The relationship between processed meat, red meat, and risk of types of cancer: A Mendelian randomization study

The Mediating Role of Plasma Inflammatory Proteins in Gut Microbiota-Driven Valvular Heart Disease: A Mendelian Randomization Study

This study investigates the causal relationships between gut microbiota (GM), plasma inflammatory proteins (PIPs), and valvular heart disease (VHD) using two-sample Mendelian Randomization (MR) analysis. We also assess whether PIPs mediate the link between GM and VHD. We conducted bidirectional MR analyses to explore causal associations between GM, PIPs, and VHD, and used multivariable MR to test the independence of associations. Genome-wide association study (GWAS) data on 196 GM taxa, 91 PIPs, and VHD were analyzed. MR methods including inverse-variance weighted (IVW), MR-Egger regression, and weighted median approaches were applied. Sensitivity analyses ensured robustness. Actinobacteria and Defluviitaleaceae were associated with lower VHD risk, while Oxalobacteraceae increased risk. At the genus level, Intestinibacter, Lachnospiraceae NC2004 group, Oscillospira, and Ruminococcaceae UCG004 were protective, whereas Oscillibacter increased risk. Among PIPs, Interleukin-10, Interleukin-17C, Leukemia inhibitory factor receptor (LIFR), and monocyte chemoattractant protein 2 were protective, while TNF-beta elevated risk. Multivariable MR confirmed the independent roles of TNF-beta, LIFR, and MCP-2. Actinobacteria's protective effect appeared partially mediated through increased LIFR expression, accounting for 14% of the effect. Our findings suggest that modulating gut microbiota, particularly enhancing Actinobacteria, may serve as a novel strategy for VHD prevention and treatment.

Common questions and misconceptions about protein supplementation: what does the scientific evidence really show?

Protein supplementation often refers to increasing the intake of this particular macronutrient through dietary supplements in the form of powders, ready-to-drink shakes, and bars. The primary purpose of protein supplementation is to augment dietary protein intake, aiding individuals in meeting their protein requirements, especially when it may be challenging to do so through regular food (i.e. chicken, beef, fish, pork, etc.) sources alone. A large body of evidence shows that protein has an important role in exercising and sedentary individuals. A PubMed search of "protein and exercise performance" reveals thousands of publications. Despite the considerable volume of evidence, it is somewhat surprising that several persistent questions and misconceptions about protein exist. The following are addressed: 1) Is protein harmful to your kidneys? 2) Does consuming "excess" protein increase fat mass? 3) Can dietary protein have a harmful effect on bone health? 4) Can vegans and vegetarians consume enough protein to support training adaptations? 5) Is cheese or peanut butter a good protein source? 6) Does consuming meat (i.e., animal protein) cause unfavorable health outcomes? 7) Do you need protein if you are not physically active? 8) Do you need to consume protein ≤ 1 hour following resistance training sessions to create an anabolic environment in skeletal muscle? 9) Do endurance athletes need additional protein? 10) Does one need protein supplements to meet the daily requirements of exercise-trained individuals? 11) Is there a limit to how much protein one can consume in a single meal? To address these questions, we have conducted a thorough scientific assessment of the literature concerning protein supplementation.

Pooled and global burdens and trends of five common cancers attributable to diet in 204 countries and territories from 1990 to 2019: an analysis of the Global Burden of Disease Study

OBJECTIVE

Increasing evidence has shown that dietary behaviors are closely correlated with the carcinogenesis and progression of many types of cancer. However, few studies have assessed the global diet-related burden of cancer. This study aimed to estimate the pooled burdens and trends of five types of cancers attributable to dietary behaviors.

METHODS

Data regarding cancer attributable to dietary behaviors were extracted from the Global Burden of Disease study 2019, including the death cases and age-standardized death rates, and disability-adjusted life years (DALYs) estimated according to diseases, age, sex, the socio-demographic index (SDI) and location.

RESULTS

According to the Global Burden of Disease study 2019, five types of cancer were affected by dietary behaviors: colon and rectum cancer; tracheal, bronchus and lung cancer; stomach cancer; esophageal cancer and breast cancer. Unhealthy dietary behaviors for cancer caused a total of 605.4 thousand deaths and 13951.3 thousand DALYs globally. The burden of cancer attributable to dietary risks was higher for men than for women. The highest age-standardized death rates in 2019 were observed in southern Latin America, and the lowest rates were observed in North Africa and the Middle East. The greatest increases in the age-standardized death rates, from 1990 to 2019, were found in Western Sub-Saharan Africa, with the greatest decreases in Central Asia. The highest attributable proportions of death or DALYs were colon and rectum cancer. The greatest diet-related cancer burden was observed in regions with a high-middle SDI.

CONCLUSION

Global age-standardized deaths and DALYs rates attributable to diet-related cancer are considerable and cause a substantial burden. Successful population-wide initiatives targeting unhealthy dietary behaviors would reduce this burden.

Mendelian randomization study to assess causality between diet and phenotype of aging

BACKGROUND AND OBJECTIVES

Observational research findings have demonstrated correlations between diet and the process of aging. Nevertheless, there remains uncertainty regarding possible disruption caused by confounding variables. To elucidate the connections between diet and aging, we employed the Mendelian randomization analysis.

METHODS AND STUDY DESIGN

The exposure factor was the daily diet, whereas accelerated aging was measured through telomere length, facial aging (FA), frailty index (FI), and senescence-associated secretory phenotypes (SASPs), representing the outcome factors. The primary analysis employed IVW analysis, with additional MR-Egger and Weighted Median analyses conducted to assess the reliability of the findings. Furthermore, we analyzed the heterogeneity and pleiotropy of the results.

RESULTS

The results revealed that the consumption of salad/raw vegetables and oily fish exhibited a negative correlation with FA, whereas coffee intake showed a positive correlation with FA. On the other hand, the intake of cheese, oily fish, dried fruit, and cereal showed negative associations with FI. Additionally, coffee, alcohol, and pork intake were positively associated with FI. Lastly, the intake of bread exhibited a positively correlated with SASPs, while the intake of cheese and coffee showed a negative correlation with SASPs.

CONCLUSIONS

Our study revealed that the consumption of cheese, vegetables, oily fish, dried fruit, bread, coffee, and alcohol was associated with the aging process. Interestingly, our findings suggest that coffee intake may accelerate aging, whereas intake of oily fish may delay the aging process. However, it is important to note that further well-designed prospective studies are required to validate our findings in the future.

Associations of Diet with Health Outcomes in the UK Biobank: A Systematic Review

The UK Biobank is a cohort study that collects data on diet, lifestyle, biomarkers, and health to examine diet-disease associations. Based on the UK Biobank, we reviewed 36 studies on diet and three health conditions: type 2 diabetes (T2DM), cardiovascular disease (CVD), and cancer. Most studies used one-time dietary data instead of repeated 24 h recalls, which may lead to measurement errors and bias in estimating diet-disease associations. We also found that most studies focused on single food groups or macronutrients, while few studies adopted a dietary pattern approach. Several studies consistently showed that eating more red and processed meat led to a higher risk of lung and colorectal cancer. The results suggest that high adherence to "healthy" dietary patterns (consuming various food types, with at least three servings/day of whole grain, fruits, and vegetables, and meat and processed meat less than twice a week) slightly lowers the risk of T2DM, CVD, and colorectal cancer. Future research should use multi-omics data and machine learning models to account for the complexity and interactions of dietary components and their effects on disease risk.

Targeting PI3K/AKT/mTOR and MAPK Signaling Pathways in Gastric Cancer

Gastric cancer (GC) is the fourth leading cause of death worldwide, with more than 1 million cases diagnosed every year. Helicobacter pylori represents the main risk factor, being responsible for 78% of the cases. Increased amounts of salt, pickled food, red meat, alcohol, smoked food, and refined sugars negatively affect the stomach wall, contributing to GC development. Several gene mutations, including PIK3CA, TP53, ARID1A, CDH1, Ras, Raf, and ERBB3 are encountered in GC pathogenesis, leading to phosphatidylinositol 3-kinase (PI3K) protein kinase B (AKT)/mammalian target of rapamycin (mTOR)-PI3K/AKT/mTOR-and mitogen-activated protein kinase (MAPK) signaling pathway activation and promoting tumoral activity. Helicobacter pylori, growth factors, cytokines, hormones, and oxidative stress also activate both pathways, enhancing GC development. In clinical trials, promising results have come from monoclonal antibodies such as trastuzumab and ramucirumab. Dual inhibitors targeting the PI3K/AKT/mTOR and MAPK signaling pathways were used in vitro studies, also with promising results. The main aim of this review is to present GC incidence and risk factors and the dysregulations of the two protein kinase complexes together with their specific inhibitors.

Red Meat Consumption and Cancer Risk: A Systematic Analysis of Global Data

The association between red meat consumption and cancer risk remains a controversy. In this study, we systematically collected and analyzed global data (from Our World in Data and Global Cancer Observatory) to investigate this association for the first time. Our results confirmed significant positive associations between red meat consumption (RMC) and overall cancer incidence (0.798, p < 0.001), or colorectal cancer incidence (0.625, p < 0.001). Several previously unreported cancer types linked to RMC were also unveiled. Gross domestic product (GDP) per capita were found to have an impact on this association. However, even after controlling it, RMC remained significantly associated with cancer incidence (0.463, p < 0.001; 0.592, p < 0.001). Meanwhile, after controlling GDP per capita, the correlation coefficients between white meat consumption and overall cancer incidence were found to be much lower and insignificant, at 0.089 (p = 0.288) for poultry consumption and at -0.055 (p = 0.514) for seafood and fish consumption. Notably, an interesting comparison was performed between changes of colorectal cancer incidence and RMC in many countries and regions. A lag of 15-20 years was found, implying causality between RMC and cancer risk. Our findings will contribute to the development of more rational meat consumption concept.

Causal associations of hyperthyroidism with prostate cancer, colon cancer, and leukemia: a Mendelian randomization study

Background

Observational studies have shown that hyperthyroidism may increase the risk of cancer, but their causal effects and direction are unclear. We conducted a two-sample Mendelian randomization (MR) study to explore the associations between genetic predisposition to hyperthyroidism and nine common types of cancer, including prostate, lung, breast, colon, leukemia, brain, skin, bladder, and esophagus cancer.

Methods

We obtained summary statistics of hyperthyroidism and nine types of cancers from genome-wide association studies (GWAS). MR analysis is performed to investigate the potential causal relationship between hyperthyroidism and cancers. The inverse variance weighted (IVW) as the primary method was carried out. The robustness of the results was evaluated by sensitivity analysis.

Results

Genetically predicted hyperthyroidism was associated with a declining risk of occurrence of prostate cancer (odds ratio (OR)_IVW= 0.859, P= 0.0004; OR _MR-Egger=0.828, P= 0.03; OR _{weighted median}= 0.827, P=0.0009). Additionally, there was a significant association between genetically predicted hyperthyroidism and colon cancer (OR _IVW= 1.13, P= 0.011; OR _MR-Egger= 1.31, P= 0.004; OR _{weighted median}= 1.18, P= 0.0009). Hyperthyroidism was also suggestively correlated with a higher risk of leukemia based on the result of IVW and weighted median (OR _IVW= 1.05, P= 0.01; OR _{weighted median}= 1.08, P= 0.001). Results from a two-sample MR analysis suggested that hyperthyroidism was not associated with the risk of lung cancer, breast cancer, brain cancer, skin cancer, bladder cancer, and esophageal cancer.

Conclusion

Our study provides evidence of a causal relationship between hyperthyroidism and the risk of prostate cancer, rectal cancer, and leukemia. Further research is needed to clarify the associations between hyperthyroidism and other cancers.