Intake of red and processed meat and risk of renal cell carcinoma: a meta-analysis of observational studies

Urology on a changing planet: links between climate change and urological disease

Urological diseases and their varied forms of management warrant special attention in the setting of climate change. Regarding urological cancers, climate change will probably increase the incidence and severity of cancer diagnoses through exposures to certain environmental risk factors, while simultaneously disrupting cancer care delivery and downstream outcomes. Regarding benign urological diseases, a burgeoning body of work exists on climate-related heat waves, dehydration, urolithiasis, renal injury and infectious and vector-borne diseases. Adding to the potential effect on disease pathogenesis, many patients with urological diseases undergo high-tech, resource-intensive interventions, such as robotic surgery, and entail intensive longitudinal assessments over many years. These features incur a considerable carbon footprint, generate substantial waste, and can introduce vulnerabilities to climate-related weather events. Links exist between planetary health (the health of humans and the natural systems that support our health), climate change and urological disease and urological care providers face many challenges in the era of anthropogenic climate change. The next steps and priorities for research, management, and health care delivery include identification and prioritization of health care delivery strategies to minimize waste and carbon emissions, while supporting climate resilience. Examples include supporting telemedicine, limiting low-value care, and building resilience to minimize impacts of climate-related disasters to prepare for the challenges ahead.

Engaging in Clinical Research and Practice Approaches that Reduce Environmental Impact

Telemedicine, virtual conferences, and reducing waste in the operating room are ways in which urologists can reduce their environmental impact in daily practice. Patient counseling should also consider advice that simultaneously promotes overall, urological, and planetary health, such as plant-based diets and active transport.

Plant-based diets and urological health

Plant-based diets have grown in popularity owing to multiple health and environmental benefits. Some evidence suggests that plant-based diets are associated with benefits for urological health. In genitourinary oncology, most research has focused on prostate cancer. Clinical trial results suggest a favourable influence of healthy lifestyle modifications including plant-based diets before and after prostate cancer treatment. Epidemiological evidence shows that a diet higher in plant-based and lower in animal-based food is associated with a lower risk of aggressive prostate cancer and better quality-of-life scores than a diet with less plant-based and more animal-based food. Studies on bladder and kidney cancer are scarce, but limited data suggest that vegetarian or plant-forward dietary patterns (increased consumption of fruits and vegetables and minimizing meat) are associated with a lower risk of development of these cancers than dietary patterns with fewer fruits and vegetables and more meat. With respect to benign urological conditions, epidemiological studies suggest that plant-based dietary patterns are associated with a lower risk of benign prostatic hyperplasia and urinary tract infections than non-plant-based dietary patterns. Compared with diets high in animal-based foods and low in plant-based foods, a substantial body of epidemiological evidence also suggests that increased consumption of healthy plant-based food is associated with a lower risk of erectile dysfunction. Plant-based dietary patterns that are high in fruits and vegetables with normal calcium intake, while limiting animal protein and salt, are associated with a lower risk of kidney stone development than dietary patterns that do not follow these parameters. Overall, increasing consumption of plant-based foods and reducing intake of animal-based foods has favourable associations with multiple urological conditions.

Bovine Meat and Milk Factor-like Sequences Are Frequently Detected in Renal Cell Carcinoma Tissues

Previous studies have indicated a potential role of diet in the pathogenesis of renal cell carcinoma (RCC). Recently, circular bovine meat and milk factor (BMMF) DNAs have been identified in peritumoral tissues of human colon and breast cancers. Here, we investigated the prevalence of the DNA of these novel human pathogenic infectious agents in RCC and adjacent peritumoral renal tissues. DNA was extracted from formalin-fixed and paraffin-embedded (FFPE) RCC and peritumoral kidney tissues, including a test (n = 11) and a validation (n = 152) collection. BMMF1 and BMMF2 consensus primers were designed to screen for the presence of BMMF1- and BMMF2-like DNA. In addition, BMMF-specific PCR was performed on selected cases to test for the presence of additional regions of BMMF1 and BMMF2 genomes. A reference collection of hepatocellular carcinomas (HCCs; n = 60) and adjacent peritumoral liver tissues (n = 50) was also included. Our results demonstrated that BMMF1 and BMMF2 DNAs are frequently found in human RCC tissues and are particularly more prevalent in peritumoral kidney tissues. Of note, BMMF1 and BMMF2 genotype heterogeneity was higher in peritumoral kidney tissues compared to RCC tissues. This is the first study to directly test human FFPE tissues for BMMF1- and BMMF2-like DNA using consensus PCR and demonstrate BMMF DNA in neoplastic and peritumoral kidney tissues. The findings are in line with the recently proposed indirect etiopathogenetic role of BMMFs in, e.g., colorectal carcinogenesis. Follow-up studies are needed to explore the potential role of BMMFs in the etiopathogenesis of RCC.

Colorectal cancer's burden attributable to a diet high in processed meat in the Belt and Road Initiative countries

BACKGROUND

Colorectal cancer (CRC) plays a significant role in morbidity, mortality, and economic cost in the Belt and Road Initiative ("B and R") countries. In addition, these countries have a substantial consumption of processed meat. However, the burden and trend of CRC in relation to the consumption of a diet high in processed meat (DHPM-CRC) in these "B and R" countries remain unknown.

AIM

To analyze the burden and trend of DHPM-CRC in the "B and R" countries from 1990 to 2019.

METHODS

We used the 2019 Global Burden of Disease Study to collate information regarding the burden of DHPM-CRC. Numbers and age-standardized rates (ASRs) of deaths along with the disability-adjusted life years (DALYs) were determined among the "B and R" countries in 1990 and 2019. Using joinpoint regression analysis, the average annual percent change (AAPC) was used to analyze the temporal trends of age-standardized DALYs rate (ASDALR) from 1990 to 2019 and in the final decade (2010-2019).

RESULTS

We found geographical differences in the burden of DHPM-CRC among "B and R" countries, with the three highest-ranking countries being the Russian Federation, China, and Ukraine in 1990, and China, the Russian Federation, and Poland in 2019. The burden of DHPM-CRC generally increased in most member countries from 1990 to 2019 (all P < 0.05). The absolute number of deaths and DALYs in DHPM-CRC were 3151.15 [95% uncertainty interval (UI) 665.74-5696.64] and 83249.31 (95%UI 15628.64-151956.31) in China in 2019. However, the number of deaths (2627.57-2528.51) and DALYs (65867.39-55378.65) for DHPM-CRC in the Russian Federation has declined. The fastest increase in ASDALR for DHPM-CRC was observed in Vietnam, Southeast Asia, with an AAPC value of 3.90% [95% confidence interval (CI): 3.63%-4.16%], whereas the fastest decline was observed in Kyrgyzstan, Central Asia, with an AAPC value of -2.05% (95% CI: -2.37% to -1.73%). A substantial upward trend in ASR of mortality, years lived with disability, years of life lost, and DALYs from DHPM-CRC changes in 1990-2019 and the final decade (2010-2019) for most Maritime Silk Route members in East Asia, South Asia, Southeast Asia, North Africa, and the Middle East, as well as Central Europe, while those of the most Land Silk Route members in Central Asia and Eastern Europe have decreased markedly (all P < 0.05). The ASDALR for DHPM-CRC increased more in males than in females (all P < 0.05). For those aged 50-74 years, the ASDALR for DHPM-CRC in 40 members exhibited an increasing trend, except for 20 members, including 7 members in Central Asia, Maldives, and 12 high or high-middle social development index (SDI) members in other regions (all P < 0.05).

CONCLUSION

The burden of DHPM-CRC varies substantially across "B and R" countries and threatens public health. Relevant evidence-based policies and interventions tailored to the different trends of countries in SDIs or Silk Routes should be adopted to reduce the future burden of CRC in "B and R" countries via extensive collaboration.

Connecting the dots in the associations between diet, obesity, cancer, and microRNAs

The prevalence of obesity has reached pandemic levels worldwide, leading to a lower quality of life and higher health costs. Obesity is a major risk factor for noncommunicable diseases, including cancer, although obesity is one of the major preventable causes of cancer. Lifestyle factors, such as dietary quality and patterns, are also closely related to the onset and development of obesity and cancer. However, the mechanisms underlying the complex association between diet, obesity, and cancer remain unclear. In the past few decades, microRNAs (miRNAs), a class of small non-coding RNAs, have been demonstrated to play critical roles in biological processes such as cell differentiation, proliferation, and metabolism, highlighting their importance in disease development and suppression and as therapeutic targets. miRNA expression levels can be modulated by diet and are involved in cancer and obesity-related diseases. Circulating miRNAs can also mediate cell-to-cell communications. These multiple aspects of miRNAs present challenges in understanding and integrating their mechanism of action. Here, we introduce a general consideration of the associations between diet, obesity, and cancer and review the current knowledge of the molecular functions of miRNA in each context. A comprehensive understanding of the interplay between diet, obesity, and cancer could be valuable for the development of effective preventive and therapeutic strategies in future.

Food groups and urologic cancers risk: a systematic review and meta-analysis of prospective studies

Background

To assess the association between 12 food groups intake and the risk of urologic cancers.

Methods

We scanned PubMed and Web of Science databases up to April 1st, 2023, and 73 publications met the inclusion criteria in the meta-analysis. We used a random effects model to estimate the summary risk ratios (RRs) and 95% confidence intervals (95% CI).

Results

In the linear dose-response meta-analysis, an inverse association was found between each additional daily 100 g of fruits [RR: 0.89, 95%CI = (0.83, 0.97)], 100 g of vegetables [RR: 0.92, 95%CI = (0.85, 0.99)], 12 g of alcohol [RR: 0.91, 95%CI = (0.88, 0.94)] and 1 cup of coffee [RR: 0.95, 95%CI = (0.83, 0.97)] intake and the risk of renal cell carcinoma. Conversely, each additional daily 100 g of red meat intake was positively associated with renal cell carcinoma [RR: 1.41, 95%CI = (1.03, 2.10)]. Inverse associations were observed between each additional daily 50 g of egg [RR: 0.73, 95%CI = (0.62, 0.87)] and each additional daily 1 cup of tea consumption and bladder cancer risk [RR: 0.97, 95%CI = (0.94, 0.99)]. There were no significant associations for nonlinear dose-response relationships between 12 food groups and urological cancers.

Conclusion

Our meta-analysis strengthens the evidence that appropriate intake of specific food groups, such as fruits, vegetables, alcohol, tea, and coffee, is associated with the risk of renal cell carcinoma or bladder cancer. More studies are required to fill the knowledge gap on the links between various food groups and urologic cancers because the evidence was less credible in this meta-analysis.

Systematic Review Registration

This study was registered on PROSPERO (CRD42022340336).

Dietary meat mutagens intake and cancer risk: A systematic review and meta-analysis

Background

Clinical and preclinical studies suggested that certain mutagens occurring as a reaction of creatine, amino acids, and sugar during the high temperature of cooking meat are involved in the pathogenesis of human cancer. Here we conducted a systematic review and meta-analysis to examine whether meat mutagens [PhIP, MeIQx, DiMeIQx, total HCA, and B(a)P] present a risk factor for human cancer.

Methods

We searched the following databases for relevant articles published from inception to 10 Oct 2021 with no language restrictions: Pubmed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), Baidu Academic, Zhejiang Digital Library. Two independent researchers screened all titles and obtained eligible texts for further screening. Independent data extraction was conducted, and meta-analysis was carried out using random-effects models to calculate the risk ratio of the meat mutagens exposure.

Results

A total of 1,786,410 participants and 70,653 cancer cases were identified. Among these, there were 12 different types of cancer at various sites, i.e., breast, bladder, colorectal, colon, rectum, prostate, lung, Non-Hodgkin lymphoma, kidney, gastric, esophagus, pancreatic, hepatocellular carcinoma. Cancer risk was significantly increased by intake of PhIP (OR = 1.13;95% CI 1.07–1.21; p < 0.001), MeIQx (OR = 1.14; 95% CI: 1.07–1.21; p < 0.001), DiMeIQx (OR = 1.07; 95% CI: 1.01–1.13; p = 0.013), total HCA (OR = 1.20; 95% CI: 1.03–1.38; p = 0.016), and cancer risk was not significantly increased by intake of B(a)P (OR = 1.04; 95% CI: 0.98–1.10; p = 0.206).

Conclusion

Meat mutagens of PhIP, MeIQx, DiMeIQx, and total HCA have a positive association with the risk of cancer.

Systematic review registration

[www.crd.york.ac.uk/prospero], identifier [CRD42022148856].

Processed meat consumption and associated factors in Chile: A cross-sectional study nested in the MAUCO cohort

Processed meat consumption is increasing in Latin America. While in developed countries processed meat consumption has been associated with cardiovascular diseases and cancer, our region lacks data associated to its consumption and health impact. We characterized processed meat intake and associated factors in a population-based cohort of a Chilean agricultural county, MAUCO. We analyzed baseline dietary data of 7,841 participants, 4,358 women and 3,483 men (38-77 years), who answered an adapted Mediterranean index food frequency questionnaire. Eight percent of the participants presented high processed meat consumption (≥5 times per week). We explored associations of processed meat consumption with participant characteristics using multinomial logistic regression models. Main factors associated with higher consumption were being men, younger and currently employed, and having a high intake (>4 times per week) of red meat (Odds ratio, 2.71, 95% CI 2.10-3.48), butter/cream (1.96, 1.60-2.41), whole-fat dairy products (1.32, 1.04-1.67) and a high intake (≥1 time per day) of sugary snacks/sweets (2.49, 2.04-3.03) and sugary drinks (1.97, 1.63-2.38). Processed meat consumption associated to chronic diseases, particularly cardiovascular disease (Prevalence ratio, 2.28, 95% CI 1.58-3.29). Obesity mediated this association in a proportion of 5.0%, whereas for diabetes the proportion was 13.9%. In this population, processed meat was associated with other unhealthy dietary and lifestyle factors, as well as with chronic diseases, particularly cardiovascular disease.

Iron imbalance in cancer: Intersection of deficiency and overload

Iron, an essential trace element, plays a complex role in tumour biology. While iron causes cancer clearance through toxic free radical generation, iron‐induced free radical flux also acts as a cancer promoter. These fates majorly guided through cellular response towards pro‐oxidant and antioxidant settings in a tumour microenvironment, designate iron‐induced oxidative stress as a common yet paradoxical factor in pro‐tumorigenesis as well as anti‐tumorigenesis, posing a challenge to laying down iron thresholds favouring tumour clearance. Additionally, complexity of iron's association with carcinogenesis has been extended to iron‐induced ROS's involvement in states of both iron deficiency and overload, conditions identified as comparable, inevitable and significant coexisting contributors as well as outcomes in chronic infections and tumorigenesis. Besides, iron overload may also develop as an unwanted outcome in certain cancer patients, as a result of symptomatic anaemia treatment owed to irrational iron‐restoration therapies without a prior knowledge of body's iron status with both conditions synergistically acting towards tumour aggravation. The co‐play of iron deficiency and overload along with iron's pro‐tumour and antitumour roles with intersecting mechanisms, thus presents an unpredictable regulatory response loop in a state of malignancy. The relevance of iron's thresholds beyond which it proves to be beneficial against tumorigenesis hence becomes questionable. These factors pose a challenge, over establishing if iron chelation or iron flooding acts as a better approach towards antitumour therapies. This review presents a critical picture of multiple contrasting features of iron's behaviour in cancer, leading towards two conditions lying at opposite ends of a spectrum: iron deficiency and overload in chronic disease conditions including cancer, hence, validating the critical significance of diagnosis of patients' iron status prior to opting for subsequent therapies.

Genesis and Mechanism of Some Cancer Types and an Overview on the Role of Diet and Nutrition in Cancer Prevention

Cancer is a major disease with a high mortality rate worldwide. In many countries, cancer is considered to be the second most common cause of death after cardiovascular disease. The clinical management of cancer continues to be a challenge as conventional treatments, such as chemotherapy and radiation therapy, have limitations due to their toxicity profiles. Unhealthy lifestyle and poor dietary habits are the key risk factors for cancer; having a healthy diet and lifestyle may minimize the risk. Epidemiological studies have shown that a high fruit and vegetable intake in our regular diet can effectively reduce the risk of developing certain types of cancers due to the high contents of antioxidants and phytochemicals. In vitro and in vivo studies have shown that phytochemicals exert significant anticancer effects due to their free radical scavenging capacity potential. There has been extensive research on the protective effects of phytochemicals in different types of cancers. This review attempts to give an overview of the etiology of different types of cancers and assesses the role of phytonutrients in the prevention of cancers, which makes the present review distinct from the others available.

The role of diet in renal cell carcinoma incidence: an umbrella review of meta-analyses of observational studies

BACKGROUND

Evidence associating diet with the incidence of renal cell carcinoma (RCC) is inconclusive. We aimed to summarize evidence associating dietary factors with RCC incidence and assess the strength and validity of this evidence.

METHODS

We conducted an umbrella review of systematic reviews or meta-analyses (SRoMAs) that assessed the association between diet and RCC incidence. Through April 2021, PubMed, Web of Science, Embase, The Cochrane Library, Scopus, and WCRF were searched. Two independent reviewers selected studies, extracted data, and appraised the quality of SRoMAs. According to credibility assessment criteria, evidence can be divided into five categories: convincing (class I), highly suggestive (class II), suggestive (class III), weak (class IV), and nonsignificant (class V).

RESULTS

Twenty-nine meta-analyses were obtained after screening. After excluding 7 overlapping meta-analyses, 22 meta-analyses including 502 individual studies and 64 summary hazard ratios for RCC incidence were included: dietary patterns or dietary quality indices (n = 6), foods (n = 13), beverages (n = 4), alcohol (n = 7), macronutrients (n =15), and micronutrients (n =19). No meta-analyses had high methodological quality. Five meta-analyses exhibited small study effects; one meta-analysis showed evidence of excess significance bias. No dietary factors showed convincing or highly suggestive evidence of association with RCC in the overall analysis. Two protective factors had suggestive evidence (vegetables (0.74, 95% confidence interval 0.63 to 0.86) and vitamin C (0.77, 0.66 to 0.90)) in overall analysis. One protective factor had convincing evidence (moderate drinking (0.77, 0.70 to 0.84)) in Europe and North America and one protective factor had highly suggestive evidence (cruciferous vegetables (0.78, 0.70 to 0.86)) in North America.

CONCLUSIONS

Although many meta-analyses have assessed associations between dietary factors and RCC, no high-quality evidence exists (classes I and II) in the overall analysis. Increased intake of vegetables and vitamin C is negatively associated with RCC risk. Moderate drinking might be beneficial for Europeans and North Americans, and cruciferous vegetables might be beneficial to North Americans, but the results should be interpreted with caution. More researches are needed in the future.

TRIAL REGISTRATION

PROSPERO CRD42021246619.

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.

Association of Processed Meats and Alcohol Consumption with Renal Cell Carcinoma: A Worldwide Population-Based Study

The link between diet and renal cell carcinoma (RCC) is still unclear. The purpose of this study was to evaluate the association of diet with RCC's incidence and mortality rates worldwide. We conducted an ecological study including 170 countries, whose data on age-standardized (AS) incidence and mortality rates of RCC, dietary factors, and potentially confounding factors such as obesity, insufficient physical activity, tobacco smoking, hypertension, diabetes, and human development index (HDI) were collected and available on May 2020 from the Global Cancer Observatory, the Global Dietary Database, the Global Health Observatory data repository, the Diabetes Atlas 9th edition and the Human Development Report 2019. Univariable and multivariable linear regression analyses were performed to determine the association of dietary factors with incidence and mortality rates of RCC adjusted for the effects of population age and potentially confounding factors. Intake of processed meats and consumption of alcohol were both positively associated with AS incidence rates of RCC (β = 0.11, P < 0.001 and β = 0.1, P = 0.044, respectively). We suggest that high consumption of processed meats and/or alcohol is a risk factor for RCC. However, they were not associated with mortality. Further research is needed at an individual level.Supplemental data for this article is available online at https://doi.org/10.1080/01635581.2020.1856388.

Reduction in the Incidence of Urological Cancers after the Ban on Chinese Herbal Products Containing Aristolochic Acid: An Interrupted Time-Series Analysis

Cancer is a public health problem worldwide. Taiwan has a higher incidence rate of urological cancers than many Asian countries do. Aristolochic acid has been considered a potent carcinogen. In this study, we examined whether the cessation of the sales and preparation of aristolochic acid-containing Chinese herbal products (AA-CHPs) in Taiwan contributed to a decline in the incidence rates of bladder cancer, carcinomas of the renal pelvis and other urinary organs, and kidney cancer. We conducted an interrupted time-series analysis of long-term trends in the incidence rates of the aforementioned cancers between 1995 and 2013 in Taiwan. The incidence rates of bladder cancer and carcinomas of the renal pelvis and other urinary organs decreased considerably after 2008 and 2011, respectively. Notably, these change-of-slope time points occurred after the year 2003, when a ban on AA-CHPs was imposed in Taiwan. The ban on AA-CHPs in Taiwan was possibly associated with the reduction in the incidence of bladder cancer and carcinomas of the renal pelvis and other urinary organs.

Processed meat intake and chronic disease morbidity and mortality: An overview of systematic reviews and meta-analyses

Despite the nutritional value of meat, a large volume of reviews and meta-analyses suggests that processed meat intake is associated with an increased risk of chronic diseases. However, assessments of the quality of these published reviews internal validity are generally lacking. We systematically reviewed and assessed the quality alongside summarizing the results of previously published systematic reviews and meta-analyses that examined the association between processed meat intake and cancers, type II diabetes (T2D), and cardiovascular diseases (CVD). Reviews and meta-analyses published until May 2018 were identified through a systematic literature search in the databases MEDLINE and EMBASE, and reference lists of included reviews. The quality of the systematic reviews and meta-analyses was assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR). All eligible reviews had to comply with two quality requirements: providing sufficient information on quality assessment of the primary studies and a comprehensive search. The results were summarized for T2D, CVD, and each of the different cancer types. The certainty in the estimates of the individual outcomes was rated using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) method. In total, 22 systematic reviews were eligible and thus included in this review. More than 100 reviews were excluded because quality assessment of the primary studies had not been performed. The AMSTAR score of the included reviews ranged from 5 to 8 indicating moderate quality. Overall, the quality assessments of primary studies of the reviews are generally lacking; the scientific quality of the systematic reviews reporting positive associations between processed meat intake and risk of various cancers, T2D and CVD is moderate, and the results from case-control studies suggest more often a positive association than the results from cohort studies. The overall certainty in the evidence was very low across all individual outcomes, due to serious risk of bias and imprecision.

Cancers Due to Excess Weight, Low Physical Activity, and Unhealthy Diet

BACKGROUND

Excess weight, low physical activity, low intakes of dietary fiber, fruits, and vegetables, and high meat and salt intake increase cancer risk.

METHODS

Numbers and proportions (population-attributable fractions, PAF) of incident cancer cases in Germany in 2018 attributable to these factors were estimated by sex and age groups for ages 35 to 84 years using population projections, national cancer incidence and exposure data, and published risk estimates.

RESULTS

Estimated numbers (percentages) of attributable cancers were 30 567 (7%) for excess weight, 27 081 (6%) for low physical activity, 14 474 (3%) for low dietary fiber intake, 9447 (2%) for low fruit and vegetable consumption, 9454 (2%) and 1687 (0.4%) for processed meat and high red meat consumption, respectively, and 1204 (0.3%) for high salt intake. Excess weight substantially contributed to endometrial, renal, and liver cancer (PAF = 24 to 35%). Low physical activity contributed to endometrial, renal, and lung cancer (PAF = 15 to 19%), and dietary factors mainly contributed to colorectal, breast, and lung cancer (PAF = 9 to 16%).

CONCLUSION

A considerable proportion of cancer cases are attributable to excess weight, physical inactivity, and unhealthy dietary habits. Major prevention efforts are needed to reduce the cancer incidence attributable to these avoidable factors.