Dietary folate and APC mutations in sporadic colorectal cancer

Folate deficiency has been associated with colorectal cancer risk and may be involved in colorectal carcinogenesis through increased chromosome instability, gene mutations, and aberrant DNA methylation. Within the Netherlands Cohort Study on diet and cancer, we investigated the associations between dietary folate intake and colorectal cancer risk with (APC(+)) and without (APC(-)) truncating APC mutations, accounting for hMLH1 expression and K-ras mutations. In total, 528 cases and 4200 subcohort members were available for data analyses of the study cohort (n = 120,852) from a follow-up period between 2.3 and 7.3 y after baseline. Adjusted gender-specific incidence rate ratios (RR) over tertiles of folate intake were calculated in case-cohort analyses for colon and rectal cancer. Although relatively high folate intake was not associated with overall colorectal cancer risk, it reduced the risk of APC(-)colon tumors in men (RR 0.58, 95% CI 0.32-1.05, P(trend) = 0.06 for the highest vs. lowest tertile of folate intake). In contrast, it was positively associated with APC(+) colon tumors in men (highest vs. lowest tertile: RR 2.77, 95% CI 1.29-5.95, P(trend) = 0.008) and was even stronger when the lack of hMLH1 expression and K-ras mutations were excluded (RR 3.99, 95% CI 1.43-11.14, P(trend) = 0.007). Such positive associations were not observed among women; nor was folate intake associated with rectal cancer when APC mutation status was taken into account. Relatively high folate consumption reduced the risk of APC(-) colon tumors, but folate intake was positively associated with APC(+) colon tumors among men. These opposite results may indicate that folate enhances colorectal carcinogenesis through a distinct APC mutated pathway.     

Association of Red Meat Intake with the Risk of Cardiovascular Mortality in General Japanese Stratified by Kidney Function: NIPPON DATA80

The consumption of red meat has been recommended for individuals with reduced kidney function. However, red meat intake was recently suspected to increase cardiovascular disease (CVD) risk. We evaluated the association of red meat intake with CVD mortality risk in Japanese with/without reduced kidney function. Overall, 9112 participants of a Japanese national survey in 1980, aged ≥30 years, were followed for 29 years. Red meat intake was assessed using weighed dietary record. Cox proportional hazards models were used to estimate the hazard ratio (HR) of CVD mortality according to sex-specific tertiles of red meat intake. We also performed stratified analyses with/without reduced kidney function defined as estimated glomerular filtration rate less than 60 mL/min/1.73 m². Red meat intake was not associated with CVD mortality risk in men and women. In stratified analyses, the HR of the highest compared with the lowest tertile of red meat intake was lower only in women with reduced kidney function (0.67, 95% confidence interval 0.46–0.98). In conclusion, there were no clear associations between red meat intake and CVD mortality risk in Japanese population; however, a higher intake of red meat was associated with lower risk of future CVD mortality in women with reduced kidney function.     

Association of vegetable, fruit, and grain intakes with colorectal cancer: the Multiethnic Cohort Study

BACKGROUND: It is uncertain whether or not vegetables, fruit, or grains protect against colorectal cancer. OBJECTIVE: In a large prospective study, we investigated the association of vegetable, fruit, and grain intakes with colorectal cancer risk. DESIGN: Between 1993 and 1996, 85 903 men and 105 108 women completed a quantitative food-frequency questionnaire that included approximately 180 foods and beverages in the Multiethnic Cohort Study. A diagnosis of colorectal cancer was made in 1138 men and 972 women after an average follow-up of 7.3 y. Cox proportional hazards models were used to calculate multivariate-adjusted relative risks and 95% CIs for colorectal cancer. RESULTS: In men, multivariate adjustment for energy intake, dietary, and nondietary variables resulted in relative risks in the highest quintile group of 0.74 (95% CI: 0.59, 0.93; P for trend = 0.02) for vegetables and fruit combined, 0.80 (95% CI: 0.64, 0.99; P for trend = 0.09) for fruit alone, and 0.85 (95% CI: 0.69, 1.05; P for trend = 0.05) for vegetables alone. When colon and rectal cases were separated among men, the inverse associations were stronger for colon than for rectal cancer. In women, none of the associations with vegetables, fruit, or vegetables and fruit combined were significant. Grain intake was not associated with colorectal cancer for either men or women. CONCLUSION: The intake of vegetables and fruit was inversely related to colorectal cancer risk among men but not among women. The association appears stronger for colon than for rectal cancer.     

Diet and colorectal cancer mortality: results from the Japan Collaborative Cohort Study

The relationship between diet and colorectal cancer mortality was analyzed in a prospective study of 45,181 men and 62,643 women aged 40-79 yr enrolled in the Japan Collaborative Cohort Study. Between 1988 and 1990, subjects completed a self-administered questionnaire on their sociodemographic characteristics, diet, and other lifestyle habits. During the follow-up period (average 9.9 yr), 284 colon cancer deaths (138 men and 146 women) and 173 rectal cancer deaths (116 men and 57 women) were confirmed. The only significant association of colorectal cancer mortality with vegetable intake was observed between male rectal cancer mortality and green leafy vegetable consumption [hazard ratio (HR) using Cox proportional hazard models = 0.6; 95% confidence interval (CI) = 0.3-0.9; P for trend = 0.02]. Yogurt intake was also inversely associated with male rectal cancer mortality (HR = 0.5; 95% CI = 0.2-1.0; P for trend = 0.04). Egg consumption was positively associated with male colon cancer mortality (P for trend = 0.04). Women with high fruit consumption had increased colon cancer mortality (HR = 1.6; 95% CI = 1.0-2.6; P for trend = 0.04). It should be noted that this study lacked statistical power due to small sample size and measurement error in the food-frequency questionnaire. Further investigation is therefore necessary to confirm the association between diet and colorectal cancer, especially by subsites and gender.     

Pancreatic cancer and exposure to dietary nitrate and nitrite in the NIH-AARP Diet and Health Study

Nitrate and nitrite are precursors of N-nitroso compounds, which induce tumors of the pancreas in animals. The authors evaluated the relation of dietary nitrate and nitrite to pancreatic cancer risk in the NIH-AARP Diet and Health Study. Nitrate and nitrite intakes were assessed at baseline using a 124-item food frequency questionnaire. During approximately 10 years of follow-up between 1995 and 2006, 1,728 incident pancreatic cancer cases were identified. There was no association between total nitrate or nitrite intake and pancreatic cancer in men or women. However, men in the highest quintile of summed nitrate/nitrite intake from processed meat had a nonsignificantly elevated risk of pancreatic cancer (hazard ratio = 1.18, 95% confidence interval: 0.95, 1.47; P-trend = 0.11). The authors observed a stronger increase in risk among men for nitrate/nitrite intake from processed meat at ages 12-13 years (highest quintile vs. lowest: hazard ratio = 1.32, 95% confidence interval: 0.99, 1.76; P-trend = 0.11), though the relation did not achieve statistical significance. The authors found no associations between adult or adolescent nitrate or nitrite intake from processed meats and pancreatic cancer among women. These results provide modest evidence that processed meat sources of dietary nitrate and nitrite may be associated with pancreatic cancer among men and provide no support for the hypothesis in women.     

Cancers in Australia in 2010 attributable to the consumption of red and processed meat

Objectives: To estimate the proportion and numbers of cancers in Australia in 2010 attributable to consuming red/processed meat. Methods: We estimated the population attributable fraction (PAF) for cancers causally associated with red/processed meat consumption (colon, rectum) using standard formulae incorporating prevalence of consumption (1995 National Nutrition Survey), relative risks associated with consumption and cancer incidence. We also estimated the proportion change in cancer incidence (potential impact fraction [PIF]) that might have occurred under two hypothetical interventions whereby Australian adults reduced their consumption of red/processed meat from prevailing levels to ≤100 g or ≤65 g per day, respectively. Results: An estimated 2,614 cases (18%) of colorectal cancer occurring in Australians in 2010 were attributable to red/processed meat consumption (16% of colon cancers; 23% of rectal cancers). We estimated that if all Australian adults had consumed ≤65 g/day or ≤100 g/day of red/processed meat, then the incidence of colorectal cancer would have been 5.4% (798 cancers) or 1.4% (204 cancers) lower, respectively. Conclusions: About one in six colorectal cancers in Australians in 2010 were attributable to red/processed meat consumption. Implications: Reducing red/processed meat intake may reduce colorectal cancer incidence, but must be balanced against nutritional benefits of modest lean meat consumption.     

Dietary patterns as identified by factor analysis and colorectal cancer among middle-aged Americans

BACKGROUND: Although diet has long been suspected as an etiological factor for colorectal cancer, studies of single foods and nutrients have provided inconsistent results. OBJECTIVE: We used factor analysis methods to study associations between dietary patterns and colorectal cancer in middle-aged Americans. DESIGN: Diet was assessed among 293,615 men and 198,767 women in the National Institutes of Health-AARP Diet and Health Study. Principal components factor analysis identified 3 primary dietary patterns: a fruit and vegetables, a diet foods, and a red meat and potatoes pattern. State cancer registries identified 2151 incident cases of colorectal cancer in men and 959 in women between 1995 and 2000. RESULTS: Men with high scores on the fruit and vegetable pattern were at decreased risk [relative risk (RR) for quintile (Q) 5 versus Q1: 0.81; 95% CI: 0.70, 0.93; P for trend = 0.004]. Both men and women had a similar risk reduction with high scores on the diet food factor: men (RR: 0.82; 95% CI: 0.72, 0.94; P for trend = 0.001) and women (RR: 0.87; 95% CI: 0.71, 1.07; P for trend = 0.06). High scores on the red meat factor were associated with increased risk: men (RR: 1.17; 95% CI: 1.02, 1.35; P for trend = 0.14) and women (RR: 1.48; 95% CI: 1.20, 1.83; P for trend = 0.0002). CONCLUSIONS: These results suggest that dietary patterns characterized by a low frequency of meat and potato consumption and frequent consumption of fruit and vegetables and fat-reduced foods are consistent with a decreased risk of colorectal cancer.     

Longitudinal changes in BMI in older adults are associated with meat consumption differentially, by type of meat consumed

Hypotheses regarding the role of meat consumption in body weight modulation are contradictory. Prospective studies on an association between meat consumption and BMI change are limited. We assessed the association between meat consumption and change in BMI over time in 3902 men and women aged 55-69 y from the Netherlands Cohort Study. Dietary intake was estimated at baseline using a FFQ. BMI was ascertained through baseline self-reported height (1986) and weight (1986, 1992, and 2000). Analyses were based on sex-specific categories of daily total fresh meat, red meat, beef, pork, minced meat, chicken, processed meat, and fish consumption at baseline. Linear mixed effect modeling adjusted for confounders was used to assess longitudinal associations. Significant cross-sectional differences in BMI between quintiles of total meat intake were observed (P-trend < 0.01; both sexes). No association between total fresh meat consumption and prospective BMI change was observed in men (BMI change highest vs. lowest quintile after 14 y: -0.06 kg/m2; P = 0.75) and women (BMI change: 0.26 kg/m2; P = 0.20). Men with the highest intake of beef experienced a significantly lower increase in BMI after 6 and 14 y than those with the lowest intake (BMI change after 14 y 0.60 kg/m2). After 14 y, a significantly higher increase in BMI was associated with higher intakes of pork in women (BMI change highest vs. lowest quintile: 0.47 kg/m2) and chicken in both sexes (BMI change highest vs. lowest category in both men and women: 0.36 kg/m2). The results remained similar when stratifying on median baseline BMI, and age-stratified analyses yielded mixed results. Differential BMI change effects were observed for several subtypes of meat. However, total meat consumption, or factors directly related to total meat intake, was not strongly associated with weight change during the 14-y prospective follow-up in this elderly population.     

The CYP1A1 genotype may alter the association of meat consumption patterns and preparation with the risk of colorectal cancer in men and women

We hypothesized that the risk of colorectal cancer associated with meat preparation methods producing heterocyclic amines or polycyclic aromatic hydrocarbons is modified by the CYP1A1 genotype alone or in combination with the GSTM1 genotype or the NAT2 imputed phenotype. A total of 952 rectal cancer cases and 1205 controls (between September 1997 and February 2002) and 1346 colon cancer cases and 1544 controls (between October 1991 and September 1994) from Utah and Northern California were recruited from a population-based case-control study. Detailed interviews ascertained lifestyle, medical history, and diet and we extracted DNA from whole blood. Risk of colorectal cancer decreased among men with the CYP1A1 *2 any variant genotype and the lowest intake of poultry and men and women with high use of white meat drippings. Risk increased among men with the CYP1A1 *1 (no variant) allele and high white meat mutagen index, but decreased among those with the CYP1A1 *2 genotype. Risk increased with a high white meat mutagen index among women with the CYP1A1 *2 genotype and the GSTM1 present genotype. Risk of colorectal cancer decreased with the CYP1A1 *2 genotype, the NAT2 slow phenotype, and the use of white meat or its drippings. The association of risk for colorectal cancer and selected red and white meat mutagen indices and the use of white meat drippings, or fried white meat variables was more evident within select combinations of the CYP1A1 genotype and either the GSTM1 genotype or NAT2 than with the CYP1A1 alone. Genetic susceptibility may modify the associations of some meat or meat preparation factors with the risk of colorectal cancer.     

Fluid Intake and Colorectal Cancer Risk in the Netherlands Cohort Study

Total fluid intake, specifically water intake, has been suggested to protect against colorectal cancer. We examined the association of total fluid intake with colorectal cancer endpoints and possible effect modification by fiber intake within the Netherlands Cohort Study (N = 120,852). We also investigated intake of specific beverages. After 13.3 yr, 1,443 male and 1,040 female colorectal cancer cases with complete baseline questionnaires were available for case-cohort analyses. Multivariate analyses showed no dose-response relationship of total fluid intake and intake of specific beverages with the risk of overall colorectal, proximal, and distal colon cancer. For rectal cancer risk in men, there was a nonsignificant positive trend for total fluid intake [> 1,500 vs. ≤ 1,000 ml/day: HR = 1.50, 95% CI = 0.95–2.37, P trend = 0.08) and a significant positive trend for coffee intake (> 6 vs. ≤ 2 cups/day: HR = 1.60, 95% CI = 0.96–2.66, P trend = 0.05). However, a nonsignificant positive trend for total fluid intake was no longer observed when additionally adjusting for coffee intake. Tests for interaction were not significant. In conclusion, total fluid intake was not associated with colorectal cancer risk in either men or women. There was no evidence that fiber intake modified associations. Of the specific beverages, coffee intake was positively associated with rectal cancer risk in men.     

Associations of red and processed meat intake with major molecular pathological features of colorectal cancer

Red and processed meat is an established risk factor for colorectal cancer (CRC). However, exact mechanisms to explain the associations remain unclear. Few studies have investigated the association with CRC by molecular tumor features, which could provide relevant information on associated molecular pathways. In this population-based case–control study from Germany (DACHS), 2449 cases and 2479 controls provided information on risk factors of CRC and completed a food frequency questionnaire. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI) for the associations between meat intake and risk of CRC by molecular pathologic features and specific subtypes. Red and processed meat intake was associated with increased risk of colorectal (>1 time/day vs ≤1 time/week OR 1.66, 95% CI 1.34–2.07), colon and rectal cancer. Among the single molecular tumor features investigated, the results were similar for associations of red and processed meat with CRC risk by microsatellite instability, CpG island methylator phenotype, BRAF, oestrogen receptor-β and p53 status. Red and processed meat intake was associated less strongly with risk of KRAS-mutated CRC (OR >1 time/day vs ≤1 time/week: 1.49, 95% CI 1.09–2.03) than with risk of KRAS-wildtype CRC (OR 1.82, 95% CI 1.42–2.34; p _{heterogeneity} 0.04). These results support an association between red and processed meat and CRC risk similar for subsites of CRC and most of the investigated major molecular pathological features. Potential differences were observed in more specific subtype analyses. Further large studies are needed to confirm these results and to help further elucidate potential underlying mechanisms.     

Coffee Consumption and Risk of Colorectal Cancer: The Japan Collaborative Cohort Study

Background

Epidemiologic studies have reported coffee consumption to be associated with various health conditions. The purpose of this study was to examine the relationship of coffee consumption with colorectal cancer incidence in a large-scale prospective cohort study in Japan.

Methods

We used data from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study). Here, we analyzed a total of 58 221 persons (23 607 men, 34 614 women) followed from 1988 to the end of 2009. During 738 669 person-years of follow-up for the analysis of colorectal cancer risk with coffee consumption at baseline, we identified 687 cases of colon cancer (355 males and 332 females) and 314 cases of rectal cancer (202 males and 112 females). We used the Cox proportional-hazard regression model to estimate hazard ratio (HR).

Results

Compared to those who consumed less than 1 cup of coffee per day, men who consumed 2–3 cups of coffee per day had an HR of 1.26 (95% confidence interval [CI] 0.93–1.70), and men who consumed more than 4 cups of coffee per day had an HR of 1.79 (95% CI 1.01–3.18). A statistically significant increase in the risk of colon cancer was associated with increasing coffee consumption among men (P for trend = 0.03). On the other hand, coffee consumption in women was not associated with incident risk of colon cancer. Coffee consumption was also not associated with rectal cancer incidence in men or women.

Conclusions

This large-scale population-based cohort study showed that coffee consumption increases the risk of colon cancer among Japanese men.Key words: coffee, colorectal cancer, incidence, prospective study, the Japan Collaborative Cohort Study     

Calcium and vitamin D intake and risk of colorectal cancer: the Multiethnic Cohort Study

The associations of intakes of calcium and vitamin D with colorectal cancer risk were examined in the Multiethnic Cohort Study (Hawaii and Los Angeles, California). In 1993-1996, 85,903 men and 105,108 women aged > or =45 years completed a quantitative food frequency questionnaire. A total of 2,110 incident cases of colorectal cancer (1,138 in men and 972 in women) were identified through December 31, 2001. Cox proportional hazards models were used to calculate multivariate-adjusted relative risks and 95% confidence intervals. Total calcium intake (from foods and supplements) was inversely associated with colorectal cancer risk in both men (highest quintile vs. lowest: relative risk (RR) = 0.70, 95% confidence interval (CI): 0.52, 0.93; p for trend = 0.006) and women (RR = 0.64, 95% CI: 0.50, 0.83; p for trend = 0.003). The inverse association was also seen for total vitamin D intake in men (RR = 0.72, 95% CI: 0.51, 1.00; p for trend = 0.03) but not in women. Intake of dairy products was inversely associated with colorectal cancer risk, especially among nonusers of supplemental calcium (men: RR = 0.77, 95% CI: 0.59, 1.01; women: RR = 0.66, 95% CI: 0.49, 0.89). The findings support the hypothesis of protective roles for calcium, vitamin D, and dairy products in the risk of colorectal cancer.     

Vegetable and fruit consumption and risks of colon and rectal cancer in a prospective cohort study: The Netherlands Cohort Study on Diet and Cancer

The relation between vegetable and fruit consumption and colorectal cancer risk was comprehensively assessed in the Netherlands Cohort Study on Diet and Cancer using a validated 150-item food frequency questionnaire. After 6.3 years of follow-up (1986-1992), over 1,000 incident cases of colorectal cancer were registered. Using case-cohort analysis, the authors calculated rate ratios and 95% confidence intervals adjusted for age, alcohol intake, and family history of colorectal cancer. For colon cancer, no statistically significant associations with total vegetable intake or total fruit intake were found. However, among women, an inverse association was observed with vegetables and fruits combined (for the highest quintile vs. the lowest, the rate ratio was 0.66 (95% confidence interval: 0.44, 1.01)). Brassica vegetables and cooked leafy vegetables showed inverse associations for both men and women. Among women and, to a lesser extent, among men, inverse associations were stronger for distal colonic tumors than for proximal colonic tumors. For rectal cancer, no statistically significant associations were found for vegetable consumption or fruit consumption or for specific groups of vegetables and fruits; only Brassica vegetables showed a positive association in women. As in other cohort studies, the observed inverse relation between vegetable and fruit consumption and occurrence of colorectal cancer was less strong than relations reported in case-control studies.     

Fruit and vegetable intake and risk of total cancer and cardiovascular disease: Japan Public Health Center-Based Prospective Study

Few studies have investigated the effects of fruit and vegetables on the risk of both cancer and cardiovascular disease (CVD). The authors examined associations between fruit and vegetable consumption and risk of total cancer and CVD in the same Japanese population. During 1995-1998, a validated food frequency questionnaire was administered in nine areas to 77,891 men and women aged 45-74 years. During as many as 459,320 person-years of follow-up until the end of 2002, 3,230 cancer cases and 1,386 CVD cases were identified. Higher consumption of fruit, but not vegetables, was associated with significantly lower risk of CVD: multivariate hazard ratios for the highest versus lowest quartiles of intake were 0.81 (95% confidence interval (CI): 0.67, 0.97; trend p = 0.01) for fruit and 0.97 (95% CI: 0.82, 1.15; trend p = 0.66) for vegetables. Consumption of fruit or vegetables was not associated with decreased risk of total cancer: corresponding hazard ratios were 1.02 (95% CI: 0.90, 1.14; trend p = 0.95) for fruit and 0.94 (95% CI: 0.84, 1.05; trend p = 0.16) for vegetables. This prospective cohort study demonstrated that, in the Japanese population, consumption of fruit is associated with lower risk of CVD, whereas fruit or vegetables may not be associated with lower risk of total cancer.     

Review of the association between meat consumption and risk of colorectal cancer

The incidence of colorectal cancer (CRC) is rapidly increasing in developing countries, especially among populations that are adopting Western-style diets. Several, but not all, epidemiological and experimental studies suggest that a high intake of meat, especially red and processed meat, is associated with increased CRC risk. Potential reasons for the association between high red and processed meat intake and CRC risk include the content of the meat (e.g. protein, heme) and compounds generated by the cooking process (e.g. N-nitroso compounds, heterocyclic amines). These factors can affect the large intestine mucosa with genotoxicity and metabolic disturbances. Increased bacterial fermentation (putrefaction) of undigested protein and production of bacterial metabolites derived from amino acids may affect colon epithelial homeostasis and renewal. This correlates with the fact that most colonic cancers are detected in the distal colon and rectum where protein fermentation actively occurs. However, there are still large controversies on the relationship between red meat consumption and CRC risk. Therefore, the purpose of this review is to enhance the current understanding on the association between high red and processed meat intakes with CRC risk. A principal focus of this review will be to discuss the meat-related components, such as proteins in the meat, heme, N-nitroso compounds, and heterocyclic amines, and the effects they have upon the large intestine mucosa and the intestinal gut microbiota.     

Dietary intakes of retinol, carotenes, vitamin C, and vitamin e and colorectal cancer risk: the fukuoka colorectal cancer study

It has long been a matter of interest whether antioxidant vitamins are protective against colorectal cancer as well as human cancers in general, but epidemiological evidence is inconclusive. We investigated associations of dietary intakes of retinol and antioxidant vitamins with colorectal cancer risk in 816 incident cases of histologically confirmed colorectal cancer and 815 controls randomly selected for the Fukuoka colorectal cancer study in Japan. Dietary intakes were assessed by a PC-assisted interview regarding 148 food items. Statistical adjustment was made for body mass index, physical activity, calcium, and n-3 fatty acid intake and other factors. Retinol intake was significantly, inversely associated with colorectal cancer risk; the odds ratio for the highest vs. lowest was 0.55 (95% CI: 0.35, 0.88; P (trend) = 0.01) in women, but a modest increase in the risk was observed among men with the highest intake of retinol. Liver was the major source of retinol intake and showed similar associations with colorectal cancer risk in men and women. Intake of carotenes, vitamin C, and vitamin E were not related to colorectal cancer risk in either men or women. The study did not support a hypothesis that dietary intake of antioxidant vitamins is protective in the development of colorectal cancer.     

Calcium and dairy food intakes are inversely associated with colorectal cancer risk in the Cohort of Swedish Men

BACKGROUND: Recent epidemiologic studies have generally reported a modest inverse association between calcium intake and the risk of colorectal cancer. However, findings pertaining to specific subsites in the colorectum have been conflicting. OBJECTIVE: Our objective was to prospectively examine the relations between intakes of calcium and dairy foods and the risk of colorectal cancer, overall and by anatomic subsite, in men from the Cohort of Swedish Men. DESIGN: In 1997, 45 306 men aged 45-79 y and without a history of cancer completed a food-frequency questionnaire. The men were followed through 31 December 2004. RESULTS: During a mean follow-up of 6.7 y, we ascertained 449 incident cases of colorectal cancer. After adjustment for age and other known or potential risk factors, the multivariate rate ratio (RR) of colorectal cancer for men in the highest quartile of total calcium intake compared with those in the lowest quartile was 0.68 (95% CI: 0.51, 0.91; P for trend = 0.01). A high consumption of dairy foods was also associated with a lower risk of colorectal cancer. The multivariate RR of colorectal cancer for > or = 7 servings/d of total dairy foods compared with <2 servings/d was 0.46 (0.30, 0.71; P for trend = 0.01). For cancer subsites, the corresponding RRs were 0.37 (0.16, 0.88) for proximal colon, 0.43 (0.20, 0.93) for distal colon, and 0.48 (0.23, 0.99) for rectum. CONCLUSION: Our findings provide support for inverse associations between intakes of calcium and dairy foods and the risk of colorectal cancer.     

Consumption of red meat, white meat and processed meat in Irish adults in relation to dietary quality

The aim of the present study was to examine the association of red meat, white meat and processed meat consumption in Irish adults with dietary quality. A cross-sectional study of subjects, randomly selected using the electoral register, estimated habitual food intakes using a 7 d food diary in a nationally representative sample of 662 men and 717 women (not pregnant or lactating) aged 18-64 years. Consumers were classified into thirds, based on the distribution of mean daily intakes for red meat, white meat and processed meat. The mean intakes of red meat, white meat and processed meat were 51, 33 and 26 g/d respectively, and men consumed significantly more (P<0.001) than women for all meat types. In men, red meat consumption was associated with lower (P<0.001) prevalence of inadequacy for Zn, riboflavin and vitamin C intakes. Increasing processed meat intake was associated with a lower (P<0.01) level of compliance with dietary recommendations for fat, carbohydrate and fibre in men. Increasing processed meat consumption was associated with lower (P<0.01) wholemeal bread, vegetables, fruit and fish intakes in men and women. Managerial occupations were associated with lower processed meat intakes. It is important to distinguish between meat groups, as there was a large variation between the dietary quality in consumers of red meat, white meat and processed meat. Processed meat consumption is negatively associated with dietary quality and might therefore be a dietary indicator of poor dietary quality. This has important implications in nutritional epidemiological studies and for the development of food-based dietary guidelines.     

Associations of Red Meat,Fat, and Protein Intake With Distal Colorectal Cancer Risk

Studies have suggested that red and processed meat consumption elevate the risk of colon cancer; however, the relationship between red meat, as well as fat and protein, and distal colorectal cancer (CRC) specifically is not clear. We determined the risk of distal CRC associated with red and processed meat, fat, and protein intakes in Whites and African Americans. There were 945 cases (720 White, 225 African American) of distal CRC and 959 controls (800 White, 159 African American). We assessed dietary intake in the previous 12 mo. Multivariate logistic regression analyses were used to obtain odds ratios (OR) and 95% confidence intervals (95% CI). There was no association between total, saturated, or monounsaturated fat and distal CRC risk. In African Americans, the OR of distal CRC for the highest category of polyunsaturated fat intake was 0.28 (95% CI = 0.08–0.96). The percent of energy from protein was associated with a 47% risk reduction in Whites (Q4 OR = 0.53, 95% CI = 0.37–0.77). Red meat consumption in Whites was associated with a marginally significant risk reduction (Q4 OR = 0.66, 95% CI = 0.43–1.00). Our results do not support the hypotheses that fat, protein, and red meat increase the risk of distal CRC.