IMPORTANCE Epidemiological evidence regarding the long-term effects of higher dietary protein intake on mortality outcomes in the general population is not clear.OBJECTIVE To evaluate the associations between animal and plant protein intake and all-cause and cause-specific mortality. DESIGN, SETTING, AND PARTICIPANTSThis prospective cohort study included 70 696 participants in the Japan Public Health Center-based Prospective Cohort who were aged 45 to 74 years and had no history of cancer, cerebrovascular disease, or ischemic heart disease at study baseline. Data were collected from January 1, 1995, through December 31, 1999, with follow-up completed December 31, 2016, during which 12 381 total deaths were documented. Dietary intake information was collected through a validated food frequency questionnaire and used to estimate protein intake in all participants. Participants were grouped into quintile categories based on their protein intake, expressed as a percentage of total energy. Data were analyzed from July 18, 2017, through April 10, 2019. MAIN OUTCOMES AND MEASURESHazard ratios (HRs) and 95% CIs for all-cause and cause-specific mortality were estimated using Cox proportional hazards regression models with adjustment for potential confounding factors.RESULTS Among the 70 696 participants, 32 201 (45.5%) were men (mean [SD] age, 55.6 [7.6] years) and 38 495 (54.5%) were women (mean [SD] age, 55.8 [7.7] years). Intake of animal protein showed no clear association with total or cause-specific mortality. In contrast, intake of plant protein was associated with lower total mortality, with multivariable-adjusted HRs of 0.89 (95% CI, 0.83-0.95) for quintile 2; 0.88 (95% CI, 0.82-0.95) for quintile 3; 0.84 (95% CI, 0.77-0.92) for quintile 4; and 0.87 (95% CI, 0.78-0.96) for quintile 5, with quintile 1 as the reference category (P = .01 for trend). For cause-specific mortality, this association with plant protein intake was evident for cardiovascular disease (CVD)-related mortality (HRs, 0.84 [95% CI, 0.73-0.96] to 0.70 [95% CI, 0.59-0.83]; P = .002 for trend). Isocaloric substitution of 3% energy from plant protein for red meat protein was associated with lower total (HR, 0.66; 95% CI, 0.55-0.80), cancer-related (HR, 0.61; 95% CI, 0.45-0.82), and CVD-related (HR, 0.58; 95% CI, 0.39-0.86) mortality; substitution for processed meat protein was associated with lower total (HR, 0.54; 95% CI, 0.38-0.75) and cancer-related (HR, 0.50; 95% CI, 0.30-0.85) mortality. CONCLUSIONS AND RELEVANCEIn this large prospective study, higher plant protein intake was associated with lower total and CVD-related mortality. Although animal protein intake was not associated with mortality outcomes, replacement of red meat protein or processed meat protein with plant protein was associated with lower total, cancer-related, and CVD-related mortality.

ObjectiveTo evaluate the association between pre-diagnostic circulating vitamin D concentration and the subsequent risk of overall and site specific cancer in a large cohort study.DesignNested case-cohort study within the Japan Public Health Center-based Prospective Study cohort.SettingNine public health centre areas across Japan.Participants3301 incident cases of cancer and 4044 randomly selected subcohort participants.ExposurePlasma concentration of 25-hydroxyvitamin D measured by enzyme immunoassay. Participants were divided into quarters based on the sex and season specific distribution of 25-hydroxyvitamin D among subcohorts. Weighted Cox proportional hazard models were used to calculate the multivariable adjusted hazard ratios for overall and site specific cancer across categories of 25-hydroxyvitamin D concentration, with the lowest quarter as the reference.Main outcome measureIncidence of overall or site specific cancer.ResultsPlasma 25-hydroxyvitamin D concentration was inversely associated with the risk of total cancer, with multivariable adjusted hazard ratios for the second to fourth quarters compared with the lowest quarter of 0.81 (95% confidence interval 0.70 to 0.94), 0.75 (0.65 to 0.87), and 0.78 (0.67 to 0.91), respectively (P for trend=0.001). Among the findings for cancers at specific sites, an inverse association was found for liver cancer, with corresponding hazard ratios of 0.70 (0.44 to 1.13), 0.65 (0.40 to 1.06), and 0.45 (0.26 to 0.79) (P for trend=0.006). A sensitivity analysis showed that alternately removing cases of cancer at one specific site from total cancer cases did not substantially change the overall hazard ratios.ConclusionsIn this large prospective study, higher vitamin D concentration was associated with lower risk of total cancer. These findings support the hypothesis that vitamin D has protective effects against cancers at many sites.

The neuroticism and extraversion scales were associated with health behaviours and BMI differently. The neuroticism scale, but not the extraversion scale, was strongly associated with higher perception of stress, poorer perceived health, and lower satisfaction with life in a Japanese population.

Background: Evidence is limited regarding the association between low-carbohydrate diet (LCD) score and mortality among Asians, a population that consumes a large amount of carbohydrates. Objective: The present study examined the association between low-carbohydrate diet (LCD) score (based on percentage of energy as carbohydrate, fat, and protein) and the risk of total and cause-specific mortality among Asians. Design: This study was a prospective cohort study in Japan with follow-up for a median of 16.9 years involving 43008 men and 50646 women aged 45e75 years. Association of LCD score, LCD score based on animal sources of protein and fat, and LCD score based on plant sources of protein and fat with risk of mortality was assessed using Cox proportional hazards model. Results: A U-shaped association was observed between LCD score and total mortality: the multivariableadjusted hazard ratios (HRs) (95% CI) of total mortality for lowest through highest scores were 1.00, 0.95 (0.91, 1.01), 0.93 (0.88, 0.98), 0.93 (0.88, 0.98), and 1.01 (0.95, 1.07) (P-non-linearity <0.01). A similar association was found for mortality from cardiovascular disease (CVD) and heart disease. LCD score based on carbohydrate, animal protein, and animal fat also showed a U-shaped association for total mortality (P-nonlinearity <0.01). In contrast, LCD score based on carbohydrate, plant protein, and plant fat was linearly associated with lower total (HR, 0.89; 95% CI: 0.83, 0.94 for highest versus lowest quintile), CVD [0.82 (0.73, 0.92)], heart disease [0.83 (0.71, 0.98)], and cerebrovascular disease [0.75 (0.62, 0.91) mortality. Conclusions: Both LCD with high animal protein and fat and high-carbohydrate diet with low animal protein and fat were associated with higher risk of mortality. Meanwhile, LCD high in plant-based sources of protein and fat was associated with a lower risk of total and CVD mortality.

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Background: While several studies have provided support for a positive association between meat intake and colorectal neoplasia, the role of heterocyclic amines (HCA), which is hypothesized to underline this relation, has been less consistent. We evaluated the association of HCA intake with colorectal adenoma risk in a case-control study in a middle-aged Japanese population.Methods: Study subjects were 738 patients with adenoma and 697 controls who underwent total colonoscopy between 2004 and 2005 and responded to self-administered lifestyle and dietary questionnaires. HCA exposure concentration was estimated from meat and fish intake based on an HCA database that was validated against 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) values measured in human hair. Logistic regression models were used to estimate ORs and 95% confidence interval (CI) for the association between HCA and colorectal adenoma risk after adjusting for potential confounders.

The findings add to epidemiologic evidence for protective effects of soy foods and isoflavones in colorectal carcinogenesis.

Few studies have addressed the relation between dietary patterns and colorectal cancer in Japan. We investigated dietary patterns in relation to colorectal cancer risk in a community-based case -control study. The association with dietary patterns was also examined for different sites of colorectal cancer. Data were derived from the Fukuoka Colorectal Cancer Study, including 800 cases and 775 controls interviewed from September 2000 to December 2003. The cases were admitted to one of the participating hospitals for the first surgical treatment during this period. We identified dietary patterns using principal component analysis of intakes of twenty-nine items of food groups and specific foods. Quartile categories of each dietary pattern were used, and non-dietary lifestyle factors and total energy intake were adjusted for in the analysis. We identified three dietary patterns: prudent, high-fat and light-meal patterns. The prudent dietary pattern characterised by high intakes of vegetables, fruits, seafoods and soya foods showed a nearly significant protective association with the overall risk of colorectal cancer (trend P¼0·054), and it was statistically significantly related to a decreased risk of distal colon cancer (trend P¼ 0·002), but not to that of either proximal colon or rectal cancer. The high-fat and light-meal dietary patterns were not materially related to the overall or site-specific risk of colorectal cancer. In summary, a prudent dietary pattern was associated with a decreased risk of colorectal cancer, especially with that of distal colon cancer, in a fairly large case -control study in Japan. Dietary patterns: Colorectal cancer: Japanese population: Principal component analysisColorectal cancer is one of the most common cancers in the world, accounting for approximately 10 % of the incident cases of cancer (1)