Naohisa Shobako

Background: We developed novel Optimized Nutri-Dense Meals (Opti meals) for women based on Japanese dietary reference intakes (DRIs). We aimed to determine the effects of Opti meals on premenstrual disorder (PMD). Method: This pilot study was an open-label randomized controlled trial. One hundred women aged 20–45 years with PMD were enrolled in the study and randomly divided into two groups: habitual diet and intervention groups. In the intervention group, two meals per day for three menstrual cycles were replaced with Opti meals based on the Japanese DRIs. The Menstrual Distress Questionnaire (MDQ) and the Japanese version of the Daily Records of Severity of Problems Short-Form version (J-DRSP) served as the primary outcome measures. Sleep quality and several saliva and serum parameters were set as secondary outcomes. Result: The intervention group had lower MDQ total scores during the premenstrual (median [Q1–Q3]: 42.0 [23.8–64.0] versus 67.0 [44.0–90.5], p < 0.01) and menstrual (34.0 [23.0–53.0] versus 67.0 [35.0–76.5], p < 0.01) phases, as well as lower final J-DRSP total scores (17.25 [13.73–19.90] versus 22.0 [16.60–28.50], p < 0.01) than the habitual diet group. Some significant differences were observed in the sleep quality test; however, no significant differences were found in saliva or serum parameters at the end of the trial. Conclusion: Optimal meals based on the Japanese DRI may improve PMD symptoms. Trial registration: UMIN000052973, https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000060324 (3/12/2023).

Background/Objectives: Reducing visceral fat is a critical factor in preventing obesity-related health complications. In this study, we evaluated the effectiveness of our previously reported novel dietary intervention program, “Optimized Nutri-Dense Meals”, designed according to the Dietary Reference Intakes (DRIs) in Japan in reducing visceral fat. Method: This open-label, randomized controlled trial included 100 Japanese males with obesity or overweight. In total, 50 participants were assigned to a control group that continued their usual diets, and the other 50 consumed test meals twice per week for four weeks (test group). Result: The primary outcome, visceral fat area, significantly decreased in the test group compared to that in the control group (−7.5 cm², confidence interval [CI]: −14.3 to −0.6). In addition, we measured the changes in gut flora and work productivity. The abundance of Bifidobacterium (+1.5%, CI: 0.3–2.7) and Christensenellaceae (+0.4%, CI: 0.01–0.8) increased significantly in the test group compared with those in the control group. Work Limitation Questionnaire Japanese version scores representing presenteeism also significantly increased in the test group (+1.2 points, CI: 0.2–2.3) compared with the control group. Conclusions: These findings suggest that dietary interventions based on Japanese DRIs can effectively decrease visceral fat and improve health outcomes over the short term without the need for a complete dietary overhaul.

Reducing visceral fat is an important issue for obesity prevention. We previously reported a novel dietary intervention program using “Optimized Nutri-Dense Meals” based on the nutrients described in Dietary Reference Intakes in Japan. This open-label randomized controlled trial evaluated the visceral fat reducing effect of the program. In total, 100 Japanese obese/overweight male patients were recruited and divided into a control group that continued their usual diets and a test group that consumed test meals twice per weekday for four weeks. Visceral fat area, set as the primary outcome, was significantly decreased in the test group compared with the control group. Regarding other outcomes, the occupancy levels of some gut floras and presenteeism scores were significantly increased in the test group compared with the control group. These results indicate that dietary intervention based on the Dietary Reference Intakes can prevent visceral fat accumulation and contribute to the improvement of health, without the need for completely replacing the everyday diet.

During the 3 years of the COVID-19 pandemic, Japanese children had to live with strict mitigation measures at school, such as eating school lunches silently and wearing masks during physical exercise classes, even after those mitigation measures have been relaxed worldwide. Excursions and other school events were frequently cancelled, especially in 2020 and 2021. This study conducts a retrospective survey on school experiences to understand how the strict mitigation measures were related to children's mental health and well-being. Results revealed school excursion cancellation to be associated with a higher risk of developing depressive symptoms {odds ratio [OR] 1.543 [95% confidence interval (CI) 1.109–2.148]}, and high cancellation rate of other school events to be associated with dissatisfaction in school experience [OR 1.650 (95% CI 1.222–2.228)]. In the subsample analysis, we found that girls and children with no extracurricular activities tended to exhibit depressive symptoms due to the cancellation of school excursions. Overall, the study demonstrated that persistent strict mitigation measures at schools might be a key factor in understanding children’s mental health and psychological well-being during a long-lasting pandemic.

Numerous studies have investigated healthy diets and nutrients. Governments and scientists have communicated their findings to the public in an easy-to-understand manner, which has played a critical role in achieving citizens’ well-being. Some countries have published dietary reference intakes (DRIs), whereas some academic organizations have provided scientific evidence on dietary methods, such as traditional diets. Recently, more user-friendly methods have been introduced; the Health Star Rating system and Optimized Nutri-Dense Meals are examples from Australia and Japan, respectively. Both organizations adopt a novel approach that incorporates nudges. This review summarizes the science communication regarding food policies, guidelines, and novel methods in Japan and other countries. In the food policies section, we discuss the advantages and disadvantages of the DRIs and food-based guidelines published by the government. Dietary methods widely known, such as The Mediterranean diet, Nordic diet, Japanese traditional diet, and the EAT-Lancet guidelines, were also reviewed. Finally, we discussed future methods of science communications, such as nudge.

Frailty is a huge concern for the aging population, and dietary nutrition is considered a key factor in the prevention of aging. To solve the problem of frailty in the aging population, we developed a novel dietary intervention program using a novel COMpletely Balanced for Frailty Prevention (COMB-FP) meal, based on the Dietary Reference Intake for Japanese; in addition, we conducted a pilot randomized control trial comparing an exercise program only (control group) with exercise plus the COMB-FP meal program (test group). We included 110 male and female healthy volunteers with pre-frailty or frailty; the trial lasted for 12 weeks. Two daily meals were replaced with the COMB-FP meals during the trial in the test group. Walking speed and cognitive function were significantly improved in the test group compared with the control group. We observed a similar pattern in other frailty-related outcomes, such as occupancy of the microbiome, World Health Organization well-being index (WHO-5), and oxidative stress. Our study might indicate the importance of a well-balanced intake of nutrients for frailty prevention.

Many people eat polished rice, while rice bran, a by-product known to be rich in protein and expected to have potential functions for health benefits, has not been effectively utilized. In this study, we determined that orally administered Val-Tyr-Thr-Pro-Gly (VYTPG) derived from rice bran protein improved cognitive decline in mice fed a high-fat diet (HFD). It was demonstrated that VYTPG was released from model peptides corresponding to fragment sequences of original rice proteins (Os01g0941500, Os01g0872700, and allergenic protein) after treatment with thermolysin, a microorganism-derived enzyme often used in industrial scale processes. The thermolysin digest also improved cognitive decline after oral administration in mice. Because VYTPG (1.0 mg/kg) potently improved cognitive decline and is enzymatically produced from the rice bran, we named it rice-memolin. Next, we investigated the mechanisms underlying the cognitive decline improvement associated with rice-memolin. Methyllycaconitine, an antagonist for α7 nicotinic acetylcholine receptor, suppressed the rice-memolin-induced effect, suggesting that rice-memolin improved cognitive decline coupled to the acetylcholine system. Rice-memolin increased the number of 5-bromo-2’-deoxyuridine (BrdU)-positive cells and promoted the mRNA expression of EGF and FGF-2 in the hippocampus, implying that these neurotropic factors play a role in hippocampal neurogenesis after rice-memolin administration. Epidemiologic studies demonstrated that diabetes is a risk factor for dementia; therefore, we also examined the effect of rice-memolin on glucose metabolism. Rice-memolin improved glucose intolerance. In conclusion, we identified a novel rice-derived peptide that can improve cognitive decline. The mechanisms are associated with acetylcholine and hippocampal neurogenesis. Rice-memolin is the first rice-brain-derived peptide able to improve cognitive decline.

It is everyone's desire to seek the sound growth of children through food education and there is a critical need for fostering an environment for this purpose. Health policies are important for this support. To the present, the Japanese society has been greatly disrupted by COVID-19 pandemic. “Stay at home”, “mokusyoku (silent eating)”, and mask wearing were encouraged in nationwide campaigns as public health measures to combat COVID-19. There are some papers reporting negative effects of “stay at home” and lockdowns such as weight gain, decrease in physical activities and change in eating habits. In Japan, while benefits and advantages of food education during mealtime were previously well studied, the “mokusyoku” rule may directly run counter to this food education. Moreover, there are several reports showing that nutrients might contribute to prevention of infectious diseases. Japanese children were also encouraged to wear masks all day long. The results of the clinical research, especially randomized control trials, show limited protective effect of masks. On the other hand, negative outcomes of the masks were reported in various scenes. This review focuses on these topics and arousing reconsideration for a better environment for children.