The objective of this study was to evaluate the validity and reproducibility of a self-administered food frequency questionnaire (FFQ) to estimate nutrient and food intake in the subjects of the Japan Public Health Center-based prospective Study on Cancer and Cardiovascular Diseases (JPHC Study Cohort II). The FFQ was originally developed to estimate intake in the JPHC Study Cohort I. A total of 392 subjects were recruited from the entire cohort participants in the 6 areas of Cohort II on a voluntary basis. The subjects completed the FFQ used for the 5-year follow-up survey twice at approximately a 1-year interval. Seven-day dietary records (DR) and blood samples were collected 4 times at 3-month intervals over a year. Daily nutrient and food intakes from FFQ and DR were estimated. The Spearman correlation coefficients for estimated intakes were calculated between FFQ and DR for validity, and between 2 identical FFQs for reproducibility. Correlation coefficients for the validity ranged from 0.09 to 0.82 among various nutrients and food groups. The correlation coefficients for most of the nutrients and food groups were improved to a level comparable to that of Cohort I by energy-adjustment. Correlation coefficients for reproducibility ranged from 0.42 to 0.82, similar to those of Cohort I.

In the Japanese population, habitual coffee drinking may be associated with reduced risk of HCC.

Heated tobacco products (HTPs), such as IQOS, glo, and Ploom TECH, with a variety of flavored tobacco-containing inserts, have reportedly achieved a significant market share in Japan. We analyzed data from Wave 1 of the ITC Japan Survey, a nationally representative web survey conducted in February to March 2018 among 4684 adult participants to estimate the prevalence of HTP use, describe characteristics of HTP users, and explore user preferences for HTP device and flavor. The overall prevalence of monthly HTP use was 2.7% (1.7% daily use). Virtually all HTP users were current cigarette smokers (67.8%) or former smokers (25.0%); only 1.0% of HTP users were never smokers. Among HTP users, IQOS was the most frequently reported brand used (64.5%), and menthol was the most common flavor reported (41.5%). IQOS was used more by younger respondents and those who reported daily use, while Ploom TECH was more popular among older respondents and non-daily HTP users. This is one of the first non-industry funded studies to explore the use of HTPs in Japan.

To evaluate the hypothesis that, in terms of all-cause death, drinking alcohol 1-4 days per week is less harmful than daily (5-7 days/week) drinking of the same quantity of alcohol, a prospective cohort study using a self-administered questionnaire was conducted in Japan between 1990 and 2003 of 88,746 subjects (41,702 men and 47,044 women) aged 40-69 years at baseline. Among male regular drinkers consuming alcohol more than 1 day per week, light drinkers (<300 g/week) showed no increase in all-cause mortality irrespective of frequency of alcohol intake. Heavy drinkers (> or = 300 g/week), however, showed an increased risk of all-cause mortality among those who consumed alcohol 5-7 days per week, while no obvious increase was observed among those who consumed alcohol less than 4 days per week. Hazard ratios for drinkers who consumed alcohol 5-7 days per week were 1.29 (95% confidence interval: 1.12, 1.50) for 300-449 g per week and 1.55 (95% confidence interval: 1.32, 1.81) for > or = 450 g per week when compared with those for occasional drinkers who consumed alcohol 1-3 days per month. These findings support the Japanese social belief that "liver holidays," abstaining from alcohol for more than 2 days per week, are important for heavy drinkers.