Red and processed meat, nitrite, and heme iron intakes and postmenopausal breast cancer risk in the NIH-AARP Diet and Health Study.

Previous studies have shown inconsistent associations between red and processed meat intake and breast cancer risk. N-nitroso compounds and heme iron have been hypothesized as contributing factors. We followed 193,742 postmenopausal women in the NIH-AARP Diet and Health Study and identified 9,305 incident breast cancers (1995-2006). Dietary intake was assessed using a food frequency questionnaire at baseline. We adjusted daily intakes of meat, nitrite and heme iron for energy intake using the nutrient density method. We estimated multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) by quintiles of dietary exposures for all breast cancer, by stage (in-situ, localized, regional/distant) and by estrogen/progesterone receptor (ER/PR) status using Cox proportional hazards regression. Total red meat intake was positively associated with risk of regional/distant cancer (p-trend = 0.02). The risk was 25% higher in the highest vs. lowest intake quintile (95% CI = 1.03-1.52). Higher processed red meat intake (Q5 vs. Q1) was associated with 27% higher risk of localized breast cancer (95% CI = 1.01-1.27, p-trend = 0.03) and a 19% higher risk of regional/distant cancer (95% CI = 0.98-1.44, p-trend = 0.10). In addition, higher nitrite intake from processed red meat was positively associated with localized cancer (HR for Q5 vs. Q1 = 1.23, 95% CI = 1.09-1.39, p-trend < 0.0001). Heme iron intake was positively associated with breast cancer risk overall and all cancer stages (p-trend = 0.02-0.05). No heterogeneity was observed in risk associations by hormone receptor status. Our findings suggest that high consumption of red meat and processed meat may increase risk of postmenopausal breast cancer. Added nitrite and heme iron may partly contribute to these observed associations.

Inoue-Choi M ，Sinha R ，Gierach GL ，Ward MH ... -  《-》

Are meat and heme iron intake associated with pancreatic cancer? Results from the NIH-AARP diet and health cohort.

Several studies on pancreatic cancer have reported significant positive associations for intake of red meat but null associations for heme iron. We assessed total, red, white and processed meat intake, meat cooking methods and doneness and heme iron and mutagen intake in relation to pancreatic cancer in the NIH-AARP Diet and Health Study cohort. A total of 322,846 participants (187,265 men and 135,581 women) successfully completed and returned the food frequency questionnaire between 1995 and 1996. After a mean follow-up of 9.2 years (up to 10.17 years), 1,417 individuals (895 men and 522 women) developed exocrine pancreatic cancer. Cox proportional hazard models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs), and trends were calculated using the median value of each quantile. Models incorporated age as the time metric and were adjusted for smoking history, body mass index, self-reported diabetes and energy-adjusted saturated fat. Pancreatic cancer risk significantly increased with intake of total meat (Q5 vs. Q1: HR = 1.20, 95% CI 1.02-1.42, p-trend = 0.03), red meat (HR = 1.22, 95% CI 1.01-1.48, p-trend = 0.02), high-temperature cooked meat (HR = 1.21, 95% CI 1.00-1.45, p-trend = 0.02), grilled/barbequed meat (HR = 1.24, 95% CI 1.03-1.50, p-trend = 0.007), well/very well done meat (HR = 1.32, 95% CI 1.10-1.58, p-trend = 0.005) and heme iron from red meat (Q4 vs. Q1: HR = 1.21, 95% CI 1.01-1.45, p-trend = 0.04). When stratified by sex, these associations remained significant in men but not women except for white meat intake in women (HR = 1.33, 95% CI 1.02-1.74, p-trend = 0.04). Additional studies should confirm our findings that consuming heme iron from red meat increases pancreatic cancer risk.

Taunk P ，Hecht E ，Stolzenberg-Solomon R 《-》

Mortality from different causes associated with meat, heme iron, nitrates, and nitrites in the NIH-AARP Diet and Health Study: population based cohort study.

Objective To determine the association of different types of meat intake and meat associated compounds with overall and cause specific mortality.Design Population based cohort study.Setting Baseline dietary data of the NIH-AARP Diet and Health Study (prospective cohort of the general population from six states and two metropolitan areas in the US) and 16 year follow-up data until 31 December 2011.Participants 536 969 AARP members aged 50-71 at baseline.Exposures Intake of total meat, processed and unprocessed red meat (beef, lamb, and pork) and white meat (poultry and fish), heme iron, and nitrate/nitrite from processed meat based on dietary questionnaire. Adjusted Cox proportional hazards regression models were used with the lowest fifth of calorie adjusted intakes as reference categories.Main outcome measure Mortality from any cause during follow-up.Results An increased risk of all cause mortality (hazard ratio for highest versus lowest fifth 1.26, 95% confidence interval 1.23 to 1.29) and death due to nine different causes associated with red meat intake was observed. Both processed and unprocessed red meat intakes were associated with all cause and cause specific mortality. Heme iron and processed meat nitrate/nitrite were independently associated with increased risk of all cause and cause specific mortality. Mediation models estimated that the increased mortality associated with processed red meat was influenced by nitrate intake (37.0-72.0%) and to a lesser degree by heme iron (20.9-24.1%). When the total meat intake was constant, the highest fifth of white meat intake was associated with a 25% reduction in risk of all cause mortality compared with the lowest intake level. Almost all causes of death showed an inverse association with white meat intake.Conclusions The results show increased risks of all cause mortality and death due to nine different causes associated with both processed and unprocessed red meat, accounted for, in part, by heme iron and nitrate/nitrite from processed meat. They also show reduced risks associated with substituting white meat, particularly unprocessed white meat.

Etemadi A ，Sinha R ，Ward MH ，Graubard BI ，Inoue-Choi M ，Dawsey SM ，Abnet CC ... -  《BMJ-British Medical Journal》

Intakes of dietary iron and heme-iron and risk of postmenopausal breast cancer in the National Institutes of Health-AARP Diet and Health Study.

Kabat GC ，Cross AJ ，Park Y ，Schatzkin A ，Hollenbeck AR ，Rohan TE ，Sinha R ... -  《-》

Association between pre-pregnancy consumption of meat, iron intake, and the risk of gestational diabetes: the SUN project.

Marí-Sanchis A ，Díaz-Jurado G ，Basterra-Gortari FJ ，de la Fuente-Arrillaga C ，Martínez-González MA ，Bes-Rastrollo M ... -  《-》