Longitudinal changes in the dietary inflammatory index: an assessment of the inflammatory potential of diet over time in postmenopausal women

Diet Quality Trajectories over Adulthood in a Biracial Urban Sample from the Healthy Aging in Neighborhoods of Diversity across the Life Span Study

Limited investigation has been done on diet quality trajectories over adulthood. The main study objectives were to determine the diet quality group trajectories (GTs) over time and to detect changes in a socio-economically and racially diverse middle-aged cohort. Data from three waves of the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study were used to determine diet quality with group-based trajectory modeling (GBTM). Three quality indices-the Healthy Eating Index (HEI), the Dietary Inflammatory Index (DII), and the Mean Adequacy Ratio (MAR)-were explored. The rate of change in quality over time was determined by mixed-effects regression analysis. Three diet quality GTs, low, middle, and high quality, were identified for each index and confirmed with spaghetti plots. Within each GT, only small changes in diet quality scores were observed, with improvements for the HEI and DII indices and a slight decline in MAR scores. Weighted kappa values revealed that the DII had better agreement with the HEI-2010 and MAR indices compared with the agreement between the HEI-2010 and MAR. Bayesian estimates revealed that the annualized rate of change in diet quality per person across the GTs was similar. There was minimal change in diet quality over time, regardless of the diet quality index used.

Association between dietary inflammatory potential and mortality after cancer diagnosis in the Women's Health Initiative

BACKGROUND

Chronic inflammation is implicated in cancer prognosis and can be modulated by diet. We examined associations between post-diagnosis dietary inflammatory potential and mortality outcomes among post-menopausal women diagnosed with cancer in the Women's Health Initiative (WHI).

METHODS

Energy-adjusted dietary inflammatory index scores (E-DII) were calculated from dietary and supplemental intake data collected on the first food frequency questionnaire following the diagnosis of primary invasive cancer for 3434 women in the WHI. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CIs) for risk of death from any cause, cancer, cardiovascular disease (CVD) and other causes by post-diagnosis quartiles of E-DII. Subgroup analyses by cancer stage and grade were performed.

RESULTS

There were 1156 deaths after a median 13 years of follow-up from the date of a cancer diagnosis. In the multivariable-adjusted analyses, a more anti-inflammatory diet plus supplements after cancer diagnosis was associated with lower all-cause mortality, cancer mortality, CVD mortality and mortality from other causes with HRsQ1vs.Q4 ranging from 0.47 to 0.68 (all P-trends < 0.05). Associations were stronger for cancers diagnosed at more distant stages or moderately differentiated grades.

CONCLUSION

A more anti-inflammatory diet plus supplements after a cancer diagnosis may improve survival for post-menopausal cancer survivors.

Change in the inflammatory potential of diet over 10 years and subsequent mortality: the Multiethnic Cohort Study

Dietary inflammatory potential assessed by the Dietary Inflammatory Index (DII®) has been associated with health outcomes. However, longitudinal changes in the DII in relation to health outcomes rarely have been studied. This study aimed to examine change in the DII score over 10 years and its association with subsequent mortality in the Multiethnic Cohort. The analysis included 56 263 African American, Japanese American, Latino, Native Hawaiian and White participants who completed baseline (45-75 years) and 10-year follow-up surveys, including a FFQ. Mean energy-adjusted DII (E-DII) decreased over 10 years in men (from -0·85 to -1·61) and women (from -1·80 to -2·47), reflecting changes towards a more anti-inflammatory diet. During an average follow-up of 13·0 years, 16 363 deaths were identified. In multivariable Cox models, compared with anti-inflammatory stable individuals, risk of all-cause mortality was increased with pro-inflammatory change in men (hazard ratio (HR) = 1·13, 95 % CI 1·03, 1·23) and women (HR = 1·22, 95 % CI 1·13, 1·32). Per one-point increase in E-DII score over time, HR was 1·02 (95 % CI 1·00, 1·03) for men and 1·06 (95 % CI 1·04, 1·07) for women (P for heterogeneity < 0·001). While no heterogeneity by race and ethnicity was observed for men, the increased risk per one-point increase among women was stronger in non-Whites than in Whites (P for heterogeneity = 0·004). Our findings suggest that a change towards a more pro-inflammatory diet is associated with an increased risk of mortality both in men and women, and that the association is stronger in women, especially non-White women, than in men.

Association between dietary inflammation and erectile dysfunction among US adults: A cross-sectional analysis of the National Health and Nutrition Examination Survey 2001-2004

BACKGROUND

Although chronic low-grade inflammation has been linked to the development of erectile dysfunction (ED), the association between pro-inflammatory diets and ED is unclear. The dietary inflammation index (DII) is a novel method to quantify the inflammatory potential of a diet.

OBJECTIVE

Our objective was to investigate the association between the DII and ED among US males.

DESIGN

This cross-sectional study included 3,693 males 20-85 year of age from the National Health and Nutrition Examination Survey (NHANES) 2001-2004. Multivariable-adjusted logistic regression models were used to assess the association between the DII and ED. All analyses accounted for the complex sampling design.

RESULTS

The mean ± SE of the DII was 0.8 ± 0.1 and 0.4 ± 0.1 among participants with and without ED, respectively. After adjusting for age, race/ethnicity, education, smoking status, physical activity, drinking status, hypertension, diabetes, cardiovascular disease, hypercholesterolemia, BMI, and eGFR, the DII score was associated with ED (odds ratio 1.12; 95% CI: 1.04-1.19). Moreover, this association was also stable in our subgroup analysis or sensitivity analyses.

CONCLUSION

Dietary inflammatory potential, as estimated by the DII score, is positively associated with ED among US males.

Diet-Driven Inflammation and Insulinemia and Risk of Interval Breast Cancer

Interval breast cancers (IBCs) emerge after a non-suspicious mammogram and before the patient's next scheduled screen. Risk factors associated with IBC have not been identified. This study evaluated if the empirical dietary inflammatory pattern (EDIP) or empirical dietary index for hyperinsulinemia (EDIH) scores are associated with IBC compared to screen-detected breast cancer. Data were from women 50-79 years-old in the Women's Health Initiative cohort who completed food frequency questionnaires at baseline (1993-98) and were followed through March 31, 2019 for breast cancer detection. Women were identified as having either IBC diagnosed within 1-year after their last negative screening mammogram (N = 317) or screen-detected breast cancer (N = 1,928). Multivariable-adjusted logistic regression analyses were used to estimate odds ratios for risk of IBC compared to screen-detected cancer in dietary index tertiles. No associations were observed between EDIP or EDIH and IBC. Odds ratios comparing the highest to the lowest dietary index tertile were 1.08; 95%CI, 0.78-1.48 for EDIP and 0.92; 95%CI, 0.67-1.27 for EDIH. The null associations persisted when stratified by BMI categories. Findings suggest that diet-driven inflammation or insulinemia may not be substantially associated with IBC risk among postmenopausal women. Future studies are warranted to identify modifiable factors for IBC prevention.

The Dietary Inflammatory Index and asthma burden in children: A latent class analysis

INTRODUCTION

Unbalanced dietary intake has been increasingly recognized as an important modifiable risk factor for asthma. In this study, we assessed whether a pro-inflammatory diet is associated with higher asthma burden in three steps: (1) identification of asthma latent classes (LC) based on symptoms, indoor exposures, and pulmonary function; (2) identification of risk factors associated with LC membership; and (3) estimation of the probabilities of LC membership with variation in DII.

METHODS

A cross-sectional study on 415 children aged 5-14 years (266 with persistent asthma and 149 controls). LC analysis was performed in asthmatic children. The DII was calculated based on a semiquantitative food frequency questionnaire. Elastic net logistic regression was used to investigate whether increasing DII was associated with worse asthma burden.

RESULTS

Two LCs were identified. Children in Class 1, "high burden," had higher symptom burden and worse lung function. Children in Class 2, "low burden," had lower symptom burden and less impaired lung function but were more subject to indoor exposures. DII was the only risk factor significantly associated with Class 1 membership. As the DII increased (from -4.0 to +4.0), the probability of Class 1 membership increased from 32% to 65% when compared with control group, whereas it increased from 41% to 72% when compared with Class 2.

CONCLUSIONS

We identified two phenotypes of persistent asthma associated with different disease burden linked to indoor exposures. An increasing DII was associated with high-burden asthma, providing further evidence about the role of a pro-inflammatory diet in asthma morbidity.

Dietary Patterns of Insulinemia, Inflammation and Glycemia, and Pancreatic Cancer Risk: Findings from the Women's Health Initiative

BACKGROUND

Pancreatic cancer risk is increasing in countries with high consumption of Western dietary patterns and rising obesity rates. We examined the hypothesis that specific dietary patterns reflecting hyperinsulinemia (empirical dietary index for hyperinsulinemia; EDIH), systemic inflammation (empirical dietary inflammatory pattern; EDIP), and postprandial glycemia [glycemic index (GI); glycemic load (GL)] are associated with pancreatic cancer risk, including the potential modifying role of type 2 diabetes (T2D) and body mass index (BMI).

METHODS

We calculated dietary scores from baseline (1993-1998) food frequency questionnaires among 129,241 women, 50-79 years-old in the Women's Health Initiative. We used multivariable-adjusted Cox regression to estimate HRs and 95% confidence intervals (95% CI) for pancreatic cancer risk.

RESULTS

During a median 19.9 years of follow-up, 850 pancreatic cancer cases were diagnosed. We observed no association between dietary scores and pancreatic cancer risk overall. However, risk was elevated among participants with longstanding T2D (present >3 years before pancreatic cancer diagnosis) for EDIH. For each 1 SD increment in dietary score, the HRs (95% CIs) were: EDIH, 1.33 (1.06-1.66); EDIP, 1.26 (0.98-1.63); GI, 1.26 (0.96-1.67); and GL, 1.23 (0.96-1.57); although interactions were not significant (all P _interaction >0.05). Separately, we observed inverse associations between GI [0.86 (0.76-0.96), P _interaction = 0.0068] and GL [0.83 (0.73-0.93), P _interaction = 0.0075], with pancreatic cancer risk among normal-weight women.

CONCLUSIONS

We observed no overall association between the dietary patterns evaluated and pancreatic cancer risk, although women with T2D appeared to have greater cancer risk.

IMPACT

The elevated risk for hyperinsulinemic diets among women with longstanding T2D and the inverse association among normal-weight women warrant further examination.

Dietary Patterns, Asthma, and Lung Function in the Hispanic Community Health Study/Study of Latinos

Rationale: Dietary patterns may alter immune responses and increase asthma risk or affect lung function.Objectives: To examine whether a proinflammatory diet (assessed by the energy-adjusted Dietary Inflammatory Index [E-DII]) or high dietary quality (assessed by the Alternative Healthy Eating Index [AHEI-2010]) are associated with current asthma, current asthma symptoms, and lung function in Hispanic adults.Methods: This was a cross-sectional study of 12,687 adults aged 18 to 76 years who participated in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). The E-DII and AHEI-2010 were calculated based on two 24-hour dietary recalls. Logistic or linear regression was used for the multivariable analysis of E-DII or AHEI-2010 scores and current asthma, asthma symptoms, and lung function measures, adjusting for age, sex, annual household income, study center, Hispanic/Latino background, smoking status, and other covariates.Results: A higher E-DII score was associated with current asthma (odds ratio [OR] for quartile 4 vs. 1, 1.35; 95% confidence interval [CI], 0.97-1.90) and asthma symptoms (OR for quartile 4 vs. 1, 1.42; 95% CI, 1.12-1.81). The AHEI-2010 score was not associated with current asthma or asthma symptoms. Among adults without asthma, a higher E-DII score was associated with lower forced expiratory volume in 1 second (FEV₁) and forced vital capacity (FVC), and a higher AHEI-2010 score was associated with higher FEV₁ and FVC.Conclusions: Our findings suggest that a proinflammatory diet increases the risk of asthma and asthma symptoms in Hispanic adults. An antiinflammatory diet (indicated by a lower E-DII or a higher AHEI-2010 score) may positively influence lung function in Hispanic adults without asthma.

Changes in Dietary Inflammatory Index Patterns with Weight Loss in Women: A Randomized Controlled Trial

Dietary composition can influence systemic inflammation; higher levels of circulating inflammatory biomarkers are associated with increased risk of breast and other cancers. A total of 438 overweight/obese, healthy, postmenopausal women were randomized to a caloric-restriction diet (goal: 10% weight-loss), aerobic-exercise (225 min/week moderate-to-vigorous activity), combined diet+exercise, or control. Dietary inflammatory index (DII) and energy-adjusted (E-DII) scores were derived from food frequency questionnaires (FFQ) and could be calculated for 365 participants with complete FFQs at baseline and 12 months. Changes from baseline to 12 months in E-DII scores in the intervention arms versus controls were analyzed using generalized estimating equations, adjusted for confounders. We examined associations between changes in previously measured biomarkers and E-DII at 12 months. Participants randomized to diet and diet+exercise arms had greater reductions in E-DII (-104.4% and -84.4%), versus controls (-34.8%, both P < 0.001). Weight change had a more marked effect than E-DII change on biomarkers at 12-months; associations between E-DII and biomarker changes were reduced after adjustment by weight change. Changes in E-DII at 12 months, adjusted for weight change, were negatively associated with changes in ghrelin [r = -0.19; P = 0.05 (diet), r = -0.29; P = 0.02 (diet+exercise)], and positively with VEGF [r = 0.22; P = 0.03 (diet+exercise)], and red blood cell counts [r = 0.30; P = 0.004 (exercise)]. C-reactive protein (CRP) and IL6 levels were not associated with E-DII changes at 12 months. In conclusion, a behavior change of low-calorie, low-fat diet significantly reduces dietary inflammatory potential, modulating biomarkers that are associated with tumorigenesis, such as VEGF, but not CRP or IL6. PREVENTION RELEVANCE: Diets high in saturated fats and low in fruit and vegetable intake are associated with increased inflammation, which increases cancer risk. This study showed that changes in diet quality had effects on factors associated with cancer; however, the majority of beneficial effects were associated with weight loss rather than diet quality.

Dietary inflammatory index and incidence of and death from primary liver cancer: A prospective study of 103,902 American adults

Chronic inflammation plays an important role in primary liver cancer (PLC) etiology and can be influenced by dietary habits. No prospective study has investigated the association of dietary inflammatory index (DII) with PLC incidence and mortality. Therefore, we used prospective data from the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial to fill this gap. The DII was calculated from a validated 137-item food frequency questionnaire in a cohort of 103,902 individuals. Cox regression was used to estimate hazard ratios (HRs) for PLC incidence, and competing risk regression was used to estimate subdistribution HRs (SHRs) for PLC mortality. Restricted cubic spline regression was employed to identify the potential dose-response pattern. A total of 120 PLC cases and 102 PLC deaths were observed during follow-up. Higher DII scores from food and supplement were found to be associated with higher risks of developing PLC (HR_{Tertile 3 vs. 1} 2.05; 95% confidence interval [CI] 1.23-3.41) and death from this disease (SHR_{Tertile 3 vs. 1} 1.97; 95% CI 1.13-3.41). Similar results were obtained for DII score from food only. A nonlinear dose-response pattern was identified for the aforementioned associations (all p_nonlinearity  < 0.05). Overall, a more pro-inflammatory diet, as suggested by higher DII scores, is associated with higher risks of PLC incidence and mortality. These findings indicate that encouraging intake of more anti-inflammatory dietary components and reducing intake of pro-inflammatory components represent an attractive strategy to reduce PLC incidence and mortality.

Absence of association between inflammatory dietary pattern and low trauma fractures: Results of the French cohort NutriNet-Santé

INTRODUCTION

The aim of our study was to assess the association between the Alternate Dietary Inflammatory Index (ADII) and the risk of fracture in a French cohort of women and men older than 50 years.

METHODS

A total of 15,096 participants were included from the French NutriNet-Santé cohort. The ADII score was calculated at inclusion. Incident low trauma fractures were retrospectively self-reported by participants on a specific additional questionnaire. Multivariate hazard ratio obtained from Cox proportional hazard regression models were used to characterize an association between ADII (in quartiles) and incident low trauma fractures.

RESULTS

In all, 12,046 participants (7607 (63.2%) women and 4439 (36.8%) men) were included in our study. For fractures, 806 (10.6%) and 191 (4.3%) low trauma fractures were recorded respectively in women and in men. Mean ADII was -1.23 (±3.13) for women and -0.87 (±3.64) for men. No association was detected between the ADII score and the risk of vertebral fracture (P=0.21), major osteoporotic fracture (P=0.93) and any low trauma fracture (P=0.72) in women nor in men (P=0.06 for major fracture and P=0.10 for low trauma fracture) after adjustment for sociodemographic, lifestyle variables and for bone treatments.

CONCLUSION

This study in postmenopausal women and men older than 50 years from the general population did not show any association between inflammatory dietary pattern measured using the ADII and the risk of incident low trauma fracture.

Education and lifestyle predict change in dietary patterns and diet quality of adults 55 years and over

Background

Diet is a key risk factor for chronic disease, and an increasing concern among older adults. We aim to examine the changes in dietary patterns using principal component analysis and a diet quality index among older adults and examine the predictors of dietary change over a 4 year period.

Methods

Data was obtained via a postal survey in a prospective cohort, the Wellbeing Eating and Exercise for a Long Life (WELL) study. Australian adults aged 55 years and over (n = 1005 men and n = 1106 women) completed a food frequency at three time points and provided self-reported personal characteristics. Principal component analysis was used to assess dietary patterns and diet quality was assessed using the 2013 Revised Dietary Guideline Index. The relationships between predictors and change in dietary patterns were assessed by multiple linear regression.

Results

Two dietary patterns were consistently identified in men and women at three time points over 4 years. One was characterised by vegetables, fruit and white meat, and the other was characterised by red and processed meat and processed foods. Reduced consumption of key food groups within the principal component analysis-determined dietary patterns was observed. An increase in diet quality over 4 years was observed in men only. Reported higher education levels and favourable lifestyle characteristics, including not smoking and physical activity, at baseline predicted an increase in healthier dietary patterns over 4 years.

Conclusions

There was stability in the main dietary patterns identified over time, however participants reported an overall decrease in the frequency of consumption of key food groups. Compliance with the Australian Dietary Guidelines remained poor and therefore targeting this population in nutritional initiatives is important. Design of nutrition promotion for older adults need to consider those with lower socioeconomic status, as having a lower level of education was a predictor of poorer dietary patterns. It is important to consider how nutrition behaviours can be targeted alongside other lifestyle behaviours, such as smoking and inadequate physical activity to improve health.

The inflammatory potential of diet in determining cancer risk; A prospective investigation of two dietary pattern scores

Purpose

Inflammation-related mechanisms may contribute to the link between diet and cancer. We sought to investigate the inflammatory impact of diet on cancer risk using the Dietary inflammatory index (DII) and an adapted Mediterranean diet score (MDS).

Methods

This population-based, prospective cohort study used self-reported dietary data from the Västerbotten Intervention Programme, including 100,881 participants, of whom 35,393 had repeated measures. Associations between dietary patterns and cancer risk were evaluated using Cox proportional hazards regression. We also used restricted cubic splines to test for potential non-linear associations.

Results

A total of 9,250 incident cancer cases were diagnosed during a median follow-up of 15 years. The two dietary patterns were moderately correlated to each other and had similar associations with cancer risk, predominantly lung cancer in men (DII per tertile decrease: Hazard ratio (HR) 0.81 (0.66–0.99), MDS per tertile increase: HR 0.86 (0.72–1.03)), and gastric cancer in men (DII: 0.73 (0.53–0.99), MDS: 0.73 (0.56–0.96)). Associations were, in general, found to be linear. We found no longitudinal association between 10-year change in diet and cancer risk.

Conclusion

We confirm small, but consistent and statistically significant associations between a more anti-inflammatory or healthier diet and reduced risk of cancer, including a lower risk of lung and gastric cancer in men. The dietary indexes produced similar associations with respect to the risk of cancer.

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.

Secular trends in Dietary Inflammatory Index among adults in the United States, 1999-2014

OBJECTIVE

The objective of this study was to evaluate secular trends in Dietary Inflammatory Index (DII) scores in the United States between 1999 and 2014.

METHODS

Data from adults over 19 years from the 1999 to 2014 National Health and Nutrition Examination Survey (N = 39,191) were used. DII scores, at each 2-year cycle, were evaluated from a 24-h recall, including 26 food parameters for DII calculation. Analyses were conducted in 2018.

RESULTS

For the entire sample, there was a quadratic trend (P_trend < 0.001), with the DII scores peaking in 2003-2004, and then decreasing during the cycles from 2005 to 2014. Similar quadratic trends (P_trend < 0.001) were observed by age, gender, race-ethnicity, and education.

CONCLUSION

Males, non-Hispanic Blacks, younger adults, and those with less education adults had the highest DII scores (i.e., indicating the greatest inflammatory potential). The overall DII scores of the US population showed a quadratic trend from 1999 to 2014. Continued monitoring of DII changes is needed to better understand changes in the inflammatory potential of diet of American adults, and how they relate to changes in the risk of chronic disease.

The Dietary Inflammatory Index and All-Cause, Cardiovascular Disease, and Cancer Mortality in the Multiethnic Cohort Study

Diet quality based on inflammatory potential, assessed by the Dietary Inflammatory Index (DII®), has been related to mortality, but studies from racially/ethnically diverse populations are scarce. Using data from the Multiethnic Cohort Study in Hawaii and California, we investigated the association of the DII with all-cause, cardiovascular disease (CVD) and cancer mortality, both overall and by race/ethnicity. The analysis included 150,405 African Americans, Native Hawaiians, Japanese Americans, Latinos, and Whites aged 45⁻75 years, with 47,436 deaths during an average follow-up of 18.2 ± 4.9 years. In multivariable-adjusted Cox models, the hazard ratios (95% confidence intervals) for the highest vs. lowest quintile of the DII in men and women were 1.15 (1.09⁻1.21) and 1.22 (1.14⁻1.28) for all-cause, 1.13 (1.03⁻1.23) and 1.29 (1.17⁻1.42) for CVD, and 1.10 (1.00⁻1.21) and 1.13 (1.02⁻1.26) for cancer mortality. In men, an increased risk of all-cause mortality with higher DII scores was found in all racial/ethnic groups except for Native Hawaiians (P for heterogeneity < 0.001). Similarly, in women, an increased risk of CVD mortality was found in the four racial/ethnic groups, but not in Native Hawaiians. These findings support the association of a pro-inflammatory diet with a higher risk of mortality and suggest the association may vary by race/ethnicity.

Dietary inflammatory index and academic performance in children

Objective

The main aim of the present study was to examine the association between the Dietary Inflammatory Index (DII®) and academic performance in children.

Design

School-based cross-sectional study. The DII was calculated based on dietary information obtained from a single 24h dietary recall. Academic performance was assessed by school records provided by the administrative services (i.e. Maths and Language).

Setting

Porto area (Portugal).

Subjects

A total of 524 children (277 girls) aged 11·56 (sd 0·86) years.

Results

The DII was associated with academic indicators (standardized β values ranging from −0·121 to −0·087; all P<0·05). Significant differences were found between quartiles of the DII (P<0·05); children in the fourth quartile had significantly lower scores in all academic indicators compared with children in the first quartile (score differences ranging from −0·377 to −0·292) after adjustment for potential confounders.

Conclusions

The inflammatory potential of diet may negatively influence academic performance. Children should avoid the consumption of a pro-inflammatory diet and adhere to a more anti-inflammatory diet to achieve academic benefits.

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.

An Empirical Dietary Inflammatory Pattern Score Is Associated with Circulating Inflammatory Biomarkers in a Multi-Ethnic Population of Postmenopausal Women in the United States

BACKGROUND

The empirical dietary inflammatory pattern (EDIP) score has been associated with concentrations of circulating inflammatory biomarkers in European Americans.

OBJECTIVE

We used the EDIP score, a weighted sum of 18 food groups that characterizes dietary inflammatory potential based on circulating concentrations of inflammatory biomarkers, to test the hypothesis that a pro-inflammatory dietary pattern is associated with inflammatory biomarker concentrations in a US multi-ethnic population.

METHODS

In this cross-sectional study, we calculated EDIP scores using baseline food frequency questionnaire data from 31,472 women, aged 50-79 y, in the Women's Health Initiative observational study and clinical trials. Circulating biomarkers outcomes at baseline were: C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor (TNF)-α, TNF receptor (TNFR) 1 and 2, and adiponectin. We used multivariable-adjusted linear regression analyses to estimate absolute concentrations and relative differences in biomarker concentrations, overall and in subgroups of race/ethnicity and BMI (body mass index) categories.

RESULTS

Independent of energy intake, BMI, physical activity, and other potential confounding variables, higher EDIP scores were significantly associated with higher (lower for adiponectin) absolute concentrations of all 6 biomarkers. On the relative scale, the percentage of difference in the concentration of biomarkers, among women in the highest compared to the lowest EDIP quintile, was: CRP, +13% (P-trend < 0.0001); IL-6, +15% (P-trend < 0.0001); TNF-α, +7% (P-trend = 0.0007); TNFR1, +4% (P-trend = 0.0009); TNFR2, +5% (P-trend < 0.0001); and adiponectin, -13% (P-trend <0.0001). These associations differed by racial/ethnic groups and by BMI categories. Whereas the absolute biomarker concentrations were lower among European-American women and among normal-weight women, the associations with diet were stronger than among women of African-American or Hispanic/Latino origin and among overweight and obese women.

CONCLUSIONS

Findings demonstrate the successful replication of an empirical hypothesis-oriented a posteriori dietary pattern score in a multi-ethnic population of postmenopausal women, with subgroup differences by race/ethnicity and body weight. Future research needs to apply the score in non-US populations.

Improvement in dietary inflammatory index score after 6-month dietary intervention is associated with reduction in interleukin-6 in patients with coronary heart disease: The AUSMED heart trial

The Dietary Inflammatory Index (DII) was designed to measure the inflammatory potential of one's diet. Evidence from observational studies supports that a higher (ie, more pro-inflammatory) DII score is associated with inflammation and cardiometabolic diseases. We hypothesized that reduction in DII score would improve inflammatory cytokines. To test this hypothesis, we assessed data from a dietary intervention trial in patients with diagnosed coronary heart disease (CHD) to determine whether reduction in DII scores through healthy diets is linked to improvement in inflammatory and related cardiometabolic risk markers. Participants (n = 65, 83% male) were randomized to a Mediterranean diet or low-fat diet intervention for 6-months. Anthropometry, body composition and blood markers were measured and DII scores were calculated from 7-day food diaries. After 6-months, in participants who completed the intervention (n = 56), reduction in DII score correlated significantly with reduction in high sensitivity interleukin-6 (hs-IL-6) (r = 0.34, 95% CI 0.05, 0.56) and triglycerides (r = -0.30, 95% CI -0.51, -0.06) but not with C-reactive protein, adiponectin, glucose, body composition or anthropometry. The adjusted mean difference in hs-IL-6 and triglycerides between the highest and lowest tertiles of DII improvement was -0.47 pg/mL (95% CI 0.41, 1.10) and +0.30 mmol/L (95% CI 1.06, 1.59), respectively. The present study found that improvement in DII score through healthy diet intervention was linked with reduced levels of hs-IL-6, but also increased triglycerides, in adult Australian patients with CHD. Future research is warranted to investigate the impact of change in DII on cardiometabolic risk markers in larger cohorts, other disease populations or healthy subjects and with longer-term follow up.

Randomization to 6-month Mediterranean diet compared with a low-fat diet leads to improvement in Dietary Inflammatory Index scores in patients with coronary heart disease: the AUSMED Heart Trial

A higher dietary inflammatory index (DII®) score is associated with inflammation and incidence of coronary heart disease (CHD). We hypothesized that a Mediterranean diet (MedDiet) intervention would reduce DII score. We assessed dietary data from a randomized controlled trial comparing 6-month MedDiet versus low-fat diet intervention, in patients with CHD. We aimed to determine the DII scores of the prescribed diets' model meal plans, followed by whether dietary intervention led to lower (i.e., more anti-inflammatory) DII scores and consequently lower high sensitivity C-reactive protein (hs-CRP) and interleukin-6 (hs-IL-6). DII scores were calculated from 7-day food diaries. The MedDiet meal plan had a markedly lower DII score than the low-fat diet meal plan (-4.55 vs. -0.33, respectively). In 56 participants who completed the trial (84% male, mean age 62 ± 9 years), the MedDiet group significantly reduced DII scores at 6 months (n = 27; -0.40 ± 3.14 to -1.74 ± 2.81, P = .008) and the low-fat diet group did not change (n = 29; -0.17 ± 2.27 to 0.05 ± 1.89, P = .65). There was a significant post-intervention adjusted difference in DII score between groups (compared to low-fat, MedDiet decreased by -1.69 DII points; P = .004). When compared to the low-fat diet, the MedDiet non-significantly reduced hs-IL-6 (-0.32 pg/mL, P = .29) and increased hs-CRP (+0.09 mg/L, P = .84). These findings demonstrated that MedDiet intervention significantly reduced DII scores compared to a low-fat diet. However, in this small cohort of patients with CHD this did not translate to a significant improvement in measured inflammatory markers. The effect of improvement in DII with MedDiet should be tested in larger intervention trials and observational cohorts.

The Dietary Inflammatory Index is associated with elevated white blood cell counts in the National Health and Nutrition Examination Survey

White blood cells (WBCs) are considered a reliable biomarker of inflammation. Elevations in both WBCs and pro-inflammatory cytokines are associated with several chronic conditions. Diet is a strong moderator of inflammation and WBCs. The purpose of this study was to examine the association between the Dietary Inflammatory Index (DII®) and WBCs using data from the United States National Health and Nutrition Examination Survey (NHANES). NHANES is a cross-sectional study that occurs in two-year cycles. Respondents from five cycles (n = 26,046) with available data on diet (collected through a single 24-h dietary recall [24HR]) and WBCs (derived using the Coulter method) were included. The DII (theoretical range is about -8 to +8) was derived from the micro and macronutrients calculated from the 24HR. Linear regression models, using survey design procedures, were used to estimate adjusted mean WBC (i.e., total, lymphocytes, monocytes, and neutrophils) counts and percentages by DII quartiles. Among all participants no statistically significant difference in WBCs were observed when comparing DII quartile 4 (most pro-inflammatory) to quartile 1 (most anti-inflammatory). However, a one-unit increase in the DII was associated with a 0.028 (1000 per µL) increase in total WBCs (p = .01). Additionally, a 0.024 increase in neutrophils (p < .01) was observed for a one-unit increase in the DII. In the group of participants with normal body mass index (BMI, 18.5-24.9 kg/m²), those in DII quartile 4 had higher levels of total WBCs compared to subjects with normal BMI in DII quartile 1 (7.12 vs. 6.88, p = .01). Similar comparisons were observed for monocytes and neutrophils. However, these relationships were not observed for participants who were overweight or obese, which are pro-inflammatory conditions. Normal-weight individuals consuming more pro-inflammatory diets were more likely to have elevated WBCs. Because of its cross-sectional design, NHANES cannot inform directly on temporal relations, thus limiting causal inference. Future research is needed to examine the impact of anti-inflammatory diet adoption on lowering levels of WBCs, in addition to other inflammatory mediators.

Inflammatory potential of diet and risk of pancreatic cancer in the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial

Inflammation plays a central role in pancreatic cancer etiology and can be modulated by diet. We aimed to examine the association between the inflammatory potential of diet, assessed with the Dietary Inflammatory Index (DII®), and pancreatic cancer risk in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial prospective cohort. Our study included 101,449 participants aged 52-78 years at baseline who completed both baseline questionnaire and a diet history questionnaire. Energy-adjusted DII (E-DII) scores were computed based on food and supplement intake. Cox proportional hazards models and time dependent Cox models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) with participants in the lowest E-DII quintile (most anti-inflammatory scores) as referent. After a median 8.5 years of follow-up, 328 pancreatic cancer cases were identified. E-DII scores were not associated with pancreatic cancer risk in the multivariable model (HR_Q5vsQ1  = 0.94; 95% CI = 0.66-1.35; p-trend = 0.43). Time significantly modified the association (p-interaction = 0.01). During follow up <4 years, there was suggestive evidence of an inverse association between E-DII and pancreatic cancer (HR_Q5vsQ1  = 0.60; 95% CI = 0.35-1.02; p-trend = 0.20) while there was a significant positive trend in the follow up ≥4 years (HR_Q5vsQ1  = 1.31; 95% CI = 0.83-2.08; p-trend = 0.03). Similar results were observed for E-DII from food only. Our study does not support an association between inflammatory potential of diet and pancreatic cancer risk; however, heterogeneous results were obtained with different follow-up times. These divergent associations may result from the influences of undetected disease in the short-term.

Association between Post-Cancer Diagnosis Dietary Inflammatory Potential and Mortality among Invasive Breast Cancer Survivors in the Women's Health Initiative

Background: Inflammation is important in chronic disease and can be modulated by dietary exposures. Our aim was to examine whether the inflammatory potential of diet after cancer diagnosis, assessed using the dietary inflammatory index (DII), is associated with all-cause and cause-specific mortality among women diagnosed with invasive breast cancer in the Women's Health Initiative (WHI).Methods: Our analytic cohort included 2,150 postmenopausal women, ages 50 to 79 years at baseline, who developed invasive breast cancer during follow-up and completed a food frequency questionnaire (FFQ) on average 1.5 years after diagnosis. Women were followed from breast cancer diagnosis until death or the end of follow-up by October 2014. Energy-adjusted DII (E-DII) scores were calculated from food plus supplements using a nutrient-density approach. Cox proportional hazards models were fit to estimate multivariable-adjusted HRs and 95% confidence intervals (CIs) for all-cause, breast cancer-specific, and cardiovascular disease (CVD) mortality.Results: After a median 13.3 years of follow-up, 580 deaths from any cause occurred, including 212 breast cancer deaths and 103 CVD deaths. Lower (i.e., more anti-inflammatory) E-DII scores were associated with a lower risk of CVD mortality (HR_Q1VSQ4 = 0.44; 95% CI, 0.24-0.82; P_trend = 0.005), but not with breast cancer-specific mortality (HR_Q1VSQ4 = 0.96; 95% CI, 0.62-1.49; P_trend = 0.96) or all-cause mortality (HR_Q1VSQ4 = 0.82; 95% CI, 0.63-1.05; P_trend = 0.17).Conclusions: Consuming a more anti-inflammatory diet after breast cancer diagnosis may be a means for reducing risk of death from CVD.Impact: Survival after invasive breast cancer diagnosis may be improved by consumption of an anti-inflammatory diet. Cancer Epidemiol Biomarkers Prev; 27(4); 454-63. ©2018 AACR.

The association between an inflammatory diet and global cognitive function and incident dementia in older women: The Women's Health Initiative Memory Study

INTRODUCTION

The Mediterranean and Dietary Approaches to Stop Hypertension diets have been associated with lower dementia risk. We evaluated dietary inflammatory potential in relation to mild cognitive impairment (MCI)/dementia risk.

METHODS

Baseline food frequency questionnaires from n = 7085 women (aged 65-79 years) were used to calculate Dietary Inflammatory Index (DII) scores that were categorized into four groups. Cognitive function was evaluated annually, and MCI and all-cause dementia cases were adjudicated centrally. Mixed effect models evaluated cognitive decline on over time; Cox models evaluated the risk of MCI or dementia across DII groups.

RESULTS

Over an average of 9.7 years, there were 1081 incident cases of cognitive impairment. Higher DII scores were associated with greater cognitive decline and earlier onset of cognitive impairment. Adjusted hazard ratios (HRs) comparing lower (anti-inflammatory; group 1 referent) DII scores to the higher scores were group 2-HR: 1.01 (0.86-1.20); group 3-HR: 0.99 (0.82-1.18); and group 4-HR: 1.27 (1.06-1.52).

CONCLUSIONS

Diets with the highest pro-inflammatory potential were associated with higher risk of MCI or dementia.

Changes in the Inflammatory Potential of Diet Over Time and Risk of Colorectal Cancer in Postmenopausal Women

We examined the associations between changes in dietary inflammatory potential and risk of colorectal cancer (CRC) in 87,042 postmenopausal women recruited from 1993-1998 by the Women's Health Initiative, conducted in the United States. Food frequency questionnaire data were used to compute patterns of change in dietary inflammatory index (DII) scores and cumulative average DII scores over 3 years. Cox regression models were used to estimate hazard ratios for CRC risk. After a median of 16.2 years of follow-up, 1,038 CRC cases were diagnosed. DII changes were not substantially associated with overall CRC, but proximal colon cancer risk was higher in the proinflammatory-change DII group than in the antiinflammatory-stable DII group (hazard ratio = 1.32, 95% confidence interval: 1.01, 1.74). Among nonusers of nonsteroidal antiinflammatory drugs (NSAIDs) (Pinteraction = 0.055), the proinflammatory-stable DII group was at increased risk of overall CRC and proximal colon cancer. Also among nonusers of NSAIDs, risks of overall CRC, colon cancer, and proximal colon cancer were higher in the highest quintile compared with the lowest cumulative average DII quintile (65%, 61%, and 91% higher risk, respectively). Dietary changes toward, or a history of, proinflammatory diets are associated with an elevated risk of colon cancer, particularly for proximal colon cancer and among nonusers of NSAIDs.

The Dietary Inflammatory Index, shift work, and depression: Results from NHANES

OBJECTIVES

Abnormal physiology (e.g., inflammation), brought on by environmental exposures (e.g., diet or shift work [SW]), can affect numerous bodily systems, including the brain, and may be associated with depressive symptomatology. The study examined the associations between SW and depressive symptoms and diet-related inflammation (estimated by the Dietary Inflammatory Index [DII]) and depressive symptoms. Additionally, diet was examined as a mediator between SW and depressive symptoms.

METHOD

Data were obtained from the U.S. National Health and Nutrition Examination Survey (Centers for Disease Control and Prevention, 2013). SW data were based on self-report. Dietary data were collected using 24-hr dietary recalls for DII calculation. Depressive symptoms were defined using a cut-point of 10 (moderate) on the Patient Health Questionnaire-9 (PHQ-9). Logistic regression was used to estimate odds ratios and 95% confidence intervals (95% CI) for depressive symptoms by SW and DII quartiles.

RESULTS

DII scores were associated with depressive symptoms among women. Women in DII quartile 4 were 30% more likely to report depressive symptoms than women in quartile 1 (95% CI [1.00-1.68]). There was no association between symptoms and SW when using a PHQ-9 cut-point of 10. When using a cut-point of 5 (mild depressive symptoms), those working any form of SW were more likely to suffer from mild symptoms than day workers (odds ratio = 1.22; 95% CI [1.04-1.43]). There was some evidence for mediation by the DII between SW and depressive symptoms.

CONCLUSIONS

Future longitudinal studies should examine effects of reductions in inflammation through diet on depressive symptoms, especially among shift workers, to elucidate the role of diet on depression among these groups. (PsycINFO Database Record