Changes in Diet During Adult Life and Risk of Colorectal Adenomas

Association between red and processed meat intake and colorectal adenoma incidence and recurrence: a systematic review and meta-analysis

The associations between red and processed meat intake and colorectal adenoma (CRA) incidence and recurrence are inconclusive. We performed a systematic review and meta-analysis to analysis these associations. We conducted a systematic search of PubMed, EMBASE and Web of Science up to December 2016. The relative risks (RRs) and 95% confidence intervals (CIs) were assessed. Subgroup analyses, dose-response-analyses, subtype analyses and analyses of CRA locations were also conducted. Twenty-seven studies that involved 208,117 participants and 19,150 cases met criteria. The RRs of the highest versus lowest intakes for CRA incidence were 1.23 (1.15–1.31) for red meat and 1.15 (1.07–1.24) for processed meat. Dose-response analyses for meat per 100 g/day yielded the results were consistent with the original analyses, with 1.14 (1.07–1.20) for red meat and 1.27 (1.03–1.50) for processed meat. Additionally, there were no associations between red and processed meat intake and CRA recurrence, including total CRA (P > 0.05), advanced CRA (P > 0.05) and multiple CRA (P > 0.05). In conclusion, our findings support the hypothesis that red and processed meat intake was associated with an increased CRA incidence but not for CRA recurrence.

Lifestyle and lifestyle-related comorbidities independently associated with colorectal adenoma recurrence in elderly Chinese people

Objective

The purpose of this study was to determine the lifestyle and lifestyle-related comorbidities independently associated with colorectal adenoma (CRA) recurrence in elderly Chinese people.

Methods

During the 5-year follow-up after the initial colonoscopy, participants aged >60 years with the diagnosis and removal of CRA underwent a complete surveillance colonoscopy, and 152 participants with CRA recurrence plus 152 participants free of recurrence were included in this analysis.

Results

Participants with CRA recurrence were more likely to consume less vegetables and fruits, and more red meats compared with the control group (P<0.05 for all). Lifestyle-related comorbidities, including hypertension and nonalcoholic fatty liver disease (NAFLD), were more common in participants with CRA recurrence than in the control group (P<0.05 for all). In the multivariate analysis, pack-years of smoking were independently associated with an increased CRA recurrence (odds ratio [OR]: 1.03; P<0.05). Eating less vegetables (OR: 099; P<0.05) and fruits (OR: 0.98; P<0.05) was identified as a statistically independent factor influencing CRA recurrence, as was eating more red meats (OR: 1.01; P<0.05). Hypertension was also found to be a factor independently associated with an increased CRA recurrence (OR: 2.44; P<0.05). NAFLD had an independent association, with an increased CRA recurrence (OR: 3.43; P<0.05).

Conclusion

Smoking cigarettes, high consumption of red meats, low intake of fruits and vegetables, and the presence of hypertension and NAFLD were independently associated with an increased CRA recurrence in elderly Chinese people. This conclusion helps elderly Chinese people to make effective behavioral changes, such as smoking cessation, substitution of fruits and vegetables for red meats, and timely treatment of hypertension and NAFLD, to reduce CRA recurrence and colorectal cancer risk.

Association Between Consumption of Fruits and Vegetables and Risk of Colorectal Adenoma: A PRISMA-Compliant Meta-Analysis of Observational Studies

There have been contradictory results about the association of fruits and vegetables intake with colorectal adenoma (CRA) risk, the precursor lesion of colorectal cancer. Herein, we have conducted a meta-analysis of the published observational studies to have a clear understanding about this association.Eligible studies up to November 30, 2014, were identified and retrieved by searching MEDLINE and EMBASE databases along with the manual review of the reference list of the retrieved studies. The quality of the included studies was evaluated using Newcastle-Ottawa Quality Assessment Scale, and random-effects model was used to calculate summary relative risk (SRR) and corresponding 95% confidence interval (CI).A total of 22 studies involving 11,696 CRA subjects were part of this meta-analysis. The SRR for the highest versus the lowest intake of vegetables alone was 0.91 (95% CI: 0.80-1.02, Pheterogeneity = 0.025), whereas for vegetables and fruits combined, it was 0.82 (95% CI: 0.75-0.91, Pheterogeneity = 0.369), and for fruits alone, it was 0.79 (95% CI: 0.71-0.88, Pheterogeneity = 0.111). In addition, linear dose-response analysis also showed similar results, for example, for per 100 g/d increment of fruits, the SRR was 0.94 (95% CI: 0.92-0.97) and for vegetables it was 0.98 (95% CI: 0.96-1.01). Nonlinear association was only observed for vegetables (Pnonlinearity = 0.024), but not for fruits (Pnonlinearity = 0.583).Thus, this meta-analysis suggested that fruits consumption have a significant protective effect on CRA risk, but not vegetables. Moreover, we recommend additional studies with prospective designs that use validated questionnaires and control for important confounders to further validate the overall results.

Meat subtypes and their association with colorectal cancer: Systematic review and meta-analysis

Associations between specific red meat subtypes and risk of colorectal cancer (CRC) have been investigated in a number of epidemiological studies. However, no publication to date has summarised the overall epidemiological evidence. We conducted a systematic review and meta-analysis of prospective studies (cohort, nested case-control or case-cohort studies), which reported relative risk (RR) estimates and 95% confidence intervals (CI) for the association between intake of meat subtypes with colorectal, colon or rectal cancer or colorectal adenoma risk. PubMed and ISI Web of Science were searched up until August 1, 2014. Nineteen studies examined meat subtypes (5 beef, 5 pork, 2 lamb, 1 veal and 19 poultry) and associations with colorectal, colon or rectal cancer risk and 4 studies examined associations with adenoma risk (1 beef and 4 poultry). Comparing highest versus lowest intake, beef consumption was associated with an increased risk of CRC (RR = 1.11, 95% CI = 1.01 to 1.22) and colon cancer (RR = 1.24, 95% CI = 1.07 to 1.44), but no association was found with rectal cancer (RR = 0.95, 95% CI = 0.78 to 1.16). Higher consumption of lamb was also associated with increased risk of CRC (RR = 1.24, 95% CI = 1.08 to 1.44). No association was observed for pork (RR = 1.07, 95% CI = 0.90 to 1.27), but some between study heterogeneity was observed. No association was observed for poultry consumption and risk of colorectal adenomas or cancer. This meta-analysis suggests that red meat subtypes differ in their association with CRC and its sub sites. Further analysis of data from prospective cohort studies is warranted, especially regarding the role of pork.

The role of dietary and lifestyle factors in the development of colorectal cancer: case control study in Minia, Egypt

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer worldwide, after lung and breast cancer, and is associated with the population dietary and lifestyle factors.

AIM

To determine the relation between dietary and lifestyle factors and development of CRC in patients attending Minia oncology centre and compare them with their control.

METHODS

Study included 150 CRC patients attending Minia oncology centre and 300 control subjects matched by age and sex. Subjects participating in the study filled in a questionnaire including questions about socio-demographic data, medical data concerning CRC and its treatment as well as dietary and lifestyle factors.

RESULTS

The most significant dietary and lifestyle CRC risk factors were higher consumption of red meat (OR = 57.1), preserved food (OR = 39.4), artificial sweeteners (OR = 20.8), fast foods (OR = 12.8), soft drinks (OR = 4.6), spicy foods (OR = 4.2), processed meat (OR = 2.4), and smoking (OR = 8.8). The most significant protective factors were physical activity (OR = 0.001), calcium rich diet (OR = 0.08), higher consumption of fruits and vegetable (OR = 0.02), cruciferous vegetables (broccoli OR = 0.11, cauliflower OR = 0.30 and cabbage OR = 0.30), high fiber bread (OR = 0.15), fruit juice (OR = 0.18), and sea foods (tuna OR = 0.28 and fish OR = 0.38).

CONCLUSION

Sedentary lifestyle and unhealthy dietary choices were prevalent among CRC cases. This study provides strong evidence that lifestyle and dietary modification are important factors in the prevention of colorectal cancer.

Red and processed meat intake and risk of colorectal adenomas: a systematic review and meta-analysis of epidemiological studies

BACKGROUND

Current evidence indicates that red and processed meat intake increases the risk of colorectal cancer; however, the association with colorectal adenomas is unclear.

OBJECTIVE

To conduct a systematic review and meta-analysis of epidemiological studies of red and processed meat intake and risk of colorectal adenomas as part of the Continuous Update Project of the World Cancer Research Fund.

DESIGN

PubMed and several other databases were searched for relevant studies from their inception up to 31 December 2011. Summary relative risks (RRs) were estimated using a random effects model.

RESULTS

Nineteen case-control studies and seven prospective studies were included in the analyses. The summary RR per 100 g/day of red meat was 1.27 (95 % CI 1.16-1.40, I (2) = 5 %, n = 16) for all studies combined, 1.20 (95 % CI 1.06-1.36, I (2) = 0 %, n = 6) for prospective studies, and 1.34 (95 % CI 1.12-1.59, I (2) = 31 %, n = 10) for case-control studies. The summary RR per 50 g/day of processed meat intake was 1.29 (95 % CI 1.10-1.53, I (2) = 27 %, n = 10) for all studies combined, 1.45 (95 % CI 1.10-1.90, I (2) = 0 %, n = 2) for prospective studies, and 1.23 (95 % CI 0.99-1.52, I (2) = 37 %, n = 8) for case-control studies. There was evidence of a nonlinear association between red meat (p nonlinearity < 0.001) and processed meat (p nonlinearity = 0.01) intake and colorectal adenoma risk.

CONCLUSION

These results indicate an elevated risk of colorectal adenomas with intake of red and processed meat, but further prospective studies are warranted.

Meat-related compounds and colorectal cancer risk by anatomical subsite

Since meat may be involved in the etiology of colorectal cancer, associations between meat-related compounds were examined to elucidate underlying mechanisms in a population-based case-control study. Participants (989 cases/1,033 healthy controls) completed a food frequency questionnaire with a meat-specific module. Multivariable logistic regression was used to examine associations between meat variables and colorectal cancer; polytomous logistic regression was used for subsite-specific analyses. The following significant positive associations were observed for meat-related compounds: 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (DiMeIQx) and colorectal, distal colon, and rectal tumors; 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) and colorectal and colon cancer tumors; nitrites/nitrates and proximal colon cancer; 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and rectal cancer; and benzo[a]pyrene and rectal cancer (P-trends < 0.05). For analyses by meat type, cooking method, and doneness preference, positive associations between red processed meat and proximal colon cancer and pan-fried red meat and colorectal cancer were found (P-trends < 0.05). Inverse associations were observed between unprocessed poultry and colorectal, colon, proximal colon, and rectal tumors; grilled/barbequed poultry and proximal colon cancer; and well-done/charred poultry and colorectal, colon, and proximal colon tumors (P-trends < 0.05). HCAs, PAHs, nitrites, and nitrates may be involved in colorectal cancer etiology. Further examination into the unexpected inverse associations between poultry and colorectal cancer is warranted.

Dietary patterns differ between urban and rural older, long-term survivors of breast, prostate, and colorectal cancer and are associated with body mass index

BACKGROUND

Older adult cancer survivors are at greater risk of cancer recurrence and other comorbidities that can be prevented through improved diet and weight management. The tertiary prevention needs of rural-dwelling survivors can be even greater, yet little is known about rural and urban differences in lifestyle factors among this high-risk population.

OBJECTIVES

To compare dietary patterns of urban and rural cancer survivors and to examine associations of dietary patterns with body mass index (BMI).

DESIGN

A secondary analysis was performed of baseline data from the Reach Out to Enhance Wellness (RENEW) trial, a diet and exercise intervention among overweight, long-term (≥5 years), older survivors of colorectal, breast, and prostate cancer. Survivors in the present analysis (n=729) underwent two 45- to 60-minute telephone surveys, which included two 24-hour dietary recalls. Principal components analysis and multivariable general linear models were used to derive dietary patterns and to evaluate associations between dietary patterns and BMI, respectively.

RESULTS

Principal components analysis identified three primary dietary patterns among rural dwellers (high sweets and starches, high reduced-fat dairy, cereal, nuts, and fruits, and mixed) and three among urban dwellers (high fruits and vegetables, high meat and refined grains, and high sugar-sweetened beverages). Among rural survivors, greater adherence to the high reduced-fat dairy, cereal, nuts, and fruits pattern was positively associated with lower BMI (P trend <0.05), whereas higher scores on the mixed pattern was associated with greater BMI (P trend <0.05). Greater adherence to the high fruits and vegetables pattern among urban survivors was inversely associated with BMI (P trend <0.05).

CONCLUSIONS

Urban and rural differences in dietary intake behavior should be considered in designing public health interventions among the increasing population of older cancer survivors. In addition, targeting overall dietary patterns might be one approach to help reduce the burden of obesity among this population.

Update on the relationship of fish intake with prostate, breast, and colorectal cancers

A systematic review of prospective cohort and case-control studies investigating relationships between the intake of fish and incidence of prostate, breast, or colorectal cancers was conducted. A total of 106 studies fulfilled the requirements stated in the "Search strategy and selection criteria." Among 273 estimates of association reported by these studies, 53 indicated decreased risk while 12 indicated increased risk associated with fish intake. The hypothesis linking fish consumption and low cancer incidence appears to be supported by little epidemiological data. However, there are several factors that may mask potential protective associations with fish intake. The type and the amount of fish eaten, the cooking method, the stage of the cancer and, amongst women, menopausal status may all be important factors that relate to whether fish is protective or not. Future epidemiologic studies with a clearer assessment of these factors are needed to know more about the effects of fish consumption on cancer risk. Therefore, until there are better measures of dietary exposure or biomarkers to correlate self-report, no conclusion can be drawn regarding the recommendation for increasing fish consumption in general to reduce the risk of developing the most common cancers in Western societies.

Main dietary compounds and pancreatic cancer risk. The quantitative analysis of case-control and cohort studies

OBJECTIVE

Estimation of the role of main dietary compounds in the risk of developing pancreatic cancer.

RESEARCH METHODS AND PROCEDURES

Literature published till 2010 was reviewed and selected for further analysis. The used terms were: red meat, minced meat, ham, bacon, sausages, white meat, poultry, vegetables, fish, eggs, fruits, lifestyle, diet, pancreatic cancer and pancreatic neoplasm. The collected data were meta-analysed with calculation of combined relative risk and 95% confidence interval as well as studies heterogeneity.

RESULTS

A meta-analysis of 11 case-control studies indicates that red meat ingestion elevates pancreatic cancer risk by 48% (95% CI=1.25-1.76). The vegetables and fruit reduce the risk by 38% (95% CI=0.54-0.73) and 29% (95% CI=0.59-0.84), respectively. The pooled analyses of 10 cohort studies do not show significant relations between main dietary compound ingestion and pancreatic cancer risk.

CONCLUSION

The red meat intake is associated with elevated risk of pancreatic cancer in contrast to vegetables and fruit ingestion. The ingestion of red meat, vegetables and fruit in cohort studies was not influenced on pancreatic cancer risk. The role of fish, poultry and eggs was not significant in both case-control and cohort studies, thus further studies were needed.

Risk of colorectal cancer in relation to frequency and total amount of red meat consumption. Systematic review and meta-analysis

INTRODUCTION

The colon and rectum are common sites of food-related cancer in developed countries. Recent studies strongly suggest that red meat intake is associated with colon cancer, whereas for rectal cancer such an association still needs to be proved. The aim of the study was to assess the role of total amount and frequency of red meat intake in colorectal carcinogenesis based on published data using meta-analysis methods.

MATERIAL AND METHODS

The literature published until 2009 was selected from: MEDLINE, PubMed, Scopus, Embase, CancerLit, Google Scholar and Cochrane Library databases. The used search terms were: colorectal cancer, colon cancer, rectal cancer, meat intake, red meat intake, red meat consumption, meat consumption, colorectal cancer risk, colon cancer risk, rectal cancer risk and lifestyle. Articles investigating red meat intake of more often than once a day or 50 g per day were reviewed and selected for further analysis.

RESULTS

Twenty-two studies fulfilled the established criteria. A meta-analysis confirmed the carcinogenic effect of the consumption of over 50 g of red meat per day for the colon (relative risk 1.21, 1.07-1.37) but not for the rectum (relative risk 1.30, 0.90-1.89). Red meat intake more frequently than once a day can induce both colonic (relative risk 1.37, 1.09-1.71) and rectal cancer (relative risk 1.43, 1.24-1.64).

CONCLUSIONS

Red meat intake is associated with elevated risk of developing colorectal cancer. The frequency of red meat consumption rather than total amount of consumed meat is associated with a higher risk of colorectal carcinogenesis.

Diet index-based and empirically derived dietary patterns are associated with colorectal cancer risk

Previous studies have derived patterns by measuring compliance with preestablished dietary guidance or empirical methods, such as principal components analysis (PCA). Our objective was to examine colorectal cancer risk associated with patterns identified by both methods. The study included 431 incident colorectal cancer cases (225 men, 206 women) and 726 healthy controls (330 men, 396 women) participating in a population-based, case-control study. PCA identified sex-specific dietary patterns and the Healthy Eating Index-2005 (HEI-05) assessed adherence to the 2005 Dietary Guidelines for Americans. A fruits and vegetables pattern and a meat, potatoes, and refined grains pattern were identified among men and women; a third pattern (alcohol and sweetened beverages) was identified in men. The fruits and vegetables pattern was inversely associated with risk among men [odds ratio (OR) = 0.38, 95% CI = 0.21-0.69 for the highest compared with the lowest quartile] and women (OR = 0.35, 95% CI = 0.19-0.65). The meat, potatoes, and refined grains pattern was positively associated with risk in women (OR = 2.20, 95% CI = 1.08-4.50) and there was a suggestion of a positive association among men (OR = 1.56, 95% CI = 0.84-2.90; P-trend = 0.070). Men and women with greater HEI-05 scores had a significantly reduced risk of colorectal cancer (OR = 0.56, 95% CI = 0.31-0.99; OR = 0.44, 95% CI = 0.24-0.77, respectively). Following the Dietary Guidelines or a dietary pattern lower in meat, potatoes, high fat, and refined foods and higher in fruits and vegetables may reduce colorectal cancer risk.

Physical activity and gastrointestinal cancer prevention

Colorectal cancer is the third most common cancer globally and is a leading cause of cancer death. Gastric cancer contributes significantly to the global cancer burden, particularly in low- and middle-income countries. We reviewed the literature for studies on physical activity or exercise and colon, rectal, and gastric cancers as well as colonic adenomatous polyps. We identified 52 studies of colon cancer, 31 studies of rectal cancer, 23 studies of colon polyps, and 16 studies of gastric cancer. Of the 52 studies of physical activity and colon cancer, 37 found a statistically significant association between increased levels of physical activity and decreased colon cancer risk in at least one comparison. Accumulated evidence suggests that physical activity is associated with a 25% reduction in colon cancer risk. In line with previous reports, we found no indication that the association was more pronounced for occupational versus recreational physical activity, with both resulting in a risk reduction of about 22%. Evidence for other domains of physical activity (i.e., transportation or household physical activity) is limited. Evidence is emerging that individuals who are consistently active across the lifetime may obtain greater risk reductions than those who are only active in recent years. Despite consistent associations with colon cancer, evidence is more limited though suggestive that physical activity reduces risk of colon adenomas or adenoma recurrence. There is clear evidence that physical activity is not associated with rectal or gastric cancers.

Processed meat and colorectal cancer: a review of epidemiologic and experimental evidence

Processed meat intake may be involved in the etiology of colorectal cancer, a major cause of death in affluent countries. The epidemiologic studies published to date conclude that the excess risk in the highest category of processed meat-eaters is comprised between 20% and 50% compared with non-eaters. In addition, the excess risk per gram of intake is clearly higher than that of fresh red meat. Several hypotheses, which are mainly based on studies carried out on red meat, may explain why processed meat intake is linked to cancer risk. Those that have been tested experimentally are (i) that high-fat diets could promote carcinogenesis via insulin resistance or fecal bile acids; (ii) that cooking meat at a high temperature forms carcinogenic heterocyclic amines and polycyclic aromatic hydrocarbons; (iii) that carcinogenic N-nitroso compounds are formed in meat and endogenously; (iv) that heme iron in red meat can promote carcinogenesis because it increases cell proliferation in the mucosa, through lipoperoxidation and/or cytotoxicity of fecal water. Nitrosation might increase the toxicity of heme in cured products. Solving this puzzle is a challenge that would permit to reduce cancer load by changing the processes rather than by banning processed meat.