Meat-related mutagens/carcinogens in the etiology of colorectal cancer

UBXN11 Predicts as a Poor Index for Colorectal Cancer and Contributes to the Tumorigenesis by Activating NF-κB Signaling

BACKGROUND

The complex mechanisms of colorectal cancer (CRC) pathogenesis and progression remain poorly understood. This study endeavors to unravel the role of UBXN11within the context of CRC.

METHODS

UBXN11 expression level in CRC, stomach adenocarcinoma and esophageal carcinoma, and the overall survival in corresponding cancers were analyzed using UALCAN database. Human CRC cell lines and xenograft mouse model with UBXN11 overexpression were established to investigate the pathological role of UBXN11 in CRC progression. Luciferase assay, qPCR, and Western blot were performed to dissect the interaction between UBXN11 and NF-κB signaling.

RESULTS

Heightened UBXN11 expression was observed in various digestive tract tumors, which was positively correlated with the reduced overall survival rates in CRC patients. Overexpression of UBXN11 significantly enhanced CRC cell proliferation in vitro and promoted tumor growth in vivo. Mechanistically, UBXN11 promoted CRC tumorigenesis through increasing the activation of NF-κB signaling pathway.

CONCLUSIONS

This study underscores the pivotal role of UBXN11 in CRC progression and paves the way for novel therapeutic strategies for CRC treatment.

Adding a Leafy Vegetable Fraction to Diets Decreases the Risk of Red Meat Mortality in MASLD Subjects: Results from the MICOL Cohort

BACKGROUND

Dietary guidelines recommend limiting red meat intake because it has been amply associated with increased cancer mortality, particularly in patients with liver conditions, such as metabolic dysfunction-associated fatty liver disease (MASLD). MASLD is the leading cause of liver dysfunction in the world today, and no specific treatment other than lifestyle correction has yet been established. The aim of this study was to explore the protective role of leafy vegetables when associated with high red meat consumption.

METHODS

The study cohort included 1646 participants assessed during the fourth recall of the MICOL study, subdivided into two groups based on red meat intake (≤50 g/die vs. >50 g/die), in order to conduct a cancer mortality analysis. The prevalence of subjects that consumed >50 g/die was only 15.73%. Leafy vegetable intake was categorized based on median g/die consumption, and it was combined with red meat intake.

CONCLUSIONS

This is the first study to demonstrate that the consumption of about 30 g/die of leafy vegetables reduces the risk of mortality. A strong association with mortality was observed in subjects with MASLD, and the protective role of vegetables was demonstrated.

Emerging challenges and efficacy of polyphenols-proteins interaction in maintaining the meat safety during thermal processing

Polyphenols are well documented against the inhibition of foodborne toxicants in meat, such as heterocyclic amines, Maillard's reaction products, and protein oxidation, by means of their radical scavenging ability, metal chelation, antioxidant properties, and ability to form protein-polyphenol complexes (PPCs). However, their thermal stability, low polarity, degree of dispersion and polymerization, reactivity, solubility, gel forming properties, low bioaccessibility index during digestion, and negative impact on sensory properties are all questionable at oil-in-water interface. This paper aims to review the possibility and efficacy of polyphenols against the inhibition of mutagenic and carcinogenic oxidative products in thermally processed meat. The major findings revealed that structure of polyphenols, for example, molecular size, no of substituted carbons, hydroxyl groups and their position, sufficient size to occupy reacting sites, and ability to form quinones, are the main technical points that affect their reactivity in order to form PPCs. Following a discussion of the future of polyphenols in meat-based products, this paper offers intervention strategies, such as the combined use of food additives and hydrocolloids, processing techniques, precursors, and structure-binding relationships, which can react synergistically with polyphenols to improve their effectiveness during intensive thermal processing. This comprehensive review serves as a valuable source for food scientists, providing insights and recommendations for the appropriate use of polyphenols in meat-based products.

Meat and meat products - a scoping review for Nordic Nutrition Recommendations 2023

Meat is not only a source of several nutrients but also a proposed risk factor for several non-communicable diseases. Here, we describe the totality of evidence for the role of meat intake for chronic disease outcomes, discuss potential mechanistic pathways, knowledge gaps, and limitations of the literature. Use of the scoping review is based on a de novo systematic review (SR) and meta-analysis on the association between poultry intake and cardiovascular disease (CVD) and type 2 diabetes (T2D), qualified SRs (as defined in the Nordic Nutrition Recommendations 2023 project) on meat intake and cancer by the World Cancer Research Fund (WCRF), the International Agency for Research on Cancer (IARC), and a systematic literature search of SRs and meta-analyses. The quality of the SRs was evaluated using a modified AMSTAR 2 tool, and the strength of evidence was evaluated based on a predefined criteria developed by the WCRF. The quality of the SRs was on average critically low. Our findings indicate that the evidence is too limited for conclusions for most of the chronic disease outcomes. However, findings from qualified SRs indicate strong evidence that processed meat increases the risk of colorectal cancer and probable evidence that red meat (unprocessed, processed, or both) increases the risk. The evidence suggests that both unprocessed red meat and processed meat (also including processed poultry meat) are probable risk factors for CVD mortality and stroke, and that total red meat and processed meat are risk factors for CHD. We found no sufficient evidence suggesting that unprocessed red meat, processed red meat, total red meat, or processed meat (including red and white meat) would be protective of any chronic disease. There was also no sufficient evidence to conclude on protective effect of poultry on any chronic diseases; effects on the risk of CVD, stroke, and T2D, to any direction, were regarded as unlikely.

Benzo[a]pyrene exposure affects colorectal cancer susceptibility by regulating ERβ-mediated LINC02977 transcription

Environmental pollutants known as polycyclic aromatic hydrocarbons (PAHs) are produced through the incomplete combustion of organic material. While PAHs have been investigated as genotoxicants, they can also operate through nongenotoxic pathways in estrogen-dependent malignancies, such as breast, cervical and ovarian cancer. However, whether PAHs induce colorectal cancer (CRC) risk through estrogenic effects is still illusive. Here, we systematically investigated the abnormal expression and activation of estrogen receptor beta (ERβ) regulated by PAHs in CRC as well as the underlying mechanisms of ERβ-mediated CRC risk. Based on the 300 plasma samples from CRC patients and healthy controls detected by GC-MS/MS, we found that the plasma concentrations of benzo[a]pyrene (BaP) were significantly higher in CRC cases than in healthy controls, with significant estrogenic effects. Moreover, histone deacetylase 2 (HDAC2)-induced deacetylation of the promoter decreases ERβ expression, which is associated with poor overall survival and advanced tumor stage. The study also revealed that BaP and estradiol (E2) had different carcinogenic effects, with BaP promoting cell proliferation and inhibiting apoptosis, while E2 had the opposite effects. Additionally, this study mapped ERβ genomic binding regions by performing ChIP-seq and ATAC-seq and identified genetic variants of rs1411680 and its high linkage disequilibrium SNP rs6477937, which were significantly associated with CRC risk through meta-analysis of two independent Chinese population genome-wide association studies comprising 2,248 cases and 3,173 controls and then validation in a large-scale European population. By integrating data from functional genomics, we validated the regulatory effect of rs6477937 as an ERβ binding-disrupting SNP that mediated allele-specific expression of LINC02977 in a long-range chromosomal interaction manner, which was found to be highly expressed in CRC tissues. Overall, this study suggests that the different active effects on ERβ by PAHs and endogenous E2 may play a crucial role in the development and progression of CRC and highlights the potential of targeting ERβ and its downstream targets for CRC prevention and treatment.

Antioxidant Genes Variants and Their Association with Sperm DNA Fragmentation

Semen possesses a variety of antioxidant defense mechanisms which protect sperm DNA from the damaging effects of oxidative stress. Correlation between antioxidant genes variants and sperm DNA fragmentation (SDF) level is not sufficiently studied. Therefore, we investigated the association between several single nucleotide polymorphisms (SNPs): CYP1A1 (rs1048943A > G), CYP4F2 (rs2108622G > A), NRF2 (rs6721961C > A), PON1 (rs662A > G), NOS3 (rs1799983G > T), GSTM1 (null), CAT (rs1001179C > T), SOD2 (rs4880A > G), GSTP1 (rs1695A > G), PON2 (rs7493G > C), EPHX2 (rs1042064T > C), and AHR (rs2066853G > A) and elevated SDF. The study employed a case-control design where, the allele and genotype frequencies of the selected SNPs were compared between 75 semen samples with abnormal SDF (the cases) and 75 samples with normal SDF (the controls). DNA was extracted from the semen samples and allele-specific PCR (AS-PCR) was used for genotyping the SNPs. Relevant data were collected from the patients' records et al.-Basma Fertility Center. Suitable statistical tests and multifactorial dimensionality reduction (MDR) test were used to anticipate SNP-SNP interactions. Comparison of semen parameters revealed significant differences between cases and controls in terms of liquefaction time, sperm total motility, and normal form. Genotype frequencies of NOS3 G > T (GT), SOD2 A > G (AA and AG), EPHX2 T > C (CC and CT), and AHR G > A (GA and GG) were significantly different between cases and controls. Allele frequencies of SOD2 (G-allele), and EPHX2 (T-allele) also significantly varied between cases and controls. MDR analysis revealed that the NOS3, SOD2, and EPHX2 SNPs combination has the highest impact on SDF. The study findings suggest that genetic variations in genes involved antioxidant defenses contribute to abnormal SDF.

Red Meat Heating Processes, Toxic Compounds Production and Nutritional Parameters Changes: What about Risk-Benefit?

The heating process is a crucial step that can lead to the formation of several harmful chemical compounds in red meat such as heterocyclic aromatic amines, N-Nitrosamines, polycyclic aromatic hydrocarbons and acrylamide. Meat has high nutritional value, providing essential amino acids, bioactive compounds and several important micronutrients which can also be affected by heating processes. This review aims to provide an updated overview of the effects of different heating processes on both the safety and nutritional parameters of cooked red meat. The most-used heating processes practices were taken into consideration in order to develop a risk-benefit scenario for each type of heating process and red meat.

The Association between Red Meat Consumption and Advanced Colorectal Adenomas in a Population Undergoing a Screening-Related Colonoscopy in Alberta, Canada

The association between red meat consumption and colorectal cancer has been rigorously examined. However, a more comprehensive understanding of how the intake of unprocessed red meat contributes to the development of early precancerous colorectal lesions, such as advanced colorectal adenomas (ACRAs), requires further investigation. We examined the associations between different types of red meat intake and ACRAs in a sample population of 1083 individuals aged ≥ 50 years undergoing an initial screening colonoscopy in Calgary, Alberta, Canada. Associations between grams per day of total, processed, and unprocessed red meat from diet history questionnaires and ACRAs were evaluated with multivariable logistic regression models. We also applied cubic spline models fitted with three knots (10th, 50th, and 90th percentiles) to identify potential nonlinear associations. We did not observe a meaningful association between unprocessed red meat intake and the presence of ACRAs. In contrast, for every 10 g/d increase in total and processed meat intake, we observed an increase in the odds of ACRAs at the screening colonoscopy (adjusted odds ratio (OR) = 1.05, 95% [CI = 1.01-1.09], p = 0.04) and (adjusted OR = 1.11, 95% [CI = 1.02-1.20], p = 0.02), respectively. This study highlights the importance of differentiating between types of red meat consumption in the context of dietary risks associated with ACRAs.

The association between empirical dietary inflammatory pattern and colorectal cancer risk: a case-control study

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer in Iran. Inflammation plays an essential role in developing CRC. A dietary pattern called the empirical dietary inflammatory pattern (EDIP) has recently been designed based on the inflammatory potential of the diet. Therefore, the present study aimed to investigate the impact of EDIP on the risk of CRC.

METHODS

The current case-control study was conducted on 142 controls and 71 CRC cases in three general hospitals and Hospital Cancer Organization in Tehran, Iran. We calculated EDIP by a semi-quantitative food frequency questionnaire. The association between EDIP and CRC were evaluated by logistic regression. The level of significance was p < 0.05.

RESULTS

The results revealed that people who were in the highest tertile of the EDIP had higher odds of CRC (in the adjusted model: odds ratio (OR) = 3.74; 95% confidence interval (CI): 1.38-10.14; P = 0.011).

CONCLUSION

The present study demonstrated the potential role of dietary-induced inflammation in developing CRC. In the current study, an increase in the intake of red meat, processed meats, and refined grains was observed in the higher EDIP tertiles compared to the lower tertiles. Consequently, to decrease the risk of CRC, it is recommended to reduce the consumption of these foods.

Associations of dietary factors and xenobiotic intake with faecal microbiota composition according to the presence of intestinal mucosa damage

Diet is a major modulator of gut microbiota, which plays a key role in the health status, including colorectal cancer (CRC) development. Several studies and meta-analyses have evidenced an association of certain dietary factors and xenobiotic intake with the incidence of CRC. Nevertheless, how these dietary factors impact the first stages of intestinal mucosa damage is still uncertain. This study aimed at exploring the associations of relevant dietary factors with the gut microbiota of control individuals and subjects diagnosed with intestinal polyps. A total of 60 volunteers were recruited, clinically classified according to colonoscopy criteria and interviewed using food frequency questionnaires (FFQs). The nutritional status of each volunteer was determined and the intake of dietary xenobiotics was quantified. The relative abundance of faecal microbiota taxonomic groups was obtained through 16S rRNA gene sequencing. The association of dietary factors and xenobiotics with faecal microbiota composition showed differences according to the clinical diagnosis group. Our results showed that the intake of red meat (≥50 g day-1) and total polycyclic aromatic hydrocarbons (PAHs) (≥0.75 μg day-1) was associated with a decreased abundance of the family Bacteroidaceae and an increased abundance of Coriobacteriaceae in control subjects. The intake of the heterocyclic amines 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP) (≥40 ng day-1) and 2-amino-3,8 dimethylimidazo(4,5,f) quinoxaline (MeIQx) (≥50 ng day-1) was associated with a decreased abundance of Akkermansiaceae in the control diagnosis group. Moreover, N-nitroso compounds (NOCs), nitrites (≥1.69 mg day-1) and N-nitrosodimethylamine (NDMA) (≥0.126 μg day-1) were associated with a decreased abundance of Bifidobacteriaceae. The intake of ethanol (≥12 g day-1) in the polyps group was associated with an increased abundance of Peptostreptococcaceae and a decreased abundance of Veillonellaceae. Moreover, linear regression analyses allowed us to identify ethanol, calcium, bioactive compounds such as flavonoids, stilbenes, cellulose, phenolic acids or total polyphenols, and dietary xenobiotics such as PhIP and MeIQx, the NOC N-nitrosopyrrolidine (NPYR) or the total PAHs as potential predictors of faecal microbiota group abundances. These results indicated that the consumption of milk, red meat, processed meat and ethanol and the intake of polyphenols, dietary PAHs, HAs and NOCs are associated with specific groups of the intestinal microbiota, depending on the clinical diagnosis group.

Wood cookstove use is associated with gastric cancer in Central America and mediated by host genetics

Biomass cookstove food preparation is linked to aero-digestive cancers, mediated by ingested and inhaled carcinogens (e.g., heterocyclic amines, and polycyclic aromatic hydrocarbons). We investigated the association between gastric adenocarcinoma, wood cookstove use, H. pylori CagA infection and risk modification by variants in genes that metabolize and affect the internal dose of carcinogens. We conducted a population-based, case-control study (814 incident cases, 1049 controls) in rural Honduras, a high-incidence region with a homogeneous diet and endemic H. pylori infection, primarily with the high-risk CagA genotype. We investigated factors including wood cookstove use, H. pylori CagA serostatus, and 15 variants from 7 metabolizing genes, and the interactions between wood stove use and the genetic variants. Male sex (OR 2.0, 1.6-2.6), age (OR 1.04, 1.03-1.05), wood cookstove use (OR 2.3, 1.6-3.3), and CagA serostatus (OR 3.5, 2.4-5.1) and two SNPs in CYP1B1 (rs1800440 and rs1056836) were independently associated with gastric cancer in multivariate analysis. In the final multivariate model, a highly significant interaction (OR 3.1, 1.2-7.8) was noted between wood cookstove use and the rs1800440 metabolizing genotype, highlighting an important gene-environment interaction. Lifetime wood cookstove use associates with gastric cancer risk in the high-incidence regions of Central America, and the association is dependent on the rs1800440 genotype in CYP1B1. H. pylori CagA infection, wood cookstove use and the rs1800440 genotype, all of which are highly prevalent, informs who is at greatest risk from biomass cookstove use.

Healthy and Unhealthy Plant-Based Diets and Glioma in the Chinese Population

Plant-based diets have been suggested to help prevent various chronic diseases, including cancer. However, there are few reports on central nervous system tumors, and data on dose-response relationships are lacking. This individual-matched case-control study included 506 cases and 506 controls. The overall plant-based diet index (PDI), the healthy plant-based diet index (hPDI), and the unhealthy plant-based diet index (uPDI) were calculated using dietary information collected through a food frequency questionnaire, with higher scores indicating better adherence. We analyzed the relationship of plant-based diets with glioma. After adequate adjustment for confounders, PDI was associated with a reduced glioma risk (OR = 0.42, 95% CI: 0.24-0.72). Conversely, uPDI was associated with an elevated glioma risk (OR = 8.04, 95% CI: 4.15-15.60). However, hPDI was not significantly associated with glioma risk (OR = 0.83, 95% CI: 0.48-1.45). For subgroups, PDI was not significant in analyzing young age, BMI, or any pathological subtypes. The restricted cubic spline function showed a significant dose-response relationship between PDI (p-nonlinearity< 0.0001) and uPDI (p-nonlinearity= 0.0711) and glioma. Further analysis found that refined grains had the greatest effect on gliomas in the less healthy plant-based food group. Therefore, following a plant-based diet was linked to a lower risk of glioma, especially when consuming fewer unhealthy plant-based foods.

The Impact of Different Types of Diet on the Prevention of Diseases among Polish Inhabitants, Including COVID-19 Disease

Proper nutrition may help in preventing deaths or at least alleviating the symptoms of many chronic diseases. While the COVID-19 disease was still taking its toll, the world had to adjust to new life conditions, which could change nutritional habits. In this observational, cross-sectional study, we aimed to identify the potential correlations between sociodemographic factors and diet and the presence of common chronic diseases among Polish inhabitants. Furthermore, we tried to determine whether the COVID-19 pandemic led to changes in nutritional habits. Therefore, based on the online study (the National Test for Poles' Health (NTPH), we collected data from 376,102 and 200,000 respondents in two different time frames (before the COVID-19 pandemic: 2019-2020 and during the COVID-19 pandemic: 2021-2022, respectively). Despite the rapid global rise of the COVID-19 pandemic, among our study group, hypertension was still the most commonly occurring disease in both time frames (32.33% in 2019-2020 and 34.95% in 2021-2022, p < 0.001). Furthermore, more chronic diseases were reported during the COVID-19 pandemic than in 2019-2020. Regarding sociodemographic factors, male respondents were more likely to develop hypertension and diabetes (OR = 1.35 CI 95% (1.28-1.43), p < 0.001; and OR = 1.20 CI 95% (1.11-1.30), p < 0.001). Vegetarian diet decreases the likelihood of hypertension, neurological disease, and diabetes (OR = 0.69, CI 95% (0.60-0.81), p < 0.001; OR = 0.72, CI 95% (0.59-0.88), p = 0.001; and OR = 0.73, CI 95% (0.55-0.96), p = 0.026). In line with this, consuming meat meals increases the risk of hypertension (OR = 1.09, CI 95% (1.02-1.17), p = 0.009). Interestingly, a reduced-sodium diet has an association with decreased morbidity of COVID-19 disease (OR = 0.72, CI 95% (0.63-0.82), p < 0.001). This result brings new light to more research to be done to allow efficient prevention of this disease. In conclusion, our study shows the beneficial role of a balanced diet in reducing the incidence rate of common chronic diseases. Our findings may be educational for those who would like to change their nutritional habits and/or for public health professionals to suggest the implementation of proper diets to their patients.

Vegetable extracts: Effective inhibitors of heterocyclic aromatic amines and advanced glycation end products in roasted Mackerel

The formation of hazardous substances, heterocyclic aromatic amines (HAAs) and advanced glycation end products (AGEs), in roasted mackerel with different cooking temperatures (180, 210, 240 °C) and vegetable extracts (celery, carrot and yam extracts) in a preheated oven was investigated. The results indicated that the introduction of vegetable extracts had inhibitory effects on HAAs and AGEs during thermal processing, especially celery extracts. Benefiting from the addition of vegetable extracts, the roasted mackerel keep high quality against lipid/protein oxidation, avoids nutrition loss of polyunsaturated fatty acids, and flavor is promoted. We also examined the variation of key precursors, including creatine, creatinine, reducing sugars, amino acids and attempted to explain the molecular pathway of inhibition of the formation of the hazardous substances by vegetable extracts. The results provide theoretical support to develop technologies for inhibiting hazardous substances formation during fish processing, which is important for food manufacturers and consumers for producing healthier meat products.

Possible Genetic Risks from Heat-Damaged DNA in Food

The consumption of foods prepared at high temperatures has been associated with numerous health risks. To date, the chief identified source of risk has been small molecules produced in trace levels by cooking and reacting with healthy DNA upon consumption. Here, we considered whether the DNA in food itself also presents a hazard. We hypothesize that high-temperature cooking may cause significant damage to the DNA in food, and this damage might find its way into cellular DNA by metabolic salvage. We tested cooked and raw foods and found high levels of hydrolytic and oxidative damage to all four DNA bases upon cooking. Exposing cultured cells to damaged 2'-deoxynucleosides (particularly pyrimidines) resulted in elevated DNA damage and repair responses in the cells. Feeding a deaminated 2'-deoxynucleoside (2'-deoxyuridine), and DNA containing it, to mice resulted in substantial uptake into intestinal genomic DNA and promoted double-strand chromosomal breaks there. The results suggest the possibility of a previously unrecognized pathway whereby high-temperature cooking may contribute to genetic risks.

Mutagens in commercial food processing and its microbial transformation

Mutagens are chemical molecules that have the ability to damage DNA. Mutagens can enter into our body upon consumption of improperly cooked or processed food products such as high temperature or prolonged cooking duration. Mutagens are found in the food products can be classified into N-nitroso derivatives, polycyclic aromatic hydrocarbons, and heterocyclic aromatic amines. Food products with high fat and protein content are more prone to mutagenic formation. Microorganisms were found to be a potent weapon in the fight against various mutagens through biotransformation. Therefore, searching for the microorganisms which have the ability to transform mutagens and the development of techniques for the identification as well as detection of mutagens in food products is much needed. In the future, methods for the identification and detection of these mutagens as well as the identification of new and more potent microorganisms which can transform mutagens into non-mutagens are much needed.

Implication of Obesity and Gut Microbiome Dysbiosis in the Etiology of Colorectal Cancer

The complexity and variety of gut microbiomes within and among individuals have been extensively studied in recent years in connection to human health and diseases. Our growing understanding of the bidirectional communication between metabolic diseases and the gut microbiome has also highlighted the significance of gut microbiome dysbiosis in the genesis and development of obesity-related cancers. Therefore, it is crucial to comprehend the possible role of the gut microbiota in the crosstalk between obesity and colorectal cancer (CRC). Through the induction of gut microbial dysbiosis, gut epithelial barrier impairment, metabolomic dysregulation, chronic inflammation, or dysregulation in energy harvesting, obesity may promote the development of colorectal tumors. It is well known that strategies for cancer prevention and treatment are most effective when combined with a healthy diet, physical activity, and active lifestyle choices. Recent studies also suggest that an improved understanding of the complex linkages between the gut microbiome and various cancers as well as metabolic diseases can potentially improve cancer treatments and overall outcomes. In this context, we herein review and summarize the clinical and experimental evidence supporting the functional role of the gut microbiome in the pathogenesis and progression of CRC concerning obesity and its metabolic correlates, which may pave the way for the development of novel prognostic tools for CRC prevention. Therapeutic approaches for restoring the microbiome homeostasis in conjunction with cancer treatments are also discussed herein.

Total and cause-specific mortality associated with meat intake in a large cohort study in Korea

Background

Asia has experienced a large increase in meat intake in the past decade, yet the health impact of meat intake is not well studied.

Objective

We examined the association of meat intake with all-cause, cancer and cardiovascular disease (CVD) mortality in an Asian country.

Methods

Participants were 113,568 adults with dietary data at recruitment (2004–2013) of the Health Examinees-Gem (HEXA-G) study, a prospective cohort study conducted in 8 regions of Korea. Participants were followed until 31 December 2020. Total, red, white, and organ meat intake were computed based on a 106-item questionnaire. Multivariable Cox proportional hazard models were implemented using the lowest quintile of meat intake as the reference category.

Findings

For 1,205,236 person-years, 3,454 deaths were recorded. High intake of processed red meat was positively associated with all-cause mortality [men: hazard ratio (HR) 1.21, 95% confidence interval (95% CI) 1.07–1.37; women: HR 1.32, 95% CI 1.12–1.56]. Increased risk of all-cause mortality (HR 1.21, 95% CI 1.05–1.39) and cancer mortality (HR 1.24, 95% CI 1.03–1.50) was observed in women with high intake of organ meat. Moderate intake of pork belly was associated with reduced risk of all-cause mortality in men (HR 0.76, 95% CI 0.62–0.93) and women (HR 0.83, 95% 0.69–0.98) but high intake was associated with increased risk of CVD mortality in women (HR 1.84, 95% CI 1.20–2.82). Low beef intake decreased the risk of CVD mortality in men (HR 0.58, 95% CI 0.40–0.84), but roasted pork increased cancer mortality in women (HR 1.26, 95% CI 1.05–1.52).

Conclusion

There was increased risk of all-cause mortality associated with intake of processed red meat in men and women, increased risk of all-cause and cancer mortality with intake of organ meat in women, and increased risk of cancer mortality with intake of roasted pork intake in women. High intake of pork belly increased the risk of CVD mortality in women, but moderate intake was inversely associated with mortality from all-causes in both men and women.

Friend or Foe? The Role of Animal-Source Foods in Healthy and Environmentally Sustainable Diets

Scientific and political discussions around the role of animal-source foods (ASFs) in healthy and environmentally sustainable diets are often polarizing. To bring clarity to this important topic, we critically reviewed the evidence on the health and environmental benefits and risks of ASFs, focusing on primary trade-offs and tensions, and summarized the evidence on alternative proteins and protein-rich foods. ASFs are rich in bioavailable nutrients commonly lacking globally and can make important contributions to food and nutrition security. Many populations in Sub-Saharan Africa and South Asia could benefit from increased consumption of ASFs through improved nutrient intakes and reduced undernutrition. Where consumption is high, processed meat should be limited, and red meat and saturated fat should be moderated to lower noncommunicable disease risk-this could also have cobenefits for environmental sustainability. ASF production generally has a large environmental impact; yet, when produced at the appropriate scale and in accordance with local ecosystems and contexts, ASFs can play an important role in circular and diverse agroecosystems that, in certain circumstances, can help restore biodiversity and degraded land and mitigate greenhouse gas emissions from food production. The amount and type of ASF that is healthy and environmentally sustainable will depend on the local context and health priorities and will change over time as populations develop, nutritional concerns evolve, and alternative foods from new technologies become more available and acceptable. Efforts by governments and civil society organizations to increase or decrease ASF consumption should be considered in light of the nutritional and environmental needs and risks in the local context and, importantly, integrally involve the local stakeholders impacted by any changes. Policies, programs, and incentives are needed to ensure best practices in production, curb excess consumption where high, and sustainably increase consumption where low.

Dietary Intake and Systemic Inflammation: Can We Use Food as Medicine?

PURPOSE OF REVIEW

This review summarizes the current literature regarding the association between diet and systemic inflammation.

RECENT FINDINGS

Data in humans suggests that consumption of plant-based nutrients is associated with a reduction in systemic inflammation, while consumption of red meat and excessive dairy has the opposite effect and may increase risk of acute flares in those that suffer from certain chronic diseases like inflammatory bowel disease or psoriasis and certain cancers. There is a known association between diet and systemic inflammation; thus, we recommend that clinicians discuss plant-based, whole food diets with patients, particularly those that suffer from chronic inflammatory diseases as an adjunct treatment for these conditions. Future research should evaluate whether adherence to these types of diets is sustainable in the long term and how these changes affect important quality of life concerns.

The intake of ultra-processed foods, all-cause, cancer and cardiovascular mortality in the Korean Genome and Epidemiology Study-Health Examinees (KoGES-HEXA) cohort

The relationship between ultra-processed food (UPF) intake and mortality is unknown in Asian countries, yet the intake of UPF is on the rise in these countries. This study examined the association of UPF intake with all-cause, cancer and cardiovascular disease (CVD) mortality. Participants were 113,576 adults who responded to a 106-item food frequency questionnaire during recruitment of the 2004-2013 Health Examinees (HEXA) study, a prospective cohort study in Korea. UPF were defined using the NOVA classification and evaluated as quartiles of the proportion of UPF in the diet (% total food weight). Multivariable Cox regression and restricted cubic spline models were used to examine the association of UPF intake with all-cause and cause specific mortality. A total of 3456 deaths were recorded during a median follow-up of 10.6 (interquartile range, 9.5-11.9) years. There was no evidence of an association of UPF intake with all-cause, cancer or CVD mortality comparing the highest with the lowest quartiles of UPF intake (all-cause mortality, men: hazard ratio [HR] 1.08, 95% confidence interval [CI] 0.95-1.22; women: HR 0.95, 95% CI 0.81-1.11; cancer mortality, men: HR 1.02, 95% confidence interval [CI] 0.84-1.22; women: HR 1.02, 95% CI 0.83-1.26; CVD mortality, men: HR 0.88, 95% CI 0.64-1.22; women: HR 0.80, 95% CI 0.53-1.19). However, the risk of all-cause mortality increased in both men and women with high consumption of ultra-processed red meat and fish (men, HR 1.26, 95% CI 1.11-1.43); women, HR 1.22 95% CI 1.05-1.43); and in men with high consumption of ultra-processed milk (HR 1.13, 95% CI 1.01-1.26); and soymilk drink (HR 1.12, 95% CI 1.00-1.25). We found no evidence of an association between total UPF intake and all-cause, cancer or CVD mortality, but ultra-processed red meat and fish in both sexes, and milk and soymilk drinks in men were positively associated with all-cause mortality.

Chemical Tools for the Study of DNA Repair

DNA repair enzymes continuously provide surveillance throughout our cells, protecting the enclosed DNA from the damage that is constantly arising from oxidation, alkylating species, and radiation. Members of this enzyme class are intimately linked to pathways controlling cancer and inflammation and are promising targets for diagnostics and future therapies. Their study is benefiting widely from the development of new tools and methods aimed at measuring their activities. Here, we provide an Account of our laboratory's work on developing chemical tools to study DNA repair processes in vitro, as well as in cells and tissues, and what we have learned by applying them.We first outline early work probing how DNA repair enzymes recognize specific forms of damage by use of chemical analogs of the damage with altered shapes and H-bonding abilities. One outcome of this was the development of an unnatural DNA base that is incorporated selectively by polymerase enzymes opposite sites of missing bases (abasic sites) in DNA, a very common form of damage.We then describe strategies for design of fluorescent probes targeted to base excision repair (BER) enzymes; these were built from small synthetic DNAs incorporating fluorescent moieties to engender light-up signals as the enzymatic reaction proceeds. Examples of targets for these DNA probes include UDG, SMUG1, Fpg, OGG1, MutYH, ALKBH2, ALKBH3, MTH1, and NTH1. Several such strategies were successful and were applied both in vitro and in cellular settings; moreover, some were used to discover small-molecule modulators of specific repair enzymes. One of these is the compound SU0268, a potent OGG1 inhibitor that is under investigation in animal models for inhibiting hyperinflammatory responses.To investigate cellular nucleotide sanitation pathways, we designed a series of "two-headed" nucleotides containing a damaged DNA nucleotide at one end and ATP at the other; these were applied to studying the three human sanitation enzymes MTH1, dUTPase, and dITPase, some of which are therapeutic targets. The MTH1 probe (ARGO) was used in collaboration with oncologists to measure the enzyme in tumors as a disease marker and also to develop the first small-molecule activators of the enzyme.We proceed to discuss the development of a "universal" probe of base excision repair processes (UBER), which reacts covalently with abasic site intermediates of base excision repair. UBER probes light up in real time as the reaction occurs, enabling the observation of base excision repair as it occurs in live cells and tissues. UBER probes can also be used in efficient and simple methods for fluorescent labeling of DNA. Finally, we suggest interesting directions for the future of this field in biomedicine and human health.

Inhalation risk to PAHs and BTEX during barbecuing: The role of fuel/food type and route of exposure

The manuscript presents an innovative and holistic approach to quantifying PAHs and BTEX emissions from the grilling process and indicates a novel driven-toxicity-based solution to recognize health effects related to BBQ emissions. The exposure scenario includes the type of grilling device, food type, and individual attitudes, but also a keen understanding of the broad health implications related to the gaseous/particulate PAHs emission, or age-related effects. The calculated incremental lifetime cancer risk (ILCR) associated with the exposure to PAH congeners and BTEX indicates an unacceptable level in the case of charcoal and briquette grilling with the highest values for professional cooks. The sum of 15 PAH concentrations in grilled foods was highest for meat grilling over charcoal briquettes - 382,020.39 ng/m³ and lowest for meat grilling on a gas grill - 1442.16 ng/m³. The emissions of BTEX from lump charcoal grilling were 130 times higher compared to the gaseous grill. In all considered scenarios lump-charcoal and charcoal briquettes grilling derive the ILCR above the 10^-4, indicating negative effects of traditional grills on human health. The paper completes knowledge of wide-ranging health implications associated with BBQs, a topic that is almost completely unaddressed among the scientific community and policymakers.

Multi-DNA Adduct and Abasic Site Quantitation In Vivo by Nano-Liquid Chromatography/High-Resolution Orbitrap Tandem Mass Spectrometry: Methodology for Biomonitoring Colorectal DNA Damage

Epidemiological and mechanistic studies suggest that processed and red meat consumption and tobacco smoking are associated with colorectal cancer (CRC) risk. Several classes of carcinogens, including N-nitroso compounds (NOCs) in processed meats and heterocyclic aromatic amines (HAAs) and polycyclic aromatic hydrocarbons (PAHs) in grilled meats and tobacco smoke, undergo metabolism to reactive intermediates that may form mutation-inducing DNA adducts in the colorectum. Heme iron in red meat may contribute to oxidative DNA damage and endogenous NOC formation. However, the chemicals involved in colorectal DNA damage and the paradigms of CRC etiology remain unproven. There is a critical need to establish physicochemical methods for identifying and quantitating DNA damage induced by genotoxicants in the human colorectum. We established robust nano-liquid chromatography/high-resolution accurate mass Orbitrap tandem mass spectrometry (LC/HRAMS2) methods to measure DNA adducts of nine meat and tobacco-associated carcinogens and lipid peroxidation products in the liver, colon, and rectum of carcinogen-treated rats employing fresh-frozen and formalin-fixed paraffin-embedded (FFPE) tissues. Some NOCs form O6-carboxymethyl-2'-deoxyguanosine, O6-methyl-2'-deoxyguanosine, and unstable quaternary N-linked purine/pyrimidine adducts, which generate apurinic/apyrimidinic (AP) sites. AP sites were quantitated following derivatization with O-(pyridin-3-yl-methyl)hydroxylamine. DNA adduct quantitation was conducted with stable isotope-labeled internal standards, and method performance was validated for accuracy and reproducibility. Limits of quantitation ranged from 0.1 to 1.1 adducts per 108 bases using 3 μg of DNA. Adduct formation in animals ranged from ∼1 in 108 to ∼1 in 105 bases, occurring at comparable levels in fresh-frozen and FFPE specimens for most adducts. AP sites increased by 25- to 75-fold in the colorectum and liver, respectively. Endogenous lipid peroxide-derived 3-(2-deoxy-β-d-erythro-pentofuranosyl)pyrimido[1,2-α]purin-10(3H)-one (M1dG) and 6-oxo-M1dG adduct levels were not increased by carcinogen dosing but increased in FFPE tissues. Human biomonitoring studies can implement LC/HRAMS2 assays for DNA adducts and AP sites outlined in this work to advance our understanding of CRC etiology.

Adherence to mediterranean diet and the risk of differentiated thyroid cancer in a European cohort: The EPIC study

Background

The Mediterranean diet (MD) has been proposed as a healthy diet with a potential to lower the incidence of several types of cancer, but there is no data regarding thyroid cancer (TC). We investigated the association between MD adherence, and its components, and the differentiated TC risk within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort.

Methods

Over 450,000 men and women from nine European countries were followed up for a mean of 14.1 years, during which 712 differentiated TC cases were identified. Adherence to MD was estimated using the relative MD (rMED) score, an 18-point scale including alcohol, and the adapted rMED (arMED) score, a 16-point scale excluding alcohol. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression models adjusted for potential confounding factors.

Results

Adherence to the arMED score was not associated with the risk of differentiated TC (HRhigh vs. low adherence = 0.94, 95% CI: 0.70-1.25; p-trend 0.27), while a suggestive, but non-statistically significant inverse relationship was observed with rMED (HRhigh vs. low adherence = 0.88, 95% CI: 0.68-1.14; p-trend 0.17). Low meat (HRlow vs. high meat intake = 0.81, 95% CI: 0.67-0.99; p-trend = 0.04) and moderate alcohol (HRmoderate vs. non-moderate intake = 0.88, 95% CI: 0.75-1.03) intake were related with lower differentiated TC risk.

Conclusions

Our study shows that a high adherence to MD is not strongly related to differentiated TC risk, although further research is required to confirm the impact of MD and, especially, meat intake in TC risk.

Colorectal Cancer in Inflammatory Bowel Diseases: Epidemiology and Prevention: A Review

Simple Summary

Colorectal cancer (CRC) is one of the most serious potential complications of inflammatory bowel diseases (IBDs). The aging of patients affected by IBDs makes this issue a challenge that will increasingly be faced by clinicians in clinical practice, especially in light of the poorer prognosis for CRC in this group of people when compared with the general population. In this review, we summarize the current epidemiology, risk factors and various prevention strategies proposed for CRC in patients with IBDs.

Abstract

Colorectal cancer (CRC) is currently the third most frequent form of malignancy and the second in terms of mortality. Inflammatory bowel diseases (IBDs) are recognized risk factors for this type of cancer. Despite a worldwide increase in the incidence of CRC, the risk of CRC-related death in IBD patients has declined over time, probably because of successful surveillance strategies, the use of more effective drugs in the management of remission and improved indications to colectomy. This notwithstanding, CRC 5-year survival in patients with IBD is poorer than in the general population. This review provides a summary of the epidemiological features, risk factors and various prevention strategies proposed for CRC in IBD patients. Moreover, there is a special focus on reporting and highlighting the various prevention strategies proposed by the most important international scientific societies, both in terms of chemoprevention and endoscopic surveillance. Indeed, in conducting the analysis, we have given attention to the current primary, secondary and tertiary prevention guidelines, attempting to emphasize unresolved research and clinical problems related to this topic in order to improve diagnostic strategies and management.

Mendelian randomization study indicates lack of causal associations between iron status and lung cancer

Observational studies provided conflicting results on the association between iron status and the risk of lung cancer. The aim of our study was to investigate the effect of genetically determined iron status on lung cancer risk using a mendelian randomization (MR) approach. Single-nucleotide polymorphisms for iron status were selected from a genome-wide meta-analysis of 48,972 subjects. Genetic association estimates for risk of lung cancer were derived from a Genome-Wide Association Study (GWAS) summary performed by the International Lung Cancer Consortium. The inverse-variance weighted method was used for the main analyses and sensitivity analyses. MR analysis demonstrated that increased genetically-predicted iron status did not causally increase risk of lung cancer. The odds ratios were 1.11 (95% CI, 0.92, 1.34; P = .26), 0.76 (95% CI, 0.52, 1.12; P = .17), 1.09 (95% CI, 0.86, 1.38; P = .47), and 0.91 (95% CI, 0.81, 1.02; P = .11) per 1 standard deviation increment of serum iron, ferritin, transferrin saturation, and transferrin levels, respectively. No observed indication of heterogeneity (P for Q > 0.05) or pleiotropy (P for intercept > 0.05) were found from the sensitivity analysis. The MR study indicated that genetic iron status was not causally associated with the risk of lung cancer, the causal relationship between iron status and lung cancer needs to be further elucidated by additional studies that strictly control for confounding factors.

A Prospective Diet-Wide Association Study for Risk of Colorectal Cancer in EPIC

BACKGROUND & AIMS

Evidence regarding the association of dietary exposures with colorectal cancer (CRC) risk is not consistent with a few exceptions. Therefore, we conducted a diet-wide association study (DWAS) in the European Prospective Investigation into Cancer and Nutrition (EPIC) to evaluate the associations between several dietary exposures with CRC risk.

METHODS

The association of 92 food and nutrient intakes with CRC risk was assessed in 386,792 participants, 5069 of whom developed incident CRC. Correction for multiple comparisons was performed using the false discovery rate, and emerging associations were examined in the Netherlands Cohort Study (NLCS). Multiplicative gene-nutrient interactions were also tested in EPIC based on known CRC-associated loci.

RESULTS

In EPIC, alcohol, liquor/spirits, wine, beer/cider, soft drinks, and pork were positively associated with CRC, whereas milk, cheese, calcium, phosphorus, magnesium, potassium, riboflavin, vitamin B6, beta carotene, fruit, fiber, nonwhite bread, banana, and total protein intakes were inversely associated. Of these 20 associations, 13 were replicated in the NLCS, for which a meta-analysis was performed, namely alcohol (summary hazard ratio [HR] per 1-SD increment in intake: 1.07; 95% confidence interval [CI], 1.04-1.09), liquor/spirits (HR per 1-SD increment in intake, 1.04; 95% CI, 1.02-1.06), wine (HR per 1-SD increment in intake, 1.04; 95% CI, 1.02-1.07), beer/cider (HR per 1-SD increment in intake, 1.06; 95% CI, 1.04-1.08), milk (HR per 1-SD increment in intake, 0.95; 95% CI, 0.93-0.98), cheese (HR per 1-SD increment in intake, 0.96; 95% CI, 0.94-0.99), calcium (HR per 1-SD increment in intake, 0.93; 95% CI, 0.90-0.95), phosphorus (HR per 1-SD increment in intake, 0.92; 95% CI, 0.90-0.95), magnesium (HR per 1-SD increment in intake, 0.95; 95% CI, 0.92-0.98), potassium (HR per 1-SD increment in intake, 0.96; 95% CI, 0.94-0.99), riboflavin (HR per 1-SD increment in intake, 0.94; 95% CI, 0.92-0.97), beta carotene (HR per 1-SD increment in intake, 0.96; 95% CI, 0.93-0.98), and total protein (HR per 1-SD increment in intake, 0.94; 95% CI, 0.92-0.97). None of the gene-nutrient interactions were significant after adjustment for multiple comparisons.

CONCLUSIONS

Our findings confirm a positive association for alcohol and an inverse association for dairy products and calcium with CRC risk, and also suggest a lower risk at higher dietary intakes of phosphorus, magnesium, potassium, riboflavin, beta carotene, and total protein.

Plant-Based Diets and Cancer Risk: What is the Evidence?

PURPOSE OF REVIEW

The purpose of this review is to summarize the recent (past 5 years) available evidence regarding the association between plant-based diets on cancer risk from clinical trials and observational studies. Biological mechanisms and gaps in the current literature will also be discussed.

RECENT FINDINGS

There is a lack of intervention studies but there are abundant observational studies assessing the association between plant-based diets and cancer risk, including multiple longitudinal cohort studies and similar data from case-control studies that demonstrate a decreased overall cancer risk with plant-based diets. Case-control studies support a decreased risk of colorectal and breast cancers with plant-based diets, but results for specific cancers remain inconsistent in cohort studies. Current evidence from observational studies indicates an inverse association between plant-based diets and overall cancer risk. Future research should include intervention studies, address inconsistencies in dietary assessment methods and provide greater detail on underrepresented groups.

Potential Role of Heterocyclic Aromatic Amines in Neurodegeneration

Heterocyclic aromatic amines (HAAs) are mainly formed in the pyrolysis process during high-temperature cooking of meat. Meat consumption is very typical of the western diet, and the amount of meat consumption in the eastern countries is growing rapidly; HAAs represents widespread exposure. HAAs are classified as possible human carcinogens; numerous epidemiological studies have demonstrated regular consumption of meat with HAAs as risk factor for cancers. Specific HAAs have received major attention. For example, 2-amino-1-methyl-6-phenylimidazo[4,5-b] pyridine has been extensively studied as a genotoxicant and mutagen, with emergent literature on neurotoxicity. Harmane has been extensively studied for a role in essential tremors and potentially Parkinson's disease (PD). Harmane levels have been demonstrated to be elevated in blood and brain in essential tremor patients. Meat consumption has been implicated in the etiology of neurodegenerative diseases; however, the role of toxicants formed during meat preparation has not been studied. Epidemiological studies are currently examining the association between HAAs and risk of neurodegenerative diseases such as essential tremors and PD. Studies from our laboratory and others have provided strong evidence that HAA exposure produces PD and Alzheimer's disease-relevant neurotoxicity in cellular and animal models. In this review, we summarize and critically evaluate previous studies on HAA-induced neurotoxicity and the molecular basis of potential neurotoxic effects of HAAs. The available studies provide strong support for the premise that HAAs may impact neurological function and that addressing gaps in understanding of adverse neurological outcomes is critical to determine whether these compounds are modifiable risk factors.

Chemical compositions, fatty acid profiles and selected contaminants in commercial potato and corn chips sold in the Tunisian market

In the last decades, the snack food market is experiencing an important expansion due to the new fast-paced life-style associated with modernization. Crispy snacks, or chips are the most popular snack around the world, nevertheless, their overconsumption is related to the incidence of many diseases. Subsequently, this work aimed to study the chemical composition of 13 brands of potato and corn chips available in the Tunisian market. The investigation was based on: the determination of their chemical, mineral, and fatty acid composition; an evaluation of their lipid quality indices; and a chromatographic analysis of pesticides, aromatic hydrocarbons and acrylamide content. The results showed that the chips samples were of a high carbohydrate and fat content of up to 64.54% and 42.98%, respectively, versus a low protein and mineral composition. The fatty acid profiling showed that saturated fatty acids represent more than 39% for the majority of samples. A poor lipid quality was also observed through their low unsaturated fatty acids /saturated Fatty Acids ratios, with a mean value of 2.24 and their high atherogenic and thrombogenic indices that reached 1.69 and 2.23 respectively. While the analysis of pesticide residues and polycyclic aromatic hydrocarbons showed that all compounds were below the maximum allowed levels, the acrylamide analysis highlighted contamination in all the samples tested, with some values exceeding the allowed threshold. In conclusion, it can be suggested that the crisps sold in the Tunisian market are of a poor nutritional quality and they are potentially unsafe for human consumption.

Heterogeneity in Meat Food Groups Can Meaningfully Alter Population-Level Intake Estimates of Red Meat and Poultry

Heterogeneity in meat food groups hinders interpretation of research regarding meat intake and chronic disease risk. Our objective was to investigate how heterogeneity in red meat (RM) and poultry food groups influences US population intake estimates. Based on a prior systematic review, we created an ontology of methods used to estimate RM [1= unprocessed RM; 2 (reference)= unprocessed RM + processed RM; 3= unprocessed RM + processed RM + processed poultry; and 4=unprocessed RM + processed RM + processed poultry + chicken patties/nuggets/tenders (PNT)] and three for poultry [A=unprocessed poultry; B= unprocessed poultry + PNT; C (reference)= unprocessed poultry + processed poultry + PNT). We applied methods to 2015-18 National Health and Nutrition Examination Survey data to estimate RM and poultry intake prevalence and amount. We estimated and compared intakes within RM and within poultry methods via the NCI Method for individuals ≥2 years old (n = 15,038), adjusted for age, sex, and race/Hispanic origin. We compared the population percentage that exceeded age- and sex-specific RM and poultry allotments from the Dietary Guidelines for Americans recommended eating patterns. The percent that consumed RM ranged from 47 ± 1.2% to 75 ± 0.8% across methods and mean amount ranged from 10.5 ± 0.28 to 18.2 ± 0.35 lean oz-equivalents/week; 38 ± 1.2% to 71 ± 0.7% and 9.8 ± 0.35 to 13.3 ± 0.35 lean oz-equivalents/week across poultry methods. Estimates for higher, but not lower, intake percentiles differed across RM methods. Compared to the reference, Method 1 was ≥3.0 oz-equivalents/week lower from 20th-70th percentiles, ≥6.0 oz-equivalents/week lower from 75th-90th percentiles, and ≥9.0 oz-equivalents/week lower for the 95th percentile. Method 4, but not Method 3, was ≥3.0 oz-equivalents/week higher than the reference from 50 to 95th percentiles. The population percentage that exceeded allotments was 27 ± 1.8% lower for Method 1, 9 ± 0.8% higher for Method 3, and 14 ± 0.9% higher for Method 4 compared to the reference. Differences were less pronounced for poultry. Our analysis quantifies the magnitude of bias introduced by heterogeneous meat food group methodology. Explicit descriptions of meat food groups are important for development of dietary recommendations to ensure that research studies are compared appropriately.

Diet and Genetic Risk Factors of Colorectal Cancer in Palestine: A Case-Control Study

To add evidence to the limited data available on colorectal cancer (CRC) from Palestine, we examine the risk factors associated with CRC using a matched hospital-based case-control study. A structured questionnaire was used to collect data from 105 cases and 105 controls. A multivariable conditional regression model was used to adjust for the association between study factors and CRC risk. In the model, compared with controls, cases from villages were significantly less likely to have CRC (Adjusted Odds Ratio, AOR = 0.194); taking aspirin lowered the likelihood of CRC by 24%; and having a multiple birth sibling by 33%. Also, the likelihood of CRC was lowered significantly by consuming five servings of fruits/vegetables per week or more (5-6 servings: AOR = 0.21, 7-8 servings per week: AOR = 0.04). However, cases had a significantly higher likelihood of CRC if they consumed 2-4 servings of grilled red meat per week (AOR = 4.25); smoked (AOR = 4.38); had a sedentary lifestyle (AOR = 2.53); reported parental consanguinity (AOR = 3.88); or had a family history of cancer (AOR = 6.39). Our results confirmed the association between CRC and red meat intake and smoking, and proved that parental consanguinity and family history of cancer are also risk factors for CRC.

Is periodontitis a risk factor of benign or malignant colorectal tumor? A population-based cohort study

OBJECTIVE

To examine the risk of developing benign or malignant colorectal tumors in patients with periodontitis within 15 years using Taiwan's National Health Insurance Database.

BACKGROUND

Studies have shown that colorectal carcinoma often develops under inflammatory conditions and changes of microbiota in the gut. Recently, a link between Fusobacterium nucleatum, a periodontal pathogen, and colorectal carcinoma has been proposed. However, whether periodontitis is a risk of developing colorectal tumor remains uncertain.

METHODS

In total, 35 124 participants were enrolled from 2000 to 2015 to examine the development risk of benign colorectal tumors, including 11 708 patients with periodontitis who received therapy (group 1), 11 708 patients with periodontitis not receiving periodontal treatment (group 2), and 11 708 non-periodontitis controls after matching for gender, age, and index year. To examine the risk of developing colorectal malignancy, 11 720 participants were assigned to each of the three groups. Cox proportional hazards model and Kaplan-Meier methods were used to compare the risks. Sensitivity analysis was performed, excluding the diagnoses during the first 1 or 5 years.

RESULTS

After the follow-up, 177, 154, and 63 participants in group 1, group 2, and control group had benign colorectal tumors. Patients with periodontitis tended to be associated with a greater rate of having a benign colorectal tumor. The adjusted hazard ratios (aHRs) were 3.77 (95% confidence interval [CI] 2.01-4.82, p < .001) and 2.85 (95% CI 1.62-3.74, p < .001) for groups 1 and 2, respectively. Regarding the risk of malignant colorectal tumor, 20, 18, and 14 participants who developed malignant tumors were included in group 1, group 2, and control group; however, no significant increase in malignancy was observed in periodontitis groups (aHR1.92, 95% CI 0.74-2.36, p = .482; aHR 1.50, 95% CI 0.68-1.97, p = .529, for the two periodontitis groups, respectively).

CONCLUSIONS

The results of this study suggest that patients with periodontitis may have an increased risk of developing benign, but not malignant, colorectal tumors.

Dietary risk factors for esophageal cancer based on World Health Organization regions

OBJECTIVES

Esophageal cancer (EC) has become one of the most alarming cancers in the world. There are significant differences in incidence and risk factors associated with the two most common histological subtypes of EC, esophageal squamous cell carcinoma and esophageal adenocarcinoma, between regions. This systematic review was undertaken to analyze dietary risk factors specific to EC and its two subtypes based on World Health Organization regions.

METHODS

A systematic search of five databases (Global Health, Google Scholar, PubMed, Scopus, and Web of Science) for the past 5 y (2015-2020) was conducted from March 2020 to July 2020. Titles and abstracts were screened to determine the primary inclusion eligibility, followed by an examination of the full-text articles. Finally, 59 articles were reviewed to identify EC risk factors and compare these by region. Data were extracted using a table developed by the research team. Risk factors found in >50% of regions were highlighted.

RESULTS

The study identified some major dietary risk factors for EC that were previously reported, as well as some uncommon dietary risk factors, such as salty foods and beverages, unpiped drinking water, sugar-related factors (e.g., sweet intake), and foods with high glycemic index.

CONCLUSIONS

EC risk factors extend beyond those previously identified. Targeting all EC risk factors by region will assist the World Health Organization and other health agencies in providing a tailored, culturally appropriate response to effectively reduce the incidence and prevalence of EC within a region.

Main mechanisms for carcinogenic heterocyclic amine reduction in cooked meat by natural materials

Carcinogens such as heterocyclic amine (HCA), produced during meat cooking, pose a risk of digestive and reproductive cancers in humans. Nevertheless, the exact mechanisms for HCA formation in meat and the control of HCA formation are not known. In this review, we provide an overview of the main cause of HCA formation in cooked meat, fundamental data on natural materials to inhibit HCA carcinogenicity, and methods to analyze HCA in cooked meat. Related past studies has shown that natural substances contain various components that act as antioxidants, and these antioxidants can prevent HCA and mutagenic factors. Free radicals and DNA adducts produced by HCA metabolism have carcinogenic properties. Antioxidants have been found to inhibit oxidative stress caused by free radicals and DNA adducts. Therefore, we can be hypothesized that various natural materials can inhibit HCA carcinogens and mutagens.

Consumption of red meat and processed meat and cancer incidence: a systematic review and meta-analysis of prospective studies

Red meat and processed meat consumption has been hypothesized to increase risk of cancer, but the evidence is inconsistent. We performed a systematic review and meta-analysis of prospective studies to summarize the evidence of associations between consumption of red meat (unprocessed), processed meat, and total red and processed meat with the incidence of various cancer types. We searched in MEDLINE and EMBASE databases through December 2020. Using a random-effect meta-analysis, we calculated the pooled relative risk (RR) and 95% confidence intervals (CI) of the highest versus the lowest category of red meat, processed meat, and total red and processed meat consumption in relation to incidence of various cancers. We identified 148 published articles. Red meat consumption was significantly associated with greater risk of breast cancer (RR = 1.09; 95% CI = 1.03-1.15), endometrial cancer (RR = 1.25; 95% CI = 1.01-1.56), colorectal cancer (RR = 1.10; 95% CI = 1.03-1.17), colon cancer (RR = 1.17; 95% CI = 1.09-1.25), rectal cancer (RR = 1.22; 95% CI = 1.01-1.46), lung cancer (RR = 1.26; 95% CI = 1.09-1.44), and hepatocellular carcinoma (RR = 1.22; 95% CI = 1.01-1.46). Processed meat consumption was significantly associated with a 6% greater breast cancer risk, an 18% greater colorectal cancer risk, a 21% greater colon cancer risk, a 22% greater rectal cancer risk, and a 12% greater lung cancer risk. Total red and processed meat consumption was significantly associated with greater risk of colorectal cancer (RR = 1.17; 95% CI = 1.08-1.26), colon cancer (RR = 1.21; 95% CI = 1.09-1.34), rectal cancer (RR = 1.26; 95% CI = 1.09-1.45), lung cancer (RR = 1.20; 95% CI = 1.09-1.33), and renal cell cancer (RR = 1.19; 95% CI = 1.04-1.37). This comprehensive systematic review and meta-analysis study showed that high red meat intake was positively associated with risk of breast cancer, endometrial cancer, colorectal cancer, colon cancer, rectal cancer, lung cancer, and hepatocellular carcinoma, and high processed meat intake was positively associated with risk of breast, colorectal, colon, rectal, and lung cancers. Higher risk of colorectal, colon, rectal, lung, and renal cell cancers were also observed with high total red and processed meat consumption.

An Analysis of the Multifaceted Roles of Heme in the Pathogenesis of Cancer and Related Diseases

Heme is an essential prosthetic group in proteins and enzymes involved in oxygen utilization and metabolism. Heme also plays versatile and fascinating roles in regulating fundamental biological processes, ranging from aerobic respiration to drug metabolism. Increasing experimental and epidemiological data have shown that altered heme homeostasis accelerates the development and progression of common diseases, including various cancers, diabetes, vascular diseases, and Alzheimer's disease. The effects of heme on the pathogenesis of these diseases may be mediated via its action on various cellular signaling and regulatory proteins, as well as its function in cellular bioenergetics, specifically, oxidative phosphorylation (OXPHOS). Elevated heme levels in cancer cells intensify OXPHOS, leading to higher ATP generation and fueling tumorigenic functions. In contrast, lowered heme levels in neurons may reduce OXPHOS, leading to defects in bioenergetics and causing neurological deficits. Further, heme has been shown to modulate the activities of diverse cellular proteins influencing disease pathogenesis. These include BTB and CNC homology 1 (BACH1), tumor suppressor P53 protein, progesterone receptor membrane component 1 protein (PGRMC1), cystathionine-β-synthase (CBS), soluble guanylate cyclase (sGC), and nitric oxide synthases (NOS). This review provides an in-depth analysis of heme function in influencing diverse molecular and cellular processes germane to disease pathogenesis and the modes by which heme modulates the activities of cellular proteins involved in the development of cancer and other common diseases.

Replacement of Nitrite in Meat Products by Natural Bioactive Compounds Results in Reduced Exposure to N-Nitroso Compounds: The PHYTOME Project

SCOPE

It has been proposed that endogenously form N-nitroso compounds (NOCs) are partly responsible for the link between red meat consumption and colorectal cancer (CRC) risk. As nitrite has been indicated as critical factor in the formation of NOCs, the impact of replacing the additive sodium nitrite (E250) by botanical extracts in the PHYTOME project is evaluated.

METHOD AND RESULTS

A human dietary intervention study is conducted in which healthy subjects consume 300 g of meat for 2 weeks, in subsequent order: conventional processed red meat, white meat, and processed red meat with standard or reduced levels of nitrite and added phytochemicals. Consumption of red meat products enriched with phytochemicals leads to a significant reduction in the faecal excretion of NOCs, as compared to traditionally processed red meat products. Gene expression changes identify cell proliferation as main affects molecular mechanism. High nitrate levels in drinking water in combination with processed red meat intake further stimulates NOC formation, an effect that could be mitigated by replacement of E250 by natural plant extracts.

CONCLUSION

These findings suggest that addition of natural extracts to conventionally processed red meat products may help to reduce CRC risk, which is mechanistically support by gene expression analyses.

Formation of Lipid and Protein Oxidation Products during In Vitro Gastrointestinal Digestion of Dry-Cured Loins with Different Contents of Nitrate/Nitrite Added

The effect of nitrate/nitrite (0, 37.5, 75, and 150 mg/kg) in the dry-cured loin formulation on the formation of lipid and protein oxidation products during in vitro digestion was evaluated. Dry-cured loins formulated with nitrate/nitrite resulted in significantly less lipid and protein oxidation than uncured loins before and after simulated digestion. Compared to loins added with 0 mg/kg nitrate/nitrite, dry-cured loins with 37.5, 75, and 150 mg/kg contained a significantly lower content of conjugated dienes, malondialdehyde, carbonyls, and non-heme iron, and higher amounts of nitrosylmioglobin and thiols. During in vitro digestion, the content of conjugated dienes, malondialdehyde, and carbonyls increased, while thiol content decreased, indicating the development of lipid and protein oxidative processes. At the end of the intestinal phase, the 75 mg/kg digests had a significantly higher content of conjugated dienes, while no differences were found among the other digests. During the in vitro intestinal phase (180 and 240 min), nitrate/nitrite curing resulted in significantly lower malondialdehyde concentrations in the 37.5, 75, and 150 mg/kg loin digests than in the uncured loin digests. No significant differences were observed at the end of the intestinal digestion phase between the cured loin digests. Digests of dried loins without nitrate/nitrite addition showed higher carbonyl contents than the nitrate/nitrite cured counterparts. The loss of thiols was significantly higher in loin digests without added nitrate/nitrite than in loin digests with different amounts of curing salts. The addition of 37.5 mg/kg nitrate/nitrite in the cured loin formulation prevents the formation of lipid peroxidation products and carbonyls from protein oxidation and thiol loss during digestion.

Food security, obesity, and meat-derived carcinogen exposure in US adults

Risk for colorectal cancer (CRC) is increased in adults with poor diet quality, low socioeconomic status, and increased body mass index (BMI). Cooked meats contain high contents of mutagenic compounds related to CRC risk. To explore differences in meat-based carcinogen exposure, a 99-item Qualtrics survey was issued to 1648 US adults. Average monthly serving size, degree of doneness, and cooking methods of meat products were obtained. The National Cancer Institute CHARRED database was used to quantify exposure to HCAs, PAHs, and Ames Predicted and Estimated mutagenicity. Questions from validated instruments assessed food security status (FSS) and demographic variables, while height and weight were self-reported to calculate BMI. Sex, FSS and obesity status (BMI > 30 kg/m²) were compared using two-sample t-tests and multivariate regression models to determine differences in meat intake and carcinogen exposure. Statistical significance was set at P < 0.05. Eight hundred fifty-six valid responses (57.4% female and 81.8% white) were obtained. Non-obese males consumed more white meat and were exposed to greater amounts of 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline. Food insecure and obese females consumed more red meat and had higher exposure rates of several carcinogens. Pan-frying and BBQ were the primary sources of meat-derived carcinogens. Greater disparities in carcinogen exposure were observed in females regarding BMI and FSS. Public health messages to modify meat cooking methods may be most effective for CRC prevention.

Weighted Gene Co-expression Network Analysis Identified a Novel Thirteen-Gene Signature Associated With Progression, Prognosis, and Immune Microenvironment of Colon Adenocarcinoma Patients

Colon adenocarcinoma (COAD) is one of the most common malignant tumors and has high migration and invasion capacity. In this study, we attempted to establish a multigene signature for predicting the prognosis of COAD patients. Weighted gene co-expression network analysis and differential gene expression analysis methods were first applied to identify differentially co-expressed genes between COAD tissues and normal tissues from the Cancer Genome Atlas (TCGA)-COAD dataset and GSE39582 dataset, and a total of 309 overlapping genes were screened out. Then, our study employed TCGA-COAD cohort as the training dataset and an independent cohort by merging the GES39582 and GSE17536 datasets as the testing dataset. After univariate and multivariate Cox regression analyses were performed for these overlapping genes and overall survival (OS) of COAD patients in the training dataset, a 13-gene signature was constructed to divide COAD patients into high- and low-risk subgroups with significantly different OS. The testing dataset exhibited the same results utilizing the same predictive signature. The area under the curve of receiver operating characteristic analysis for predicting OS in the training and testing datasets were 0.789 and 0.868, respectively, which revealed the enhanced predictive power of the signature. Multivariate Cox regression analysis further suggested that the 13-gene signature could independently predict OS. Among the 13 prognostic genes, NAT1 and NAT2 were downregulated with deep deletions in tumor tissues in multiple COAD cohorts and exhibited significant correlations with poorer OS based on the GEPIA database. Notably, NAT1 and NAT2 expression levels were positively correlated with infiltrating levels of CD8+ T cells and dendritic cells, exhibiting a foundation for further research investigating the antitumor immune roles played by NAT1 and NAT2 in COAD. Taken together, the results of our study showed that the 13-gene signature could efficiently predict OS and that NAT1 and NAT2 could function as biomarkers for prognosis and the immune response in COAD.

Probiotics: A Promising Candidate for Management of Colorectal Cancer

Colorectal cancer (CRC) is the World's third most frequently diagnosed cancer type. It accounted for about 9.4% mortality out of the total incidences of cancer in the year 2020. According to estimated facts by World Health Organization (WHO), by 2030, 27 million new CRC cases, 17 million deaths, and around 75 million people living with the disease will appear. The facts and evidence that establish a link between the intestinal microflora and the occurrence of CRC are quite intuitive. Current shortcomings of chemo- and radiotherapies and the unavailability of appropriate treatment strategies for CRC are becoming the driving force to search for an alternative approach for the prevention, therapy, and management of CRC. Probiotics have been used for a long time due to their beneficial health effects, and now, it has become a popular candidate for the preventive and therapeutic treatment of CRC. The probiotics adopt different strategies such as the improvement of the intestinal barrier function, balancing of natural gut microflora, secretion of anticancer compounds, and degradation of carcinogenic compounds, which are useful in the prophylactic treatment of CRC. The pro-apoptotic ability of probiotics against cancerous cells makes them a potential therapeutic candidate against cancer diseases. Moreover, the immunomodulatory properties of probiotics have created interest among researchers to explore the therapeutic strategy by activating the immune system against cancerous cells. The present review discusses in detail different strategies and mechanisms of probiotics towards the prevention and treatment of CRC.

Effects of processed meat and drinking water nitrate on oral and fecal microbial populations in a controlled feeding study

BACKGROUND

One mechanism that can explain the link between processed meat consumption and colorectal cancer (CRC) is the production of carcinogenic N-nitroso compounds (NOCs) in the gastrointestinal tract. Oral and gut microbes metabolize ingested proteins (a source of secondary and tertiary amines and amides) and can reduce nitrate to nitrite, generating potentially carcinogenic NOCs.

OBJECTIVE

We evaluated whether nitrate/nitrite in processed meat or water influences the fecal or salivary microbiota.

DESIGN

In this dietary intervention study, 63 volunteers consumed diets high in conventional processed meats for two weeks, switched to diets high in poultry for two weeks, and then consumed phytochemical-enriched conventional processed or low-nitrite processed meat diets for two weeks. During the intervention, they drank water with low nitrate concentrations and consumed a healthy diet with low antioxidants. Then the volunteers drank nitrate-enriched water for 1 week, in combination with one of the four different diets. We measured creatinine-adjusted urinary nitrate levels and characterized the oral and fecal microbiota using 16S rRNA amplicon sequencing.

RESULTS

Using linear mixed models, we found that, compared to baseline, urinary nitrate levels were reduced during the phytochemical-enriched low-nitrite meat diet (p-value = 0.009) and modestly during the poultry diet (p-value = 0.048). In contrast, urinary nitrate increased after 1-week of drinking nitrate-enriched water (p-value<10^-5). Nitrate-enriched water, but not processed meats with or without phytochemicals, altered the saliva microbial population (p-value ≤0.001), and significantly increased abundance of 8 bacterial taxa, especially genus Neisseria and other nitrate-reducing taxa. Meats, phytochemicals and nitrate-enriched water had no significant effects on saliva alpha diversity or any diversity parameter measured for the fecal microbiota.

CONCLUSION

These findings support the hypothesis that drinking high nitrate water increases oral nitrate-reducing bacteria, which likely results in increased NOC. However, meat nitrate/nitrite at the levels tested had no effect on either the gut or oral bacteria. CLINICALTRIALS.

GOV IDENTIFIER

NCT04138654.

Tumour necrosis factor-α (TNF-α) enhances dietary carcinogen-induced DNA damage in colorectal cancer epithelial cells through activation of JNK signaling pathway

Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer death. Benzo[a]pyrene (BaP) and 2-amino-1-methyl-6-phenylimidazol [4,5-b] pyridine (PhIP) present in cooked meat are pro-carcinogens and considered to be potential risk factors for CRC. Their carcinogenic and mutagenic effects require metabolic activation primarily by cytochrome P450 1 family enzymes (CYPs); the expression of these enzymes can be modulated by aryl hydrocarbon receptor (AhR) activation and the tumour microenvironment, involving mediators of inflammation. In this study, we hypothesized that tumour necrosis factor-α (TNF-α), a key mediator of inflammation, modulates BaP- and PhIP-induced DNA damage in colon cancer epithelial cells. Importantly, we observed that TNF-α alone (0.1-100 pg/ml) induced DNA damage (micronuclei formation) in HCT-116 cells and co-treatment of TNF-α with BaP or PhIP showed higher levels of DNA damage compared to the individual single treatments. TNF-α alone or in combination with BaP or PhIP did not affect the expression levels of CYP1A1 and CYP1B1 (target genes of AhR signaling pathways). The DNA damage induced by TNF-α was elevated in p53 null HTC-116 cells compared to wild type cells, suggesting that TNF-α-induced DNA damage is suppressed by functional p53. In contrast, p53 status failed to affect BaP and PhIP induced micronucleus frequency. Furthermore, JNK and NF-κB signaling pathway were activated by TNF-α treatment but only inhibition of JNK significantly reduced TNF-α-induced DNA damage. Collectively, these findings suggest that TNF-α induced DNA damage involves JNK signaling pathway rather than AhR and NF-κB pathways in colon cancer epithelial cells.

Non-thermal processing has an impact on the digestibility of the muscle proteins

Muscle proteins undergo several processes before being ready in a final consumable form. All these processes affect the digestibility of muscle proteins and subsequent release of amino acids and peptides during digestion in the human gut. The present review examines the effects of different processing techniques, such as curing, drying, ripening, comminution, aging, and marination on the digestibility of muscle proteins. The review also examines how the source of muscle proteins alters the gastrointestinal protein digestion. Processing techniques affect the structural and functional properties of muscle proteins and can affect their digestibility negatively or positively depending on the processing conditions. Some of these techniques, such as aging and mincing, can induce favorable changes in muscle proteins, such as partial unfolding or exposure of cleavage sites, and increase susceptibility to hydrolysis by digestive enzymes whereas others, such as drying and marination, can induce unfavorable changes, such as severe cross-linking, protein aggregation, oxidation induced changes or increased disulfide (S-S) bond content, thereby decreasing proteolysis. The underlying mechanisms have been discussed in detail and the conclusions drawn in the light of existing knowledge provide information with potential industrial importance.

Dietary energy density and risk of prostate cancer: (A case-control study)

OBJECTIVE

Some observational studies investigated the association between dietary energy density (DED) and risk of cancers with inconstant results. In addition, there is no study on such association among patients with prostate cancer (PC). The present study was performed to evaluate the association between dietary energy density (DED) and PC risk.

METHODS

In this case-control study, one hundred and twenty-five participants were enrolled (62 cases and 63 controls). Dietary intakes were assessed using 160-item semi-quantitative food frequency questionnaire. In addition, demographic characteristics were collected using a general questionnaire and anthropometric indices were measured based on the available guidelines. The association between DED and PC risk was evaluated using multivariable logistic regression.

RESULTS

The results showed that higher DED score was associated with increased risk of PC (OR = 2.59; 95% CI= (1.24-5.40)). Interestingly, after adjusting for potential confounders ((smoking, physical activity, energy intake, education, ethnicity, job, anti-hyperlipidemic drugs, antihypertensive drugs, and aspirin) the results remained significant (OR = 2.87; 95% CI= (1.17-7.05)).

CONCLUSION

Our findings suggest that DED may increase the risk of PC. However, more prospective studies are warranted to confirm these results.