Published papers

Food intake biomarkers can be critical tools that can be used to objectively assess dietary exposure for both epidemiological and clinical nutrition studies. While an accurate estimation of food intake is essential to unravel associations between the intake and specific health conditions, random and systematic errors affect self-reported assessments. This study aimed to clarify how habitual food intake influences the circulating plasma metabolome in a free-living Japanese regional population and to identify potential food intake biomarkers. To achieve this aim, we conducted a cross-sectional analysis as part of a large cohort study. From a baseline survey of the Tsuruoka Metabolome Cohort Study, 7, 012 eligible male and female participants aged 40-69 years were chosen for this study. All data on patients' health status and dietary intake were assessed via a food frequency questionnaire, and plasma samples were obtained during an annual physical examination. Ninety-four charged plasma metabolites were measured using capillary electrophoresis mass spectrometry, by a non-targeted approach. Statistical analysis was performed using partial-least-square regression. A total of 21 plasma metabolites were likely to be associated with long-term food intake of nine food groups. In particular, the influential compounds in each food group were hydroxyproline for meat, trimethylamine- N-oxide for fish, choline for eggs, galactarate for dairy, cystine and betaine for soy products, threonate and galactarate for carotenoid-rich vegetables, proline betaine for fruits, quinate and trigonelline for coffee, and pipecolate for alcohol, and these were considered as prominent food intake markers in Japanese eating habits. A set of circulating plasma metabolites was identified as potential food intake biomarkers in the Japanese community-dwelling population. These results will open the way for the application of new reliable dietary assessment tools not by self-reported measurements but through objective quantification of biofluids.

Background: Health literacy (HL) has gained increasing attention as a factor related to health behaviors and outcomes. This study aimed to investigate geographic differences in HL levels and effect modification by geographic area on their relationship with self-rated health in the Japanese population using a nationwide sample. Methods: Data for this study were derived from a nationally representative cross-sectional survey on health information access for consumers in Japan using a mailed self-administered questionnaire in 2020 (INFORM Study 2020). Valid responses from 3,511 survey participants, selected using two-stage stratified random sampling, were analyzed in this study. HL was measured using the Communicative and Critical Health Literacy Scale (CCHL). Multiple regression and logistic regression analyses were conducted to examine the associations between geographic characteristics and HL and effect modification on the association between HL and self-rated health by geographic area, controlling for sociodemographic characteristics. Results: The mean HL score was 3.45 (SD = 0.78), somewhat lower compared with previous studies on the Japanese general population. HL was higher in Kanto area than in Chubu area, after controlling for sociodemographic factors and municipality size. Furthermore, HL was positively associated with self-rated health after controlling for sociodemographic and geographic factors; however, this association was more evident in eastern areas than in western areas. Conclusion: The findings indicate geographic differences in HL levels and effect modification by geographic area on the relationship between HL and self-rated health in the general Japanese population. HL was more strongly associated with self-rated health in eastern areas than in western areas. Further investigation is needed to explore the moderating effects of areal features, including the distribution of primary care physicians and social capital, when formulating strategies to improve HL in different contexts.

Background: Alcohol use is a serious public health challenge worldwide. Japan has no government regulations or legal penalties against advertising alcoholic beverages on television (TV). Instead, advertisements depend on the Japanese alcohol industry’s self-regulation on airtime (no advertisements from 5 am to 6 pm) and the content of alcoholic beverages, which must not tempt minors. However, many adolescents (10 to 19 years old) watch TV from 6 pm to 11 pm. The aim of this study was to describe the pattern in the advertising of alcoholic beverages and alcohol-flavoured non-alcoholic beverages (AFNAB) in Japan during the popular TV viewing time for adolescents. Methods: A secondary analysis of advertising airtime data from five free-to-air Japanese TV networks in the Greater Tokyo area that aired between 12 August and 3 November 2019, was performed. Results: During the study period, 5215 advertisements for alcoholic beverages and AFNABs aired (1451.75 min). In total, 2303 advertisements (44.2%) were beer, low-malt beer, or beer-taste beverages, 277 (5.3%) were whisky, 2334 (44.8%) were local alcoholic beverages (shochu and seishu), and 301 (5.8%) were AFNAB. On average, more advertisements aired on weekends (67.6 advertisements) than on weekdays (59.3 advertisements) per day. Approximately 30% of advertisements for AFNABs were aired during the time restricted for alcohol advertising, although AFNABs are considered alcohol according to industry guidelines. During the popular television viewing time for young adolescents, about two to three times more advertisements were aired per hour than during the rest of the day, on both weekdays and weekends (p < 0.001). Conclusion: The number of alcohol advertisements aired at times when adolescents often watch TV is 2 to 3.2 times higher than that at other times of the day. Furthermore, despite the industry’s self-imposed regulations, some alcoholic beverages are still advertised. Therefore, other methods to protect children and adolescents from exposure to advertisements for alcoholic beverages should be investigated and implemented.

Purpose: We examined cancerscreening practices and related beliefs in cancer survivors and individuals with family or close friends with a cancer diagnosis compared to individuals without the above cancer history for 5 population-based (gastric, colorectal, lung, breast, cervical) and 1 opportunistic (prostate) cancer screenings using nationally representative cross-sectional survey in Japan. Methods: We analyzed 3269 data from 3605 respondents (response rate, 37.1%) and compared the screening beliefs and practices of cancer survivors (n = 391), individuals with family members (n = 1674), and close friends with a cancer diagnosis (n = 685) to those without any cancer history (n = 519). Results: Being a cancer survivor was associated with screening for gastric (OR, 1.75; 95% CI, 1.04–2.95), colorectal (OR, 1.56; 95% CI, 1.03–2.36), and lung cancer (OR, 1.71; 95% CI, 1.10–2.66) but not breast, cervical cancer or PSA test. Having a family cancer diagnosis was associated with colorectal and lung cancer screening. Having friends with a cancer diagnosis was associated with PSA test. Cancer survivors and family members perceived themselves as being more susceptible and worried about getting cancer than individuals without any cancer history. Cancer survivors strongly believed screening can detect cancer and were more likely to undergo screening. Subgroup analysis indicated an interrelation between gastric and colorectal cancer screening among survivors. Conclusions: A cancer diagnosis in oneself or family or friend influences an individual’s health-related belief and risk perception, which can increase the likelihood of cancer screening. Implications for Cancer Survivors: Targeted and tailored communication strategies can increase awareness of cancer screening.