BACKGROUND A high body-mass index (BMI, the weight in kilograms divided by the square of the height in meters) is associated with increased mortality from cardiovascular disease and certain cancers, but the precise relationship between BMI and all-cause mortality remains uncertain. METHODS We used Cox regression to estimate hazard ratios and 95% confidence intervals for an association between BMI and all-cause mortality, adjusting for age, study, physical activity, alcohol consumption, education, and marital status in pooled data from 19 prospective studies encompassing 1.46 million white adults, 19 to 84 years of age (median, 58). RESULTS The median baseline BMI was 26.2. During a median follow-up period of 10 years (range, 5 to 28), 160,087 deaths were identified. Among healthy participants who never smoked, there was a J-shaped relationship between BMI and all-cause mortality. With a BMI of 22.5 to 24.9 as the reference category, hazard ratios among women were 1.47 (95 percent confidence interval [CI], 1.33 to 1.62) for a BMI of 15.0 to 18.4; 1.14 (95% CI, 1.07 to 1.22) for a BMI of 18.5 to 19.9; 1.00 (95% CI, 0.96 to 1.04) for a BMI of 20.0 to 22.4; 1.13 (95% CI, 1.09 to 1.17) for a BMI of 25.0 to 29.9; 1.44 (95% CI, 1.38 to 1.50) for a BMI of 30.0 to 34.9; 1.88 (95% CI, 1.77 to 2.00) for a BMI of 35.0 to 39.9; and 2.51 (95% CI, 2.30 to 2.73) for a BMI of 40.0 to 49.9. In general, the hazard ratios for the men were similar. Hazard ratios for a BMI below 20.0 were attenuated with longer-term follow-up. CONCLUSIONS In white adults, overweight and obesity (and possibly underweight) are associated with increased all-cause mortality. All-cause mortality is generally lowest with a BMI of 20.0 to 24.9.

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IMPORTANCE Colorectal cancers are a leading cause of cancer mortality, and their primary prevention by diet is highly desirable. The relationship of vegetarian dietary patterns to colorectal cancer risk is not well established.OBJECTIVE To evaluate the association between vegetarian dietary patterns and incident colorectal cancers. DESIGN, SETTING, AND PARTICIPANTSThe Adventist Health Study 2 (AHS-2) is a large, prospective, North American cohort trial including 96 354 Seventh-Day Adventist men and women recruited between January 1, 2002, and December 31, 2007. Follow-up varied by state and was indicated by the cancer registry linkage dates. Of these participants, an analytic sample of 77 659 remained after exclusions. Analysis was conducted using Cox proportional hazards regression, controlling for important demographic and lifestyle confounders. The analysis was conducted between June 1, 2014, and October 20, 2014.EXPOSURES Diet was assessed at baseline by a validated quantitative food frequency questionnaire and categorized into 4 vegetarian dietary patterns (vegan, lacto-ovo vegetarian, pescovegetarian, and semivegetarian) and a nonvegetarian dietary pattern. MAIN OUTCOMES AND MEASURESThe relationship between dietary patterns and incident cancers of the colon and rectum; colorectal cancer cases were identified primarily by state cancer registry linkages.RESULTS During a mean follow-up of 7.3 years, 380 cases of colon cancer and 110 cases of rectal cancer were documented. The adjusted hazard ratios (HRs) in all vegetarians combined vs nonvegetarians were 0.78 (95% CI, 0.64-0.95) for all colorectal cancers, 0.81 (95% CI, 0.65-1.00) for colon cancer, and 0.71 (95% CI, 0.47-1.06) for rectal cancer. The adjusted HR for colorectal cancer in vegans was 0.84 (95% CI, 0.59-1.19); in lacto-ovo vegetarians, 0.82 (95% CI, 0.65-1.02); in pescovegetarians, 0.57 (95% CI, 0.40-0.82); and in semivegetarians, 0.92 (95% CI, 0.62-1.37) compared with nonvegetarians. Effect estimates were similar for men and women and for black and nonblack individuals.CONCLUSIONS AND RELEVANCE Vegetarian diets are associated with an overall lower incidence of colorectal cancers. Pescovegetarians in particular have a much lower risk compared with nonvegetarians. If such associations are causal, they may be important for primary prevention of colorectal cancers.

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Objective To validate a 204-item quantitative FFQ for measurement of nutrient intake in the Adventist Health Study-2 (AHS-2). Design Calibration study participants were randomly selected from the AHS-2 cohort by church, and then subject-within-church. Each participant provided two sets of three weighted 24 h dietary recalls and a 204-item FFQ. Race-specific correlation coefficients (r), corrected for attenuation from within-person variation in the recalls, were calculated for selected energy-adjusted macro- and micronutrients. Setting Adult members of the AHS-2 cohort geographically spread throughout the USA and Canada. Subjects Calibration study participants included 461 blacks of American and Caribbean origin and 550 whites. Results Calibration study subjects represented the total cohort very well with respect to demographic variables. Approximately 33 % were males. Whites were older, had higher education and lower BMI compared with blacks. Across fifty-one variables, average deattenuated energy-adjusted validity correlations were 0·60 in whites and 0·52 in blacks. Individual components of protein had validity ranging from 0·40 to 0·68 in blacks and from 0·63 to 0·85 in whites; for total fat and fatty acids, validity ranged from 0·43 to 0·75 in blacks and from 0·46 to 0·77 in whites. Of the eighteen micronutrients assessed, sixteen in blacks and sixteen in whites had deattenuated energy-adjusted correlations ≥0·4, averaging 0·60 and 0·53 in whites and blacks, respectively. Conclusions With few exceptions validity coefficients were moderate to high for macronutrients, fatty acids, vitamins, minerals and fibre. We expect to successfully use these data for measurement error correction in analyses of diet and disease risk.

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The Adventist Health Study is a prospective cohort study of 34,198 non-Hispanic white Seventh-day Adventists (13,857 men; 20,341 women, age 25-100 years) followed for 6 years (1977-1982). Within this population, 55.2% were lacto-ovovegetarian (consumed meat, poultry, or fish less than one time per week with no restrictions as to egg or dairy product consumption) in 1976 and most abstained from alcohol, tobacco, and pork products. Baseline data included demographic variables, information on current and past dietary habits, exercise patterns, use of prescription drugs, use of alcohol and tobacco, measures of religiosity, occupation and residential histories, anthropometric data, and menstrual and reproductive histories. Nonfatal case ascertainment was completed through review of self-reported hospitalizations obtained from annual self-administered mailed questionnaires and through computerized record linkage with two California population-based tumor registries. Fatal case ascertainment was completed via record linkage with computerized California state death certificate files, the National Death Index, and individual follow-up. During the 6 years of follow-up, 52.8% of the 34,198 study subjects reported at least one hospitalization. A total of 20,702 medical charts were reviewed for cancer and cardiovascular disease incidence and 1406 incident cancer cases and 2716 deaths from all causes were identified after baseline data collection.Cancer 64570-581, 1989.EVENTH-DAY ADVENTISTS (SDA) represent a unique S population in which to study the relationship between lifestyle (including dietary habits) and chronic disease. This conservative religious group prohibits the use of alcohol, tobacco, and pork and strongly recommends that members adhere to a lacto-ovovegetarian diet. In 1976, 55.2% of California SDA were lacto-ovovegetarian and many of the remainder ate relatively little meat. Lacto-ovovegetarianism was defined as consumption of meat, poultry, or fish less than once per week as we believed this level of consumption was not biologically important in the possible etiology of specific diseases. There were insufficient numbers of pure vegetarians (vegans: no consumption of animal products) to justify separate analyses. Furthermore, approximately 50% are adult converts

The purpose of this study was to evaluate the relationship of long-term concentrations of ambient air pollutants and risk of incident lung cancer in nonsmoking California adults. A cohort study of 6,338 nonsmoking, non-Hispanic, white Californian adults, ages 27-95, was followed from 1977 to 1992 for newly diagnosed cancers. Monthly ambient air pollution data were interpolated to zip code centroids according to home and work location histories, cumulated, and then averaged over time. The increased relative risk (RR) of incident lung cancer in males associated with an interquartile range (IQR) increase in 100 ppb ozone (O3) was 3.56 [95% confidence interval (CI), 1.35-9.42]. Incident lung cancer in males was also positively associated with IQR increases for mean concentrations of particulate matter <10 microm (PM10; RR = 5.21; CI, 1.94-13.99) and SO2 (RR = 2.66; CI, 1.62-4.39). For females, incident lung cancer was positively associated with IQR increases for SO2 (RR = 2.14; CI, 1.36-3.37) and IQR increases for PM10 exceedance frequencies of 50 microg/m3 (RR = 1.21; CI, 0.55-2.66) and 60 microg/m3 (RR = 1.25; CI, 0.57-2.71). Increased risks of incident lung cancer were associated with elevated long-term ambient concentrations of PM10 and SO2 in both genders and with O3 in males. The gender differences for the O3 and PM10 results appeared to be partially due to gender differences in exposure.