Diets, Dietary Patterns, Single Foods and Pancreatic Cancer Risk: An Umbrella Review of Meta-Analyses

Clinical risk factors for pancreatic cancer: protocol for an umbrella review

INTRODUCTION

Identifying cancer earlier can help save lives. An increasingly popular approach to diagnosing cancer earlier is in the development of risk prediction models to be applied to the electronic healthcare record of patients. Development of these models requires systematic and thorough identification of the risk factors that might increase an individual's propensity to develop the disease. This protocol sets out the methods for an umbrella review to identify risk factors that might be included in these models. The example used is pancreatic cancer, a disease with a high percentage of late-stage diagnoses and consequent high mortality.

METHODS AND ANALYSIS

Relevant systematic reviews will be identified through searching of MEDLINE and EMBASE via Ovid and the Science Citation Index Expanded of the Web of Science Core Collection. Screening will be performed by two independent reviewers using Covidence software and the results reported as a Preferred Reporting Items for Systematic Reviews and Meta-Analyses flow diagram. Data from eligible studies will be extracted independently by two reviewers and each systematic review will be graded using defined credibility assessment criteria and the ROBIS (Risk of Bias in Systematic Reviews) tool. Results will be presented in detail for each paper. Summary results for each risk factor will be discussed in the narrative and summarised using a table, graphical summary and an infographic.

ETHICS AND DISSEMINATION

Ethical approval is not required for this review. Results of the review will be disseminated by publication in a peer-reviewed journal and presented at conferences.

PROSPERO REGISTRATION NUMBER

CRD42024526338.

Adherence to a Cholesterol-Lowering Diet and the Risk of Pancreatic Cancer: A Case-Control Study

BACKGROUND

Pancreatic cancer risk has been associated with increased serum cholesterol level, which is in turn partially influenced by diet. This study aimed at evaluating the association between pancreatic cancer risk and the adherence to a plant-based cholesterol-lowering diet.

METHODS

Data were derived from an Italian case-control study including 258 pancreatic cancer patients and 551 controls. The cholesterol-lowering diet score was based on seven components: high intakes of (i) non-cellulosic polysaccharides (a proxy of viscous fibers), (ii) monounsaturated fatty acids, (iii) legumes, and (iv) seeds/corn oils (a proxy of phytosterols); and low intakes of (v) saturated fatty acids, (vi) dietary cholesterol, and (vii) food with a high glycemic index. The score was calculated adding one point for each fulfilled component, thus ranging from zero (no adherence) to seven (complete adherence). The odds ratios (ORs) and 95% confidence intervals (CIs) were estimated through the logistic regression model.

RESULTS

Scores 5-7 were associated with reduced cancer risk (OR = 0.30; 95% CI: 0.18-0.52) compared to scores 0-2.

CONCLUSIONS

Adherence to a plant-based cholesterol-lowering diet was associated with a reduced risk of pancreatic cancer.

The association between major gastrointestinal cancers and red and processed meat and fish consumption: A systematic review and meta-analysis of the observational studies

BACKGROUND

The association between red meat, fish, and processed meat consumption and the risk of developing gastrointestinal (GI) cancers remains inconclusive despite several investigations. Therefore, we conducted a systematic review and meta-analysis of observational studies to update the existing scientific evidence.

METHODS

We searched PubMed, Web of Science, and Scopus databases until May 20, 2023. We analyzed observational studies that examined the associations between red and processed meat and fish consumption and GI cancers. We assessed between-study heterogeneity using the χ2 and τ2 tests, as well as I2 statistics. We explored the likelihood of publication bias using Begg's and Egger's tests and trim-and-fill analysis. We reported the overall effect sizes as odds ratios (ORs) with a 95% confidence interval (CI) using a random-effects model.

RESULTS

Of the 21,004 studies identified, 95 studies involving 5,794,219 participants were included in the meta-analysis. The consumption of high levels of red meat, as compared to low levels, was found to significantly increase the risk of developing esophageal, pancreatic, liver, colon, rectal, and colorectal cancers. Similarly, the consumption of high levels of processed meat, as compared to low levels, significantly increased the risk of pancreatic, colon, rectal, and colorectal cancers. In contrast, the consumption of high levels of fish, as compared to low levels, significantly reduced the risk of colon, rectal, and colorectal cancers.

CONCLUSIONS

This meta-analysis provides updated evidence on the association between red meat, processed meat, and fish consumption and the risk of developing five major types of GI cancers.

Cardiovascular health and cancer risk associated with plant based diets: An umbrella review

CONTEXT

Cardiovascular diseases (CVDs) and cancer are the two main leading causes of death and disability worldwide. Suboptimal diet, poor in vegetables, fruits, legumes and whole grain, and rich in processed and red meat, refined grains, and added sugars, is a primary modifiable risk factor. Based on health, economic and ethical concerns, plant-based diets have progressively widespread worldwide.

OBJECTIVE

This umbrella review aims at assessing the impact of animal-free and animal-products-free diets (A/APFDs) on the risk factors associated with the development of cardiometabolic diseases, cancer and their related mortalities.

DATA SOURCES

PubMed and Scopus were searched for reviews, systematic reviews, and meta-analyses published from 1st January 2000 to 31st June 2023, written in English and involving human subjects of all ages. Primary studies and reviews/meta-analyses based on interventional trials which used A/APFDs as a therapy for people with metabolic diseases were excluded.

DATA EXTRACTION

The umbrella review approach was applied for data extraction and analysis. The revised AMSTAR-R 11-item tool was applied to assess the quality of reviews/meta-analyses.

RESULTS

Overall, vegetarian and vegan diets are significantly associated with better lipid profile, glycemic control, body weight/BMI, inflammation, and lower risk of ischemic heart disease and cancer. Vegetarian diet is also associated with lower mortality from CVDs. On the other hand, no difference in the risk of developing gestational diabetes and hypertension were reported in pregnant women following vegetarian diets. Study quality was average. A key limitation is represented by the high heterogeneity of the study population in terms of sample size, demography, geographical origin, dietary patterns, and other lifestyle confounders.

CONCLUSIONS

Plant-based diets appear beneficial in reducing cardiometabolic risk factors, as well as CVDs, cancer risk and mortality. However, caution should be paid before broadly suggesting the adoption of A/AFPDs since the strength-of-evidence of study results is significantly limited by the large study heterogeneity alongside the potential risks associated with potentially restrictive regimens.

Physical Activity, Sedentary Behavior, and Pancreatic Cancer Risk: A Mendelian Randomization Study

Pancreatic cancer is currently the seventh leading cause of cancer death worldwide. Understanding whether modifiable factors increase or decrease the risk of this disease is central to facilitating primary prevention. Several epidemiological studies have described the benefits of physical activity, and the risks associated with sedentary behavior, in relation to cancer. This study aimed to assess evidence of causal effects of physical activity and sedentary behavior on pancreatic cancer risk. We conducted a two-sample Mendelian randomization study using publicly available data for genetic variants associated with physical activity and sedentary behavior traits and genetic data from the Pancreatic Cancer Cohort Consortium (PanScan), the Pancreatic Cancer Case-Control Consortium (PanC4), and the FinnGen study for a total of 10 018 pancreatic cancer cases and 266 638 controls. We also investigated the role of body mass index (BMI) as a possible mediator between physical activity and sedentary traits and risk of developing pancreatic cancer. We found evidence of a causal association between genetically determined hours spent watching television (hours per day) and increased risk of pancreatic cancer for each hour increment (PanScan-PanC4 odds ratio = 1.52, 95% confidence interval 1.17-1.98, P = .002). Additionally, mediation analysis showed that genetically determined television-watching time was strongly associated with BMI, and the estimated proportion of the effect of television-watching time on pancreatic cancer risk mediated by BMI was 54%. This study reports the first Mendelian randomization-based evidence of a causal association between a measure of sedentary behavior (television-watching time) and risk of pancreatic cancer and that this is strongly mediated by BMI. Summary: Pancreatic cancer is a deadly disease that is predicted to become the second leading cause of cancer-related deaths by 2030. Physical activity and sedentary behaviors have been linked to cancer risk and survival. However, there is limited research on their correlation with pancreatic cancer. To investigate this, we used a Mendelian randomization approach to examine the genetic predisposition to physical activity and sedentariness and their relation to pancreatic cancer risk, while excluding external confounders. Our findings revealed a causal link between the time spent watching television and an increased risk of pancreatic cancer. Additionally, we determined that over half of the effect of watching television on pancreatic risk is mediated by the individual's BMI.

Scientific evidence supporting the newly developed one-health labeling tool "Med-Index": an umbrella systematic review on health benefits of mediterranean diet principles and adherence in a planeterranean perspective

BACKGROUND

Med-Index is a one-health front-of-pack (FOP) label, based on Mediterranean diet (MedDiet) principles, developed to summarize information about the nutritional properties and related-health benefits of any food as well as its sustainable production processes, and the associated food company's social responsibility parameters in a new "Planeterranean" perspective. Thus, Med-Index can be adopted in and by any European region and authority as well as worldwide; this is achieved by consumption and cooking of locally available and sourced foods that respect MedDiet principles, both in terms of healthy nutrition and sustainable production. The huge body of scientific evidence about the health benefits of the MedDiet model and principles requires a comprehensive framework to encompass the scientific reliability and robustness of this tool. A systematic review was carried out to examine the association between human health and adherence to MedDiet patterns upon which the "Med-Index" tool was subsequently developed.

METHODS

MEDLINE and PubMed databases were searched for eligible publications from 1990 to April 2023. Systematic literature reviews, with or without meta-analysis, of clinical trials and observational studies were screened by two independent investigators for eligibility, data extraction, and quality assessment. English language and the time interval 1990-2023 were applied. A registry code CRD42023464807 was generated on PROSPERO and approved for this search protocol. The corrected covered area (CCA), calculated to quantify the degree of overlap between reviews, gave a slight overlap (CCA = 4%).

RESULTS

A total of 84 systematic reviews out of 6681 screened records were selected. Eligible reviews included studies with predominantly observational designs (61/84, 72.6%%), of which 26/61 referenced studies of mixed observational and RCT designs, while 23/84 (27.4%) were RCT-only systematic reviews. Seventy-nine different entries were identified for health outcomes, clustered into 10 macro-categories, each reporting a statistically significant association with exposure to the MedDiet. Adherence to MedDiet was found to strongly benefit age-related chronic diseases (21.5%), neurological disorders (19%), and obesity-related metabolic features (12.65), followed by CVDs (11.4%), cancer (10.1%), diabetes (7.5%), liver health (6.3%), inflammation (5%), mortality (5%), and renal health (1.2%). The quality of the studies was moderate to high.

CONCLUSION

In the context of a "Planeterranean" framework and perspective that can be adopted in any European region and worldwide, MedDiet represents a healthy and sustainable lifestyle model, able to prevent several diseases and reduce premature mortality. In addition, the availability of a FOP, such as Med-Index, might foster more conscious food choices among consumers, paying attention both to human and planetary health.

Dietary patterns in relation to incidence rate of pancreatic cancer - the Norwegian women and cancer cohort study

Despite development in cancer treatment and prevention options during the past few years, cancer of the pancreas remains a diagnosis associated with poor prognosis and limited options for prevention. Diet has proven to be an important risk factor for development of many types of cancer, particularly for cancers of the digestive system. Still, evidence regarding its relation to pancreatic cancer remains ambiguous. To investigate the relationship between diet and pancreatic cancer, an analysis of dietary patterns in participants from the Norwegian Women and Cancer Study (n = 89,156; 305 pancreatic cancer cases) was performed. Cox regression analysis was used for studying possible associations between dietary patterns, derived from principal component analysis, and pancreatic cancer incidence. The four most prominent dietary patterns were identified and described: European pattern, animal food consumers' dietary pattern, traditional Norwegian pattern, and alcohol-abstaining dietary pattern. In analysis without adjustment for confounders, being in the highest tertile of the abstaining dietary pattern was associated with lower risk of pancreatic cancer in comparison to the lowest tertile (hazard ratios [HR]: 0.66, 95% confidence interval [CI]: 0.49-0.89). After additional adjustment for height and smoking status, no dietary pattern was associated with increased pancreatic cancer risk, nor was there any difference in effect estimates between strata of smokers and non-smokers. The results of our current analysis do not support the role of major dietary patterns in the development of pancreatic cancer.

On the Menu: Analyzing the Macronutrients, Micronutrients, Beverages, Dietary Patterns, and Pancreatic Cancer Risk

This narrative review summarizes the principal findings of observational studies, systematic reviews, and meta-analyses on diet and dietary patterns' role in the risk of pancreatic cancer. Etiologically pancreatic cancer is multifactorial. Evidence exists of an association between nutrients, dietary patterns, and pancreatic cancer. An extensive literature search was conducted on PubMed, Cochrane, and Google Scholar. A thorough search of articles published in English till May 2023 and related to the review was performed. The relationship between all macronutrients, micronutrients, and various dietary patterns with the risk of pancreatic cancer was assessed. It is concluded that a diet high in nutrients like red and processed meat, refined sugars, saturated and monounsaturated fats, alcohol, copper, and a Western dietary pattern can increase the likelihood of pancreatic cancer. Contrary to this, a diet consisting of fruits, vegetables, appropriate quantities of vitamins and minerals, and a Mediterranean dietary pattern is associated with a decreased risk of pancreatic cancer.

Dietary Factors and Pancreatic Cancer Risk: An Umbrella Review of Meta-Analyses of Prospective Observational Studies

Dietary factors may be associated with the occurrence of pancreatic cancer. This umbrella review aimed to review and grade the evidence for the associations between dietary factors and pancreatic cancer risk. We searched PubMed, EMBASE, Web of Science, Scopus, Cochrane Database of Systematic Reviews, and CINAHL for eligible literature. We included meta-analyses of randomized controlled trials (RCTs) or prospective observational studies. We used AMSTAR-2, a measurement tool to assess systematic reviews, to evaluate the methodological quality of the included meta-analyses. For each association, we calculated the summary effect size, 95% CI, heterogeneity, number of cases, 95% prediction interval, small-study effect, and excess significance bias. The protocol for this review was registered in the PROSPERO database (CRD42022333669). We included 41 meta-analyses of prospective observational studies describing 59 associations between dietary factors and pancreatic cancer risk. None of the retrieved meta-analyses included RCTs. No association was supported by convincing or highly suggestive evidence; however, there was suggestive evidence of a positive association between fructose intake and pancreatic cancer risk. There was weak evidence for an inverse association of nuts intake or adherence to the Mediterranean diet with pancreatic cancer incidence, and for positive associations between a higher intake of red meat or heavy alcohol intake and pancreatic cancer incidence. The remaining 54 associations were nonsignificant. Consistent with the American Institute for Cancer Research review, this umbrella review found that regular consumption of nuts and reduced intake of fructose, red meat, and alcohol were associated with a lower risk of pancreatic cancer. Emerging weak evidence supported an inverse association between adherence to the Mediterranean diet and pancreatic cancer risk. As some associations were rated as weak and most were considered nonsignificant, further prospective studies are needed to investigate the role of dietary factors and risk of pancreatic cancer.

A Cross-Sectional Study Based on Forty Systematic Reviews of Foods with Function Claims (FFC) in Japan: Quality Assessment Using AMSTAR 2

BACKGROUND

The Foods with Function Claims (FFC) was introduced in Japan in April 2015 to make more products available that are labeled with health functions. The products' functionality of function claims must be explained by scientific evidence presented in systematic reviews (SRs), but the quality of recent SRs is unclear. This study assessed the quality of SRs in the FFC registered on the Consumer Affairs Agency (CAA) website in Japan.

METHODS

We searched the database from 1 April to 31 October 2022. Confidence in the methodological quality of each SR was evaluated by the AMSTAR 2 checklist.

RESULTS

Forty SRs were randomly extracted on the basis of the eligibility criteria and recruitment procedures. Overall confidence was rated as "high" (N = 0, 0%), "moderate" (N = 0, 0%), "low" (N = 2, 5%), or "critically low" (N = 38, 95%). The mean AMSTAR 2 score was 51.1% (SD 12.1%; range 19-73%). Among the 40 SRs, the number of critical domain deficiencies was 4 in 7.5% of SRs, 3 in 52.5% of SRs, 2 in 35% of SRs, and 1 in 5% of SRs. Registering the review's protocol and comprehensive search strategies were particularly common deficiencies. Additionally, the risk of bias (RoB) was insufficiently considered.

CONCLUSION

Overall, the methodological quality of the SRs based on the FFC, introduced eight years earlier, was very poor. This was especially true in the interpretation and discussion of critical domains, which had many deficiencies in terms of protocol registration, a comprehensive literature search strategy, and accounting for the RoB.

Adherence to Mediterranean Diet and Risk of Pancreatic Cancer: Systematic Review and Meta-Analysis

Pancreatic cancer (PC) represents the 6th cause of cancer death. Although the aetiology of PC is not completely understood, numerous risk factors have been identified in association with this cancer, among them diet. However, little is known about the association between the Mediterranean Diet (MedDiet) and the risk of PC. For this reason, we conducted a systematic review with meta-analysis according to the PRISMA guidelines, searching on three databases (PubMed/MEDLINE, Scopus, and EMBASE). The protocol was registered in PROSPERO. Both fixed and random effect models were performed. The Effect size was reported as a hazard ratio (HR) with a 95% Confidence Interval (CI). A total of eight articles were included. The methodological quality of the included meta-analyses was high. Our results show that a higher adherence to the MedDiet is associated with a lower risk of PC [HR:0.82 (0.76-0.88) p < 0.001, based on 1,301,320 subjects]. The results were also confirmed in sensitivity and subgroups analyses (avoidance of potential overlapping effects, type of tools used to assess dietary intake and the diagnosis of PC, prevalence and incidence of PC risk, country where the studies took place, sex, and cancer site). Promoting a higher adherence to the MedDiet could be an effective approach to reduce the risk of PC.

Knowledge, Attitudes, Behavior, Acceptance, and Hesitancy in Relation to the COVID-19 Vaccine among Pregnant and Breastfeeding Women: A Systematic Review Protocol

A new coronavirus, SARS-CoV-2, was identified at the end of 2019. It swiftly spread all over the world, affecting more than 600 million people and causing over 6 million deaths worldwide. Different COVID-19 vaccines became available by the end of 2020. Healthcare workers and more vulnerable people (such as the elderly and those with comorbidities) were initially prioritized, followed by the entire population, including pregnant and breastfeeding women. Despite the safety and efficacy of COVID-19 vaccines, a certain level of skepticism was expressed, including among pregnant and breastfeeding women. There were several reasons for this reluctancy, among them, fear of side-effects for both women and fetuses. Nevertheless, acceptance, as well as hesitancy, were time, country and vaccine specific. This review will collect available evidence assessing knowledge, attitudes, behaviour, practice and acceptance/hesitancy of pregnant/breastfeeding women in relation to the COVID-19 vaccination. The PubMed/MEDLINE, Scopus and EMBASE databases will be consulted. A predefined search strategy that combines both free text and MESH terms will be used. The systematic review will adhere to the PRISMA guidelines and the results will be reported in both narrative and summary tables. A meta-analysis will be conducted if data are available.