Dietary patterns and colorectal cancer risk in middle-aged adults: A large population-based prospective cohort study

Difference in Gastrointestinal Cancer Risk and Mortality by Dietary Pattern Analysis: A Systematic Review and Meta-Analysis

CONTEXT

Several studies have demonstrated that dietary patterns identified by a posteriori and hybrid methods are associated with gastrointestinal (GI) cancer risk and mortality. These studies applied different methods for analyzing dietary data and reported inconsistent findings.

OBJECTIVE

This systematic review and meta-analysis were aimed to determine the association between dietary patterns, derived using principal component analysis (PCA) and reduced rank regression (RRR), and GI cancer risk and GI cancer-caused mortality.

DATA SOURCE

Articles published up to June 2023 in English were eligible for inclusion. The Medline, SCOPUS, Cochrane Library, CINHAL, PsycINFO, ProQuest, and Web of Sciences databases were used to identify prospective studies. The Preferred Reporting Item for Systematic Review and Meta-analysis Protocol 2020 was used to report results.

DATA EXTRACTION

A total of 28 studies were eligible for inclusion. Varied approaches to deriving dietary patterns were used, including PCA (n = 22), RRR (n = 2), combined PCA and RRR (n = 1), cluster analysis (CA; n = 2) and combined PCA and CA (n = 1).

DATA ANALYSIS

Two dietary patterns, "healthy" and "unhealthy," were derived using PCA and RRR. The healthy dietary pattern was characterized by a higher intake of fruits, whole grains, legumes, vegetables, milk, and other dairy products, whereas the unhealthy dietary pattern was characterized by a higher intake of red and processed meat, alcohol, and both refined and sugar-sweetened beverages. The findings indicated that the PCA-derived healthy dietary pattern was associated with an 8% reduced risk (relative risk [RR], 0.92; 95% CI, 0.87-0.98), and the unhealthy dietary pattern was associated with a 14% increased risk (RR, 1.14; 95% CI, 1.07-1.22) of GI cancers. Similarly, the RRR-derived healthy dietary pattern (RR, 0.83; 95% CI, 0.61-1.12) may be associated with reduced risk of GI cancers. In contrast, the RRR-derived unhealthy dietary pattern (RR, 0.93; 95% CI, 0.57-1.52) had no association with a reduced risk of GI cancers. Similarly, evidence suggested that PCA-derived healthy dietary patterns may reduce the risk of death from GI cancers, whereas PCA-derived unhealthy dietary patterns may increase the risk.

CONCLUSION

Findings from prospective studies on the association of PCA-derived dietary patterns and the risk of GI cancers support the evidence of healthy and unhealthy dietary patterns as either protective or risk-increasing factors for GI cancers and for survivorship, respectively. The findings also suggest that the RRR-derived healthy dietary pattern reduces the risk of GI cancers (albeit with low precision), but no association was found for the RRR-derived unhealthy dietary pattern. Prospective studies are required to further clarify disparities in the association between PCA- and RRR-derived dietary patterns and the risk of GI cancers. Systematic review registration: PROSPERO registration no. CRD42022321644.

Intestinal Bacteria Fluctuating in Early-Stage Colorectal Cancer Carcinogenesis are Associated with Diet in Healthy Adults

This hospital-based, cross-sectional study aimed to explore the association between diet and fluctuating intestinal bacteria in early-stage colorectal cancer (CRC) (Atopobium parvulum, Actinomyces odontolyticus, Solobacterium moorei, and Bifidobacterium longum). Healthy participants (n = 212) who underwent total colonoscopy at National Cancer Center Hospital (Tokyo, Japan) were divided into two groups according to the relative abundance of bacteria in their feces: those in the top 25% of relative bacterial abundance as cases and the bottom 25% as controls. The participants were divided into three groups (low, medium, and high) according to their intake of food groups associated with CRC. Multivariable logistic regression analysis was conducted to estimate the association between dietary intake and higher relative abundance of bacteria. Dairy products were inversely associated with a higher relative abundance of A. parvulum, A. odontolyticus, and S. moorei, with odds ratios (high vs. low) and 95% confidence interval as follows: 0.16 (0.06-0.44), 0.25 (0.08-0.82), and 0.29 (0.11-0.78), respectively. Additionally, dietary fiber was inversely associated with a higher relative abundance of S.moorei (0.29 [0.11-0.78]). No association was observed between diet and B.longum. In conclusion, healthy adults with a higher intake of dairy products and fiber had lower odds of having a higher relative abundance of CRC-associated microbiota.

Possible Involvement of Long Non-Coding RNAs GNAS-AS1 and MIR205HG in the Modulation of 5-Fluorouracil Chemosensitivity in Colon Cancer Cells through Increased Extracellular Release of Exosomes

A growing number of studies have suggested the involvement of long non-coding RNAs as the key players in not just the initiation and progression of the tumor microenvironment, but also in chemotherapy tolerance. In the present study, generated 5-FU-resistant SW480/DR cells were analyzed via cDNA microarray for its aberrant lncRNAs and mRNAs expression in comparison with the 5-FU-susceptible SW480/DS cells. Among the 126 lncRNAs described, lncRNAs GNAS-AS1, MIR205HG, and LOC102723721 have been identified to be significantly upregulated, while lncRNs lnc-RP11-597K23.2.1-2, LOC100507639, and CCDC144NL-AS1 have been found to be significantly downregulated. In the meantime, bioinformatic analysis through gene ontology studies of aberrantly expressed mRNAs revealed "regulated exocytosis", among others, as the biological process most impacted in SW480/DR cells. To investigate, exosome purification was then carried out and its characterization were validated via transmission electron microscopy and nanoparticle tracking analysis. Interestingly, it was determined that the 5-FU-resistant SW480/DR cells secretes significantly higher concentration of extracellular vesicles, particularly, exosomes when compared to the 5-FU-susceptible SW480/DS cells. Based on the lncRNA-mRNA interaction network analysis generated, lncRNA GNAS-AS1 and MIR205HG have been identified to be potentially involved in the incidence of 5-FU resistance in SW480 colon cancer cells through promoting increased release of exosomes into the intercellular matrix. Our study hopes not only to provide insights on the list of involved candidate lncRNAs, but also to elucidate the role exosomes play in the initiation and development of 5-FU chemotherapy resistance in colon cancer cells.

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 of the healthy eating index with risk of colorectal cancers (overall and by subsite) among Canadians

BACKGROUND

Healthy dietary patterns characterized by high intake of fruits and vegetables, grains/cereals, and lean meat/fish, and low intake of red/processed meats and refined carbohydrates, have been shown to be associated with reduced risk of colorectal cancer, but evidence regarding their association with colorectal cancer subsites is limited. Hence, this study was conducted to assess the association of a healthy dietary pattern, as reflected in the Healthy Eating Index (HEI) (a composite score based on consumption of various food groups), with risk of colorectal cancer, overall and by subsite.

METHODS

We conducted a case-cohort study in the Canadian Study of Diet, Lifestyle and Health (CSDLH). The study included all cases of incident colorectal cancer in the entire cohort, and an age-stratified subcohort of 3185 women and 2622 men. Cox regression models were used to estimate hazard ratios (HR) for the association between the HEI and the risk of colorectal cancer, overall and by subsite. We also assessed the association by sex and by selected metabolic factors.

RESULTS

For both sexes combined, the highest quintile of the HEI score was inversely associated with risk of colorectal cancer, colon cancer and proximal colon cancer (HR: 0.65; 95% CI: 0. 49-0.85, HR: 0.60, 95% CI: 0.44-0.83 and HR: 0.54, 95% CI: 0.35-0.85, respectively). However, these associations were mostly observed among men (HR: 0.56; 95% CI: 0.38-0.81, HR: 0.44, 95% CI: 0.28-0.69 and HR: 0.26; 95% CI: 0.12-0.56, for colorectal cancer, colon cancer and proximal colon cancer, respectively; p-interactions=0.029, 0.032 and 0.063, respectively). An inverse association was also observed between the HEI and risk of colorectal cancer among normal weight participants, overweight/obese participants, non-smokers, non-alcohol drinkers and participants who were physically inactive.

CONCLUSION

A healthy dietary pattern may reduce risk of colorectal cancer, particularly among men.

Dietary patterns associated with colorectal cancer risk in the Malaysian population: a case-control study with exploratory factor and regression analysis

BACKGROUND

Studies on the relationship between diet and colorectal cancer (CRC) risk using single food or nutrient approach are widely conducted as opposed to dietary pattern approach. Therefore, this study aimed to determine the major dietary patterns and their association with CRC risk among Malaysians.

METHODS

Patients aged between 18 and 80 years old from two teaching hospitals in Peninsular Malaysia were recruited through purposive sampling. Socio-demographic information and anthropometry data were assessed before the colonoscopy procedure, and dietary intake was also recorded using a validated semi-quantitative food frequency questionnaire (FFQ). Cases were those patients having histopathologically proven CRC, while controls were those without.

RESULTS

Four major dietary patterns were identified: the allergenic diet, plant-based diet, processed diet, and energy-dense diet pattern. After adjusting for potential covariates, the processed diet pattern was consistently associated with CRC (OR = 3.45; 95% CI = 1.25-9.52; P = 0.017) while the plant-based diet, energy-dense diet, and allergenic diet were not associated with CRC risk.

CONCLUSIONS

The processed diet pattern attributed to a diet high in confectionaries and fast foods was associated with an increased risk of CRC in the Malaysian population. In order to give prevention measures through lifestyle change, more research could be done on the effect of food patterns on faecal microbiota associated with CRC.

Association Between Diet and Fusobacterium nucleatum in the Feces of Healthy Adults: A Hospital-based Cross-sectional Study

Fusobacterium nucleatum is involved in the development and progression of colorectal cancer. Although the gut microbiota is influenced by diet, studies on the association between diet and F. nucleatum are limited. We aimed to evaluate the association between various dietary factors and fecal F. nucleatum in healthy adults without a history of colorectal cancer or precancerous lesions. This was a cross-sectional study. Subjects who underwent total colonoscopy at the National Cancer Center Hospital (Tokyo, Japan) were included. Healthy subjects (n = 212) were divided into two groups according to the presence or absence of F. nucleatum in their feces which was calculated from data of whole-genome shotgun sequencing, with the group with F. nucleatum serving as cases and the group without F. nucleatum serving as controls. Multivariable logistic regression analysis adjusted potential confounders was conducted to estimate the associations between dietary intake and nutrients estimated by a validated food frequency questionnaire and the presence of F. nucleatum in the feces. There was a significant inverse association between dairy products and the presence of fecal F. nucleatum [high vs. low; OR, 0.41; 95% confidence interval, 0.17-0.95; Ptrend, 0.039]. These results may have important implications for colorectal cancer prevention through nutritional intervention.

PREVENTION RELEVANCE

F. nucleatum is well known as a colorectal cancer-associated bacterium. Dietary habits alter the composition and function of the intestinal microbiota. A high intake of dairy products in healthy adults may reduce F. nucleatum and prevent colorectal cancer.

Adherence to the Western, Prudent and Mediterranean Dietary Patterns and Colorectal Cancer Risk: Findings from the Spanish Cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Spain)

The aim of this study was to explore the association between three previously identified dietary patterns (Western, Prudent, and Mediterranean) and colorectal cancer (CRC) risk by sex and cancer subtype. The Spanish cohort of the European Prospective Investigation into Cancer and Nutrition study provided dietary and epidemiological information from 15,629 men and 25,808 women recruited between 1992 and 1996. Among them, 568 CRC cases and 3289 deaths were identified during a median follow-up of 16.98 years. The associations between adherence to the three dietary patterns and CRC risk (overall, by sex, and by tumour location: proximal and distal colon and rectum) were investigated by fitting multivariate Cox proportional hazards regression models stratified by study centre and age. Possible heterogeneity of the effects by sex and follow-up time (1–10 vs. ≥10 years) was also explored. While no clear effect of the Prudent dietary pattern on CRC risk was found, a suggestive detrimental effect of the Western dietary pattern was observed, especially during the first 10 years of follow-up (HR_1SD-increase (95% CI): 1.17 (0.99–1.37)), among females (HR_1SD-increase (95% CI): 1.31 (1.06–1.61)), and for rectal cancer (HR_1SD-increase (95% CI): 1.38 (1.03–1.84)). In addition, high adherence to the Mediterranean pattern seemed to protect against CRC, especially when restricting the analyses to the first 10 years of follow-up (HR_1SD-increase (95% CI): 0.84 (0.73–0.98)), among males (HR_1SD-increase (95% CI): 0.80 (0.65–0.98)), and specifically against distal colon cancer (HR_1SD-increase (95% CI): 0.81 (0.63–1.03)). In conclusion, low adherence to the Western diet and high adherence to the Mediterranean dietary pattern could prevent CRC, especially distal colon and rectal cancer.

The Relationship Between Plant-Based Diet and Risk of Digestive System Cancers: A Meta-Analysis Based on 3,059,009 Subjects

Background and Objectives

Diets containing red or processed meat are associated with a growing risk of digestive system cancers. Whether a plant-based diet is protective against cancer needs a high level of statistical evidence.

Methods

We performed a meta-analysis of five English databases, including PubMed, Medline, Embase, Web of Science databases, and Scopus, on October 24, 2021 to identify published papers. Cohort studies or case-control studies that reported a relationship between plant-based diets and cancers of the digestive system were included. Summary effect-size estimates are expressed as Risk ratios (RRs) or Odds ratios (ORs) with 95% confidence intervals and were evaluated using random-effect models. The inconsistency index (I²) and τ² (Tau²) index were used to quantify the magnitude of heterogeneity derived from the random-effects Mantel-Haenszel model.

Results

The same results were found in cohort (adjusted RR = 0.82, 95% CI: 0.78–0.86, P < 0.001, I² = 46.4%, Tau² = 0.017) and case-control (adjusted OR = 0.70, 95% CI: 0.64–0.77, P < 0.001, I² = 83.8%, Tau² = 0.160) studies. The overall analysis concluded that plant-based diets played a protective role in the risk of digestive system neoplasms. Subgroup analyses demonstrated that the plant-based diets reduced the risk of cancers, especially pancreatic (adjusted RR = 0.71, 95% CI: 0.59–0.86, P < 0.001, I² = 55.1%, Tau² = 0.028), colorectal (adjusted RR = 0.76, 95% CI: 0.69–0.83, P < 0.001, I² = 53.4%, Tau² = 0.023), rectal (adjusted RR = 0.84, 95% CI: 0.78–0.91, P < 0.001, I² = 1.6%, Tau² = 0.005) and colon (adjusted RR = 0.88, 95% CI: 0.82–0.95, P < 0.001, I² = 0.0%, Tau² = 0.000) cancers, in cohort studies. The correlation between vegan and other plant-based diets was compared using Z-tests, and the results showed no difference.

Conclusions

Plant-based diets were protective against cancers of the digestive system, with no significant differences between different types of cancer.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022322276, Identifier: CRD42022322276.

Low-carbohydrate diet and risk of cancer incidence: The Japan Public Health Center-based prospective study

Epidemiological evidence on the effects of a long‐term low‐carbohydrate diet (LCD) on cancer incidence remains sparse. We investigate the association between LCD and the risk of overall and specific cancer site incidence in a Japanese population‐based prospective cohort study among 90 171 participants aged 45‐74. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs). During a median 17.0 y of follow‐up, we identified 15 203 cancer cases. A higher overall LCD score was associated with increased overall cancer risk (HR = 1.08 [CI: 1.02‐1.14], P‐trend = .012), while it was associated with decreased gastric cancer (GC) risk (0.81 [0.71‐0.93], P‐trend = .006). A higher animal‐based LCD score was associated with higher risk of overall cancer (1.08 [1.02‐1.14], P‐trend = .003), colorectal cancer (CRC) (1.11 [0.98‐1.25], P‐trend = .018), rectal cancer (RC) (1.24 [1.00‐1.54], P‐trend = .025), lung cancer (LC) (1.16 [1.00‐1.34], P‐trend = .042), and lower risk of GC (0.90 [0.79‐1.01], P‐trend = .033). Furthermore, we found that plant‐based LCD score was related to lower GC incidence (0.87 [0.77‐0.99], P‐trend = .031). Additionally, adjusted for plant fat intake amplified the adverse associations (overall cancer: 1.08 [1.02‐1.14] vs. 1.11 [1.05‐1.18]; CRC: 1.08 [0.95‐1.22] vs. 1.13 [0.99‐1.30]; LC: 1.14 [0.98‐1.33] vs. 1.19 [1.01‐1.41]). We conclude that LCD enriching with animal products was associated with increased overall cancer, CRC, and LC incidence. These adverse associations could be attenuated by plant fat consumption. LCD reduces the risk of developing GC. Long‐term adherence to LCD without paying attention to the balance between animal and plant food source consumption might cause adverse overall cancer incidence consequences.

The Role of Fruit by-Products as Bioactive Compounds for Intestinal Health

The fruit processing industry generates large amounts of wastes (pomace, seeds, peels) that causes negative environmental impact with considerable treatment expenses. Nevertheless, various studies demonstrated that these by-products are still rich in bioactive compounds, especially dietary fibres and phenolic compounds, thus leading to significant chemical, physical and biological properties. These characteristics make fruits by-products a good source for new supplements in food products having important effect on intestinal function. Thus, the aim of this review is to evaluate the different bioactive compounds isolated from fruit by-products and to analyse their application in various formulations for the food and nutraceutical industries. In consideration of the biological properties of these compounds, their role in the functioning and action on intestine and gut flora was discussed.

Influence of gastrectomy for gastric cancer treatment on faecal microbiome and metabolome profiles

OBJECTIVE

Recent evidence points to the gut microbiome's involvement in postoperative outcomes, including after gastrectomy. Here, we investigated the influence of gastrectomy for gastric cancer on the gut microbiome and metabolome, and how it related to postgastrectomy conditions.

DESIGN

We performed shotgun metagenomics sequencing and capillary electrophoresis time-of-flight mass spectrometry-based metabolomics analyses on faecal samples collected from participants with a history of gastrectomy for gastric cancer (n=50) and compared them with control participants (n=56).

RESULTS

The gut microbiota in the gastrectomy group showed higher species diversity and richness (p<0.05), together with greater abundance of aerobes, facultative anaerobes and oral microbes. Moreover, bile acids such as genotoxic deoxycholic acid and branched-chain amino acids were differentially abundant between the two groups (linear discriminant analysis (LDA) effect size (LEfSe): p<0.05, q<0.1, LDA>2.0), as were also Kyoto Encyclopedia of Genes and Genomes modules involved in nutrient transport and organic compounds biosynthesis (LEfSe: p<0.05, q<0.1, LDA>2.0).

CONCLUSION

Our results reveal alterations of gut microbiota after gastrectomy, suggesting its association with postoperative comorbidities. The multi-omic approach applied in this study could complement the follow-up of patients after gastrectomy.

KRAS, NRAS, and BRAF mutation prevalence, clinicopathological association, and their application in a predictive model in Mexican patients with metastatic colorectal cancer: A retrospective cohort study

Mutations in KRAS, NRAS, and BRAF (RAS/BRAF) genes are the main predictive biomarkers for the response to anti-EGFR monoclonal antibodies (MAbs) targeted therapy in metastatic colorectal cancer (mCRC). This retrospective study aimed to report the mutational status prevalence of these genes, explore their possible associations with clinicopathological features, and build and validate a predictive model. To achieve these objectives, 500 mCRC Mexican patients were screened for clinically relevant mutations in RAS/BRAF genes. Fifty-two percent of these specimens harbored clinically relevant mutations in at least one screened gene. Among these, 86% had a mutation in KRAS, 7% in NRAS, 6% in BRAF, and 2% in both NRAS and BRAF. Only tumor location in the proximal colon exhibited a significant correlation with KRAS and BRAF mutational status (p-value = 0.0414 and 0.0065, respectively). Further t-SNE analyses were made to 191 specimens to reveal patterns among patients with clinical parameters and KRAS mutational status. Then, directed by the results from classical statistical tests and t-SNE analysis, neural network models utilized entity embeddings to learn patterns and build predictive models using a minimal number of trainable parameters. This study could be the first step in the prediction for RAS/BRAF mutational status from tumoral features and could lead the way to a more detailed and more diverse dataset that could benefit from machine learning methods.

Genoprotective activities of plant natural substances in cancer and chemopreventive strategies in the context of 3P medicine

Severe durable changes may occur to the DNA structure caused by exogenous and endogenous risk factors initiating the process of carcinogenesis. By evidence, a large portion of malignancies have been demonstrated as being preventable. Moreover, the targeted prevention of cancer onset is possible, due to unique properties of plant bioactive compounds. Although genoprotective effects of phytochemicals have been well documented, there is an evident lack of articles which would systematically present the spectrum of anticancer effects by phytochemicals, plant extracts, and plant-derived diet applicable to stratified patient groups at the level of targeted primary (cancer development) and secondary (cancer progression and metastatic disease) prevention. Consequently, clinical implementation of knowledge accumulated in the area is still highly restricted. To stimulate coherent co-development of the dedicated plant bioactive compound investigation on one hand and comprehensive cancer preventive strategies on the other hand, the current paper highlights and deeply analyses relevant evidence available in the area. Key molecular mechanisms are presented to detail genoprotective and anticancer activities of plants and phytochemicals. Clinical implementation is discussed. Based on the presented evidence, advanced chemopreventive strategies in the context of 3P medicine are considered.

Significance of the gut microbiome in multistep colorectal carcinogenesis

Colorectal cancer (CRC) is highly prevalent worldwide. In 2018, there were over 1.8 million new cases. Most sporadic CRC develop from polypoid adenomas and are preceded by intramucosal carcinoma (stage 0), which can progress into more malignant forms. This developmental process is known as the adenoma-carcinoma sequence. Early detection and endoscopic removal are crucial for CRC management. Accumulating evidence suggests that the gut microbiota is associated with CRC development in humans. Comprehensive characterization of this microbiota is of great importance to assess its potential as a diagnostic marker in the very early stages of CRC. In this review, we summarized recent studies on CRC-associated bacteria and their carcinogenic mechanisms in animal models, human cell lines and human cohorts. High-throughput technologies have facilitated the identification of CRC-associated bacteria in human samples. We have presented our metagenome and metabolome studies on fecal samples collected from a large Japanese cohort that revealed stage-specific phenotypes of the microbiota in CRC. Furthermore, we have discussed the potential carcinogenic mechanisms of the gut microbiota, from which we can infer whether changes in the gut microbiota are a cause or effect in the multi-step process of CRC carcinogenesis.

Recommendation-based dietary indexes and risk of colorectal cancer in the Nurses' Health Study and Health Professionals Follow-up Study

Background

Many dietary indexes exist for chronic disease prevention, but the optimal dietary pattern for colorectal cancer prevention is unknown.

Objective

We sought to determine associations between adherence to various dietary indexes and incident colorectal cancer in 2 prospective cohort studies.

Design

We followed 78,012 women in the Nurses' Health Study and 46,695 men in the Health Professionals Follow-up Study from 1986 and 1988, respectively, until 2012. We created dietary index scores for the Dietary Approaches to Stop Hypertension (DASH) diet, Alternative Mediterranean Diet (AMED), and Alternative Healthy Eating Index-2010 (AHEI-2010) and used Cox regression to estimate HRs and 95% CIs for risk of colorectal cancer (CRC) and by anatomic subsite. We also conducted latency analyses to examine associations between diet and CRC risk during different windows of exposure. We conducted analyses in men and women separately, and subsequently pooled these results in a random-effects meta-analysis.

Results

We documented 2690 colorectal cancer cases. Pooled multivariable HRs for colorectal cancer risk comparing the highest to lowest quintile of diet scores were 0.89 (95% CI: 0.74, 1.08; P-trend = 0.10) for DASH, 0.89 (95% CI: 0.73, 1.10; P-trend = 0.31) for AMED, and 0.95 (95% CI: 0.83, 1.09; P-trend = 0.56) for AHEI-2010 (P-heterogeneity ≥ 0.07 for all). In sex-specific analyses, we observed stronger associations in men for all dietary indexes (DASH: multivariable HR = 0.81, 95% CI: 0.66, 0.98; P-trend = 0.003; AMED: multivariable HR = 0.80, 95% CI: 0.65, 0.98; P-trend = 0.02; AHEI-2010: multivariable HR = 0.88, 95% CI: 0.72, 1.07; P-trend = 0.04) than in women (multivariable HRs range from 0.98 to 1.01).

Conclusions

Adherence to the DASH, AMED, and AHEI-2010 diets was inversely associated with colorectal cancer risk in men. These diets were not associated with colorectal cancer risk in women. This observational study was registered at http://www.clinicaltrials.gov as NCT03364582.

Dietary patterns and primary liver cancer in Chinese adults: a case-control study

Introduction

Healthy dietary patterns may prevent many chronic diseases, and is emphasized by 2015 US dietary guideline, but it remains unclear which dietary patterns may be benefit to prevention of primary liver cancer (PLC).

Materials and Methods

We recruited 782 PLC cases and 1:1 age- and sex-matched controls in Guangzhou, China. Habitual dietary intake was assessed by face-to-face interview using a 79-item food frequency questionnaire, and used to explore dietary patterns by factor analysis.

Results

Three dietary patterns were identified: 1) an urban prudent dietary pattern (UPDP) characterized by high in dairy products, eggs, mushrooms, nuts and soy foods, but low in refined grains; 2) a traditional Cantonese dietary pattern (TCDP) consisting of a high intake of fruit and vegetables, fish, Cantonese soup, and Chinese herb tea; and 3) a high meat and preserved food pattern (MPFP). Multivariable analyses showed favorable associations for the first two dietary patterns, but unfavorable association for the last one (all p-trend < 0.01). Odds ratios (95% CI) of PLC for the highest (vs. lowest) quartile of pattern scores of the three patterns were 0.25 (0.18–0.35), 0.61 (0.46–0.82), and 1.98 (1.46–2.69), respectively.

Conclusions

Our findings suggest that the UPDP and TCDP were associated with lower, whereas the MPFP with higher, risk of PLC.

Dietary patterns and risk of recurrence and progression in non-muscle-invasive bladder cancer

The association of dietary factors with urinary bladder cancer prognosis has scarcely been investigated, and results of studies conducted to date are inconsistent. We investigated whether empirically derived dietary patterns are associated with risks of recurrence and progression in non-muscle-invasive bladder cancer (NMIBC) patients. Data from 595 newly diagnosed NMIBC patients from an ongoing prospective cohort study were used to derive dietary patterns using exploratory factor analysis. Factor scores were calculated and then categorized in sex-specific tertiles. Multivariable-adjusted proportional hazards regression models were used to estimate hazard ratios and 95% confidence intervals for the associations between tertiles of adherence to the dietary patterns and risks of recurrence and progression. We identified four dietary patterns: "fruits and vegetables," "Western," "low-fat," and "Tex-Mex." Patients in the highest tertile of adherence to the Western pattern experienced a 1.48 times higher risk of recurrence (95% CI 1.06-2.06) compared to patients in the lowest tertile. No statistically significant associations of a Western diet with risk of progression or of the other dietary patterns with risk of recurrence and progression were found. Overall, we found that adherence to a Western diet was associated with a higher risk of recurrence but further studies are needed to confirm our findings.