The association between dietary inflammatory index and risk of colorectal cancer among postmenopausal women: results from the Women's Health Initiative

Association of Dietary Inflammatory Potential With Colorectal Cancer Risk in Men and Women

Importance

Inflammation is important in colorectal cancer development. Diet modulates inflammation and may thus be a crucial modifiable factor in colorectal cancer prevention.

Objective

To examine whether proinflammatory diets are associated with increased colorectal cancer risk by using an empirical dietary inflammatory pattern (EDIP) score based on a weighted sum of 18 food groups that characterizes dietary inflammatory potential based on circulating levels of inflammation biomarkers.

Design, Settings, and Participants

Cohort study of 46 804 men (Health Professionals Follow-up Study: 1986-2012) and 74 246 women (Nurses' Health Study: 1984-2012) followed for 26 years to examine associations between EDIP scores and colorectal cancer risk using Cox regression. We also examined associations in categories of alcohol intake and body weight. Data analysis began January 17, 2017, and was completed August 9, 2017.

Exposures

EDIP scores calculated from food frequency questionnaires administered every 4 years.

Main Outcomes and Measures

Incident colorectal cancer.

Results

We documented 2699 incident colorectal cancer cases over 2 571 831 person-years of follow-up. Compared with participants in the lowest EDIP quintile (Q) who had a colorectal cancer incidence rate (per 100 000 person-years) of 113 (men) and 80 (women), those in the highest Q had an incidence rate of 151 (men) and 92 (women), leading to an unadjusted rate difference of 38 and 12 more colorectal cancer cases, respectively, among those consuming highly proinflammatory diets. Comparing participants in the highest vs lowest EDIP Qs in multivariable-adjusted analyses, higher EDIP scores were associated with 44% (men: hazard ratio [HR], 1.44; 95% CI, 1.19-1.74; P < .001 for trend), 22% (women: HR, 1.22; 95% CI, 1.02-1.45; P = .007 for trend), and 32% (men and women: pooled HR, 1.32; 95% CI, 1.12-1.55; P < .001 for trend) higher risk of developing colorectal cancer. In both men and women, associations were observed in all anatomic subsites except for the rectum in women. In subgroups (P ≤ .02 for all interactions), associations differed by alcohol intake level, with stronger associations among men (Q5 vs Q1 HR, 1.62; 95% CI, 1.05-2.49; P = .002 for trend) and women (Q5 vs Q1 HR, 1.33; 95% CI, 0.97-1.81; P = .03 for trend) not consuming alcohol; and by body weight, with stronger associations among overweight/obese men (Q5 vs Q1 HR, 1.48; 95% CI, 1.12-1.94; P = .008 for trend) and lean women (Q5 vs Q1 HR, 1.31; 95% CI, 0.99-1.74; P = .01 for trend).

Conclusions and Relevance

Findings suggest that inflammation is a potential mechanism linking dietary patterns and colorectal cancer development. Interventions to reduce the adverse role of proinflammatory diets may be more effective among overweight/obese men and lean women or men and women who do not consume alcohol.

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.

Dietary Inflammatory Index, Dietary Non-Enzymatic Antioxidant Capacity, and Colorectal and Breast Cancer Risk (MCC-Spain Study)

Inflammation and antioxidant capacity have been associated with colorectal and breast cancer. We computed the dietary inflammatory index (DII^®), and the total dietary non-enzymatic antioxidant capacity (NEAC) and associated them with colorectal and breast cancer risk in the population-based multi case-control study in Spain (MCC-Spain). We included 1852 colorectal cancer and 1567 breast cancer cases, and 3447 and 1486 population controls, respectively. DII score and NEAC were derived using data from a semi-quantitative validated food frequency questionnaire. Unconditional logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals (95%CI) for energy-adjusted DII (E-DII), and a score combining E-DII and NEAC. E-DII was associated with colorectal cancer risk (OR = 1.93, highest quartile versus lowest, 95%CI:1.60–2.32; p-trend: <0.001); this increase was observed for both colon and rectal cancer. Less pronounced increased risks were observed for breast cancer (OR = 1.22, highest quartile versus lowest, 95%CI:0.99–1.52, p-trend: >0.10). The combined score of high E-DII scores and low antioxidant values were associated with colorectal cancer risk (OR = 1.48, highest quartile versus lowest, 95%CI: 1.26–1.74; p-trend: <0.001), but not breast cancer. This study provides evidence that a pro-inflammatory diet is associated with increased colorectal cancer risk while findings for breast cancer were less consistent.

The association between the dietary inflammatory index and glioma: A case-control study

BACKGROUND & AIMS

Dietary inflammatory potential has been associated with several cancers. However, the relationship between the dietary inflammatory index (DII®) and glioma is not clear. The aim of this study was to examine DII in relation to glioma.

METHODS

In a hospital-based case-control study, we selected 128 newly-diagnosed cases of glioma and 256 controls. Cases were medically confirmed glioma patients, with no history of other cancers. A validated food frequency questionnaire was used to assess diet. DII scores were calculated based on the quantity of dietary components with inflammatory or anti-inflammatory potential. We used conditional logistic regression models to examine the association between the DII and glioma.

RESULT

Study participants were on average 43 years old and predominantly male (58%). After controlling for age, sex and energy intake, individuals in the highest quartile of DII had 87% (95% CI: 1.00-3.47) increased risk of glioma compared to those in the lowest quartile. Additional adjustment for environmental confounders strengthened the relationship; participants with the greatest DII scores had approximately 2.1 times (95% CI: 1.06, 3.83) increased odds of glioma than those with the lowest intake scores. The association was not substantially altered by further adjustment for BMI (2.76; 1.15-6.60).

CONCLUSION

In conclusion, diets with high anti-inflammatory and low inflammatory nutrient contents are recommended to prevent glioma.

Dietary Inflammatory Index and Odds of Colorectal Cancer and Colorectal Adenomatous Polyps in A Case-Control Study from Iran

BACKGROUND

Chronic inflammation is implicated in the development of colorectal cancer (CRC) and its precursor; colorectal adenomatous polyps (CAP). Some dietary factors are important triggers for systemic inflammation. Therefore, the present study aimed to investigate the association between the dietary inflammatory index (DII®) and the risk of CRC and CAP in an Iranian case-control study.

METHODS

134 newly diagnosed CRC patients, 130 newly diagnosed CAP patients, and 240 hospitalized controls were recruited using convenience sampling. Energy-adjusted DII (E-DII) scores were computed based on dietary intake assessed using a reproducible and valid 148-item food frequency questionnaire. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CI) after adjusting for confounders.

RESULTS

The E-DII score ranged between -4.23 (the most anti-inflammatory score) to +3.89 (the most pro-inflammatory score). The multivariable-adjusted ORs for participants in the 3rd tertile compared to the 1st tertile was 5.08 (95%CI: 2.70-9.56; P-trend < 0.0001) for CRC and 2.33 (95% CI: 1.30-4.02; P-trend = 0.005) for CAP.

CONCLUSIONS

Our findings suggest that more pro-inflammatory diets, indicated by higher E-DII scores, might increase the risk of both CRC and CAP. Future steps should include testing these associations in a prospective setting in Iran.

Heterogeneity of colon and rectum cancer incidence across 612 SEER counties, 2000-2014

Recent analyses have suggested decreases over time in colorectal cancer incidence at older ages (≥55 years) but increases at younger ages (20-54 years). Understanding the geographic heterogeneity of incidence facilitates resource allocation for potential interventions and advances our knowledge of differential etiologies for these cancers. We performed age-period-cohort analysis using 2000-2014 county-level incidence from the Surveillance, Epidemiology, and End Results (SEER) database, estimating relative risk (RR) and age-adjusted annual percent change (Net Drifts) simultaneously for 612 counties via a hierarchical model, separately for colon and rectum cancer, stratified by age group (20-54 vs. 55-84). We also studied correlates of RR and Net Drift with various county-level characteristics. In all SEER counties, colon and rectum cancer incidence rates increased at ages 20-54, whereas rates decreased at ages 55-84. There was marked heterogeneity in both RR and Net Drift among states and counties for both cancer types. Maps of county RR and Net Drift revealed localized clusters in several states. For both cancer types, counties with high RR and unfavorable Net Drift tended to have higher prevalence of obesity and diabetes and to be of a lower socioeconomic status. Counties with higher overall screening rates tended to have lower Net Drifts for both cancer types. Increasing colorectal cancer incidence in the younger age group is geographically widespread, although there is significant heterogeneity in temporal trends and risk both within and between states. These geographic patterns correlate with different county-level characteristics depending on cancer type and age group.

Increased Inflammatory Potential of Diet Is Associated with Increased Risk of Bladder Cancer in an Iranian Case-Control Study

Purpose: Various aspects of diet have been implicated to play a role in the etiology of bladder cancer. Studies examining this association have been conducted primarily in Western countries but none in Middle Eastern Countries. Method: We examined the association between the dietary inflammatory index (DII^®) and bladder cancer in an Iranian case-control study. A total of 56 incident cases with a mean age of 60 years and 109 controls with a mean age of 57 years, attending the same hospital as the cases during the same time period, were recruited. The DII is a literature-derived index developed to determine the inflammatory potential of diet and was computed using a validated food frequency questionnaire. Logistic regression was used to estimate odds ratios, with DII fit as continuous and as a dichotomous variable. Results: Multivariate analyses revealed that subjects with higher DII score (>-0.12) are at higher risk of bladder cancer [odds ratio (OR) = 2.46; 95% CI = 1.12-5.41, P value = 0.02)] compared to subjects with lower DII scores (≤-0.12). Stratified results showed stronger association was among current/ex-smokers (OR_{DII (>-0.12/≤-0.12)} = 3.30; 95% CI = 1.07-10.16). Conclusion: These data suggest a pro-inflammatory diet may be a risk factor for bladder cancer among Iranians.

Post-cancer diagnosis dietary inflammatory potential is associated with survival among women diagnosed with colorectal cancer in the Women's Health Initiative

PURPOSE

Dietary factors may influence colorectal cancer (CRC) survival through effects on inflammation. We examined the association between post-CRC diagnosis inflammatory potential of diet and all-cause and cancer-specific mortality in the Women's Health Initiative.

METHODS

The study included 463 postmenopausal women who developed CRC during follow-up and completed a food frequency questionnaire (FFQ), on average 1.7 years after diagnosis. Women were followed from CRC diagnosis until death, censoring, or the end of follow-up in October 2014. Energy-adjusted dietary inflammatory index (E-DII)^® scores were calculated from the FFQ and dietary supplement inventory. Cox proportional hazards models were fitted to estimate multivariable-adjusted HRs and 95% confidence intervals (CIs) for all-cause, total cancer, and CRC-specific mortality with the most pro-inflammatory E-DII scores (tertile 3) as referent.

RESULTS

After a median 11.6 years of follow-up, 162 deaths occurred, including 77 from CRC. Lowest tertile (i.e., most anti-inflammatory) E-DII scores from diet plus supplements were associated with significantly lower all-cause mortality (HR_T1vsT3 = 0.49; 95% CI 0.31-0.79) compared to the most pro-inflammatory E-DII tertile. Modest associations with total cancer mortality or CRC-specific mortality were observed, though 95% CIs included 1.

CONCLUSIONS

Consuming a dietary pattern and supplements with more anti-inflammatory potential after CRC diagnosis may improve overall survival among postmenopausal women.

Dietary inflammatory index and odds of coronary artery disease in a case-control study from Jordan

OBJECTIVE

The aim of this study was to examine the association between inflammatory potential diet as determined by dietary inflammatory index (DII) scores and coronary artery disease (CAD) in a population-based, case-control study of middle-aged Jordanian adults.

METHODS

In the present study, 388 patients who were referred for elective coronary angiography at Prince Hamza Hospital, Amman, were enrolled. Of these, 198 were confirmed CAD cases and 190 were CAD-free control participants. DII scores were computed from dietary intake assessed by a food frequency questionnaire. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

CAD cases had significantly higher DII scores, higher body mass index (BMI), higher prevalence of diabetes, lower educational attainment, and lower physical activity than the CAD-free controls. A statistically significant higher risk for CAD was observed in those with DII scores in the highest tertile than in those in the lowest (OR_tertile3vs1, 2.10; 95% CI, 1.18-3.66), after adjusting for cardiovascular risk factors. A positive association was found between higher DII and CAD risk when DII score was used as a continuous variable (OR_continuous, 1.13 per unit increase in DII corresponding to ∼11% of its range in the current study; 95% CI, 1.00-1.32).

CONCLUSIONS

The present findings, obtained in this ordanian population, add to the growing literature indicating that a proinflammatory diet is associated with higher risk for developing CAD.

High dietary inflammatory index scores are associated with an elevated risk of hepatocellular carcinoma in a case-control study

Chronic inflammation and diet play crucial roles in the development of hepatocellular carcinoma (HCC); yet the association between dietary inflammatory potential and risk of HCC has rarely been investigated. This study aimed to examine whether a higher dietary inflammatory index (DII®) score (indicating a pro-inflammatory diet) is associated with an increased risk of HCC in a matched case-control study conducted between September 2013 and October 2017 in South China. A total of 659 cases with newly diagnosed, previously untreated HCC and 659 controls individually matched on age (±3 years) and sex were included in this study. DII scores were computed based on dietary intake information collected via a validated 79-item food frequency questionnaire (FFQ) during the one year prior to diagnosis (for the cases) or interview (for the controls). Logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (CI) between the DII score and the risk of HCC, adjusted for age, energy intake, body mass index, physical activity, marital status, education, household income, smoking status, and hepatitis B virus (HBV) infection status. Compared with subjects in the lowest DII tertile, subjects in the highest tertile had an elevated risk of HCC (fully adjusted OR: 3.22, 95% CI: 1.30-7.98, P-trend = 0.009). In stratified analyses, a significantly positive association was observed only in men, individuals with lower education level, smokers and non-alcohol drinkers. In conclusion, a higher DII score, representing a more inflammatory diet, was associated with an increased risk of HCC, in men, individuals with lower education level, smokers and non-alcohol drinkers.

Perspective: The Dietary Inflammatory Index (DII)-Lessons Learned, Improvements Made, and Future Directions

The literature on the role of inflammation in health has grown exponentially over the past several decades. Paralleling this growth has been an equally intense focus on the role of diet in modulating inflammation, with a doubling in the size of the literature approximately every 4 y. The Dietary Inflammatory Index (DII) was developed to provide a quantitative means for assessing the role of diet in relation to health outcomes ranging from blood concentrations of inflammatory cytokines to chronic diseases. Based on literature from a variety of different study designs ranging from cell culture to observational and experimental studies in humans, the DII was designed to be universally applicable across all human studies with adequate dietary assessment. Over the past 4 y, the DII has been used in >200 studies and forms the basis for 12 meta-analyses. In the process of conducting this work, lessons were learned with regard to methodologic issues related to total energy and nutrient intake and energy and nutrient densities. Accordingly, refinements to the original algorithm have been made. In this article we discuss these improvements and observations that we made with regard to misuse and misinterpretation of the DII and provide suggestions for future developments.

Associations between Dietary Inflammatory Index Scores and Inflammatory Biomarkers among Older Adults in the Lothian Birth Cohort 1936 Study

OBJECTIVES

Chronic low-grade inflammation is a key underlying mechanism in several age-related chronic conditions and previous studies have shown that diet can modulate the inflammatory process. We investigated the ability of the Dietary Inflammatory Index (DII®), a summary measure of dietary inflammatory potential, to predict concentrations of plasma inflammatory markers in a sample of older people.

DESIGN

Cross-sectional and 3-year follow-up analysis of Lothian Birth Cohort 1936 (LBC1936) study data.

SETTING

Baseline data collection occurred between 2004 and 2007 in Edinburgh, Scotland.

PARTICIPANTS

Men and women (n 928, age ~70 at baseline) living in Edinburgh and surrounding regions who are surviving participants of the Scottish Mental Survey of 1947.

MEASUREMENTS

Energy-adjusted DII (E-DII) scores at age 70 (derived from a food-frequency questionnaire), plasma concentrations of inflammatory biomarkers at age 70 (C-reactive protein (CRP), fibrinogen) and age 73 (CRP, fibrinogen, hs-CRP, Interleukin-6 (IL-6)). Analyses were performed using multivariable logistic regression adjusting for age, sex, smoking, body mass index, physical activity, and hypercholesterolaemia.

RESULTS

Higher E-DII scores (pro-inflammatory diet) were associated with increased odds of elevated CRP (>3mg/L) at age 70 (OR 1.12; 95% CI: 1.02, 1.24, P = 0.02), and elevated IL-6 (>1.6pg/ml) at age 73 (OR 1.11; 95% CI: 1.00, 1.23, P = 0.04), but not with fibrinogen.

CONCLUSION

These results are consistent with the ability of the DII to predict inflammatory biomarker concentrations and suggest that diet plays a role in the regulation of inflammation, even after controlling for potential confounders. This validation study provides support for using the DII in research among older populations.

Diet-related inflammation and risk of prostate cancer in the California Men's Health Study

PURPOSE

The purpose of the study was to examine the relationship between proinflammatory diet and prostate cancer risk.

METHODS

Energy-adjusted Dietary Inflammatory Index (E-DII) scores were computed among 40,161 participants in the California Men's Health Study. Over 9.7 ± 3.8 years of follow-up, 2707 incident prostate cancer cases were diagnosed and categorized as low-, intermediate-, or high-risk, based on disease grade and stage. Accelerated failure-time models assessed time to diagnosis of prostate cancer. Cox proportional hazard models estimated hazard ratios (HR) and 95% confidence intervals (95% CI). Nonlinear effects of E-DII were modeled as third-order polynomials.

RESULTS

Time to prostate cancer diagnosis did not differ by E-DII quartile. The HR for high-risk prostate cancer increased in the third E-DII quartile (HRQ3 vs. Q1 = 1.36; 95% CI: 1.04-1.76), but not in the fourth (HRQ4 vs. Q1 = 0.99; 95% CI: 0.74-1.32, Ptrend = .74), suggesting a nonlinear dose-response. HR curves for prostate cancer increased exponentially above an E-DII threshold of ≈+3.0. HR curves for high-risk prostate cancer had a much steeper incline above an E-DII threshold of ≈+2.5. Curves were higher among Blacks and Whites relative to other races and among overweight or obese men. No relationship was observed between E-DII scores and intermediate- or low-risk disease.

CONCLUSIONS

Relationships between proinflammatory diet and prostate cancer risk may be nonlinear, with an increased risk above an E-DII threshold of ≈+2.5.

Positive Association between Dietary Inflammatory Index and the Risk of Osteoporosis: Results from the KoGES_Health Examinee (HEXA) Cohort Study

Previous studies have found that diet’s inflammatory potential is related to various diseases. However, little is known about its relationship with osteoporosis. The aim of this study was to investigate the association between the dietary inflammatory index (DII^®) and osteoporosis risk in a large-scale prospective cohort study in Korea. This prospective cohort study included 159,846 participants (men 57,740; women 102,106) from South Korea with a mean follow-up of 7.9 years. The DII was calculated through a validated semi-quantitative FFQ (SQFFQ), and information on osteoporosis was self-reported by the participants. Analyses were performed by using a multivariable Cox proportional hazard model. Higher DII scores were associated with higher osteoporosis risk (HR 1.33; 95% CI 1.12–1.58). In women, a higher DII score indicated a higher risk of osteoporosis (HR 1.33; 95% CI 1.11–1.59). However, a hazards ratio of similar magnitude in men was not significant (HR 1.32; 95% CI 0.64–2.71). Post-menopausal women had higher risks of osteoporosis for higher DII scores (HR 1.33; 95% CI 1.09–1.63), whereas among pre-menopausal women, the relationship was not statistically significant (HR 1.39; 95% CI 0.87–2.21). Also, there was an increase in osteoporosis risk when the DII increased among women participants with irregular physical activity (HR 1.53; 95% CI 1.17–2.01); however, there was no statistically significant increase in osteoporosis risk among women participants with regular physical activity (HR 1.19; 95% CI 0.93–1.52). A more pro-inflammatory diet was significantly associated with higher osteoporosis risk in women. Given the similar magnitude of the hazards ratio, studies with sufficient numbers of men are warranted.

Dietary inflammatory index and its association with renal function and progression of chronic kidney disease

BACKGROUND

While evidence exists for an association between the dietary inflammatory index (DII) and cardiovascular diseases, the relation between DII and chronic kidney disease (CKD) is not known.

OBJECTIVE

To examine the association between DII, renal function and progression of CKD.

METHODS

In this cross-sectional study, dietary data from 221 subjects with diagnosed CKD were collected using a validated food frequency questionnaire. DII was calculated based on overall inflammatory effect scores. Renal function was measured by blood urea nitrogen (BUN) and serum creatinine (Cr) level as well as estimated glomerular filtration rate (eGFR).

RESULTS

Patients in the first tertile of DII consumed higher quantities of vegetables, fruits, dairy, calcium, potassium and phosphorus and lower amounts of grains (P < 0.01 for all). We did not detect any significant trend for BUN, Cr and eGFR across tertiles of DII in crude and two adjusted models. In a fully adjusted model, an increased risk of being in the higher stage of CKD was found among those in the top tertiles of DII (odds ratio: 2.12; 95% CI: 1.05, 4.26; P for trend = 0.03).

CONCLUSION

We observed that compliance with a pro-inflammatory diet in patients with CKD may be associated with disease progression.

Association between the dietary inflammatory index and all-cause mortality in colorectal cancer long-term survivors

Pro-inflammatory dietary factors have been shown to be associated with the incidence of a range of cancers. However, there are many fewer studies on the association between the inflammatory potential of diet and survival after cancer diagnosis. We examined the association between post-diagnosis dietary inflammatory index (DII®) scores and all-cause mortality in long-term survivors of colorectal cancer (CRC). DII scores were calculated from dietary data of 1,404 CRC survivors collected at a median of 6 years after CRC diagnosis. Using multivariable-adjusted Cox proportional hazards regression models, hazard ratios (HR) and 95% confidence intervals (CI) were estimated for the association of DII scores, modeled continuous and in quartiles, with all-cause mortality. After a median follow-up time of 7 years (after dietary assessment), 204 study participants had died. Overall, in the fully adjusted model there was a suggestion of a positive association between DII score and all-cause mortality (HR_{DIIquartile4vs1} : 1.36; 95% CI: 0.88-2.09 and HR_{DIIcontinuous} : 1.08; 95% CI: 0.97-1.20). However, in subgroup analyses, we found significant differences in individuals with metastatic disease (HR_{DIIcontinuous} : 1.34; 95% CI: 1.07-1.67) and the absence of stoma (HR_{DIIcontinuous} : 1.15; 95% CI: 1.02-1.29). Overall, the post-diagnosis DII was not statistically significantly associated with all-cause mortality in CRC long-term survivors; however, there was suggestive evidence of an association in select subgroups.

Dietary inflammatory index is positively associated with serum high-sensitivity C-reactive protein in a Korean adult population

OBJECTIVE

To our knowledge, only a few studies have explored the relationship between the inflammatory potential of diet and serum inflammatory markers in Korean adults. The likely novel aim of this study was to examine the association between the dietary inflammatory index (DII) and serum high-sensitivity C-reactive protein (hs-CRP) in a Korean adult population.

METHODS

A cross-sectional study was conducted using the data set from the Korea National Health and Nutrition Examination Survey (KNHANES) 2015. Korean adults ≥19 y of age with hs-CRP values were included in this study. After excluding individuals with missing variables for covariates, the final analytic sample for the study was 3014 adults (1295 men and 1719 women). DII scores were calculated from a 1-d 24-h dietary recall, and hs-CRP was measured using the immunoturbidimetric method. Multivariable logistic regression analyses were performed to calculate adjusted odds ratios (AORs) and 95% confidence intervals (CIs) to test the effect of the DII score on serum hs-CRP as dichotomous (>2 versus ≤2 mg/L).

RESULTS

A significant association was observed between increasing DII scores and elevated hs-CRP. Korean adults in the highest quintile of the DII (indicating the most proinflammatory diet), compared with the lowest quintile of the DII (indicating the most anti-inflammatory diet), had increased odds of having elevated hs-CRP concentrations (>2 mg/L; AOR, 1.70; 95% CI, 1.07-2.69; P_trend < 0.0001) after controlling for age, sex, education, marital status, alcohol consumption, smoking status, body mass index, high-density lipoprotein cholesterol, and physical activity.

CONCLUSION

Higher DII scores were positively associated with elevated hs-CRP levels in Korean adults. Because inflammation affects the risk for cancer, cardiovascular disease, and other inflammation-related conditions, future studies are warranted to examine the effect of the DII on other inflammatory biomarkers and chronic disease outcomes among the Korean population.

Association between dietary inflammatory index and psychological profile in adults

BACKGROUND & AIMS

Limited data are available on the association of inflammatory potential of the diet and odds of psychological disorders. We investigated the association between adherence to a pro-inflammatory diet, as measured by Dietary Inflammatory Index (DII), and odds of psychological disorders.

METHODS

In this cross-sectional study, dietary intakes of 3363 Iranian adult participants were collected using a validated Dish-based 106-item Semi-quantitative Food Frequency Questionnaire (DS-FFQ). DII score was calculated based on participants' dietary intakes obtained from DS-FFQ. The Iranian validated version of Hospital Anxiety and Depression Scale (HADS) and General Health Questionnaire (GHQ) was used to assess psychological disorders. For depression and anxiety, scores of 8 or more on either subscale were considered as psychological disorders and scores of 0-7 were defined as "normal". In terms of psychological distress, the score of 4 or more was defined as psychological distress.

RESULTS

Overall, 28% (n = 943) of study participants had depression, 13.3% (n = 448) were affected by anxiety and 22.6% (n = 760) by psychological distress. After controlling for potential confounders, individuals in the highest quintile of DII score had higher scores of depression (6.56 ± 0.16 vs. 5.48 ± 0.16; P < 0.001), anxiety (3.85 ± 0.17 vs. 3.09 ± 0.17; P = 0.006), and psychological distress (2.42 ± 0.13 vs. 1.77 ± 0.13; P = 0.001), compared with those in the lowest quintile. Participants in the top quintile of DII score had greater odds of depression (OR: 1.84, 95% CI: 1.30-2.60), anxiety (OR: 1.69, 95% CI: 1.07-2.67), and psychological distress (OR: 1.72, 95% CI: 1.20-2.46) than those in the bottom quintile.

CONCLUSIONS

We found that adherence to a pro-inflammatory diet was positively associated with psychological disorders.

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.

Association between the Dietary Inflammatory Index and Risk of Frailty in Older Individuals with Poor Nutritional Status

Both inflammation and poor nutritional status are major risk factors of frailty, and the dietary inflammatory index (DII) has been suggested as being associated with the risk of frailty. The present study aimed to investigate whether DII scores were positively associated with the risk of frailty in older individuals, particularly those with poor nutritional status. In total, 321 community-dwelling older individuals aged 70–85 years were recruited and categorized as non-frail, pre-frail, and frail according to the Cardiovascular Health Study index. DII scores were calculated based on 24-h dietary recall, and nutritional status was assessed using the Mini Nutritional Assessment. Multinomial logistic regression analysis showed that DII scores were positively associated with the risk of frailty in older individuals (odds ratio, OR 1.64, 95% confidence interval, 95% CI 1.25–2.17), particularly those with poor nutritional status (OR 1.68, 95% CI 1.21–2.34). Among the frailty criteria, weight loss (OR 1.29, 95% CI 1.03–1.60), low walking speed (OR 1.33, 95% CI 1.10–1.61), and low grip strength (OR 1.34, 95% CI 1.13–1.60) were associated with DII scores. In addition, the optimal DII cut-off score for frailty was ≥0.93 (sensitivity 71%; specificity: 72%; area under the receiver operating characteristic curve, AUC = 0.792). The present study showed that a pro-inflammatory diet was associated with increased risk of frailty, particularly in older individuals with poor nutritional status. Future randomized controlled trials with a low DII diet for the prevention of frailty are needed to confirm our finding.

Dietary Inflammatory Index and Odds of Breast Cancer in a Case-Control Study from Iran

Chronic inflammation is implicated in breast cancer (BrCa) development; however, studies on the association of the inflammatory potential of diet and breast cancer have produced conflicting results. With this as background, we investigated the association between dietary inflammatory index (DII^®) scores and BrCa risk in an Iranian case-control study. In this study, 136 newly diagnosed breast cancer patients and 272 hospitalized controls were recruited using convenience sampling. DII scores were computed from dietary intake data collected through a validated food frequency questionnaire (FFQ). Adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association between the DII and BrCa risk were estimated by logistic regression. After controlling for multiple potential confounders, a significantly increased BrCa odds was observed in the highest quartile of DII score compared to the lowest quartile (OR_{quartile 4 vs. 1} = 2.64, 95% CI: 1.12-6.25; P_trend = 0.01). In subanalysis based on menopausal status, a positive association was observed between the DII and BrCa risk among premenopausal women (OR_{quartile 4 vs. 1} = 5.51, 95% CI: 1.45-20.93; P_trend = 0.005); however, no association was detected in postmenopausal women. Our findings suggest that more proinflammatory diets, indicated by higher DII scores, may increase the odds of BrCa, especially among premenopausal women.

Maternal Stress Potentiates the Effect of an Inflammatory Diet in Pregnancy on Maternal Concentrations of Tumor Necrosis Factor Alpha

Maternal inflammation during pregnancy is known to adversely impact fetal development, birth outcomes, and offspring physical and mental health. Diet and stress have been identified as important determinants of inflammation, yet their combined effects have not been examined in the context of pregnancy. The aim of this study was to examine the relationship between maternal diet with inflammatory potential and psychological stress, and to determine their interaction effect on concentrations of tumor necrosis factor (TNF)-α across pregnancy. We conducted a prospective longitudinal study of n = 202 women with three assessments during pregnancy, which included: ecological momentary assessment (EMA) of maternal stress using the perceived stress scale (PSS) short version; 24-h dietary recalls from which the dietary inflammatory index (DII) was computed; and serum measurements of TNF-α. Across pregnancy, higher perceived stress was associated with consumption of a more pro-inflammatory diet (r = 0.137; p < 0.05). In a linear regression model adjusted for covariates, DII was positively associated with TNF-α (B = 0.093, p = 0.010). The effect of the pro-inflammatory diet on concentrations of TNF-α was more pronounced in women reporting higher levels of stress (B = 0.134, p = 0.018 for DII*PSS interaction). These results highlight the need to consider nutrition and stress concurrently in the context of inflammation during pregnancy.

Increased inflammatory potential of diet is associated with increased odds of prostate cancer in Argentinian men

PURPOSE

Various aspects of diet, including specific food items and nutrients, have been shown to modulate inflammation and have been implicated in the etiology of prostate cancer (PrCA). No study examining the role of diet-associated inflammation in PrCA has been conducted in Latin America.

METHOD

We examined the association between the Dietary Inflammatory Index (DII®) and PrCA in a population-based case-control study in Córdoba, Argentina. A total of 153 incident cases of PrCA and 309 controls frequency matched on sex, age (± 5 years), and place of residence were recruited from 2008 to 2015. The DII was developed to determine the inflammatory potential of individuals' diets and was computed from a validated food frequency questionnaire using nutrient data from diet only. Multi-level logistic regression models were fit to evaluate the association between DII scores and PrCA, adjusting for age, body mass index, energy intake, and occupational exposure as first-level covariates and family history of prostate cancer as the second-level variable. Odds ratios were estimated in all subject and stratified by BMI (< 30 vs. ≥ 30 kg/m2).

RESULTS

Men in the most pro-inflammatory group (tertile 3) had 50% higher odds of having PrCA compared to men in the most anti-inflammatory group (tertile 1) (ORtertile3 vs. tertile1 1.50; 95% CI 1.24-1.80). The odds of prostate cancer were higher in obese men (n = 109, ORtertile3 vs. tertile1 1.81; 95% CI 1.45-2.27), while no association was found among non-obese men (n = 375, ORtertile3 vs. tertile1 0.93; 95% CI 0.25-3.51).

CONCLUSIONS

A pro-inflammatory diet, reflected by higher DII scores, was positively associated with PrCA occurrence. Based on these results and those from other studies, steps should be taken to promote a diet rich in anti-inflammatory foods, in order to reduce risk of PrCA and other chronic diseases. Future studies should explore this association in a prospective setting.

The relationship between the dietary inflammatory index (DII®) and incident depressive symptoms: A longitudinal cohort study

BACKGROUND

Diet is a common source of inflammation, and inflammation is associated with depression. We examined the association between the dietary inflammatory index (DII^®), a validated measure of inflammatory potential of the diet, and risk of depression in a cohort of older North American adults.

METHODS

This longitudinal study, with a follow-up of 8 years, included 3648 participants (1577 males, 2071 females; mean age: 60.6 years) with/at risk of knee osteoarthritis. DII^® scores were calculated using the validated Block Brief 2000 Food-Frequency Questionnaire. Center for Epidemiological Studies Depression-20 scale was used to define depressive symptoms. The relationship between baseline DII^® score and incident depression was assessed through Cox's regression analysis, adjusted for potential confounders, and reported as hazard ratios (HRs).

RESULTS

In total, 837 individuals (310 men and 527 women) developed incident depressive symptoms over the course of 8 years. Participants in the most pro-inflammatory group (quartile 4) had approximately 24% higher risk of developing depressive symptoms compared to subjects with the most anti-inflammatory diet (HR: 1.24; 95% CI: 1.01-1.53; p = 0.04).

CONCLUSION

These results suggest that a pro-inflammatory diet may be associated with higher incidence of depressive symptoms in a cohort of older Americans. Transitioning to a more anti-inflammatory diet may reduce depression risk.

Dietary Inflammatory Index and Odds of Colorectal Cancer in a Case- Control Study from Iran

Background

In Iran, colorectal cancer (CRC) is the third and fourth leading cause of cancer incidence among men and women, respectively. Diet and inflammation have been suggested as important risk factors for CRC. We examined the association between dietary inflammatory index (DII) scores and CRC in a case-control study conducted in Iran.

Methods

This study included 71 CRC cases and 142 controls hospitalized for acute non-neoplastic diseases. DII scores were computed from dietary intake assessed by a previously validated food frequency questionnaire. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CI) adjusted for age, sex, education, energy intake, exercise, body mass index (BMI), smoking, family history of cancer, and history of aspirin, acetaminophen, and multivitamin use.

Results

Subjects with higher DII scores (i.e., indicating a more pro-inflammatory diet) had a higher odds of CRC with the DII being used as both a continuous variable (OR continuous = 2.20, 95% CI: 1.22-3.87) and as a categorical variable (OR tertile 3 vs tertile1 = 2.47, 95%CI: 1.10-5.55).

Conclusion

These results indicate that a pro-inflammatory diet is associated with increased odds of CRC in this Iranian population.

Impact of Edible Cricket Consumption on Gut Microbiota in Healthy Adults, a Double-blind, Randomized Crossover Trial

Edible insects are often considered a nutritious, protein-rich, environmentally sustainable alternative to traditional livestock with growing popularity among North American consumers. While the nutrient composition of several insects is characterized, all potential health impacts have not been evaluated. In addition to high protein levels, crickets contain chitin and other fibers that may influence gut health. In this study, we evaluated the effects of consuming 25 grams/day whole cricket powder on gut microbiota composition, while assessing safety and tolerability. Twenty healthy adults participated in this six-week, double-blind, crossover dietary intervention. Participants were randomized into two study arms and consumed either cricket-containing or control breakfast foods for 14 days, followed by a washout period and assignment to the opposite treatment. Blood and stool samples were collected at baseline and after each treatment period to assess liver function and microbiota changes. Results demonstrate cricket consumption is tolerable and non-toxic at the studied dose. Cricket powder supported growth of the probiotic bacterium, Bifidobacterium animalis, which increased 5.7-fold. Cricket consumption was also associated with reduced plasma TNF-α. These data suggest that eating crickets may improve gut health and reduce systemic inflammation; however, more research is needed to understand these effects and underlying mechanisms.

Dietary Inflammatory Index and Site-Specific Cancer Risk: A Systematic Review and Dose-Response Meta-Analysis

Existing evidence suggests a link between the inflammatory potential of diet and risk of cancer. This study aimed to test the linear and potential nonlinear dose-response associations of the Dietary Inflammatory Index (DII), as being representative of inflammatory features of the diet, and site-specific cancer risk. A systematic search was conducted with the use of PubMed and Scopus from 2014 to November 2017. Prospective cohort or case-control studies reporting the risk estimates of any cancer type for ≥3 categories of the DII were selected. Studies that reported the association between continuous DII score and cancer risk were also included. Pooled RRs were calculated by using a random-effects model. Eleven prospective cohort studies (total n = 1,187,474) with 28,614 incident cases and 29 case-control studies with 19,718 cases and 33,229 controls were identified. The pooled RRs for a 1-unit increment in the DII were as follows: colorectal cancer, 1.06 (95% CI: 1.04, 1.08; I2 = 72.5%; n = 9); breast cancer, 1.03 (95% CI: 1.00, 1.07; I2 = 84.0%; n = 7); prostate cancer, 1.06 (95% CI: 0.97, 1.15; I2 = 56.2%; n = 6); pancreatic cancer, 1.16 (95% CI: 1.05, 1.28; I2 = 61.6%; n = 2); ovarian cancer, 1.08 (95% CI: 1.03, 1.13; I2 = 0%; n = 2); esophageal squamous cell carcinoma, 1.24 (95% CI: 1.10, 1.38; I2 = 64.3%; n = 2); renal cell carcinoma, 1.08 (95% CI: 1.02, 1.13; I2 = 0%; n = 2); and esophageal adenocarcinoma, 1.26 (95% CI: 1.13, 1.39; I2 = 0%; n = 2). A nonlinear dose-response meta-analysis showed that, after a somewhat unchanged risk within initial scores of the DII, the risk of colorectal cancer increased linearly with increasing DII score. In the analyses of breast and prostate cancers, the risk increased with a very slight trend with increasing DII score. In conclusion, the results showed that dietary habits with high inflammatory features might increase the risk of site-specific cancers.

Relationships between the inflammatory potential of the diet, aging and anthropometric measurements in a cross-sectional study in Pakistan

BACKGROUND

Little is known about associations between dietary inflammation, age and anthropometric measurements.

OBJECTIVE

In this regard, we examine how DII is related to age, anthropometrics [weight, Body mass index (BMI), waist to hip ratio (WHR)] and other parameters of nutrition (energy, protein, fats and cholesterol intake, Net Endogenous Acid Production (NEAP) and Phytochemical Index (PI)) in a cross-sectional study in Pakistan.

DESIGN

Only men (n = 651, age 54-95 years) participated in the study. Anthropometric data were collected using standard methods. DII was calculated from nutrients derived from 24-hr Dietary Recall questionnaires. NEAP and PI were calculated by established algorithms using information on nutrient intake.

RESULTS

The results show that with increasing age, there was a significant increase in the DII score (p < 0.05). Similarly significant positive correlations were found between DII score and weight, BMI, WHR and % BF (p, for all trends < 0.05). DII score significantly positively correlated with the dietary factors studied i.e. energy, protein, and fats (p, for all trends < 0.0001) but non-significantly with cholesterol (p > 0.05). Similarly, a significant positive correlation with NEAP (p < 0.0001) was found, but negative with PI (p < 0.0001).

CONCLUSION

In conclusion, the present study shows direct positive correlations between the DII, age and indices of obesity, and thus supports the hypothesis that diet may have a role in the development of obesity through inflammatory modulation mechanisms in elderly.

Associations between Food Security Status and Dietary Inflammatory Potential within Lower-Income Adults from the United States National Health and Nutrition Examination Survey, Cycles 2007 to 2014

BACKGROUND

Evidence suggests both that chronic inflammation mediates the association of food insecurity with adverse health outcomes and that diet may be a significant source of inflammation among food insecure individuals.

OBJECTIVE

To examine whether food security status is associated with dietary inflammatory potential.

DESIGN AND PARTICIPANTS

Cross-sectional data came from the National Health and Nutrition Examination Survey (NHANES), cycles 2007 to 2014 (n=10,630). The analysis sample is representative of noninstitutionalized US adults with an income-to-poverty ratio ≤3.00.

MAIN OUTCOME

Dietary Inflammatory Index (DII) score, calculated using the average of two 24-hour dietary recalls, was the main outcome measure.

STATISTICAL ANALYSIS

Type III F tests or χ2 tests compared population characteristics by food security status, defined using the US Food Security Survey Module. Multivariable linear regression was used to estimate the association between food security status and the DII score and moderation by demographic factors. Survey weighting procedures accounted for the effects of stratification and clustering used in the NHANES study design.

RESULTS

When accounting for socioeconomic status, demographic factors, and health status, DII score was higher at greater levels of food insecurity (P=0.0033). Those with very low food security had a 0.31 (95% CI=0.12 to 0.49) higher DII score than those with high food security. Age moderated the association between food security status and DII score (interaction P=0.0103), where the magnitude of the association between DII score and severity of food insecurity was higher for those >65 years than for younger age groups.

CONCLUSION

Food security status may be associated with dietary inflammatory potential, which is hypothesized to play a role in multiple chronic health conditions. Further research is needed to determine the causal nature of this relationship and evaluate how best to implement programs designed to address health disparities within food insecure populations.

Dietary inflammatory index and risk of upper aerodigestive tract cancer in Japanese adults

Background

The inflammatory potential of diet that has been shown to be associated with cancer risk. We examined the association between dietary inflammatory potential as measured by the dietary inflammatory index (DII^®) and risk of upper aerodigestive tract cancers in a Japanese case-control study.

Results

A positive association was observed between increasing DII scores and overall upper aerodigestive tract cancers, and across anatomic subsites. For upper aerodigestive tract cancers, the OR_Q4vsQ1 = 1.73 (95% CI: 1.37–2.20); head and neck cancer, the OR_Q4vsQ1 was 1.92 (95% CI: 1.42–2.59); and for esophageal cancer, the OR_Q4vsQ1 was1.71 (95% CI: 1.54–1.90). Risks for hypopharyngeal and nasopharyngeal cancers were greatly elevated: (OR_Q4vsQ1 = 4.05 (95% CI: 1.24–13.25) for hypopharyngeal cancer and OR_Q4vsQ1 = 4.99 (95% CI: 1.14–21.79) for nasopharyngeal cancer.

Conclusion

A more pro-inflammatory diet was associated with an elevated risk of upper aerodigestive tract cancers after accounting for important confounders. All anatomic subsites, except larynx, showed the consistently elevated risk with increasing DII score. Those subsites with known etiological associations with persistent infection showed the largest elevation in risk. These results warrant further evaluation in future studies.

Materials and Methods

This is a case-control study of 1,028 cases and 3,081 age- and sex-matched non-cancer controls recruited at Aichi Cancer Center. DII scores were computed based on estimates of macro- and micro-nutrients from a self-administered food frequency questionnaire. Scores were further categorized into quartiles (based on the distribution in controls). Conditional logistic regression models were fit to estimate odds ratio (OR) and 95% confidence intervals (CIs) adjusted for smoking, ethanol consumption, alcohol flushing, number of teeth, and occupation group.

The Dietary Inflammatory Index and Current Wheeze Among Children and Adults in the United States

BACKGROUND

A proinflammatory diet may increase allergic airway inflammation by affecting innate and adaptive immune responses.

OBJECTIVE

In this study, we examine the relation between the diet's inflammatory potential, measured by the Dietary Inflammatory Index (DII), and current asthma, current wheeze, and lung function in U.S. children and adults.

METHODS

We analyzed data from 8,175 children (aged 6-17 years) and 22,294 adults (aged 18-79 years) who participated in the 2007-2012 National Health and Nutrition Examination Survey. The DII was calculated by nutrient intake based on 24-hour dietary recalls, and normalized as per 1,000 calories of food consumed to account for total energy intake. Multivariable regression models were used for the analysis of the DII and current asthma, current wheeze, and lung function measures.

RESULTS

Higher DII (a proinflammatory diet) was associated with current wheeze among adults (eg, odds ratio [OR] for quartile 4 vs 1, OR = 1.41, 95% confidence interval [CI] = 1.17-1.70; Ptrend < .01) and among children with high fractional exhaled nitric oxide (a marker of eosinophilic airway inflammation; OR = 2.38, 95% CI = 1.13-5.02; Ptrend = .05). The DII also was associated with decreased forced expiratory volume in 1 second and forced vital capacity in adults without asthma or wheezing. The DII was not associated with lung function in children or current asthma in either age group.

CONCLUSIONS

Our findings suggest that a proinflammatory diet, assessed by the DII, increases the odds of current wheeze in adults and children with allergic (atopic) wheeze. These results further support testing dietary interventions as part of the management of asthma.

Dietary inflammatory index or Mediterranean diet score as risk factors for total and cardiovascular mortality

BACKGROUND AND AIMS

Dietary patterns are associated with risk of cardiovascular disease (CVD). We aimed to examine associations of the Dietary Inflammatory Index (DII) and the Mediterranean Diet Score (MDS) with total, cardiovascular disease (CVD) and coronary heart disease (CHD) mortality in the Melbourne Collaborative Cohort Study; and compare the strengths of the associations.

METHODS AND RESULTS

In our prospective cohort study of 41,513 men and women aged 40-69 years, a food frequency questionnaire was completed at baseline and mortality data were obtained via linkage with local and national registries over an average of 19 years follow up. At baseline, questionnaires were completed and physical measures and blood samples taken. Cox proportional hazards models, adjusting for age, alcohol consumption, sex, region of origin, personal history of CVD or diabetes and family history of CVD, were used to assess associations between dietary scores and mortality. More Mediterranean or less inflammatory diets were associated with lower total, CVD and CHD mortality. The hazard ratio for total mortality comparing the highest and lowest quintiles was 1.16 (95%CI: 1.08-1.24) for DII; and 0.86 (95%CI: 0.80-0.93) comparing the highest and lowest three categories of MDS. Using the Bayesian information criterion, there was no evidence that the DII score was more strongly associated with total and CVD mortality than was the MDS.

CONCLUSIONS

The MDI and the DII show similar associations with total and cardiovascular mortality, consistent with the consensus that plant-based diets are beneficial for health.

Association between the Dietary Inflammatory Index (DII) and urinary enterolignans and C-reactive protein from the National Health and Nutrition Examination Survey-2003-2008

BACKGROUND

Enterolignans are important biomarkers of microbiota diversity, with higher levels indicating greater diversity. Diet and inflammation have been shown to play a role in maintaining microbiota diversity. This study examined whether inflammatory potential of diet, as measured by the Dietary Inflammatory Index (DII^®) has an impact on levels of urinary enterolignans in the National Health and Nutrition Examination Survey (NHANES) 2003-2008. We also carried out construct validation of the DII with C-reactive protein (CRP).

METHODS

Data came from NHANES 2003-2008. Enterolignans [enterodiol (END) and enterolactone (ENL)] and CRP were assayed from urine and serum specimens, respectively. Energy-adjusted DII (E-DII) scores were calculated from food intakes assessed using 24-h dietary recalls and expressed per 1000 calories consumed. Associations were examined using survey-based multivariable linear and logistic regression for enterolignans, and logistic regression for CRP.

RESULTS

After multivariable adjustment, higher E-DII scores (i.e., indicating a relatively more pro-inflammatory diet) were associated with lower levels of creatinine-normalized END [beta coefficient (b)_{DIIquartile4vs1} = - 1.22; 95% CI = - 0.69, - 1.74; P_trend ≤ 0.001] and ENL (b_{DIIquartile4vs1} = - 7.80; 95% CI = - 5.33, - 10.26; P_trend ≤ 0.001). A positive association was also observed when enterolignans were dichotomized based on the cut-off of the 75th percentile value. In this same sample, the E-DII also was associated with CRP ≥ 3 mg/l (OR_{DIIcontinuous} = 1.12; 95% CI 1.05, 1.19).

CONCLUSION

In these NHANES data, there was an association between E-DII score and enterolignans. This study also provided construct validation of the E-DII using CRP in a nationally representative sample. The results indicate that dietary inflammatory potential is associated with urinary enterolignans, a potential marker for microbiota diversity. However, studies are required to understand the direct association between DII and microbiota.

Inflammatory potential of the diet and risk of gastric cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) study

Background

Chronic inflammation plays a critical role in the pathogenesis of the 2 major types of gastric cancer. Several foods, nutrients, and nonnutrient food components seem to be involved in the regulation of chronic inflammation.

Objective

We assessed the association between the inflammatory potential of the diet and the risk of gastric carcinoma, overall and for the 2 major subsites: cardia cancers and noncardia cancers.

Design

A total of 476,160 subjects (30% men, 70% women) from the European Investigation into Cancer and Nutrition (EPIC) study were followed for 14 y, during which 913 incident cases of gastric carcinoma were identified, including 236 located in the cardia, 341 in the distal part of the stomach (noncardia), and 336 with overlapping or unknown tumor site. The dietary inflammatory potential was assessed by means of an inflammatory score of the diet (ISD), calculated with the use of 28 dietary components and their corresponding inflammatory scores. The association between the ISD and gastric cancer risk was estimated by HRs and 95% CIs calculated by multivariate Cox regression models adjusted for confounders.

Results

The inflammatory potential of the diet was associated with an increased risk of gastric cancer. The HR (95% CI) for each increase in 1 SD of the ISD were 1.25 (1.12, 1.39) for all gastric cancers, 1.30 (1.06, 1.59) for cardia cancers, and 1.07 (0.89, 1.28) for noncardia cancers. The corresponding values for the highest compared with the lowest quartiles of the ISD were 1.66 (1.26, 2.20), 1.94 (1.14, 3.30), and 1.07 (0.70, 1.70), respectively.

Conclusions

Our results suggest that low-grade chronic inflammation induced by the diet may be associated with gastric cancer risk. This pattern seems to be more consistent for gastric carcinomas located in the cardia than for those located in the distal stomach. This study is listed on the ISRCTN registry as ISRCTN12136108.

Dietary inflammatory index and risk of oesophageal cancer in Xinjiang Uyghur Autonomous Region, China

Diet has been shown to have an effect on both inflammation and oesophageal cancer. This study investigated the association between the dietary inflammatory index (DII®) and the risk of oesophageal cancer in Xinjiang Uyghur Autonomous Region, China. A case-control study was conducted during 2008-2009 in Urumqi and Shihezi. DII scores were calculated based on dietary intake assessed by a validated FFQ administered to 359 incident oesophageal cancer patients and 380 hospital-based controls. Higher DII scores indicate more pro-inflammatory diets. Logistic regression analyses were performed to assess the association between DII scores and oesophageal cancer risk. Oesophageal cancer patients had a significantly higher median DII score (-0·35; interquartile range (IQR)=-2·25, 1·86) than that of controls (-1·41; IQR -3·07, 0·40). Multivariable logistic analysis revealed a positive association between higher DII scores and oesophageal cancer risk (ORQuartile 4 v. 1 2·55; 95 % CI 1·61, 4·06; P trend<0·001). A pro-inflammatory diet appears to be associated with an increased risk of oesophageal cancer in Xinjiang Uyghur Autonomous Region. Specific carcinogenic mechanisms are discussed. Accumulating evidence, to which the study contributes, indicates that encouraging the intake of more anti-inflammatory foods may be a strategy to protect against oesophageal cancer in this high-risk area of China.

Dose-response relation between dietary inflammatory index and human cancer risk: evidence from 44 epidemiologic studies involving 1,082,092 participants

Background

A newly developed dietary inflammatory index (DII) to evaluate the inflammatory potential of diets was published recently. Many studies have investigated the link between diet-related inflammation and human cancer risk, but the results remain controversial.

Objective

We sought to determine the dose-response relation between DII and human cancer risk based on published epidemiologic literature.

Design

To summarize evidence, we performed a dose-response meta-analysis to investigate the association between DII and cancer incidence. We systematically searched PubMed, Embase, Web of Science, and the Cochrane library up to 5 November 2017. After data extraction, pooled RRs were calculated and dose-response analyses were performed using a restricted cubic spline model with 4 knots. Subgroup analyses, sensitivity analyses, and tests for publication bias were also performed.

Results

In all, 44 high-quality studies with 1,082,092 participants were included. The results showed that an elevated DII (continuous-RR: 1.13; 95% CI: 1.09, 1.16; category DIIhighest vs lowest-RR: 1.58; 95% CI: 1.45, 1.72) independently indicated higher cancer risk except for lung cancer and Australian studies. A linear dose-response relation between DII and overall cancer risk was found, with an 8.3% increase in the risk of cancer per DII score. The pooled RR of DII and cancer risk was 1.86 (95% CI: 1.63, 2.13) from 30 case-control studies but was lower in 14 prospective cohorts (RR: 1.29; 95% CI: 1.19, 1.40). The sensitivity analysis and Egger's test supported the main results.

Conclusions

Our analysis indicated that higher DII is significantly correlated with cancer risk. More prospective studies with large sample sizes, involving more ethnic groups and different cancer types, are required in the future. This review was registered with PROSPERO as CRD42017077075.

Association between Dietary Inflammatory Index and Prostate Cancer in Shiraz Province of Iran

Background: Dietary components like food items and nutrients have been implicated to play a role in modulating inflammation and the development of prostate cancer. Studies examining this association have not been extensively explored in Middle Eastern Countries. Material and Methods: We examined the association between the dietary inflammatory index (DIITM) and prostate cancer in the Shiraz province of Iran. A total of 60 incident cases and 60 controls attending the same hospital as the cases were recruited. The energy adjusted DII (E-DIITM) was computed based on dietary intake assessed using a validated food frequency questionnaire (FFQ). Logistic regression was used to estimate odds ratios. Results: Men with higher E-DII (>0.96) were at higher risk of prostate cancer (OR = 2.55; 95% CI =1.04–6.23) compared to men with E-DII ≤0.96. Conclusion: These data suggest a pro-inflammatory diet, as indicated by increasing DII score, may be a risk factor for prostate cancer in Iranian men.

Dietary inflammatory index: a potent association with cardiovascular risk factors among patients candidate for coronary artery bypass grafting (CABG) surgery

BACKGROUND

Recently, the clinical importance of dietary inflammatory index (DII) in predicting the inflammatory potential of diet and its role in pathogenesis of several chronic disease including some types of cancers, osteoporosis, cardiovascular disease and renal disease has been proposed. However, its association with the disease severity and progression and cardio-metabolic risk factors among patients candidate for coronary artery bypass graft surgery (CABG) has not been evaluated yet. In the current study, the association of DII with cardiovascular risk factors among patients candidate for CABG has been investigated.

METHODS

In the current cross-sectional study, 454 patients aged 35-80 years as candidates of CABG and hospitalized in Tehran Heart Center were enrolled. Anthropometric and demographic characteristics were obtained from all of the participants. Dietary intakes were evaluated with a semi-quantitative food-frequency questionnaire (FFQ) and DII was calculated. Biochemical parameters including hemoglobin (Hb) A1C, serum lipids, albumin, creatinine and high-sensitive C-reactive protein (hs-CRP), lipoprotein (a), creatinine, blood urea nitrogen (BUN), albumin and hematocrit (HCT) were also assessed by commercial laboratory methods. Left ventricular ejection- fraction, number of diseased vessels, New York Heart Association (NYHA) functional class and the European system for cardiac operative risk evaluation (EuroSCORE) were estimated for clinical assessment. One way analysis of variance and chi square tests were used for comparison of demographic parameters between groups. Beta estimates and 95% confidence intervals (CI) for the association between DII and clinical parameters were estimated using linear regression adjusted for the confounders.

RESULTS

According to our findings, high DII scores were associated with higher age, lower body mass index (BMI), higher prevalence of diabetes and myocardial infarction (MI) and lower educational attainment (P < 0.05). Male patients in 4th and 3rd quartile of DII had significantly higher total cholesterol (TC), triglyceride (TG), albumin, creatinine, BUN and hs-CRP concentrations and lower high density lipoprotein cholesterol (HDL) concentrations compared with male patients in lower quartiles (P < 0.05). While in female patients, only lipoprotein (a) concentrations and hematocrit (HCT) percentage in the 4th and 2nd quartile were significantly higher than lower quartiles. EuroSCORE was also significantly higher in top quartiles of DII (P = 0.006).

CONCLUSION

As shown in our results, DII was in a positive association with several cardiovascular risk factors. The higher inflammatory potential of diet denoted higher values of serum lipids, CRP and kidney function tests and higher EuroSCORE as a predictor of post-operative mortality. Therefore, DII can be demonstrated as a target of nutritional interventions for ameliorating the CVD risk factors among patients candidate for CABG especially in male patients.

Association between dietary inflammatory index and Hodgkin's lymphoma in an Italian case-control study

OBJECTIVES

The components of a diet can modulate inflammation and may have an effect on the development of Hodgkin's lymphoma (HL). Little is known about the inflammatory potential of diet in relation to HL.

METHODS

Data from an Italian multicenter case-control study that was conducted between 1992 and 2008 were used to estimate the relation between a dietary inflammatory index (DII^®) and the risk of HL. The data included 179 cases with incident, histologically confirmed HL and 186 control cases who were hospitalized for acute non-neoplastic diseases. The DII was computed on the basis of a validated, 78-item, food-frequency questionnaire. Logistic regression models were used to estimate odds ratios that were adjusted for age, sex, total energy intake, center, body mass index, years of education, tobacco use, and alcohol consumption.

RESULTS

No significant association was observed between an increasing DII and the risk of HL when used either as a continuous or categorical variable. The multivariate odds ratio for the highest versus the lowest DII tertile was 1.20 (95% confidence interval: 0.71-2.04). Similarly, no positive association was observed when analyses were carried out by different strata of selected covariates.

CONCLUSIONS

These results do not support the hypothesis that the inflammatory potential of a diet plays a major role in the development of HL.

The relationship between the dietary inflammatory index and prevalence of radiographic symptomatic osteoarthritis: data from the Osteoarthritis Initiative

PURPOSE

To investigate whether higher dietary inflammatory index (DII^®) scores were associated with higher prevalence of radiographic symptomatic knee osteoarthritis in a large cohort of North American people from the Osteoarthritis Initiative database.

METHODS

A total of 4358 community-dwelling participants (2527 females; mean age 61.2 years) from the Osteoarthritis Initiative were identified. DII^® scores were calculated using the validated Block Brief 2000 Food-Frequency Questionnaire and scores were categorized into quartiles. Knee radiographic symptomatic osteoarthritis was diagnosed clinically and radiologically. The strength of association between divided into quartiles (DII^®) and knee osteoarthritis was investigated through a logistic regression analysis, which adjusted for potential confounders, and results were reported as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Participants with a higher DII^® score, indicating a more pro-inflammatory diet, had a significantly higher prevalence of radiographic symptomatic knee osteoarthritis compared to those with lower DII^® score (quartile 4: 35.4% vs. quartile 1: 24.0%; p < 0.0001). Using a logistic regression analysis, adjusting for 11 potential confounders, participants with the highest DII^® score (quartile 4) had a significantly higher probability of experiencing radiographic symptomatic knee osteoarthritis (OR 1.40; 95% CI 1.14-1.72; p = 0.002) compared to participants with the lowest DII^® score (quartile 1).

CONCLUSIONS

Higher DII^® values are associated with higher prevalence of radiographic symptomatic knee osteoarthritis.

Association Between Inflammatory Diet Pattern and Risk of Colorectal Carcinoma Subtypes Classified by Immune Responses to Tumor

BACKGROUND & AIMS

Dietary patterns affect systemic and local intestinal inflammation, which have been linked to colorectal carcinogenesis. Chronic inflammation can interfere with the adaptive immune response. We investigated whether the association of a diet that promotes intestinal inflammation with risk of colorectal carcinoma was stronger for tumors with lower lymphocytic reactions than tumors with higher lymphocytic reactions.

METHODS

We collected data from the molecular pathological epidemiology databases of 2 prospective cohort studies: the Nurses' Health Study (since 1976) and the Health Professionals Follow-Up Study (since 1986). We used duplication-method time-varying Cox proportional cause-specific hazards regression to assess the association of empirical dietary inflammatory pattern (EDIP) score (derived from food frequency questionnaire data) with colorectal carcinoma subtype. Foods that contribute to high EDIP scores include red and processed meats, refined grains, carbonated beverages, and some vegetables; foods that contribute to low EDIP scores include beer, wine, coffee, tea, yellow and leafy vegetables, and fruit juice. Colorectal tissue samples were analyzed histologically for patterns of lymphocytic reactions (Crohn's-like lymphoid reaction, peritumoral lymphocytic reaction, intratumoral periglandular reaction, and tumor-infiltrating lymphocytes).

RESULTS

During follow-up of 124,433 participants, we documented 1311 incident colon and rectal cancer cases with available tissue data. The association between the EDIP and colorectal cancer risk was significant (Ptrend = .02), and varied with degree of peritumoral lymphocytic reaction (Pheterogeneity < .001). Higher EDIP scores were associated with increased risk of colorectal cancer with an absent or low peritumoral lymphocytic reaction (highest vs lowest EDIP score quintile hazard ratio, 2.60; 95% confidence interval, 1.60-4.23; Ptrend < .001), but not risk of tumors with intermediate or high peritumoral lymphocytic reaction (Ptrend > .80).

CONCLUSIONS

In 2 prospective cohort studies, we associated inflammatory diets with a higher risk of colorectal cancer subtype that contains little or no peritumoral lymphocytic reaction. These findings suggest that diet-related inflammation might contribute to development of colorectal cancer, by suppressing the adaptive anti-tumor immune response.

Dietary Patterns and Colorectal Cancer Risk: A Review of 17 Years of Evidence (2000-2016)

PURPOSE OF REVIEW

Colorectal cancer (CRC) is a global public health problem, with an estimated 1.4 million cases diagnosed worldwide in 2012. Evidence suggests that diet may be important for primary prevention.

RECENT FINDINGS

The 2017 WCRF/AICR Continuous Update Project on colorectal cancer concluded that there is convincing evidence linking several individual dietary factors with CRC risk but the evidence for dietary patterns was limited and inconclusive. Also, previous reviews and meta-analyses have not critically synthesized various dietary patterns. This review synthesized data from dietary patterns studies over a 17-year period from 2000 to 2016.

SUMMARY

We included 49 studies (28 cohort and 21 case-control) that examined the association of index-based and empirically-derived dietary patterns and CRC risk. A synthesis of food group components comprising the different index-based and empirically-derived patterns revealed two distinct dietary patterns associated with CRC risk. A "healthy" pattern, generally characterized by high intake of fruits and vegetables, wholegrains, nuts and legumes, fish and other seafood, milk and other dairy products, was associated with lower CRC risk. In contrast, the "unhealthy" pattern, characterized by high intakes of red meat, processed meat, sugar-sweetened beverages, refined grains, desserts and potatoes was associated with higher CRC risk. It is notable that the number of food groups, the intake quantity, the exact types of foods in each food group, differed between populations, yet the two dietary patterns remained consistent across regions, especially in empirically-derived patterns, an indication of the high reproducibility of these patterns. However, findings for CRC risk in both index-based and empirically-derived patterns, differed by sex, with stronger associations among men than women; study design, a higher proportion of case-control studies reported significant findings compared to prospective studies. Consuming a dietary pattern high in fruits and vegetables and low in meats and sweets is protective against CRC risk. However, important questions remain about mechanisms underlying differences by sex; life-course timing of exposure to dietary patterns; interaction of dietary patterns with the microbiome or with lifestyle factors including physical activity; and elucidation of subsite differences.

Inflammatory potential of the diet and colorectal tumor risk in persons with Lynch syndrome

Background: Persons with Lynch syndrome (LS) have high lifetime risk of developing colorectal tumors (CRTs) because of a germline mutation in one of their mismatch repair (MMR) genes. An important process in the development of CRTs is inflammation, which has been shown to be modulated by diet.Objective: We aimed to investigate the association between the inflammatory potential of the diet and the risk of CRTs in persons with LS.Design: We used the dietary intake of 457 persons with LS from a prospective cohort study to calculate the adapted dietary inflammatory index (ADII). The ADII was split into tertiles in which the highest tertile reflects the most proinflammatory potential of the diet. Cox proportional hazard models, with robust sandwich variance estimates to adjust for dependency within families, were used to calculate HRs and 95% CIs of CRTs by ADII tertile. HRs were adjusted for age, smoking status, and education level, and number of colonoscopies as a time-dependent variable. A potential effect measure modification was explored by stratifying the results by mutated MMR gene, sex, and a history of CRTs. We performed sensitivity analyses by repeating the analyses in non-nonsteroidal anti-inflammatory drug (NSAID) users (n = 315).Results: During a median follow-up time of 59 mo, 200 participants (43.8%) developed CRTs. No significant association was shown between highest compared with lowest ADII tertiles (HR for highest compared with lowest tertiles: 1.37; 95% CI: 0.80, 2.34). Stratification by mutated MMR gene, sex, and CRT history did not show significantly differential associations (P-interactions ≥ 0.64). In non-NSAID users, an HR of 1.60 (95% CI: 0.88, 2.93) for highest compared with lowest tertiles was shown. No significant effect modification was shown in this group either (P-interactions ≥ 0.24).Conclusion: A proinflammatory potential of the diet does not seem to be significantly associated with CRT risk in persons with LS.

The association between dietary inflammatory properties and bone mineral density and risk of fracture in US adults

BACKGROUND/OBJECTIVES

To examine the associations of dietary inflammatory index (DII) with bone mineral density (BMD) and fracture risk in adult Americans.Subjects/Method:The United States National Health and Nutrition Examination Survey participants during 2005-2010 were included if they had measured data on dietary intake and BMD. DII scores were calculated from estimated micro- and macronutrients from a single 24-h dietary recall. BMD was measured using dual-energy X-ray absorptiometry densitometers. Risk of fractures was obtained from participant self-report (ever) based on doctor information. Analyze of covariance and χ²-tests were employed, while accounting for the complex survey design.

RESULTS

A total of 18 318 participants were included, with 51.3% (9397) being men. Age, sex, race, physical activity, smoking, C-reactive protein and body mass index-adjusted mean BMD (g/cm²) in different bodily sites significantly decreased across increasing quarters of the DII (all P<0.001). After further adjustment for calcium intake, the trend in BMD across DII quarters remained significant for total femur, femoral neck, trochanter and intertrochanter BMD (all P<0.001). Across increasing quarters of the DII, the proportion of fractures ranged from 1.1 to 1.5% for hip fracture (P=0.02), from 7.9 to 10.5% for wrist fracture (P<0.001) and from 2.2 to 2.7% for spine fracture (P=0.002. Prevalent wrist fractures significantly differed across DII quarters (P<0.0001), driven by high prevalence in the top quarter, while hip and spine fractures' prevalence did not vary significantly.

CONCLUSIONS

The current study provides evidence suggesting a potential adverse effect of pro-inflammatory diet on bone health; which may have implications for dietary approaches for those with history of abnormal bone health complications.

Index-Based Dietary Patterns and the Risk of Prostate Cancer

Prostate cancer is the second leading cause for cancer incidence in male. Although this high incidence is due to prostate specific antigen screening, other risk-factors, such as diet, might also be involved. The results of previous studies on the association between prostate cancer risk and individual dietary components have been conflicting. Thus, evaluation by dietary pattern analysis rather than individual dietary factors is suggested. The purpose of this study was to review the association of prostate cancer with a priori dietary indices, which are less studied and reviewed to date compared to a posteriori indices. Studies reviewed in this research were published from January 1997 to March 2017. Seventeen studies with nine indices were selected. In Mediterranean Diet Score (MDS), all four studies were non-significant. In Dietary Inflammatory Index (DII), 3 out of 4 studies significantly increased risk by 1.33-2.39 times, suggesting that a higher pro-inflammatory diet may be a possible prostate cancer risk factor. In Oxidative Balance Score (OBS), 2 out of 5 studies had decreased risk by 0.28 and 0.34 times, whereas 1 study had increased risk by 1.17 times. Among other indices, Healthy Eating Index (HEI) and prostate cancer dietary index were associated with decreased risk, while the results from 2 studies of Low Carbohydrate, High Protein Diet (LCHP) score were conflicting. In conclusion, we observed that it is insufficient to support the association between a priori indices and prostate cancer risk, except for MDS and DII, which had relatively constant results among studies. Therefore, further studies are required to identify consistent criteria for each a priori index, and should be conducted actively in various populations.

Dietary inflammatory index and ovarian cancer risk in a New Jersey case-control study

OBJECTIVE

Diet may influence the development of ovarian cancer. Although it has been shown that inflammation plays an important etiologic role in ovarian carcinogenesis, little is known about the influence of the inflammatory potential of food consumption. The aim of this study was to evaluate the effect of a proinflammatory diet, as indicated by a high dietary inflammatory index (DII^®) score, on ovarian cancer risk, in a New Jersey population.

METHODS

Data from a case-control study conducted in New Jersey were used to estimate the relation between DII score and the risk for ovarian cancer. The study consisted of 205 cases with incident, histologically confirmed ovarian cancer, and 390 controls identified by random-digit dialing, based on Centers for Medicare & Medicaid Service lists, and area sampling. Computation of the DII was based on the intake of selected dietary factors assessed by a validated food frequency questionnaire (FFQ). Logistic regression models were fit to estimate odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for potential covariates.

RESULTS

Although there was no significant association observed in pre- and perimenopausal women, a significant association was observed between the most proinflammatory DII scores and ovarian cancer among postmenopausal women (OR_{Quartile4 vs1}, 1.89; 95% CI, 1.02-3.52; P_trend = 0.03).

CONCLUSION

Findings from the present study suggested that a proinflammatory diet may increase risk for ovarian cancer among postmenopausal women, and warrants further study to confirm this association.

The Relationship Between the Dietary Inflammatory Index and Incident Frailty: A Longitudinal Cohort Study

OBJECTIVE

Inflammation is key risk factor for several conditions in the elderly. However, the relationship between inflammation and frailty is still unclear. We investigated whether higher dietary inflammatory index (DII) scores were associated with higher incidence of frailty in a cohort of North Americans.

DESIGN

Longitudinal, with a follow-up of 8 years.

SETTING

Osteoarthritis Initiative.

PARTICIPANTS

A total of 4421 participants with, or at high risk of, knee osteoarthritis.

MEASUREMENTS

DII scores were calculated using the validated Block Brief 2000 Food-Frequency Questionnaire and categorized into sex-specific quartiles. Frailty was defined as 2 out of 3 of the criteria of the Study of Osteoporotic Fracture study (ie, weight loss, inability to rise from a chair 5 times, and poor energy). The strength of the association between baseline DII score and incident frailty was assessed through a Cox's regression analysis, adjusted for potential baseline confounders, and reported as hazard ratios.

RESULTS

A total of 4421 community-dwelling participants (2564 female participants; mean age: 61.3 years) without frailty at baseline were identified from the Osteoarthritis Initiative. During 8 years of follow-up, 356 individuals developed frailty (8.2%). Using Cox's regression analysis, adjusting for 11 potential confounders, participants with the highest DII score (quartile 4) had a significantly higher risk of experiencing frailty (hazard ratio 1.37; 95% confidence interval 1.01-1.89; P = .04) compared with participants with the lowest DII score (quartile 1). The association between DII score and frailty was significant only in men.

CONCLUSIONS

Higher DII scores, indicating a more proinflammatory diet, are associated with higher incidence of frailty, particularly in men.