Animal food intake and cooking methods in relation to endometrial cancer risk in Shanghai

We evaluated animal food intake and cooking methods in relation to endometrial cancer risk in a population-based case-control study in Shanghai, China. A validated food frequency questionnaire was used to collect the usual dietary habits of 1204 cases and 1212 controls aged 30-69 years between 1997 and 2003. Statistical analyses were based on an unconditional logistic regression model adjusting for potential confounders. High intake of meat and fish was associated with an increased risk of endometrial cancer, with adjusted odds ratios for the highest vs the lowest quartile groups being 1.7 (95% confidence interval: 1.3-2.2) and 2.4 (1.8-3.1), respectively. The elevated risk was observed for all types of meat and fish intake. Intake of eggs and milk was not related to risk. Cooking methods and doneness levels for meat and fish were not associated with risk, nor did they modify the association with meat and fish consumption. Our study suggests that animal food consumption may play an important role in the aetiology of endometrial cancer, but cooking methods have minimal influence on risk among Chinese women.     

Meat consumption and colorectal cancer risk in Japan: The Takayama study

Compared with the abundant data from Western countries, evidence regarding meat consumption and colorectal cancer is limited in the Japanese population. We evaluated colorectal cancer risk in relation to meat consumption in a population‐based prospective cohort study in Japan. Participants were 13 957 men and 16 374 women aged ≥35 years in September 1992. Meat intake, assessed with a validated food frequency questionnaire, was controlled for the total energy intake. The incidence of colorectal cancer was confirmed through regional population‐based cancer registries and histological identification from colonoscopy in two main hospitals in the study area. From September 1992 to March 2008, 429 men and 343 women developed colorectal cancer. After adjustments for multiple confounders, a significantly increased relative risk of colorectal cancer was observed in the highest versus lowest quartile of the intake of total and red meat among men; the estimated hazard ratios were 1.36 (95% CI: 1.03, 1.79) for total meat (P for trend = 0.022), and 1.44 (95% CI: 1.10, 1.89) for red meat (P for trend = 0.009). A positive association between processed meat intake and colon cancer risk was also observed in men. There was no significant association between colorectal cancer and meat consumption in women. These results suggest that the intake of red and processed meat increases the risk of colorectal or colon cancer among Japanese men. Abstaining from excessive consumption of meat might be protective against developing colorectal cancer.     

Fatty acids found in dairy,protein and unsaturated fatty acids are associated with risk of pancreatic cancer in a case–control study

Although many studies have investigated meat and total fat in relation to pancreatic cancer risk, few have investigated dairy, fish and specific fatty acids (FAs). We evaluated the association between intake of meat, fish, dairy, specific FAs and related nutrients and pancreatic cancer. In our American‐based Mayo Clinic case–control study 384 cases and 983 controls frequency matched on recruitment age, race, sex and residence area (Minnesota, Wisconsin or Iowa, USA) between 2004 and 2009. All subjects provided demographic information and completed 144‐item food frequency questionnaire. Logistic regression‐calculated odds ratios (ORs) and 95% confidence intervals (95% CIs) were adjusted for age, sex, cigarette smoking, body mass index and diabetes mellitus. Significant inverse association (trend p‐value < 0.05) between pancreatic cancer and the groupings (highest vs. lowest consumption quintile OR [95% CI]) was as follows: meat replacement (0.67 [0.43–1.02]), total protein (0.58 [0.39–0.86]), vitamin B12 (0.67 [0.44, 1.01]), zinc (0.48 [0.32, 0.71]), phosphorus (0.62 [0.41, 0.93]), vitamin E (0.51 [0.33, 0.78]), polyunsaturated FAs (0.64 [0.42, 0.98]) and linoleic acid (FA 18:2) (0.62 [0.40–0.95]). Increased risk associations were observed for saturated FAs (1.48 [0.97–2.23]), butyric acid (FA 4:0) (1.77 [1.19–2.64]), caproic acid (FA 6:0) (2.15 [1.42–3.27]), caprylic acid (FA 8:0) (1.87 [1.27–2.76]) and capric acid (FA 10:0) (1.83 [1.23–2.74]). Our study suggests that eating a diet high in total protein and certain unsaturated FAs is associated with decreased risk of developing pancreatic cancer in a dose‐dependent manner, whereas fats found in dairy increase risk.     

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.     

Food groups and risk of colorectal cancer

The aim of this systematic review and meta‐analysis was to summarize the evidence on the relationship between intake of 12 major food groups, including whole grains, refined grains, vegetables, fruit, nuts, legumes, eggs, dairy, fish, red meat, processed meat and sugar‐sweetened beverages with risk of colorectal cancer (CRC). We conducted a systematic search in PubMed and Embase for prospective studies investigating the association between these 12 food groups and risk of CRC until April 2017. Summary risk ratios (RRs) and 95% confidence intervals (95% CI) were estimated using a random effects model for high vs. low intake categories, as well as for linear and nonlinear relationships. An inverse association was observed for whole grains (RR_30g/d: 0.95, 95% CI 0.93, 0.97; n = 9 studies), vegetables (RR_100g/d: 0.97, 95% CI 0.96, 0.98; n = 15), fruit (RR_100g/d: 0.97, 95% CI 0.95, 0.99; n = 16) and dairy (RR_200g/d: 0.93, 95% CI 0.91, 0.94; n = 15), while a positive association for red meat (RR_100g/d: 1.12, 95% CI 1.06, 1.19; n = 21) and processed meat (RR_50g/d: 1.17, 95% CI 1.10, 1.23; n = 16), was seen in the linear dose‐response meta‐analysis. Some evidence for nonlinear relationships was observed between vegetables, fruit and dairy and risk of colorectal cancer. Findings of this meta‐analysis showed that a diet characterized by high intake of whole grains, vegetables, fruit and dairy products and low amounts of red meat and processed meat was associated with lower risk of CRC.     

Meat, fish and fat intake in relation to subsite-specific risk of colorectal cancer: The Fukuoka Colorectal Cancer Study

High intake of red meat has been associated with increased risk of colorectal cancer in Western countries. There has been much interest in the role of n-3 polyunsaturated fatty acids (PUFA) in colorectal cancer prevention, but epidemiological findings are limited and inconsistent. The objective of our study was to examine associations of meat, fish and fat intake with risk of colorectal cancer, paying particular attention to the subsite within the colorectum. Data were from the Fukuoka Colorectal Cancer Study, a population-based case-control study, covering 782 cases and 793 controls. Diet was assessed by interview, using newly developed personal-computer software for registering semiquantitative food frequencies. The intake of beef/pork, processed meat, total fat, saturated fat or n-6 PUFA showed no clear association with the overall or subsite-specific risk of colorectal cancer. There was an almost significant inverse association between n-3 PUFA and the risk of colorectal cancer; the covariate-adjusted odds ratio for the highest (median 3.94 g/day) versus lowest (median 1.99 g/day) quintile of energy-adjusted intake was 0.74 (95% confidence interval 0.52-1.06, trend P=0.050). The consumption of fish and fish products was similarly inversely related to the risk although the association was not statistically significant. These associations were more evident for distal colon cancer; adjusted odds ratio for the highest versus lowest quintile of n-3 PUFA intake was 0.56 (95% confidence interval 0.34-0.92, trend P=0.02). Our findings do not support the hypothesis that consumption of red meat increases colorectal cancer risk but do suggest that high intake of fish may decrease the risk, particularly of distal colon cancer.     

Animal products, calcium and protein and prostate cancer risk in The Netherlands Cohort Study.

Prostate cancer risk in relation to consumption of animal products, and intake of calcium and protein was investigated in the Netherlands Cohort Study. At baseline in 1986, 58,279 men aged 55-69 years completed a self-administered 150-item food frequency questionnaire and a questionnaire on other risk factors for cancer. After 6.3 years of follow-up, 642 prostate cancer cases were available for analysis. In multivariate case-cohort analyses adjusted for age, family history of prostate cancer and socioeconomic status, no associations were found for consumption of fresh meat, fish, cheese and eggs. Positive trends in risk were found for consumption of cured meat and milk products (P-values 0.04 and 0.02 respectively). For calcium and protein intake, no associations were observed. The hypothesis that dietary factors might be more strongly related to advanced prostate tumours could not be confirmed in our study. We conclude that, in this study, animal products are not strongly related to prostate cancer risk.     

Meat intake,cooking methods and risk of proximal colon,distal colon and rectal cancer: The Norwegian Women and Cancer (NOWAC) cohort study

Red and processed meat intake is an established risk factor for colorectal cancer (CRC), but epidemiological evidence by subsite and sex is still limited. In the population‐based Norwegian Women and Cancer cohort, we examined associations of meat intake with incident proximal colon, distal colon and rectal cancer, in 84,538 women who completed a validated food frequency questionnaire (FFQ) during 1996–1998 or 2003–2005 (baseline or exposure update) at age 41–70 years, with follow‐up by register linkages through 2009. We also examined the effect of meat cooking methods in a subsample (n = 43,636). Multivariable hazard ratios (HRs) were estimated by Cox regression. There were 459 colon (242 proximal and 167 distal), and 215 rectal cancer cases with follow‐up ≥ 1 (median 11.1) year. Processed meat intake ≥60 vs. <15 g/day was associated with significantly increased cancer risk in all subsites with HRs (95% confidence interval, CI) of 1.69 (1.05–2.72) for proximal colon, 2.13 (1.18–3.83) for distal colon and 1.71 (1.02–2.85) for rectal cancer. Regression calibration of continuous effects based on repeated 24‐hr dietary recalls, indicated attenuation due to measurement errors in FFQ data, but corrected HRs were not statistically significant due to wider CIs. Our study did not support an association between CRC risk and intake of red meat, chicken, or meat cooking methods, but a high processed meat intake was associated with increased risk of proximal colon, distal colon and rectal cancer. The effect of processed meat was mainly driven by the intake of sausages.     

Fat and meat intake and prostate cancer risk: the multiethnic cohort study

Dietary fat and meat as potential risk factors for prostate cancer have been the focus of many epidemiologic investigations, and findings from recent studies in particular have been inconsistent. Therefore, we examined the association between these exposures and prostate cancer risk in the Multiethnic Cohort Study. The analyses included 82,483 men in Hawaii and Los Angeles aged >or=45, who completed a detailed quantitative food frequency questionnaire in 1993-1996. During the follow-up period of 8 years, a total of 4,404 incident cases, including 1,278 nonlocalized or high-grade cancer cases, were identified. Cox proportional hazard models were used to estimate relative risks of prostate cancer after adjustment for time on study, ethnicity, family history of prostate cancer, education, body mass index, smoking status and energy intake. Intake of different types of fat (total, saturated, monounsaturated or polyunsaturated), n-6 fatty acid, cholesterol, various meats, and fats from meat showed no association with overall prostate cancer risk or with nonlocalized or high-grade prostate cancer. Furthermore, we found little evidence of any relation of fat and meat intake with prostate cancer risk within any of the 4 racial/ethnic groups (African Americans, Japanese Americans, Latinos and Whites). There was a suggestion of a protective effect of n-3 fatty acid intake that was limited to Latinos and Whites. However, overall, our findings from a large cohort study of ethnically diverse population give no indication that intake of fat and meat substantially affects prostate cancer risk.     

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.     

Ingested nitrate and nitrite,disinfection by‐products,and pancreatic cancer risk in postmenopausal women

Nitrate and nitrite are precursors of N‐nitroso compounds (NOC), probable human carcinogens that cause pancreatic tumors in animals. Disinfection by‐products (DBP) exposures have also been linked with digestive system cancers, but few studies have evaluated relationships with pancreatic cancer. We investigated the association of pancreatic cancer with these drinking water contaminants and dietary nitrate/nitrite in a cohort of postmenopausal women in Iowa (1986–2011). We used historical monitoring and treatment data to estimate levels of long‐term average nitrate and total trihalomethanes (TTHM; the sum of the most prevalent DBP class) and the duration exceeding one‐half the maximum contaminant level (>½ MCL; 5 mg/L nitrate‐nitrogen, 40 µg/L TTHM) among participants on public water supplies (PWS) >10 years. We estimated dietary nitrate and nitrite intakes using a food frequency questionnaire. We computed hazard ratios (HR) and 95% confidence intervals (CI) using Cox regression and evaluated nitrate interactions with smoking and vitamin C intake. We identified 313 cases among 34,242 women, including 152 with >10 years PWS use (N = 15,710). Multivariable models of average nitrate showed no association with pancreatic cancer (HR_{p95 vs. Q1} = 1.16, 95% CI: 0.51–2.64). Associations with average TTHM levels were also null (HR_{Q4 vs. Q1} = 0.70, 95% CI:0.42–1.18). We observed no trend with increasing years of exposure to either contaminant at levels >½ MCL. Positive associations were suggested in the highest dietary nitrite intake from processed meat (HR_{p95 vs. Q1} = 1.66, 95% CI 1.00–2.75;p_trend = 0.05). We found no interactions of nitrate with known modifiers of endogenous NOC formation. Our results suggest that nitrite intake from processed meat may be a risk factor for pancreatic cancer.     

Dietary fat and meat intakes and risk of reflux esophagitis, Barrett's esophagus and esophageal adenocarcinoma

The aim of our study was to investigate whether dietary fat and meat intakes are associated with reflux esophagitis (RE), Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). In this all-Ireland case-control study, dietary intake data were collected using a food frequency questionnaire in 219 RE patients, 220 BE patients, 224 EAC patients and 256 frequency-matched controls between 2002 and 2005. Unconditional multiple logistic regression analysis was used to examine the association between dietary variables and disease risk using quartiles of intake, to attain odds ratios (ORs) and 95% confidence intervals (95% CIs), while adjusting for potential confounders. Patients in the highest quartile of total fat intake had a higher risk of RE (OR = 3.54; 95% CI = 1.32-9.46) and EAC (OR = 5.44; 95% CI = 2.08-14.27). A higher risk of RE and EAC was also reported for patients in the highest quartile of saturated fat intake (OR = 2.79; 95% CI = 1.11-7.04; OR = 2.41; 95% CI = 1.14-5.08, respectively) and monounsaturated fat intake (OR = 2.63; 95% CI = 1.01-6.86; OR = 5.35; 95% CI = 2.14-13.34, respectively). Patients in the highest quartile of fresh red meat intake had a higher risk of EAC (OR = 3.15; 95% CI = 1.38-7.20). Patients in the highest category of processed meat intake had a higher risk of RE (OR = 4.67; 95% CI = 1.71-12.74). No consistent associations were seen for BE with either fat or meat intakes. Further studies investigating the association between dietary fat and food sources of fat are needed to confirm these results.     

Food groups and risk of colorectal cancer in Italy

The proportion of colorectal cancer attributed to dietary habits is high, but several inconsistencies remain, especially with respect to the influence of some food groups. To further elucidate the role of dietary habits, 1,225 subjects with cancer of the colon, 728 with cancer of the rectum and 4,154 controls, hospitalized with acute non-neoplastic diseases, were interviewed between 1992 and 1996 in 6 different Italian areas. The validated food-frequency questionnaire included 79 questions on food items and recipes, categorised into 16 food groups. After allowance for non-dietary confounding factors and total energy intake, significant trends of increasing risk of colorectal cancer with increasing intake emerged for bread and cereal dishes (odds ratio [OR] in highest vs. lowest quintile = 1.7), potatoes (OR = 1.2), cakes and desserts (OR = 1.1), and refined sugar (OR = 1.4). Intakes of fish (OR = 0.7), raw and cooked vegetables (OR = 0.6 for both) and fruit other than citrus fruit (OR = 0.7) showed a negative association with risk. Consumption of eggs and meat (white, red or processed meats) seemed uninfluential. Most findings were similar for colon and rectum, but some negative associations (i.e., coffee and tea, and fish) appeared stronger for colon cancer. Our findings lead us to reconsider the role of starchy foods and refined sugar in light of recent knowledge on the digestive physiology of carbohydrates and the insulin/colon cancer hypothesis. The beneficial role of most vegetables is confirmed, with more than 20% reduction in risk of colorectal cancer from the addition of one daily serving. Int. J. Cancer 72:56–61, 1997. © 1997 Wiley-Liss Inc.     

Meat intake and risk of gastric cancer in the Stomach cancer Pooling (StoP) project

The consumption of processed meat has been associated with noncardia gastric cancer, but evidence regarding a possible role of red meat is more limited. Our study aims to quantify the association between meat consumption, namely white, red and processed meat, and the risk of gastric cancer, through individual participant data meta-analysis of studies participating in the “Stomach cancer Pooling (StoP) Project”. Data from 22 studies, including 11,443 cases and 28,029 controls, were used. Study-specific odds ratios (ORs) were pooled through a two-stage approach based on random-effects models. An exposure-response relationship was modeled, using one and two-order fractional polynomials, to evaluate the possible nonlinear association between meat intake and gastric cancer. An increased risk of gastric cancer was observed for the consumption of all types of meat (highest vs. lowest tertile), which was statistically significant for red (OR: 1.24; 95% CI: 1.00–1.53), processed (OR: 1.23; 95% CI: 1.06–1.43) and total meat (OR: 1.30; 95% CI: 1.09–1.55). Exposure-response analyses showed an increasing risk of gastric cancer with increasing consumption of both processed and red meat, with the highest OR being observed for an intake of 150 g/day of red meat (OR: 1.85; 95% CI: 1.56–2.20). This work provides robust evidence on the relation between the consumption of different types of meat and gastric cancer. Adherence to dietary recommendations to reduce meat consumption may contribute to a reduction in the burden of gastric cancer.     

Prospective investigation of poultry and fish intake in relation to cancer risk

Dietary guidelines advise consumers to limit intake of red meat and choose lean protein sources, such as poultry and fish. Poultry consumption has been steadily increasing in the United States, but the effect on cancer risk remains unclear. In a large U.S. cohort, we prospectively investigated poultry and fish intake and cancer risk across a range of malignancies in men and women. Diet was assessed at baseline (1995-1996) with a food frequency questionnaire in 492,186 participants of the NIH-AARP Diet and Health Study. Over a mean follow-up of 9 years, we identified 74,418 incident cancer cases. In multivariable Cox proportional hazards regression models, we estimated the substitution and addition effects of white meat (poultry and fish) intake in relation to cancer risk. In substitution models with total meat intake held constant, a 10-g (per 1,000 kcal) increase in white meat intake offset by an equal decrease in red meat intake was associated with a statistically significant reduced (3%-20%) risk of cancers of the esophagus, liver, colon, rectum, anus, lung, and pleura. In addition models with red meat intake held constant, poultry intake remained inversely associated with esophageal squamous cell carcinoma, liver cancer, and lung cancer, but we observed mixed findings for fish intake. As the dietary recommendations intend, the inverse association observed between white meat intake and cancer risk may be largely due to the substitution of red meat. Simply increasing fish or poultry intake, without reducing red meat intake, may be less beneficial for cancer prevention.     

Meat and dairy consumption and subsequent risk of prostate cancer in a US cohort study

Objective To evaluate the association of meat and dairy food consumption with subsequent risk of prostate cancer. Methods In 1989, 3,892 men 35+ years old, who participated in the CLUE II study of Washington County, MD, completed an abbreviated Block food frequency questionnaire. Intake of meat and dairy foods was calculated using consumption frequency and portion size. Incident prostate cancer cases (n = 199) were ascertained through October 2004. Cox proportional hazards regression was used to calculate hazard ratios (HR) of total and advanced (SEER stages three and four; n = 54) prostate cancer and 95% confidence intervals (CI) adjusted for age, BMI at age 21, and intake of energy, saturated fat, and tomato products. Results Intakes of total meat (HR = 0.90, 95% CI 0.60–1.33, comparing highest to lowest tertile) and red meat (HR = 0.87, 95% CI 0.59–1.32) were not statistically significantly associated with prostate cancer. However, processed meat consumption was associated with a non-statistically significant higher risk of total (5+ vs. ≤1 servings/week: HR = 1.53, 95% CI 0.98–2.39) and advanced (HR = 2.24; 95% CI 0.90–5.59) prostate cancer. There was no association across tertiles of dairy or calcium with total prostate cancer, although compared to ≤1 serving/week consumption of 5+ servings/week of dairy foods was associated with an increased risk of prostate cancer (HR = 1.65, 95% CI 1.02–2.66). Conclusion Overall, consumption of processed meat, but not total meat or red meat, was associated with a possible increased risk of total prostate cancer in this prospective study. Higher intake of dairy foods but not calcium was positively associated with prostate cancer. Further investigation into the mechanisms by which processed meat and dairy consumption might increase the risk of prostate cancer is suggested.     

Consumption of meat and fish and risk of lung cancer: results from the European Prospective Investigation into Cancer and Nutrition

Evidence from case-control studies, but less so from cohort studies, suggests a positive association between meat intake and risk of lung cancer. Therefore, this association was evaluated in the frame of the European Prospective Investigation into Cancer and Nutrition, EPIC. Data from 478,021 participants, recruited from 10 European countries, who completed a dietary questionnaire in 1992-2000 were evaluated; 1,822 incident primary lung cancer cases were included in the present evaluation. Relative risk estimates were calculated for categories of meat intake using multi-variably adjusted Cox proportional hazard models. In addition, the continuous intake variables were calibrated by means of 24-h diet recall data to account for part of the measurement error. There were no consistent associations between meat consumption and the risk of lung cancer. Neither red meat (RR = 1.06, 95% CI 0.89-1.27 per 50 g intake/day; calibrated model) nor processed meat (RR = 1.13, 95% CI 0.95-1.34 per 50 g/day; calibrated model) was significantly related to an increased risk of lung cancer. Also, consumption of white meat and fish was not associated with the risk of lung cancer. These findings do not support the hypothesis that a high intake of red and processed meat is a risk factor for lung cancer.     

Dietary nitrate and nitrite intake and risk of colorectal cancer in the Shanghai Women's Health Study

Nitrate and nitrite are precursors of endogenously formed N‐nitroso compounds (NOC), known animal carcinogens. Nitrosation reactions forming NOCs can be inhibited by vitamin C and other antioxidants. We prospectively investigated the association between dietary nitrate and nitrite intake and risk of colorectal cancer in the Shanghai Women's Health Study, a cohort of 73,118 women ages 40–70 residing in Shanghai. We evaluated effect modification by factors that affect endogenous formation of NOCs: vitamin C (at or above/below median) and red meat intake (at or above/below median). Nitrate, nitrite and other dietary intakes were estimated from a 77‐item food frequency questionnaire administered at baseline. Over a mean of 11 years of follow‐up, we identified 619 colorectal cancer cases (n = 383, colon; n = 236, rectum). Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazard regression. Overall, nitrate intake was not associated with colorectal cancer risk (HR = 1.08; 95% CI: 0.73–1.59). However, among women with vitamin C intake below the median (83.9 mg day^?1) and hence higher potential exposure to NOCs, risk of colorectal cancer increased with increasing quintiles of nitrate intake (highest vs. lowest quintile HR = 2.45; 95% CI: 1.15–5.18; p trend = 0.02). There was no association among women with higher vitamin C intake. We found no association between nitrite intake and risk of colorectal cancer overall or by intake level of vitamin C. Our findings suggest that high dietary nitrate intake among subgroups expected to have higher exposure to endogenously formed NOCs increases risk of colorectal cancer.     

Red meat, chicken, and fish consumption and risk of colorectal cancer.

BACKGROUND: Red meat and processed meat consumption have been associated with increased risk of colorectal cancer in some, but not all, relevant cohort studies. Evidence on the relationship between risk of colorectal cancer and poultry and fish consumption is inconsistent. METHODS: We conducted a prospective cohort study of 37,112 residents of Melbourne, Australia recruited from 1990 to 1994. Diet was measured with a food frequency questionnaire. We categorized the frequency of fresh red meat, processed meat, chicken, and fish consumption into approximate quartiles. Adenocarcinomas of the colon or rectum were ascertained via the Victorian Cancer Registry. RESULTS: We identified 283 colon cancers and 169 rectal cancers in an average of 9 years of follow-up. For rectal cancer, the hazard ratios [95% confidence intervals (95% CI)] in the highest quartile of consumption of fresh red meat and processed meat were 2.3 (1.2-4.2; P for trend = 0.07) and 2.0 (1.1-3.4; P for trend = 0.09), respectively. The corresponding hazard ratios (95% CIs) for colon cancer were 1.1 (0.7-1.6; P for trend = 0.9) and 1.3 (0.9-1.9; P for trend = 0.06). However, for neither type of meat was the heterogeneity between subsites significant. Chicken consumption was weakly negatively associated with colorectal cancer (hazard ratio highest quartile, 0.7; 95% CI, 0.6-1.0; P for trend = 0.03), whereas hazard ratios for fish consumption were close to unity. CONCLUSION: Consumption of fresh red meat and processed meat seemed to be associated with an increased risk of rectal cancer. Consumption of chicken and fish did not increase risk.     

Foods as risk factors for colorectal cancer: a case-control study in Burgundy (France).

Although the high meat-low vegetable diet is considered the reference high-risk diet for colorectal cancer, particularly in USA communities, other at-risk dietary patterns, such as high intakes of processed meat and refined carbohydrates are emerging. Little is known about risk factors for colorectal cancer in France, a country at high risk of rectal cancer and moderately high risk of colon cancer. We compared diet of colorectal cancer cases (n = 171) and general population controls (n = 309) in Burgundy (France). Categories of intake were established by sex and based on the distributions of food intakes in controls. Odds ratios for the fourth vs first quartile of intake (OR4) were 2.0 (1.1-3.6) for refined cereal products (rice, pasta and pastry), 2.4 (1.3-4.5) for delicatessen, 2.3 (1.2-4.2) for patés, 1.7 (1.1-2.8) for offal and 2.1 (1.1-4.0) for butter, lard and cream. There was no association with consumption of fresh meat (OR4 = 1.2), fish (OR4 = 1.5), egg (OR4 = 1.1) or dairy products (OR4 = 1.0). A protective effect of vegetables was only observed for left colon cancer (OR3 = 0.3; 0.1-0.6). In men, the most significant risk factors were refined cereal products, seasoning animal fats, chocolate and coffee, whereas risk factors were delicatessen, fat meat, pasta, rice, and chocolate in women. The strong association with refined cereal products is consistent with the hypothesis of a role of hyperinsulinism in colorectal carcinogenesis. The association with processed but not fresh meat suggests the importance of exogenous carcinogenesis in that area.