Dietary inflammatory index (DII) and risk of prostate cancer in a case-control study among Black and White US Veteran men

The Association between Dietary Inflammatory Potential and Urologic Cancers: A Meta-analysis

A meta-analysis published in 2018 indicated a significant association between the dietary inflammatory index (DII) and risk of urologic cancers (UC). The number of included studies was limited, and more research has been published on this topic since then. The current study aimed to find a more precise estimate of the association between dietary inflammatory potential and risk of UC by updating the previous meta-analysis. The PubMed and Embase databases were searched between January 2015 and April 2023 to identify eligible articles. Combined relative risk (RR) and 95% confidence intervals (CI) were calculated by random-effects model to assess the association between dietary inflammatory potential and risk of UC by comparison of the highest versus the lowest category of the DII/empirical dietary inflammatory pattern (EDIP) or by using the continuous DII/EDIP score. The analysis, including 23 studies with 557,576 subjects, showed different results for UC. There was a significant association for prostate cancer among case-control studies (RR = 1.75, 95% CI: 1.34-2.28), whereas among cohort studies a null association was found (RR = 1.02, 95% CI: 0.96-1.08). For bladder cancer, a nonsignificant association was observed in both case-control (RR = 1.59, 95% CI: 0.95-2.64) and cohort studies (RR = 1.03, 95% CI: 0.86-1.24). Pooled RR from 3 case-control studies displayed a statistically significant association between the DII and risk of kidney cancer (RR = 1.27, 95% CI: 1.03-1.56). Although DII was positively associated with all types of UC, no association was found for EDIP. The present meta-analysis confirmed that an inflammatory diet has a direct effect on the development of prostate cancer and kidney cancer. Large-scale studies are needed to demonstrate the association between dietary inflammatory potential and risk of UC and provide effective nutritional advice for UC prevention. PROTOCOL REGISTRATION: The protocol was registered in the International Prospective Register of Systematic Reviews (CRD42023391204).

Atopic allergic conditions and prostate cancer risk and survival in the Multiethnic Cohort study

BACKGROUND

Previous studies investigating relationship between atopic allergic conditions (AACs)-a highly reactive immune state-and prostate cancer (PCa) risk were inconclusive, and few have studied diverse racial/ethnic populations.

METHODS

We analysed 74,714 men aged ≥45 years at enrollment in Multiethnic Cohort study. Using multivariable Cox regression, we estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for self-reported AAC status on PCa outcomes.

RESULTS

Through 2017, 8697 incident PCa and 1170 related deaths occurred. Twenty-one percent of men reported a history of AACs. AACs were not associated with incident PCa (HR = 0.98, 95% CI: 0.93-1.03) but were significantly inversely associated with PCa mortality (HR = 0.79, 95% CI: 0.67-0.92). This inverse association was consistently observed across all racial/ethnic groups (HR range: 0.60-0.90). Among men diagnosed with PCa, AACs were inversely associated with PCa-specific death (HR = 0.75, 95% CI: 0.63-0.89). Adjusting for potential confounding effect of PSA screening did not meaningfully change the results. No significant heterogeneity was observed in the effect of AACs on PCa incidence or mortality by Dietary Inflammatory Index.

CONCLUSIONS

Hyper-allergic conditions were not associated with PCa incidence but were inversely associated with PCa mortality, suggesting a potential role in reducing tumour progression. Further aetiological research is warranted to understand underlying mechanisms.

Interaction between drinking and dietary inflammatory index affects prostate specific antigen: a cross-sectional study

BACKGROUND

Numerous studies have shown that the dietary inflammatory index (DII) is associated with adverse health effects. However, the relationship between DII and prostate cancer (PCa) remains controversial. Although alcohol is included in DII as a dietary factor, the various adverse health effects of alcohol consumption are not only related to inflammation. On the other hand, it has been a long-standing debate whether alcohol consumption is linked to the risk of PCa. Therefore, to clarify whether drinking affects the relationship between DII and PCa, we evaluated the correlation between DII and prostate-specific antigen (PSA) based on the National Health and Nutrition Examination Survey (NHANES) database.

METHODS

We used data from the NHANES spanning from 2005 to 2010 to analyze the relationship between PCa and DII. Out of the 31,034 NHANES participants, we enrolled 4,120 individuals in our study, utilizing dietary intake data from a twenty-four-hour period to determine DII scores. Demographic data, physical and laboratory test results were collected to compare between low PSA and high PSA groups, and to calculate the odds ratio between both groups, we employed a logistic regression analysis.

RESULTS

In this cross-sectional investigation of PCa, drinkers and non-drinkers had different relationships between DII and PSA levels (OR: 1.2, 95% Cl: 1-1.44 vs. OR: 0.98, 95% Cl: 0.9-1.07), and DII and abstaining from alcohol were effective in reducing the incidence of PSA (p-value for significant interaction = 0.037).

CONCLUSION

The results of our study suggest that drinking may influence the relationship between DII and PSA levels. DII is likely to be a reliable indicator for estimating PSA levels among non-drinkers, who may limit their intake of pro-inflammatory ingredients to lower the incidence and death of PCa.

Dietary inflammatory index and prostate cancer risk: MCC-Spain study

BACKGROUND

The etiology of prostate cancer (PCa) is not well-known, and the role of diet is not well established. We aimed to evaluate the role of the inflammatory power of the diet, measured by the Dietary Inflammatory Index (DII^®), on the risk of PCa.

METHODOLOGY

A population-based multicase-control (MCC-Spain) study was conducted. Information was collected on sociodemographic characteristics, personal and family antecedents, and lifestyles, including diet from a Food Frequency Questionnaire. The inflammatory potential of the diet was assessed using the energy-adjusted Dietary Inflammatory Index (E-DII) based on 30 parameters (a higher score indicates a higher inflammatory capacity of the diet). Tertiles of E-DII were created using the cut-off points from the control group. The International Society of Urology Pathology (ISUP) was grouped as ISUP 1, ISUP 2, or ISUP 3-5. Unconditional logistic regression models were used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI) for the association between E-DII score and PCa risk.

RESULTS

A total of 928 PCa cases and 1278 population controls were included. Among PCa cases, the mean value of the E-DII score was 0.18 (SD: 1.9) vs. 0.07 (SD: 1.9) in the control group (p = 0.162). Cases with a more pro-inflammatory diet (3rd tertile) had the highest risk of PCa, aOR_T3vsT1= 1.30 (95% CI 1.03-1.65) (p-trend = 0.026). When stratifying by ISUP, this risk association was observed only for ISUP 2 and ISUP 3-5, aOR_T3vsT1= 1.46 (95% CI 1.02-2.10) and 1.60 (95% CI 1.10-2.34), respectively.

CONCLUSION

A positive association was observed between consuming a pro-inflammatory diet and PCa in the MCC-Spain population, specifically for an ISUP grade greater or equal than 2.

Immune response and inflammation in cancer health disparities

Cancer death rates vary among population groups. Underserved populations continue to experience an excessive burden of lethal cancers that is largely explained by health-care disparities. However, the prominent role of advanced-stage disease as a driver of cancer survival disparities may indicate that some cancers are more aggressive in certain population groups than others. The tumor mutational burden can show large differences among patients with similar-stage disease but differences in race/ethnicity or residence. These dissimilarities may result from environmental or chronic inflammatory exposures, altering tumor biology and the immune response. We discuss the evidence that inflammation and immune response dissimilarities among population groups contribute to cancer disparities and how they can be targeted to reduce these disparities.

Investigating Associations Between Depressive Symptoms and Anti-/Pro-Inflammatory Nutrients in an Elderly Population in Northern China: A Bayesian Kernel Machine Regression Approach

Backgroud

The potential for dietary inflammation has been shown to be associated with a variety of chronic diseases. The relationship between the potential for dietary inflammation and depression in the elderly is unclear.

Objective

This study aimed to exam the relationship between different nutrients and the risk of depression symptoms in the elderly.

Methods

In total, 1865 elderly in northern China were investigated at baseline from 2018 to 2019 and followed up in 2020. We measured the baseline intake of 22 nutrients and used Least Absolute Shrinkage and Selection Operator(LASSO) regression analysis and Bayesian Kernel Machine Regression (BKMR) to explore the association between exposure to a variety of nutrients with different inflammatory potentials and the risk of depressive symptoms.

Results

A total of 447 individuals (24.0%) were diagnosed with depressive symptoms. Through the lasso regression model, it was found that 11 nutrients are significantly related to the risk of depressive symptoms, of which 6 nutrients are pro-inflammatory nutrients (inflammation effect score>0), and 5 are anti-inflammatory nutrients (inflammation effect score<0). We incorporated the inflammatory effect scores of 11 nutrients into the BKMR model at the same time, and found that the overall inflammatory effect of 11 nutrients increased with the increase of total inflammatory scores, suggesting that the overall effect was pro-inflammatory. BKMR subgroup analysis shows that whether in the pro-inflammatory nutrient group or the anti-inflammatory nutrient group, multiple nutrients have a significant combined effect on depressive symptoms. By comparing the overall and group effects, we found that the inflammatory effects of the pro-inflammatory diet and the anti-inflammatory diet in the study’s diet are offset by each other (P<0.005).

Conclusion

We determined the combined effect of multiple nutrients of different inflammatory potential classifications on depressive symptoms in the elderly.

Immune Inflammation Pathways as Therapeutic Targets to Reduce Lethal Prostate Cancer in African American Men

Despite substantial improvements in cancer survival, not all population groups have benefitted equally from this progress. For prostate cancer, men of African descent in the United States and England continue to have about double the rate of fatal disease compared to other men. Studies suggest that when there is equal access to care, survival disparities are greatly diminished. However, notable differences exist in prostate tumor biology across population groups. Ancestral factors and disparate exposures can lead to altered tumor biology, resulting in a distinct disease etiology by population group. While equal care remains the key target to improve survival, additional efforts should be made to gain comprehensive knowledge of the tumor biology in prostate cancer patients of African descent. Such an approach may identify novel intervention strategies in the era of precision medicine. A growing body of evidence shows that inflammation and the immune response may play a distinct role in prostate cancer disparities. Low-grade chronic inflammation and an inflammatory tumor microenvironment are more prevalent in African American patients and have been associated with adverse outcomes. Thus, differences in activation of immune-inflammatory pathways between African American and European American men with prostate cancer may exist. These differences may influence the response to immune therapy which is consistent with recent observations. This review will discuss mechanisms by which inflammation may contribute to the disparate outcomes experienced by African American men with prostate cancer and how these immunogenic and inflammatory vulnerabilities could be exploited to improve their survival.

An overview of cancer health disparities: new approaches and insights and why they matter

Cancer health disparities remain stubbornly entrenched in the US health care system. The Affordable Care Act was legislation to target these disparities in health outcomes. Expanded access to health care, reduction in tobacco use, uptake of other preventive measures and cancer screening, and improved cancer therapies greatly reduced cancer mortality among women and men and underserved communities in this country. Yet, disparities in cancer outcomes remain. Underserved populations continue to experience an excessive cancer burden. This burden is largely explained by health care disparities, lifestyle factors, cultural barriers, and disparate exposures to carcinogens and pathogens, as exemplified by the COVID-19 epidemic. However, research also shows that comorbidities, social stress, ancestral and immunobiological factors, and the microbiome, may contribute to health disparities in cancer risk and survival. Recent studies revealed that comorbid conditions can induce an adverse tumor biology, leading to a more aggressive disease and decreased patient survival. In this review, we will discuss unanswered questions and new opportunities in cancer health disparity research related to comorbid chronic diseases, stress signaling, the immune response, and the microbiome, and what contribution these factors may have as causes of cancer health disparities.

Higher Dietary Inflammatory Index Scores Increase the Risk of Diabetes Mellitus: A Meta-Analysis and Systematic Review

The relationship between dietary inflammatory index (DII) scores and the risk of diabetes mellitus (DM) is unclear; therefore, a systematic review and meta-analysis of the current published literature was conducted. Relevant studies published online (PubMed, Embase, and Web of Science) until February 1, 2021 were identified for review. The initial search yielded 13 reports, and after perusing their titles, abstracts, and full texts, 5 studies were deemed appropriate for inclusion in the systematic review and meta-analysis. Individuals with higher DII scores (representing a more proinflammatory diet) had a higher risk of DM (pooled odds ratio 1.32, 95% confidence interval 1.01-1.72, I² 58.6%, p < 0.05). Although the current meta-analysis indicated a trend toward a positive association between DII and DM, further evidence-especially from larger prospective studies in different countries-is needed to clarify this association.

Inflammatory and Insulinemic Dietary Patterns: Influence on Circulating Biomarkers and Prostate Cancer Risk

Prostate cancer is common in countries with affluent dietary patterns and represents a heterogeneous collection of subtypes with varying behavior. Reductionist strategies focusing on individual nutrients or foods have not clearly defined risk factors. We have developed mechanisms-based dietary patterns focusing upon inflammation and chronic insulin hypersecretion, processes that are hypothesized to impact prostate carcinogenesis. In the Prostate, Lung, Colorectal, and Ovarian cancer cohort, we calculated the empirical dietary index for hyperinsulinemia (EDIH) and empirical dietary inflammatory pattern (EDIP) scores from food frequency questionnaire data among 3,517 men and women who provided a blood sample at enrollment. We used these scores in multivariable-adjusted linear regression to validate EDIH and EDIP against relevant circulating biomarkers. In a separate sample of 49,317 men, we used multivariable-adjusted Cox regression to evaluate associations of EDIH and EDIP with prostate cancer (total and subtypes) risk. Participants consuming the most hyperinsulinemic diets (EDIH quintile 5) had significantly higher concentrations of C-peptide, insulin, c-reactive protein, TNFα-R2, and lower adiponectin, than those in quintile 1. Similarly, participants consuming the most proinflammatory diets had significantly higher concentrations of IL6, TNFα-R2, C-peptide, insulin, and lower adiponectin. Men consuming hyperinsulinemic diets were at higher total prostate cancer risk: HRquintile5vs1, 1.11; 95% confidence interval (CI), 1.01-1.23; P trend = 0.03, especially high-grade cancer: HRquintile5vs1, 1.18; 95% CI, 1.02-1.37; P trend = 0.06. The EDIP was not associated with prostate cancer risk. In summary, EDIH and EDIP predicted concentrations of known insulinemic and inflammatory biomarkers, and EDIH further predicted risk of future prostate cancer. Interventions to reduce the adverse role of hyperinsulinemic diets may be a means of prostate cancer prevention.

Dietary Inflammatory Index and Non-Communicable Disease Risk: A Narrative Review

There are over 1,000,000 publications on diet and health and over 480,000 references on inflammation in the National Library of Medicine database. In addition, there have now been over 30,000 peer-reviewed articles published on the relationship between diet, inflammation, and health outcomes. Based on this voluminous literature, it is now recognized that low-grade, chronic systemic inflammation is associated with most non-communicable diseases (NCDs), including diabetes, obesity, cardiovascular disease, cancers, respiratory and musculoskeletal disorders, as well as impaired neurodevelopment and adverse mental health outcomes. Dietary components modulate inflammatory status. In recent years, the Dietary Inflammatory Index (DII®), a literature-derived dietary index, was developed to characterize the inflammatory potential of habitual diet. Subsequently, a large and rapidly growing body of research investigating associations between dietary inflammatory potential, determined by the DII, and risk of a wide range of NCDs has emerged. In this narrative review, we examine the current state of the science regarding relationships between the DII and cancer, cardiometabolic, respiratory and musculoskeletal diseases, neurodevelopment, and adverse mental health outcomes. We synthesize the findings from recent studies, discuss potential underlying mechanisms, and look to the future regarding novel applications of the adult and children's DII (C-DII) scores and new avenues of investigation in this field of nutritional research.