.g., BH3), "nucleotide-excision repair" (e.g., HUS1), and "negative regulation of inflammatory response" (e.g., NLRP12 and SHARPIN). EREG was classified into "ovarian cumulus expansion" within the "organism growth and organization" category. Our data imply that LBW might be associated with epigenetic modifications, which regulate the immune system and cell maturation.
  • Satomi Minato, Shinsuke Nirengi, Ikuyo Hayashi, Ken Yamaguchi, Kenji Takakura, Naoki Sakane, Narumi Nagai
    J Jpn Soc Clin Nutr, 41(2) 124-133, 2020  Peer-reviewedLast author
  • Nagai N, Shindo N, Wada A, Izu H, Fujii T, Matsubara K, Wada Y, Sakane N
    Journal of Alzheimer's Diseases, 7(2) 95-103, 2020  Peer-reviewedLead authorCorresponding author
    © 2019, Serdi and Springer Nature Switzerland AG. Background: Rice wine lees (RWL), a Japanese traditional fermented product, is a rich source of one-carbon metabolism-related nutrients, which may have beneficial effects on cognitive function. Objectives: We aimed to examine the effect of the RWL on cognitive function in community-dwelling physically active older adults. Design: Double-blind, randomized, placebo-controlled study (clinical trial number: UMIN 000027158). Setting: Community-based intervention including assessments conducted at the University of Hyogo and a public liberal arts school in Himeji City, Japan. Participants: A total of 35 community-dwelling older adults (68–80 years) who performed mild exercise before and during the trial were assigned to either the RWL (n=17) or the placebo group (n=18). Intervention: Daily consumption of 50 g RWL powder, which contained one-carbon metabolism-related nutrients, or the placebo powder (made from soy protein and dextrin) for 12 weeks. Both supplements included equivalent amounts of energy and protein. Measurements: Montreal Cognitive Assessment, computerized cognitive function test, and measurements of serum predictive biomarkers (transthyretin, apolipoprotein A1, and complement C3) were conducted at baseline and follow-up. Results: Visual selective attention and serum transthyretin significantly improved in the RWL group, whereas there was no significant change in the placebo group. No significant group difference was observed in the remaining cognitive performance tests. Conclusions: RWL supplements seem to have a few effects on cognitive function in community-dwelling physically active older adults. However, the impact was limited; therefore, further studies with sufficient sample size are warranted to elucidate this issue.
  • Ikuyo Hayashi, Kenji Takakura, Ken Yamaguchi, Masahiro Sumitomo, Maki Suzuki, Aya Sumitomo, Satomi Minato, Yoko Nose, Narumi Nagai, Naoki Sakane
    The journal of obstetrics and gynaecology research, 46(1) 110-118, Jan, 2020  Peer-reviewed
    AIM: Small-for-gestational-age (SGA) status has negative health consequences in neonates and later life. Low socioeconomic status (SES) is a reported risk factor for adverse birth outcomes, such as SGA and preterm birth (PTB). The present study investigated whether maternal SES is associated with adverse outcomes in Japanese pregnant women. METHODS: Retrospective data were collected for 1970 Japanese women with singleton pregnancies who delivered between January 2007 and December 2011 at a single center: low SES group (n = 197); and controls (n = 1773). Low SES was defined according to the criteria of the Japanese pregnant-childbirth hospitalization support policy system. RESULTS: The low SES group included a significantly higher proportion of young women, women with single marital status, greater parity, pre-pregnancy smoking and a lack of regular employment (P < 0.001, respectively). The crude odds ratio (OR) for the association between low maternal SES and SGA was 1.80 (95% confidence interval [CI] 1.15-2.82, P = 0.010). After adjustment for baseline maternal age, parity, body mass index, smoking and gestational weight gain, the adjusted OR for the association between low maternal SES and SGA was 1.92 (95% CI 1.17-3.17, P = 0.010). No significant association was found between maternal SES and PTB. CONCLUSION: The present results suggest that low maternal SES is associated with SGA births in the Japanese population. Mitigation of low maternal SES could be urgent public health to prevent disadvantage birth outcome.
  • Yamamura S, Yamaguchi K, Hayashi I, Nagai N, Sakane N, Ikeda A, Takakura M, Emoto I, Ujita M, Kawasaki K, Abiko K, Takao Y, Takakura K, Konishi I
    Clinical and Experimental Obstetrics &amp; Gynecology, 47(6) 920-920, 2020  Peer-reviewed
  • Satomi Minato-Inokawa, Ikuyo Hayashi, Shinsuke Nirengi, Ken Yamaguchi, Kenji Takakura, Naoki Sakane, Narumi Nagai
    Journal of nutritional science and vitaminology, 66(3) 246-254, 2020  Peer-reviewedCorresponding author
    Being born with large birthweight is considered as a risk of non-communicable diseases later in life. However, it is not fully understood what kind of maternal dietary intake during pregnancy affect large birthweight. Therefore, we examined the association of dietary intakes and its changes during pregnancy with large-for-gestational-age (LGA) births in Japanese pregnant women. In the prospective study, 245 pregnant women who visited Kyoto Medical Center were enrolled. Nutrition survey using brief-type self-administered diet history questionnaire (BDHQ) at all trimester was completed in 171 pregnant women. Based on birthweight and gestational age, participants were divided into three groups, such as small-for-gestational-age (<10th, SGA, n=17), appropriate-for-gestational-age (≥10th and <90th, AGA, n=144), and LGA (≥90th, n=10) groups. Compared with those without LGA births, mothers with LGA births showed: 1) greater weight gain during pregnancy (LGA: 14.0±3.2 kg, AGA: 9.9±3.9 kg, SGA: 8.4±3.1 kg, p<0.05); 2) higher energy intake throughout pregnancy (LGA: 310±368 kcal, AGA: 7±490 kcal, SGA: -97±293 kcal, ptrend<0.05); 3) larger changes in plant oil and sucrose consumptions from the 1st to 2nd trimester, probably due to the results of greater consumption of bread, Western confectionery, Japanese confectionery, and mayonnaise and dressing during the same period (ptrend<0.05, respectively). Our results suggest that higher energy intake throughout pregnancy, as well as greater consumption of plant oil and sucrose from the first to second trimester could be associated with LGA births.
  • The Japanese Journal of Nutrition and Dietetics, 77(Supplement) S1-S2, Dec 1, 2019  Peer-reviewed
  • Hisami Okumura, Tomomi Nagahata, Yuya Asami, Noriyo Kimura, Narumi Nagai
    The Japanese Journal of Nutrition and Dietetics., 77(Suppl) S35-S43, Dec, 2019  Peer-reviewedLast author
  • Tomomi Nagahata, Yuya Asami, Hisami Okumura, Noriyo Kimura, Narumi Nagai
    The Japanese Journal of Nutrition and Dietetics., 77(Suppl) S26-S34, Dec, 2019  Peer-reviewedLast author
  • Yuya Asami, Hisami Okumura, Noriyo Kimura, Tomomi Nagahata, Narumi Nagai
    Japanese Journal of Nutrition and Dietics, 77(Suppl) S15-S25, Dec, 2019  Peer-reviewedLast author
  • 湊 聡美, 二連木 晋輔, 林 育代, 山口 建, 高倉 賢二, 坂根 直樹, 永井 成美
    日本臨床栄養学会雑誌, 41(2) 172-181, Dec, 2019  Peer-reviewedLast author
    【目的】パタチン様ホスホリパーゼ3(PNPLA3)遺伝子多型(rs738409、C/G)は、非アルコール性脂肪性肝疾患(NAFLD)発症と病態悪化に関連することが知られている。小児期以降では、本遺伝子多型のGG型と食事中のn-6/n-3比との相互作用がNAFLD発症リスクとなるとの報告があるが、妊娠期における影響は不明な点が多い。そこで日本人妊婦において、PNPLA3遺伝子多型と食事中のn-6/n-3比の相互作用が妊娠中体重増加量に与える影響を検討した。【方法】日本人妊婦245人に、食物摂取頻度調査票を用いて妊娠初期、中期、後期の3回、食事調査を行った。基本情報や妊婦健診時の臨床・生化学データは診療録から得た。遺伝子多型解析は、TaqMan PCR法で行った。【結果】PNPLA3遺伝子多型の頻度はCC型0.232、CG型0.530、GG型0.238であった。GG型では、肝障害の指標であるALT値が妊娠後期時点でCG型より有意に高かった。またGG型において、妊娠後期のn-6/n-3比と妊娠中体重増加量が有意な正相関を示した。多変量解析から、妊娠後期のn-6/n-3比は、GG型の妊娠中体重増加量を規定する独立した因子であった。【結論】PNPLA3遺伝子GG型の日本人妊婦において、妊娠後期のn-6/n-3比が高い食事が妊娠中体重増加量を規定する要因の一つである可能性が示唆された。(著者抄録)
  • Narumi Nagai, Satomi Yagyu, Anna Hata, Shinsuke Nirengi, Kazuhiko Kotani, Toshio Moritani, Naoki Sakane
    Journal of clinical biochemistry and nutrition, 64(3) 224-230, May, 2019  Peer-reviewedLead authorCorresponding author
    Maslinic acid, derived from olive fruit, reduces pro-inflammation cytokines, which are involved in muscle fiber atrophy. Therefore, the maslinic acid ingestion may enhance the muscular response to resistance training through anti-inflammatory action. We therefore conducted a parallel, double-blind, randomized, placebo-controlled trial that examined whether a combination of maslinic acid supplementation and resistance training improve mobility functions in community-dwelling elderly persons. Over a 12-week period, 36 participants underwent moderate resistance training and are assigned to the maslinic acid supplementation (n = 17, 60 mg/day) or the placebo (n = 19) group. At baseline and at 12-weeks, we assessed body composition, grip strength, walking speed, leg strength, mobility functions, and knee pain scores. Following the 12-weeks, skeletal muscle mass, segmental muscle mass (right arm, left arm, and trunk) and knee pain score of the right leg were significantly improved in the maslinic acid group, while there was no change or parameters had worsened in the placebo group. Grip strength of the better side significantly increased only in the maslinic acid group. These results suggest that maslinic acid supplementation combined with moderate resistance training may increase upper muscle mass and grip strength, and reduce knee pain, could be effective for preventing mobility-related disability in elderly persons. Clinical trial registration number: UMIN000017207.
  • Satomi Minato, Naoki Sakane, Kazuhiko Kotani, Shinsuke Nirengi, Ikuyo Hayashi, Akiko Suganuma, Ken Yamaguchi, Kenji Takakura, Narumi Nagai
    Journal of clinical medicine research, 10(12) 904-910, Dec, 2018  Peer-reviewed
    Background: Polycystic ovary syndrome (PCOS) is a common endocrine disorder among reproductive-aged women. While PCOS is associated with an increased risk of obesity and insulin resistance, little is known regarding the prevalence of and risk factors for nonalcoholic fatty liver disease (NAFLD) among Japanese women with PCOS. We estimated the prevalence of and risk factors for elevated liver enzymes, as the index of NAFLD, in Japanese women with PCOS. Methods: We retrospectively reviewed 102 reproductive-aged women who visited the Department of Gynecology, Kyoto Medical Center in Japan from January 2000 to September 2016. Inclusion criterion was confirmed diagnosis of PCOS using International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10) codes. Exclusion criteria were women with a history of liver diseases, missing body mass index (BMI) and serum alanine aminotransferase (ALT) data, and pregnancy. Data regarding age; BMI; and levels of blood glucose, serum lipid, liver enzymes, and sex hormones were obtained from medical records. Elevated liver enzymes was defined as ALT > 19 IU/L. Optimal cutoffs for risk factors for elevated liver enzymes were calculated to determine predictors of elevated liver enzymes using area under the curve (AUC) by receiver-operating characteristics (ROC). Results: The prevalence of elevated liver enzymes was 33.3%. BMI was significantly higher in PCOS patients than in those without elevated liver enzymes (25.3 vs. 20.7 kg/m2, P < 0.05). ROC analyses were performed using BMI and blood glucose and testosterone levels because BMI and blood glucose showed differences between the groups and testosterone is related to fatty liver. AUC of the model including BMI and blood glucose and testosterone levels was 0.861 (sensitivity, 66.7%; specificity, 100%). Conclusions: These findings suggest that elevated liver enzymes are common in women with PCOS. An algorism using BMI and blood glucose and testosterone levels might be useful to determine elevated liver enzymes in women with PCOS. Our finding may be useful for the study of NAFLD among Japanese women with PCOS since several previous studies have indicated elevated liver enzymes to be related to the potential presence of NAFLD. Further examination, including abdominal ultrasonography and/or liver biopsy data, is required to confirm these results.
  • 井上紗奈, 本田秀仁, 森数馬, 山本(前田)万里, 椎名武夫, 曲山幸生, 永井成美, 和田有史
    認知科学, 25(1) 7‐25, Mar 1, 2018  Peer-reviewed
  • Narumi Nagai, Satomi Minato, Ikuyo Hayashi
    Journal of Japan Society for the Study of Obesity : 日本肥満学会誌, 24(1) 22-29, 2018  Invited
  • Koda H, Awaji Y, Uchida M, Nagai N
    J Jpn Soc Nutr Food Sci, 71(5) 243-250, 2018  Peer-reviewedLast authorCorresponding author
  • 能瀬陽子, 是兼有葵, 小谷和彦, 永井成美
    小児保健研究, 77(4) 355-363, 2018  Peer-reviewedLast authorCorresponding author
  • Inoue T, Kobayashi Y, Mori N, Sakagawa M, Xiao J, Moritani T, Sakane N, Nagai N
    Beneficial Microbes, 9(6) 843-853, 2018  Peer-reviewedLast authorCorresponding author
    Physical exercise exerts favourable effects on brain health and quality of life of the elderly; some of these positive health effects are induced by the modulation of microbiota composition. We therefore conducted a randomised, double blind, placebo-controlled trial that assessed whether a combination of Bifidobacterium spp. supplementation and moderate resistance training improved the cognitive function and other health-related parameters in healthy elderly subjects. Over a 12-week period, 38 participants (66-78 years) underwent resistance training and were assigned to the probiotic Bifidobacterium supplementation (n=20; 1.25×1010 cfu each of Bifidobacterium longum subsp. longum BB536, B. longum subsp. infantis M-63, Bifidobacterium breve M-16V and B. breve B-3) or the placebo (n=18) group. At baseline and at 12 weeks, we assessed the cognitive function, using the Japanese version of the Montreal Cognitive Assessment instrument (MoCA-J); modified flanker task scores; depression-anxiety scores; body composition; and bowel habits. At 12 weeks, the MoCA-J scores showed a significant increase in both the groups, while the flanker task scores of the probiotic group increased more significantly than those of the placebo group (0.35±0.9 vs -0.29±1.1, P=0.056). Only the probiotic group showed a significant decrease in the depression-anxiety scores (5.2±6.3 to 3.4±5.5, P=0.012) and body mass index (24.0±2.8 to 23.5±2.8 kg/m2, P<0.001), with a significant increase in the defecation frequency (5.3±2.3 to 6.4±2.3 times/5 days, P=0.023) at 12 weeks. Thus, in healthy elderly subjects, combined probiotic bifidobacteria supplementation and moderate resistance training may improve the mental condition, body weight and bowel movement frequency.
  • Maki Suzuki, Rie Kimura, Yasue Kido, Tomoko Inoue, Toshio Moritani, Narumi Nagai
    Appetite, 114 209-216, Jul 1, 2017  Peer-reviewedLast authorCorresponding author
    The color of food is known to modulate not only consumers' motivation to eat, but also thermal perception. Here we investigated whether the colors of hot soup can influence thermal sensations and body temperature, in addition to the food acceptability and appetite. Twelve young female participants consumed commercial white potage soup, modified to yellow or blue by adding food dyes, at 9 a.m. on 3 separated days. During the test, visual impression (willingness to eat, palatability, comfort, warmth, and anxiety) and thermal sensations were self-reported using visual analog scales. Core (intra-aural) and peripheral (toe) temperatures were continuously recorded 10 min before and 60 min after ingestion. Blue soup significantly decreased willingness to eat, palatability, comfort, and warmth ratings, and significantly increased anxiety feelings compared to the white and yellow soups. After ingestion, the blue soup showed significantly smaller satiety ratings and the tendency of lower thermal sensation scores of the whole body compared to the white and yellow soups. Moreover, a significantly greater increase in toe temperature was found with the yellow soup than the white or blue soup. In conclusion, this study provides new evidence that the colors of hot food may modulate postprandial satiety, thermal sensations and peripheral temperature. Such effects of color may be useful for dietary strategies for individuals who need to control their appetite.
  • Yoko Nose, Rina Fujinaga, Maki Suzuki, Ikuyo Hayashi, Toshio Moritani, Kazuhiko Kotani, Narumi Nagai
    Child's nervous system : ChNS : official journal of the International Society for Pediatric Neurosurgery, 33(4) 653-658, Apr, 2017  Peer-reviewedLast authorCorresponding author
    PURPOSE: Smartphones are prevalently used among adolescents; however, nighttime exposure to blue-enriched light, through electric devices, is known to induce delays of the circadian rhythm phases and poor morning somatic conditions. We therefore investigated whether evening smartphone use may affect sleep-wake cycle and cardiac autonomic nervous system (ANS) activity after awaking in dormitory students. METHODS: The participants were high school students, living under dormitory rules regarding the curfew, study, meals, lights-out, and wake-up times. The students were forbidden from the use of both television and personal computer in their private rooms, and only the use of a smartphone was permitted. According to prior assessment of smartphone use, we chose age-, sex-, exercise time-matched long (n = 22, >120 min) and short (n = 14, ≤60 min) groups and compared sleep-wake cycle and physiological parameters, such as cardiac ANS activity, blood pressure, and intra-aural temperature. All measurements were performed during 6:30 to 7:00 a.m. in the dormitories. RESULTS: Compared with the short group, the long group showed a significantly lower cardiac ANS activity (2727 ± 308 vs. 4455 ± 667 ms2, p = 0.030) with a tendency toward a high heart rate, in addition to later bedtimes during weekdays and more delayed wake-up times over the weekend. Blood pressure and intra-aural temperature did not differ between the groups. CONCLUSIONS: In this population, evening smartphone use may be associated with altered sleep-wake cycle and a diminished cardiac ANS activity after awakening could be affecting daytime activities.
  • hayashi I, Suzuki M, Nose Y, Minato S, Sumitomo A, Nirengi S, Tsuzaki K, Sakane N, Sumitomo M, Takakura K, Nagai N
    JASSO, 23(3) 233-240, 2017  Peer-reviewedLast authorCorresponding author
  • Mitsue Yamaguchi, Kazuhiko Kotani, Kokoro Tsuzaki, Naoko Motokubota, Naho Komai, Naoki Sakane, Toshio Moritani, Narumi Nagai
    Chronobiology international, 34(10) 1478-1482, 2017  Peer-reviewedLast authorCorresponding author
    The 3111T/C single nucleotide polymorphism (SNP) of Circadian Locomotor Output Cycles Kaput (CLOCK) gene reportedly affects gastric motility before breakfast. It is of interest to know whether this SNP can affect the motility during the daytime. We investigated the association between the CLOCK 3111T/C SNP and several gastric motility parameters during the time period from 8:00 to 20:00 in 34 young women with scheduled meals. There were similar daytime fluctuations in gastric motility before and after the meals between the major (T/T) and minor (T/C) allele carriers. The CLOCK SNP may affect daytime gastric motility less than food stimulation.
  • Maki Suzuki, Emi Mura, Ayako Taniguchi, Toshio Moritani, Narumi Nagai
    Journal of nutritional science and vitaminology, 63(3) 186-192, 2017  Peer-reviewedLast authorCorresponding author
    We previously reported that carbonated water ingestion induced fullness and gastric motility. In order to determine whether such satiating effects occur through oral carbonic stimulation alone, we conducted modified sham-feeding (SF) tests (carbonated water ingestion (CW), water ingestion (W), carbonated water sham-feeding (CW-SF), and water sham-feeding (W-SF)), employing an equivalent volume and standardized temperature of carbonated and plain water, in a randomized crossover design. Thirteen young women began fasting at 10 p.m. on the previous night and were loaded with each sample (15ºC, 250 mL) at 9 a.m. on separate days. Electrogastrography (EGG) recordings were obtained from 20 min before to 45 min after the loading to determine the power and frequency of the gastric myoelectrical activity. Appetite was assessed using visual analog scales. After ingestion, significantly increased fullness and decreased hunger ratings were observed in the CW group. After the load, transiently but significantly increased fullness as well as decreased hunger ratings were observed in the CW-SF group. The powers of normogastria (2-4 cpm) and tachygastria (4-9 cpm) showed significant increases in the CW and W groups, but not in the CW-SF and W-SF groups. The peak frequency of normogastria tended to shift toward a higher band in the CW group, whereas it shifted toward a lower band in the CW-SF group, indicating a different EGG rhythm. Our results suggest that CO2-induced oral stimulation is solely responsible for the feeling of satiety. Moreover, different gastric-contraction rhythms (slow or fast) were induced by oral carbonic stimulation alone and carbonated water ingestion.
  • 鈴木麻希, 大竹恵子, 永井成美, 永井成美
    子どもの心とからだ, 25(3) 202‐211, Nov 1, 2016  Last authorCorresponding author
  • Suzuki Maki, Izumi Anna, Mura Emi, Hayashi Ikuyo, Moritani Toshio, Nagai Narumi
    Nippon Eiyo Shokuryo Gakkaishi, 69(4) 163-171, 2016  Last authorCorresponding author
    <p>The aim of this study was to clarify differences in subjective appetite and gastric motility after ingestion of a solution of either a noncaloric artificial sweetener, sucralose (SR) , or sucrose (S) . Twelve young women began fasting at 10:00 pm on the previous night, then ingested SR and S, or plain water (W) as control, at equivalent temperature, volume (15℃, 150 mL) and sweetness at 9:00 am on different days. The subjects were administered the separate sweet samples (30 mL) orally and instructed to swallow after sufficient mixing in the mouth, which was repeated 5 times. For evaluation of sweet taste, the scores before ingestion, and during ingestion of the 1st and 5th cups of the sample were used. Electrogastrograms, electrocardiograms (heart rate) , and body temperatures were obtained 20 min before and 65 min after sample ingestion. Subjective appetite was evaluated before and every 15 min after ingestion. Both of the sweet-tasting samples, but especially SR, suppressed hunger immediately after ingestion, and postprandial subjective appetite increased according to the perceived sweetness (S and SR) . Differences in electrogastrogram responses were found after ingestion of S and SR; elevated HR was observed only after ingestion of S. Our results suggest that SR increases neither heart rate nor body temperature, but temporarily suppresses subjective appetite and alters gastric motility in comparison with S.</p>
  • Takagi Ayaka, Kishida Nana, Suzuki Maki, Takeda Kazuhiko, Kimura Rie, Nagai Narumi
    The Japanese Journal of Nutrition and Dietetics, 74(6) 165-173, 2016  Last authorCorresponding author
    Objective: A previous study on young women showed that, after ingestion of hot soup, palatability enhanced the sense of relief, and soup temperature was associated with postprandial body temperatures. However, the effect of sodium on such physiological responses remains unclear. Here, we studied the effect of sodium (amount for daily consumption) on the sense of relief, thermal sensations, and core/peripheral temperatures after ingestion of soup (S) or salt-free soup (SFS).<br>Methods: Twelve young women, who began fasting from the night before the examination day, were provided with S (Na 440 mg), SFS (Na 61 mg) or Blank (no soup) at 9 a.m. on 3 different days in a randomized order. Immediately after ingestion of soup (65&deg;C, 150 ml), palatability was self-recorded. Core (eardrum) and peripheral (fingertip and toe) temperatures and heart rate (HR) were measured 10 min before and 65 min after ingestion. Subjective parameters were self-reported before and every 15 min after ingestion (6 times) using questionnaires.<br>Results: Palatable score and postprandial toe-temperature were significantly higher after S than after SFS. Multiple regression analysis revealed associate of the increase in toe-temperature with palatable scores. Postprandial sense of relief, thermal sensations, core-temperatures, and HR were higher in S and SFS than in Blank, with no differences between S and SFS.<br>Conclusion: Sodium enhanced the palatability of soup, and may be associated with postprandial peripheral temperature. The remaining parameters showed similar changes after both S and SFS, suggesting a limited effect of sodium.
  • Nose Yoko, Hayashi Ikuyo, Fujinaga Rina, Suzuki Maki, Kotani Kazuhiko, Nagai Narumi
    The Japanese Journal of Nutrition and Dietetics, 74(6) 157-164, 2016  Last authorCorresponding author
    Objective: A previous study on female students with evening preference showed an attenuated activity of the cardiac autonomic nervous system (ANS) in morning and a fluctuated gastric motility caused by mealtime. We further examined the association of morning-evening (ME) preference with morning gastric motility and vital parameters in female high school students who have the same mealtime, as they live in a school dormitory.<br>Methods: Forty-one students were measured in terms of blood pressure, eardrum temperatures, electrocardiography (ECG), and electrogastrography for 10 min before breakfast at temporally setting measurement room in the dormitory. Cardiac ANS activity and averaged heart rate (HR) were calculated from the ECG. To evaluate fasting gastric motility (occurring 3 cycles/min), an action potential was derived from electrodes placed on the abdomen. Thereafter, power and peak frequency was analyzed by a power spectral analysis method. According to total ME scores, calculated from 10 questions (1-5 points, respectively), students were divided into morning (&ge; 28.5 [mean] points) or evening preference groups (< 28.5 points) and the parameters were compared between the groups.<br>Results: As compared to the morning preference group, the evening preference group showed 1) a significantly delayed wake-up time on both weekdays and weekends, 2) a significantly higher HR, and 3) a significantly higher frequency of gastric motility without any differences in gastric contraction power.<br>Conclusion: Female high school students with evening preference showed a high HR after awakening without a diminished gastric motility, possibly suggesting the occurrence of food anticipated activity induced by regular mealtime.
  • Mori K, Honda S, Nagai N, Wada Y
    JSHEP, 22 49-68, 2016  Peer-reviewed
  • Motokubota Naoko, Komai Naho, Suzuki Maki, Hayashi Ikuyo, Moritani Toshio, Nagai Narumi
    Nippon Eiyo Shokuryo Gakkaishi, 69(2) 65-74, 2016  Peer-reviewedLast authorCorresponding author
    Humans show individual differences of biological rhythm phase, and can be classified into the "morning type" (peak performance being achieved in the early part of the day) or the "evening type" (peak performance towards the end of the day) . We therefore hypothesized that evening-type individuals would show different daytime variations of autonomic nervous activity, gastric motility and appetite sensations, which are under the control of the biological clock. In this study, 34 young women began fasting at 22:00 h on the previous night and ate test meals at a pre-determined time on the test day. Electrogastrography, electrocardiography (cardiac autonomic nerve activity) , appetite sensations, sleepiness, and core (eardrum) temperature were measured from 8:00 to 20:00 h at 1-hour intervals. After completion of all measurements, the subjects completed a morningness-eveningness questionnaire, and were divided into morning- or evening-preference types. Evening-preference individuals demonstrated a higher heart rate, a predominance of sympathetic nerve activity and greater sleepiness in the daytime. Moreover, they had a significantly lower hunger score during the morning, and did not show a significant shift in the frequency of postprandial gastric motility as compared with morning-preference individuals. Our results suggest that an evening-preference lifestyle may be associated with attenuation of appetite and vitality during the morning.
  • Naho Komai, Naoko Motokubota, Maki Suzuki, Ikuyo Hayashi, Toshio Moritani, Narumi Nagai
    Journal of nutritional science and vitaminology, 62(5) 288-294, 2016  Peer-reviewedLast authorCorresponding author
    There is evidence to support that mastication may contribute to the prevention of weight gain via reduction of appetite sensations and subsequent energy intake. However, the metabolic effect of mastication after consumption of a daily meal, composed of the staple food (rice), soup, main and side dishes, is limited. Therefore, the effect of thorough mastication on greater satiety and the thermic effect of a meal (TEM) was investigated in young women. In study 1, energy expenditure (EE) derived from masticatory muscle activity for 20 min was measured while chewing hard, tasteless, non-caloric gum in seven subjects. In study 2, ten subjects consumed a solid meal performing 30 chews per mouthful (30 CPM), or swallowed the same, pureed meal without chewing (0 CPM) on two separate days, and postprandial EE, substrate oxidation, subjective appetite ratings and autonomic nervous system (ANS) activity for 3 h were examined. Both test meals were iso-caloric (2,510 kJ) and -weighted (884 g), and consumed in 20 min. From study 1, the EE of mastication itself for the 20 min was estimated to be 3.7±0.8 kJ. From study 2, significantly higher TEM (134.2±15.5 vs. 67.8±13.8 kJ/3 h, p<0.001) as well as satiety (p=0.005), and tendency toward greater fat oxidation (p=0.090) and ANS activity (p=0.069) were observed after consumption of the meal with 30 CPM compared to 0 CPM. In conclusion, thorough mastication before swallowing increased postprandial satiety and the TEM in young women, suggesting such eating behavior may be useful for preventing obesity.

Misc.

 29

Books and Other Publications

 22
  • Narumi Nagai, Rie Akamatsu (Role: Joint editor)
    Apr, 2022 (ISBN: 9784521742922)
  • Narumi NAGAI (Role: Contributor, Shift-work and chrono-nutrition)
    Jun, 2020
  • 赤松利恵, 永井成美 (Role: Joint editor)
    化学同人, 2020
  • 永井 成美 (Role: Contributor, 体内時計から見た青年期の課題と食育)
    杏林書院, Dec, 2019
  • 永井 成美 (Role: Contributor, きちんと食べるダイエット(第5章))
    ディジタルアーカイブス株式会社, Mar, 2018

Presentations

 26

Teaching Experience

 13

Research Projects

 11

Social Activities

 31

Media Coverage

 1