Dose–response meta-analysis of poultry intake and colorectal cancer incidence and mortality

Does Poultry Consumption Increase the Risk of Mortality for Gastrointestinal Cancers? A Preliminary Competing Risk Analysis

Background: Poultry meat is currently among the most widely consumed meats in Italy and worldwide. Poultry is reasonably affordable and accessible, explaining the high global consumption rates. This population-based prospective cohort study investigated the association between meat consumption and gastrointestinal cancers (GCs) and other causes of mortality in southern Italy. Methods: Data were collected from 4869 participants in the MICOL and NUTRIHEP cohorts. The EPIC questionnaire was used to elicit information on food and drink consumption. For analytical purposes, weekly meat consumption was grouped into four categories: total meat: <200 g, 201-300 g, 301-400 g, and >400 g red meat: <150 g, 150-250 g, 251-350 g, and >350 g; poultry: <100 g, 100-200 g, 201-300 g, and >300 g. Cox proportional hazard regression and competing risk models were employed for statistical analysis. Results: Analyzing weekly poultry consumption, it was observed that subjects consuming more than 300 g had a 27% higher risk of death from all causes [HR 1.27; 95% CI (1.00; 1.61)] than those consuming less than 100 g. In addition, for GCs, the SHR for weekly poultry consumption above 300 g was 2.27 [95% CI (1.23; 4.17)], a risk that for men increased to 2.61 [95% CI (1.31; 5.19)]. Conclusions: Our study showed that poultry consumption above 300 g/week is associated with a statistically significant increased mortality risk both from all causes and from GCs. The risk is higher for men than for women.

Heterogeneity in diet-related non-communicable disease risks in a Chinese population

PURPOSE

Sub-optimal food choices contribute to the risk of multiple non-communicable diseases (NCDs) which can be mitigated by improving diet quality. Food consumption patterns may partly account for variation of NCD risks in population subgroups in China. This study aimed to evaluate the risk of diet-related NCDs of observed Chinese diets, and to assess the potential reduction in NCD risks by adhering to certain diet recommendations.

METHODS

Dose-response meta-analyses were used to derive relative risks between three diet-related NCDs and consumption of 15 food groups. 24-h dietary recall data of 12,809 adults from the 2011 China Health and Nutrition Survey were used to estimate the diet-related summed risks (SRs) of NCDs. Twelve Chinese provinces were aggregated into five regions, and stratified by age, gender, overweight status, education, income, and urbanicity. The Chinese Dietary Guideline-2016 (CDG-2016) and the EAT-Lancet diet were used as recommended diets.

RESULTS

Associations between SRs and gender, age, educational level, income level, and urbanicity were observed. No association was found between SRs and overweight status. Both diet recommendations have lower SRs compared to observed diets among all regions. The food groups that contributed most to the variation of the SRs of diet-related NCDs in China were high consumption of red meat and refined grains, and low consumption of whole grains, fruits, and legumes.

CONCLUSION

To address the heterogeneity in diet-related NCD risks, focusing on region-specific dietary practical is imperative for Chinese population, in order to propose tailored guidance to adhere to diet recommendations.

Comparing the Associations of Dietary Patterns Identified through Principal Component Analysis and Cluster Analysis with Colorectal Cancer Risk: A Large Case-Control Study in China

Examining the association between dietary patterns and colorectal cancer (CRC) risk can provide valuable insights beyond the assessment of individual foods or nutrients. However, there is a lack of in-depth analysis of dietary patterns and CRC risk in Chinese populations, and few studies have compared dietary patterns derived from different posteriori methods with the aim of predicting disease risk. The aim of this study was to derive dietary patterns using both principal component analysis (PCA) and cluster analysis (CA) and to assess their respective associations with CRC risk. A large-scale case-control study was conducted in Guangdong Province, China, including 2799 incident colorectal cancer cases and an equal number of frequency-matched controls. Dietary intake information was gathered through the use of a validated food frequency questionnaire. PCA and CA were used to derive dietary patterns. A multivariable logistic regression model was used to calculate the adjusted odds ratio (aOR) and 95% confidence interval (CI). Four major dietary patterns were identified by PCA. CA identified two dietary patterns, referred to as the "Balanced dietary pattern" and the "Refined grain dietary pattern". Notably, there were significant inverse associations between the milk-egg-nut-soy dietary pattern (aOR, 0.51; 95% CI, 0.42, 0.62), the vegetable-fruit dietary pattern (aOR, 0.61; 95%CI, 0.51, 0.74), and the poultry-fish dietary pattern (aOR, 0.81; 95%CI, 0.68, 0.97) and CRC risk. However, the red meat-preserved food dietary pattern was associated with an increased risk of CRC (aOR, 2.99; 95%CI, 2.43, 3.67). When compared with the Refined grain dietary pattern, the Balanced dietary pattern showed a decreased risk of CRC (aOR, 0.59; 95%CI, 0.52, 0.66). The results from the comparison of the two methods indicate that both CA and PCA derived remarkably similar patterns. The combined use of PCA and CA identified consistent underlying patterns, showing comparable associations with CRC risk. These findings suggest that individuals who prefer dietary patterns characterized by a high intake of red meat, preserved food, and refined grains should be cautious about their increased CRC risk. Conversely, dietary patterns rich in fruits, vegetables, and high-quality protein sources are advisable for the prevention of CRC in the Chinese population.

The association between red, processed and white meat consumption and risk of pancreatic cancer: a meta-analysis of prospective cohort studies

PURPOSE

The association between meat consumption and the risk of pancreatic cancer has not been comprehensively investigated by different types of meat. The current study was conducted to evaluate this association.

METHODS

PubMed and Web of Science databases were used to search for prospective cohort studies on meat consumption and pancreatic cancer risk through May 2022. A meta-analysis was performed using random-effects models to combine study-specific relative risks (RR). The quality of the included studies was evaluated using the Newcastle-Ottawa quality assessment scale.

RESULTS

Twenty prospective cohort studies including 3,934,909 participants and 11,315 pancreatic cancer cases were identified. The pooled RR of pancreatic cancer for the highest versus lowest white meat intake category was 1.14 (95% CI: 1.03-1.27). There was no significant association between consumption of red meat and processed meat and pancreatic cancer risk in the highest versus lowest analysis. In dose-response analyses, pooled RRs were 1.14 (95% CI: 1.01-1.28) for an increase in red meat consumption of 120 g per day and 1.26 (95% CI: 1.08-1.47) for an increase in white meat consumption of 100 g per day, respectively. Processed meat consumption showed neither a linear nor a non-linear association with pancreatic cancer risk.

CONCLUSION

Findings from this meta-analysis suggested that high consumption of red meat and white meat is associated with an increased risk of pancreatic cancer. Future prospective studies are warranted to confirm the association between meat consumption and the risk of pancreatic cancer.

Poultry Consumption and Human Health: How Much Is Really Known? A Systematically Searched Scoping Review and Research Perspective

This scoping review was conducted to systematically search and chronicle scientific literature pertinent to poultry intake and human health. The protocol (uploaded to Open Science Framework, https://osf.io/2k7bj/) was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews guidelines. Articles with observational and experimental research, narrative and systematic reviews, and meta-analyses were included. Among 13,141 articles identified, 525 met inclusion criteria. Among these 525 articles, 212 focused on cancer morbidity and mortality; 41 on cardiovascular disease (CVD) morbidity and mortality; 52 on CVD risk factors; 32 on type 2 diabetes mellitus (T2DM) morbidity and mortality; 33 on T2DM risk factors; and 42 on body weight and body composition. An "Other" category (181 articles) included nutrient status, psychological well-being/mental health, cognition, microbiome, chronic kidney disease, nonalcoholic fatty liver disease, skin disorders, and fertility, among others. Among the 525 included articles, 366 were observational, 64 were experimental, and 76 were reviews and meta-analyses. Eighty-three percent of articles focused on adults or older adults. A paucity of research exists to support poultry as health-promoting foods, with most research only indirectly assessing poultry intake compared with other foods of interest (e.g., red meats or plant-based protein foods). No randomized controlled trials and only 1% of OBS assessed the influence of processed poultry intake on human health. In the future, the relative health effects of consuming poultry will be compared with a widening array of traditional and new protein-rich food products, necessitating the need for research to assess poultry as foods of choice. Science and health professionals, the poultry industry, and the public will benefit from new observational and experimental research to address cutting-edge scientific, public policy, and consumer topics pertinent to poultry intake and human health.

How Far Are We from the Planetary Health Diet? A Threshold Regression Analysis of Global Diets

Global diets and food system not only influence human health conditions but also have a great effect on environmental sustainability. The Planetary Health Diet (PHD) proposed by the Lancet Commission is considered as a sustainable diet that meets human’s nutritional demands yet poses less pressure on the environment. In this study, we examine how the economic condition, i.e., Gross Domestic Product per capita (GDP per capita), affects the deviations of current diets from the PHD at the country level by using a threshold regression model. The results show three dimensions regarding food consumption patterns in all 11 kinds of foods across the globe, as evidenced from the data in 147 countries as of 2018. First, the findings indicate that there exist deviations from the PHD for all kinds of foods, which could guide policymakers to make dietary improvements. Second, we find that GDP per capita impacts food consumption patterns with all kinds of foods. The results demonstrate that the changing rates of food consumption amounts decrease as the GDP per capita increases. Finally, we calculate the GDP per capita thresholds for all kinds of foods, and we find the number of thresholds ranging from zero to two. Specifically, 20,000 PPP (current international $), the GDP per capita boundary distinguishing developing and developed countries, is the first GDP per capita threshold influencing the food consumption amount. What is more, the second GDP threshold is 40,000 PPP (current international $), which is the average GDP per capita of developed countries. Thus, we identify the countries that require more financial assistance from a GDP per capita perspective.

Dietary Intake of Red Meat, Processed Meat, and Poultry and Risk of Colorectal Cancer and All-Cause Mortality in the Context of Dietary Guideline Compliance

Meat intake has been linked to increased risk of colorectal cancer (CRC) and mortality. However, diet composition may affect the risks. We aimed to estimate associations between red and processed meat and poultry intake and risk of CRC and all-cause mortality and if they are modified by dietary quality using Cox regression analyses. Baseline dietary data were obtained from three survey rounds of the Danish National Survey on Diet and Physical Activity. Data on CRC and all-cause mortality were extracted from national registers. The cohort was followed from date of survey interview—or for CRC, from age 50 years, whichever came last, until 31 December 2017. Meat intake was analysed categorically and continuously, and stratified by dietary quality for 15–75-year-old Danes at baseline, n 6282 for CRC and n 9848 for mortality analyses. We found no significant association between red and processed meat intake and CRC risk. For poultry, increased CRC risk for high versus low intake (HR 1.62; 95%CI 1.13–2.31) was found, but not when examining risk change per 100 g increased intake. We showed no association between meat intake and all-cause mortality. The association between meat intake and CRC or mortality risk was not modified by dietary quality.

Children and adults should avoid consuming animal products to reduce risk for chronic disease: NO

Excessive attention to the animal versus plant binary food choice reflects society's moral views on eating right. To claim that avoidance of animal products is required to prevent chronic disease is not supported by evidence, makes little sense from an evolutionary perspective, and distracts policy makers from common-sense approaches to achieve adequate nutrition. Animal products provide highly bioavailable nutrients, some of which are not easily obtained from plants, and can play a key role in meeting the nutritional challenges of populations in both high- and low-income countries. This role goes beyond the need for protein and relates to vitamins, minerals, and numerous often-overlooked nutrients, such as long-chain fatty acids, taurine, and choline. Restrictive dietary prescriptions that exclude animal products complicate the quest for optimal nutrition by undermining dietary diversity and flexibility, and by introducing a dependency on fortification and supplementation. Thus, a vegan diet may put the general population at increased risk of poor nutrition, a problem of particular concern for those with special nutritional requirements.

Development of the anti-cancer food scoring system 2.0: Validation and nutritional analyses of quantitative anti-cancer food scoring model

BACKGROUND/OBJECTIVES

We have previously designed the anti-cancer food scoring model (ACFS) 1.0, an evidence-based quantitative tool analyzing the anti-cancer or carcinogenic potential of diets. Analysis was performed using simple quantitative indexes divided into 6 categories (S, A, B, C, D, and E). In this study, we applied this scoring model to wider recipes and evaluated its nutritional relevance.

MATERIALS/METHODS

National or known regional databases were searched for recipes from 6 categories: Korean out-dining, Korean home-dining, Western, Chinese, Mediterranean, and vegetarian. These recipes were scored using the ACFS formula and the nutrition profiles were analyzed.

RESULTS

Eighty-eight international recipes were analyzed. All S-graded recipes were from vegetarian or Mediterranean categories. The median code values of each category were B (Korean home-dining), C (Korean out-dining), B (Chinese), A (Mediterranean), S (vegetarian), and D (Western). The following profiles were correlated (P < 0.05) with ACFS grades in the univariate trend analysis: total calories, total fat, animal fat, animal protein, total protein, vitamin D, riboflavin, niacin, vitamin B₁₂, pantothenic acid, sodium, animal iron, zinc, selenium, and cholesterol (negative trends), and carbohydrate rate, fiber, water-soluble fiber, vitamin K, vitamin C, and plant calcium (positive trends). Multivariate analysis revealed that animal fat, animal iron, and niacin (negative trends) and animal protein, fiber, and vitamin C (positive trends) were statistically significant. Pantothenic acid and sodium showed non-significant negative trends (P < 0.1), and vitamin B₁₂ showed a non-significant positive trend.

CONCLUSION

This study provided a nutritional basis and extended the utility of ACFS, which is a bridgehead for future cancer-preventive clinical trials using ACFS.

Multiple health and environmental impacts of foods

Dietary choices are a leading global cause of mortality and environmental degradation and threaten the attainability of the UN’s Sustainable Development Goals and the Paris Climate Agreement. To inform decision making and to better identify the multifaceted health and environmental impacts of dietary choices, we describe how consuming 15 different food groups is associated with 5 health outcomes and 5 aspects of environmental degradation. We find that foods associated with improved adult health also often have low environmental impacts, indicating that the same dietary transitions that would lower incidences of noncommunicable diseases would also help meet environmental sustainability targets.

Food choices are shifting globally in ways that are negatively affecting both human health and the environment. Here we consider how consuming an additional serving per day of each of 15 foods is associated with 5 health outcomes in adults and 5 aspects of agriculturally driven environmental degradation. We find that while there is substantial variation in the health outcomes of different foods, foods associated with a larger reduction in disease risk for one health outcome are often associated with larger reductions in disease risk for other health outcomes. Likewise, foods with lower impacts on one metric of environmental harm tend to have lower impacts on others. Additionally, of the foods associated with improved health (whole grain cereals, fruits, vegetables, legumes, nuts, olive oil, and fish), all except fish have among the lowest environmental impacts, and fish has markedly lower impacts than red meats and processed meats. Foods associated with the largest negative environmental impacts—unprocessed and processed red meat—are consistently associated with the largest increases in disease risk. Thus, dietary transitions toward greater consumption of healthier foods would generally improve environmental sustainability, although processed foods high in sugars harm health but can have relatively low environmental impacts. These findings could help consumers, policy makers, and food companies to better understand the multiple health and environmental implications of food choices.

Consumption of meat, traditional and modern processed meat and colorectal cancer risk among the Moroccan population: A large-scale case-control study

The current study aimed to investigate the relationship between red and white meat subtypes, processed meat (divided into traditional "Khlii, Kaddid" and industrially processed meat) and colorectal cancer (CRC) risk, considering CRC subsites, in Moroccan adults. A case-control study was conducted including 2,906 matched case-control pairs recruited from the five largest university hospitals in Morocco. Dietary data were collected through a validated Food Frequency Questionnaire (FFQ). Multivariable odds ratios (OR) and 95% confidence intervals (CI), for the association of CRC risk with meat consumption (high vs. low intake), were estimated using conditional logistic regression models, adjusted for relevant confounding variables. Overall, consumption of red meat was positively associated with colon cancer and CRC risk (OR = 1.23, 95% CI = 1.05-1.44; OR = 1.14, 95% CI = 1.02-1.27), respectively. In contrast, no significant association was observed between the consumption of red meat and rectal cancer risk (OR = 1.05, 95% = 0.90-1.23). Interestingly, while processed meat from industrial processes was positively associated with colon cancer, rectal cancer and CRC (OR = 1.61, 95% CI = 1.27-2.04; OR = 1.73, 95% CI = 1.34-2.23; OR = 1.67, 95% CI = 1.41-1.98), processed meat prepared using traditional methods was inversely associated with colon cancer and CRC risk (OR = 0.74, 95% CI = 0.57-0.98; OR = 0.77, 95% CI = 0.64-0.93), respectively. Furthermore, positive associations were observed between poultry intake and colon cancer risk among men (OR = 1.27, 95% CI = 1.01-1.59). Our study showed similar associations between the consumption of red meat and CRC risk in Morocco as in developed countries, while inverse associations were found for traditionally processed meat products. This is the first study to investigate the differential effects of traditional vs. westernized processed meat products in a developing country. Other studies are needed to confirm these findings and to understand the physiological pathways underlying these associations.

Mediterranean Diet Pyramid: A Proposal for Italian People. A Systematic Review of Prospective Studies to Derive Serving Sizes

In the last decade, a number of meta-analyses of mostly observational studies evaluated the relation between the intake of food groups and the risk of noncommunicable diseases (NCDs). In this study, we systematically reviewed dose-response meta-analyses of prospective studies with the aim to derive the quantities of food to consume to attain a protective (Mediterranean food) or a non-adverse (non-Mediterranean food) effect toward selected NCDs such as cardiovascular disease (CVD) including coronary heart disease (CHD) and stroke, type 2 diabetes (T2DM), colorectal (CRC) and breast cancer. These derived quantities, wherever possible, were suggested for a quantification of food servings of the Mediterranean Diet Pyramid proposed for Italian People (MDPPI). This pyramid came from the Modern Mediterranean Diet Pyramid developed in 2009 for Italian people. A weekly menu plan was built on the advice about frequency of intakes and serving sizes of such pyramid and the nutritional composition of this diet was compared with the Reference Italian Mediterranean Diet followed in 1960 in Nicotera. The diet built according the advice of MDPPI was very similar to that of Nicotera in the late 1950s that has been chosen as Italian Reference Mediterranean Diet with the exception of percentage of energy provided by cereals that was lower and of fruits and vegetables that was higher. Saturated fatty acids were only the 6% of daily energy intake. Also the Mediterranean Adequacy Index (MAI) was very similar to that of the aforementioned diet.

The association of dietary animal and plant protein with putative risk markers of colorectal cancer in overweight pre-diabetic individuals during a weight-reducing programme: a PREVIEW sub-study

PURPOSE

Diets with increased protein content are popular strategies for body weight regulation, but the effect of such diets for the colonic luminal environment is unclear. We aimed to investigate the associations between putative colorectal cancer-related markers and total protein intake, plant and animal proteins, and protein from red and processed meat in pre-diabetic adults (> 25 years).

METHODS

Analyses were based on clinical and dietary assessments at baseline and after 1 year of intervention. Protein intake was assessed from 4-day dietary records. Putative colorectal cancer-related markers identified from 24-h faecal samples collected over three consecutive days were: concentration of short-chain fatty acids, phenols, ammonia, and pH.

RESULTS

In total, 79 participants were included in the analyses. We found a positive association between change in total protein intake (slope: 74.72 ± 28.84 µmol per g faeces/E%, p = 0.01), including animal protein intake (slope: 87.63 ± 32.04 µmol per g faeces/E%, p = 0.009), and change in faecal ammonia concentration. For change in ammonia, there was a dose-response trend from the most negative (lowest tertile) to the most positive (highest tertile) association (p = 0.01): in the high tertile, a change in intake of red meat was positively associated with an increase in ammonia excretion (slope: 2.0 ± 0.5 µmol per g faeces/g/day, p < 0.001), whereas no such association was found in the low and medium tertile groups.

CONCLUSION

Increases in total and animal protein intakes were associated with higher excretion of ammonia in faeces after 1 year in overweight pre-diabetic adults undertaking a weight-loss intervention. An increase in total or relative protein intake, or in the ratio of animal to plant protein, was not associated with an increase in faeces of any of the other putative colorectal cancer risk markers.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01777893.

Adherence to the Mediterranean diet and risk of lung cancer in the Netherlands Cohort Study

The evidence on a cancer-protective effect of the Mediterranean diet (MD) is still limited. Therefore, we investigated the association between MD adherence and lung cancer risk. Data were used from 120 852 participants of the Netherlands Cohort Study (NLCS), aged 55-69 years. Dietary habits were assessed at baseline (1986) using a validated FFQ and alternate and modified Mediterranean diet scores (aMED and mMED, respectively), including and excluding alcohol, were calculated. After 20·3 years of follow-up, 2861 lung cancer cases and 3720 subcohort members (case-cohort design) could be included in multivariable Cox regression analyses. High (6-8) v. low (0-3) aMED excluding alcohol was associated with non-significantly reduced lung cancer risks in men and women with hazard ratios of 0·91 (95 % CI 0·72, 1·15) and 0·73 (95 % CI 0·49, 1·09), respectively. aMED-containing models generally fitted better than mMED-containing models. In never smokers, a borderline significant decreasing trend in lung cancer risk was observed with increasing aMED excluding alcohol. Analyses stratified by the histological lung cancer subtypes did not identify subtypes with a particularly strong inverse relation with MD adherence. Generally, the performance of aMED and World Cancer Research Fund/American Institute for Cancer Research dietary score variants without alcohol was comparable. In conclusion, MD adherence was non-significantly inversely associated with lung cancer risk in the NLCS. Future studies should focus on differences in associations across the sexes and histological subtypes. Furthermore, exclusion of alcohol from MD scores should be investigated more extensively, primarily with respect to a potential role of the MD in cancer prevention.

The Mediterranean diet and risk of colorectal cancer in the UK Women's Cohort Study

Background

Evidence from epidemiological studies investigating associations between adherence to the Mediterranean diet and colorectal cancer is inconsistent. The aim of this study is to assess in the UK Women's Cohort Study whether adherence to the Mediterranean dietary pattern is associated with reduced incidence of cancers of the colon and rectum.

Method

A total of 35 372 women were followed for a median of 17.4 years. A 10-component score indicating adherence to the Mediterranean diet was generated for each cohort participant, using a 217-item food frequency questionnaire. The Mediterranean diet score ranged from 0 for minimal adherence to 10 for maximal adherence. Cox proportional hazards regression was used to provide adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for colon and rectal cancer risk.

Results

A total of 465 incident colorectal cancer cases were documented. In the multivariable adjusted model, the test for trend was positive (HR = 0.88, 95% CI: 0.78 to 0.99; Ptrend = 0.03) for a 2-point increment in the Mediterranean diet score. For rectal cancer, a 2-point increment in the Mediterranean diet score resulted in an HR (95% CI) of 0.69 (0.56 to 0.86), whereas a 62% linear reduced risk (HR 0.38; 95% CI: 0.20 to 0.74; Ptrend < 0.001) was observed for women within the highest vs the lowest category of the MD score. Estimates for an association with colon cancer were weak (Ptrend = 0.41).

Conclusions

Findings suggest that women adhering to a Mediterranean dietary pattern may have a lower risk of colorectal cancer, especially rectal cancer.

Late effect of the food consumption on colorectal cancer rate

Studies have suggested that higher meat intake may increase colorectal cancer (CRC) risk while higher vegetable intake may reduce this risk. There is a substantial lag between the time of exposure to a risk factor (or protective factor) and incidence of cancer. For CRC, in particular, the time from formation of adenoma to occurrence of CRC takes from 10 to 15 years, or even more. This study correlates food disappearance data per capita for vegetable and meat with future age-adjusted CRC rates in USA. The lag weights, with a high confidence, showed that there is a positive correlation between the red meat availability and CRC age-adjusted incidence rates with a lag of at least 17 years and an Almon polynomial degree of 2. Conversely, there was a negative correlation between vegetables availability and future age-adjusted incidence rates of CRC.

Meat intake, cooking methods and doneness and risk of colorectal tumours in the Spanish multicase-control study (MCC-Spain)

PURPOSE

Although there is convincing evidence that red and processed meat intake increases the risk of colorectal cancer (CRC), the potential role of meat cooking practices has not been established yet and could partly explain the current heterogeneity of results among studies. Therefore, we aimed to investigate the association between meat consumption and cooking practices and the risk of CRC in a population-based case-control study.

METHODS

A total of 1671 CRC cases and 3095 controls recruited in Spain between September 2008 and December 2013 completing a food frequency questionnaire with a meat-specific module were included in the analyses. Odds ratios (OR) and confidence intervals (CI) were estimated by logistic regression models adjusted for known confounders.

RESULTS

Total meat intake was associated with increased risk of CRC (OR T3-T1 1.41; 95% CI 1.19-1.67; p trend < 0.001), and similar associations were found for white, red and processed/cured/organ meat. Rare-cooked meat preference was associated with low risk of CRC in red meat (ORrare vs. medium 0.66; 95% CI 0.51-0.85) and total meat (ORrare vs. medium 0.56; 95% CI 0.37-0.86) consumers, these associations being stronger in women than in men. Griddle-grilled/barbecued meat was associated with an increased CRC risk (total meat: OR 1.45; 95% CI 1.13-1.87). Stewing (OR 1.25; 95% CI 1.04-1.51) and oven-baking (OR 1.18; 95% CI 1.00-1.40) were associated with increased CRC risk of white, but not red, meat.

CONCLUSIONS

Our study supports an association of white, red, processed/cured/organ and total meat intake with an increased risk of CRC. Moreover, our study showed that cooking practices can modulate such risk.

Meat and milk intake in the rice-based Korean diet: impact on cancer and metabolic syndrome

Over a few decades, Korean diet has changed from traditional diet, mainly composed of rice and vegetables, to Westernised diet rich, in meat and milk, along with the economic development and globalisation. Increasing prevalence of diet-related chronic diseases such as cancer and metabolic syndrome (MetS) is becoming a heavy burden to society and requires further attention. In this review, the association of meat and milk consumption with cancer and MetS among Koreans was discussed. Previous meta-analyses showed that meat intake was positively associated with increased risk of cancers, especially colon, as well as obesity and type 2 diabetes mellitus, and that the intake of milk and dairy products was negatively associated with colorectal cancer, obesity, and type 2 diabetes mellitus, based on studies conducted mostly in Western countries. In Korea and other Asian countries, the association of meat and milk intake with cancers were inconclusive and varied by types of cancers. Conversely, milk intake was negatively associated with MetS risk as reported in Western countries. The difference in results between Korea and Western countries might come from the differences in dietary patterns and study designs. Most Koreans still maintain traditional dietary pattern, although rapid change towards Westernised diet is underway among the younger age group. Randomised clinical trials or prospective cohort studies with consideration of combined effects of various dietary factors in Korea and other Asian countries are needed to elucidate the impact of meat and milk or related dietary patterns in their diet.

Nutrients, foods, and colorectal cancer prevention

Diet has an important role in the development of colorectal cancer. In the past few decades, findings from extensive epidemiologic and experimental investigations have linked consumption of several foods and nutrients to the risk of colorectal neoplasia. Calcium, fiber, milk, and whole grains have been associated with a lower risk of colorectal cancer, and red meat and processed meat have been associated with an increased risk. There is substantial evidence for the potential chemopreventive effects of vitamin D, folate, fruits, and vegetables. Nutrients and foods also may interact, as a dietary pattern, to influence colorectal cancer risk. Diet likely influences colorectal carcinogenesis through several interacting mechanisms. These include the direct effects on immune responsiveness and inflammation, and the indirect effects of overnutrition and obesity-risk factors for colorectal cancer. Emerging evidence also implicates the gut microbiota as an important effector in the relationship between diet and cancer. Dietary modification therefore has the promise of reducing colorectal cancer incidence.