Foods and their components promoting gastrointestinal cancer

A Scoping Review of the Causal Pathways and Biological Mechanisms Linking Nutrition Exposures and Health Outcomes

BACKGROUND/AIM

Building on the evidence for multifaceted effects of different nutrients, foods and dietary patterns is a new priority for nutrition science. This review aims to describe the causal pathways and biological mechanisms that elucidate the associations between different nutrition exposures (nutrients, foods and dietary patterns) and health outcomes.

METHODS

A scoping review was conducted in two stages: 1) review of nutrition science textbooks; and 2) a review of reviews of empirical literature using a systematic approach to elucidate causal pathways and biological mechanisms for nutrition exposures and health outcomes. Reviews were eligible for inclusion if they reported biological mechanistic pathways between exposures and outcomes of interest among free-living healthy adults and/or children. Causal pathways within and between the exposures and the outcomes were identified and summarised visually.

RESULTS

A total of seven core textbooks and 1,934 reviews of relevant empirical literature were included. The complexity of the causal pathways and the number of biological mechanisms progressively increases as the nutrition exposure changes from nutrients to foods to dietary patterns. The biological mechanisms demonstrate that associations with beneficial or adverse health outcomes are determined by the contrasting chemical composition and physical structure of the different types and forms of nutrition exposures, and that contextual factors (e.g., food processing) can influence these chemical and physical factors for food and dietary pattern exposures.

CONCLUSION

This review provides models that can guide future research, and has several implications for the generation and interpretation of the nutrition evidence, and its synthesis and translation to inform nutrition guidelines and policies.

Barbecued desi chicken: an investigation on the impact of polluted milieu upon formation and ingestion of polycyclic aromatic hydrocarbons (PAHs) in commercial versus laboratory barbecued organs along with stochastic cancer risk assessments in people from an industrial district of Punjab, Pakistan

8∑PAHs in 2- and 4-month-old desi chicken organs collected from Faisalabad district, Punjab, Pakistan, were examined via high-performance liquid chromatography (HPLC). Exposure doses (A_VDD) of PAHs with consequential lifetime excess cancer risks (L_tECR) were also estimated in people ingesting laboratory barbecued (L_b) and commercially barbecued (C_b) desi meat organs. The results exposed the presence of 8ΣPAH in 2- and 4-month-old L_b and C_b chicken organs: drumsticks (D_s), breast (B_S), and wings (W_s) (0.45, 3.10, 0.97 ng g^-1; 2.52, 4.31, 1.22 ng g^-1; and 10.09, 15.04, and 9.06 ng g^-1 respectively). BαP was found only in C_b organs with the highest concentrations (5.08 ng g^-1) in B_s. It was above the EU's tolerable limit, while it was not detected in all L_b organs. The lowest level of 8ΣPAH was found in 2-month-old desi W_s. A comparative percentage increase in 8ΣPAH levels between all L_b and C_b organs was found in the range of 1500-2416.67%. L_tECR for males and adults were ranging from 1.35 × E^-13 to 4.49 × E^-5 at different consumption rates with A_VDD ranging from 1.08 E^-6 to 6.01 E^-5. In contrast to 2- and 4- month-old chicken meat, 2-month-old desi meat is better having less PAH load. Comparing different organs, W_s of former one displayed abridged PAH levels. In conclusion, L_b desi meat is less carcinogenic relative to C_b. More PAH levels are due to secondary smoke in C_b samples collected from the metropolitan. Ingestion of L_b 2-month-old desi chicken organs could be safe to dine as compared with 4-month-old desi and C_b organs. Graphical abstract.

The Facts about Food after Cancer Diagnosis: A Systematic Review of Prospective Cohort Studies

Nutritional guidelines suggest specific energy and protein requirements for patients with cancer. However, cancer patients, often malnourished, use self-made or web-based diets to ameliorate the prognosis of their disease. This review aimed to investigate the associations between post-diagnostic diet and prognostic outcomes in cancer patients. A systematic literature search was performed in Pubmed and Web of Science databases from inception to 30 October 2019, based on fixed inclusion and exclusion criteria. The risk of bias was assessed. A total of 29 prospective studies was identified. Breast (n = 11), colorectal (n = 9), prostate (n = 8) cancers are the most studied. Low- fat diet, healthy quality diet, regular consumption of fiber such as vegetables and high-quality protein intake are beneficial while Western diet (WD) and high consumption of saturated fats could be associated with a higher risk of mortality. Bladder (n = 1), gynecological (n = 1), lung, stomach, and pancreatic cancers still remain almost unexplored. This systematic review suggested that detrimental dietary patterns such as WD should be avoided but none of the food categories (meat, dairy products) should be eliminated in cancer patients' diet. Further large prospective studies are needed to assess the role of post-diagnostic diet in patients with cancer.

Association between dietary inflammatory index and upper aerodigestive tract cancer risk: A systematic review and dose-response meta-analysis

OBJECTIVES

The relationship between dietary inflammatory index (DII) and upper aerodigestive tract (UADT) cancer risk have been investigated in a growing number of epidemiological studies. However, their findings were inconsistent, and no systematic review or meta-analysis has been conducted up to now. This meta-analysis was carried out to examine potential dose-response relationship between DII score and UADT cancer risk.

MATERIAL AND METHODS

A systematic search was conducted for relevant studies in PubMed and Web of Science up to March 28, 2019. Categorical meta-analysis as well as linear and non-linear dose-response meta-analysis were performed to evaluate association between DII and UADT cancer risk.

RESULTS

Nine case-control studies with a total of 4138 cases and 15,326 healthy controls were eligible in the present meta-analysis. The pooled odds ratios (ORs) of UADT cancer risk were 2.07 [95% confidence interval (CI): 1.82, 2.35] for the highest DII score compared with the lowest and 1.53 (95% CI: 1.39, 1.69) for higher DII score compared with lower score, respectively. Furthermore, a one-unit increment in DII score was associated with an increased risk of 18% for UADT cancers (OR: 1.18; 95% CI: 1.15, 1.21). An upward trend towards a positive association between elevated DII score and UADT cancer risk was also observed in non-linear dose-response meta-analysis.

CONCLUSIONS

The present meta-analysis provides evidence of highly pro-inflammatory diets that might increase risk of UADT cancers. Therefore, reducing pro-inflammatory components in diets should be considered to prevent and control UADT cancers.

Index-based dietary patterns in relation to gastric cancer risk: a systematic review and meta-analysis

Dietary indices are widely used in diet quality measurement, and the index-based dietary patterns are related to gastric cancer risk. To evaluate the relationship between different kinds of index-based dietary patterns and gastric cancer risk, we systematically searched four English-language databases and four Chinese-language databases. The quality of studies was assessed by the Newcastle–Ottawa Scale. Meta-analyses were performed to estimate the association between gastric cancer incidence and different types of index-based dietary patterns. The OR and hazard ratios (HR) of gastric cancer incidence were calculated by regression models in case–control studies and prospective cohort studies, respectively. The studies were pooled in the random effects model to calculate the summarised risk estimate of the highest quantile interval of dietary indices, taking the lowest as the referent. The dietary indices included different versions of Mediterranean diet score (MDS) and dietary inflammatory index (DII), healthy eating index, Chinese Food Pagoda score and food index score. The meta-analysis was carried out for studies on MDS and DII. The combined OR of gastric cancer for the highest MDS v. the referent was 0·42 (95 % CI 0·2, 0·86), and the combined HR was 0·89 (95 % CI 0·68, 1·17). The combined OR for DII was 2·11 (95 % CI 1·41, 3·15). Higher Mediterranean dietary pattern consumption might reduce gastric cancer risk, while higher inflammatory diet pattern consumption might increase gastric cancer risk.

Accumulation and translocation of phenanthrene, anthracene and pyrene in winter wheat affected by soil water content

Polycyclic aromatic hydrocarbons (PAHs) are universal organic pollutants in the agro ecosystems in China, therefore, it is important to understand the uptake and accumulation of PAHs in crops growing on PAHs contaminated soils for human health risk assessments. Water management is a common practice to maintain high grain yields during wheat production. However, the effects of soil water content on the accumulation and translocation of PAHs in wheat are still not clear. The main objectives of the present study were to investigate the effects of soil water content on the accumulation of three selected PAHs (Σ₃PAHs, phenanthrene, anthracene and pyrene) in wheat during whole plant growth stage and on translocation or remobilization of Σ₃PAHs from vegetative tissues to wheat grains. Winter wheat (Triticum aestivum cv. Xiaoyan22) were grown on Σ₃PAHs spiked soils maintaining 80%, 60% or 40% water-holding capacity during the whole plant growth stage. Plant samplings were performed at jointing, anthesis or maturity stage, respectively. The present study showed that grain yield and biomass of the crop increased with soil water content increasing. Transpiration rate of wheat leaf under 80% and 60% water-holding capacity treatments was significantly (p < 0.05) higher than that under 40% water-holding capacity treatment at both anthesis and filling stage. Soil water content and plant growth stage had significant (p < 0.0001) effects on concentrations of phenanthrene, anthracene and pyrene in winter wheat. When exposed to 0, 15, 60, and 150 mg kg^-1 Σ₃PAHs in soils, Σ₃PAHs concentrations in the grains under 60% water-holding capacity treatment were 46.6%, 69.9%, 89.5% and 81.7% of those under 80% water-holding capacity treatment, respectively. The highest concentrations of Σ₃PAHs in the crop were recorded at anthesis stage. The distribution of PAHs in different tissues of wheat varied among different soil water treatments and plant growth stages. The present study indicated that optimizing soil water content during winter wheat production could apparently reduce concentrations of Σ₃PAHs in grains via influence root uptake of Σ₃PAHs and translocation of Σ₃PAHs from stem or leaf into grain, suggesting the potential of water management to cope with PAHs contamination in crops growing on PAHs contaminated soils.

Association between the dietary inflammatory index and the incidence of cancer: a systematic review and meta-analysis of prospective studies

OBJECTIVE

Although many risk factors for cancers have been well defined, the effects of dietary inflammation have remained controversial. We aimed to summarize the association between the dietary inflammatory index (DII) and the risk of cancer.

STUDY DESIGN

A systematic review and meta-analysis on prospective studies.

METHODS

Electronic databases including PubMed/MEDLINE, Scopus, and Web of Science were searched to find relevant articles published in English up to February 2017. Prospective studies that reported the relative risk (RR) or hazard ratio for the most pro-inflammatory vs the most anti-inflammatory diets and cancer were included. Random effects model was used to pool the effect sizes.

RESULTS

Finally, 11 effect sizes from 10 prospective studies were included. Findings indicated that the most pro-inflammatory vs the most anti-inflammatory diets were significantly associated with an increased risk for total cancer (overall RR: 1.17; 95% confidence interval [CI]: 1.09-1.26) with a substantial heterogeneity (I²: 85.5%, P < 0.001). Subgroup analysis revealed that the association between DII and breast cancer was 1.04 (95% CI: 1.02, 1.07; I²:0%; P = 0.66), while it was 1.26 (95% CI: 1.17, 1.36; I² = 58.1%; P = 0.03) for colorectal cancer.

CONCLUSIONS

Although the findings of the current meta-analysis support the hypothesis that diets with high pro-inflammatory components can increase the risk of cancer, the heterogeneity was high. Therefore, further studies are required to clarify this association.

Residuals, bioaccessibility and health risk assessment of PAHs in winter wheat grains from areas influenced by coal combustion in China

Polycyclic aromatic hydrocarbons (PAHs) contamination in atmospheric and soil was serious, which is mainly due to high level of emission of PAHs in China resulted from the predominating use of coal in energy consumption and continuous development of economy and society for years. However, the status of PAHs in winter wheat grains from the areas influenced by coal combustion in China was still not clear. During harvest season, the winter wheat grains were collected from agricultural fields surrounding coal-fired power plants located in Shaanxi and Henan Provinces. This study found that the mean concentrations of 15 priority PAHs ranged from 69.58 to 557.0μgkg^-1. Three-ring PAHs (acenaphthene, acenaphthylene, fluorene, phenanthrene and anthracene) were dominant in the grains, accounting for approximately 70-81% of the total PAHs. The bioaccessibility of low molecular weight (LMW, 2-3 ring) PAHs (51.1-52.8%), high molecular weight (HMW, 4-6 ring) PAHs (19.8-27.6%) and total PAHs (40.9-48.0%) in the intestinal condition was significantly (p<0.001) higher than that (37.4-38.6%; 15.6-22.5%; 30.7-35.5%) in the gastric condition, respectively. Based on total PAHs, the values of incremental lifetime cancer risk (ILCR) for children, adolescents, adults and seniors were all higher than the baseline value (10^-6) and some even fell in the range of 10^-5-10^-4, which indicated that most grains from the areas affected by coal combustion possessed considerable cancer risk. The present study also indicated that the children were the age group most sensitive to PAHs contamination. The pilot research provided relevant information for the regulation of PAHs in the winter wheat grains and for the safety of the agro-products growing in the PAHs-contaminated areas.