High masticatory ability attenuates psychosocial stress: A cross-sectional study.

Mastication interventions have previously been shown to alleviate acute stress. However, the relationship between masticatory performance and stress response among individuals remains unclear. This study aimed to examine the relationship between masticatory ability and stress response in young women by measuring the autonomic nerve function and salivary α-amylase activity during psychosocial stress. Eighty women (aged 20.0 ± 1.9 years) were divided into either a low or high masticatory performance group, and the Trier Social Stress Test was conducted. Moreover, the autonomic function was measured at rest, immediately before stress, immediately after stress, and 10 min after stress. The salivary α-amylase activity was also measured at rest, 5 min after stress, and 15 min after stress. The visual analog scale (VAS) was used for subjective stress evaluation. There was a significant increase in the autonomic balance of both groups immediately before stress loading, but whilst the high masticatory ability group showed a return to resting-state levels after stress loading, the low masticatory ability group showed elevated levels after stress loading. Salivary α-amylase activity significantly increased 5 min after stress loading in the low, but not high, masticatory ability group. Furthermore, the VAS scores for tension and confusion after stress were significantly higher in the low masticatory ability group than in the high masticatory ability group. Our findings suggest that high masticatory performance may contribute to alleviating psychosocial stress. This is the first study to clarify the relationship between habitual masticatory performance and psychosocial stress suppression in young women.

The Relationship between Family Meals and Mental Health Problems in Japanese Elementary School Children: A Cross-Sectional Study.

The relative burden of mental health problems in children is increasing worldwide. Family meals have attracted attention as an effective modifiable factor for preventing children's mental health problems. We examined the relationship between family meals and mental health problems in Japanese elementary schoolchildren. A cross-sectional, self-administered questionnaire survey was conducted with guardians of children aged 7 to 12 years in Gifu Prefecture, Japan. Frequency of family meals and with whom the child eats breakfast, lunch, and dinner were assessed separately for weekdays and weekends/holidays. Mental health was assessed using the Japanese version of the parent-reported Strengths and Difficulties Questionnaire. Multivariate adjusted odds ratios (ORs) for borderline/abnormal mental health status were calculated using logistic regression analysis. Of the 678 children, 24.9% had borderline/abnormal mental health status. Children eating breakfast with their family less than once a week (adjusted OR, 4.79; 95% confidence interval (CI), 1.51-15.25) and those eating weekend breakfast alone (adjusted OR, 3.61; 95% CI, 1.42-9.23) had a higher prevalence of borderline/abnormal mental health status compared to those eating breakfast seven times a week and weekend breakfast with their family, respectively. These results suggest that family meals, especially breakfast, might be positively associated with better mental health in children.

Low energy intake and dietary quality are associated with low objective sleep quality in young Japanese women.

Literature reports suggest that subjective sleep quality is associated with nutrient intake in elderly people and workers. However, few studies have suggested an association between objective sleep quality and dietary intake in adolescents and young women. We hypothesized that objective sleep quality is associated with dietary intake in adolescents and young women. We evaluated the association between energy and nutrient intake and objective sleep quality in adolescents and young Japanese women. In a cross-sectional study of 80 women aged 18-27 years, dietary intake was assessed using the self-administered diet history questionnaire. Objective sleep quality was assessed by actigraphy. Lifestyle characteristics, dietary habits, and mental health were assessed using specific questionnaires. Subjects were classified into 3 groups according to sleep efficiency (SE <80%, 80%-85%, and ≥85%), and the relationships between dietary intake and objective sleep quality were statistically evaluated. No significant differences occurred in lifestyle characteristics, physical activity levels, eating behavior, and mental health status among the 3 SE groups. Energy intake was significantly lower in the low-SE group than in the middle- (P = .004) and high- (P = .015) SE groups. Protein intake was significantly lower in the low-SE group than in the high-SE group (P = .034). The mean energy-adjusted intakes of vitamin K, vitamin B2, potassium, magnesium, iron, zinc, copper, and tryptophan were significantly lower in the low-SE group than in the high-SE group. Adequate energy intake and a high-quality diet including vitamins, minerals, and tryptophan may result in high sleep quality and help prevent sleep problems.

Perceived 6-n-Propylthiouracil (PROP) Bitterness Is Associated with Dietary Sodium Intake in Female Japanese College Students.

Despite the negative health consequences of a high sodium consumption, humans consume well above the recommended levels. This study examines whether or not the dietary intake of sodium was affected by individual variation of the perceived bitterness of 6-n-propylthiouracil (PROP), and examines the relationship between the perceived bitterness of PROP and the preferred NaCl concentration of broth. Female students (20-22 y old) were recruited from the university community. Genotypes of A49P and I296V polymorphism of the TAS2R38 bitter taste receptor were determined for each subject. Samples containing NaCl, PROP or broth in 5-mL portions were evaluated by sensory testing. The participants completed a food record for each diet. Our results indicate that the individuals perceiving PROP to be more bitter had consumed a greater amount of dietary sodium. In contrast, there was no significant positive correlation between an individual's perceived saltiness and the dietary sodium intake. Those who perceived PROP to be more bitter preferred a broth containing a higher concentration of NaCl. All of these correlations were apparent even after those subjects with TAS2R38 AI/AI homozygotes (PROP non-taster) had been excluded. In conclusion, the results of this study suggest that a factor affecting the bitter rating of PROP other than the AI/AI homozygotes of TAS2R38 contributes to the variation in sodium intake and the preference for salty food.

Compared with the intake of commercial vegetable juice, the intake of fresh fruit and komatsuna (Brassica rapa L. var. perviridis) juice mixture reduces serum cholesterol in middle-aged men: a randomized controlled pilot study.

BACKGROUND: Vegetables and fruits are rich in vitamins, minerals and, dietary fiber and contribute to the prevention and improvement of obesity and metabolic syndrome. However, inadequate intake of vegetable and fruit is a concern in Japan.We therefore produced a juice mixture of fresh fruit and komatsuna (Brassica rapa L. var. perviridis: B. rapa) with the aim to investigate the effects of this juice mixture on anthropometric data, blood parameters, and dietary intake differences. METHODS: This study was performed as a single blind and randomized controlled trial. Subjects were 16 men (mean age, 46.4 ± 7.1 years), and they were divided into two groups (control group and intervention group). The intervention group consumed the juice mixture of fresh fruit and B. rapa. The control group consumed commercial vegetable juice. Subjects consumed juice twice a day throughout the weekday, for 4 weeks. We prepared both juices with an equivalent energy balance. RESULTS: Weight and body mass index (BMI) of the control group after 4 weeks were significantly increased compared with baseline values. Serum total cholesterol (T-Chol) and low-density lipoprotein cholesterol (LDL-Chol) of the intervention group after 4 weeks were significantly reduced compared with baseline values. Furthermore, intake of total vegetables and fruits were significantly increased compared with baseline values in both groups. CONCLUSIONS: Both vegetable juices contributed to improved intake of total vegetables and fruit. Compared with the intake of commercial vegetable juice, the intake of fresh fruit and B. rapa juice is highly effective in reducing serum cholesterol. Short-term intake of fresh fruit and B. rapa juice was shown to enhance cholesterol metabolism.

Short-term intake of a Japanese-style healthy lunch menu contributes to prevention and/or improvement in metabolic syndrome among middle-aged men: a non-randomized controlled trial.

BACKGROUND: Metabolic syndrome is now widely appreciated as a cluster of metabolic abnormalities such as visceral obesity, hypertension, hyperglycemia and dyslipidemia. To date, incidence of metabolic syndrome is continuously increasing worldwide.In addition, low vegetable consumption has recently become a serious issue in Japan. Furthermore, Japan is facing a shortfall in places offering food that can help prevent metabolic syndrome in the first place. Our study is designed to influence these developments. We conducted a non-randomized controlled trial by offering a Japanese-style healthy lunch menu to middle-aged men in a workplace cafeteria. This menu was designed to prevent and reduce metabolic syndrome. METHODS: This intervention study took the form of a non-randomized controlled trial. Participants chose the control or intervention group. The control group consumed their habitual lunches without restriction and only nutrient contents were assessed. The intervention group received a Japanese-style healthy lunch at a workplace cafeteria for 3 months. The participants worked in offices at a city hall and mostly had low levels of physical activity. Data of 35 males (control group: 7 males, intervention group: 28 males, mean age: 47.2 ± 7.9 years) were collected and analyzed. RESULTS: We obtained an effective outcome by demonstrating that ongoing intake of a Japanese-style healthy lunch decreased blood pressure and serum lipids and increased plasma ghrelin levels. The results grew more pronounced as intake of Japanese-style healthy lunches increased in frequency. CONCLUSIONS: This study presents new empirical data as a result of an original intervention program undertaken in Japan. A Japanese-style healthy lunch menu containing many vegetables consumed can help prevent and/or improve metabolic syndrome.

A case study on the association of variation of bitter-taste receptor gene TAS2R38 with the height, weight and energy intake in Japanese female college students.

One of the critical factors that determines individual differences in dietary behavior and nutritional status is the sensory-affecting quality of food, in particular its taste. Variation of one bitter taste receptor gene, TAS2R38, which is associated with the differential sensitivity to phenylthiocarbamide (PTC) and 6-n-propylthiouracil (PROP), has been demonstrated to affect the dietary intake pattern. A case study was performed to examine the association of the TAS2R38 genotypes/haplotypes with the body size (height, weight and BMI) and with the food and nutrient intake. Eighty-four college students, all females, with an age range of 18-21 y were recruited from the University of Shizuoka. The genotypes of two common single nucleotide polymorphisms in TAS2R38 (A49P and I296V) were determined by PCR-restriction fragment length polymorphism (RFLP) method. The height, weight and body mass index (BMI), and (in a subgroup of 47 subjects) food and nutrition intake estimated from 3 d of food recording, were compared between homozygotes for the PTC/PROP-nontaster haplotype (AI haplotype) and carriers with the PTC/PROP-taster haplotype (PV haplotype). The results show that the homozygotes with AI haplotype were taller and heavier than the carriers of PV haplotype, while BMI values were similar between them. The former group also had higher energy and carbohydrate intakes than the latter group. Neither vegetable nor dairy product intake was different between the homozygotes with AI haplotype and the carriers of PV haplotype. In conclusion, the PTC/PROP-nontaster TAS2R38 genotype/haplotype was associated with height and weight but not with BMI, which may in turn have influenced the energy and carbohydrate intakes.