Construct validation of the dietary inflammatory index among postmenopausal women

The Effects of the Dietary and Nutrient Intake on Gynecologic Cancers

The contribution of diet to cancer risk has been considered to be higher in advanced countries than in developing countries. In this paper, I review the current issues (a review of the relevant literature), and the effects of the dietary and nutrient intake on three types of gynecologic cancer (cervical, endometrial and ovarian cancers). In cervical cancer, the most important roles of diet/nutrition in relation to cancer are prophylaxis and countermeasures against human papillomavirus (HPV) infection. The main preventive and reductive factors of cervical cancer are antioxidants, such as vitamin A, C, D and E, carotenoids, vegetables and fruits. These antioxidants may have different abilities to intervene in the natural history of diseases associated with HPV infection. For endometrial cancer, the increase in peripheral estrogens as a result of the aromatization of androgens to estrogens in adipose tissue in obese women and insulin resistance are risk factors. Thus, we must mainly take care to avoid the continuous intake of fat energy and sugar. In ovarian cancer, the etiology has not been fully understood. To the best of our knowledge, the long-term consumption of pro-inflammatory foods, including saturated fat, carbohydrates and animal proteins is a risk factor. The intake of acrylamide is also a risk factor for both endometrial and ovarian cancer. Most papers have been epidemiological studies. Thus, further research using in vitro and in vivo approaches is needed to clarify the effects of the dietary and nutrient intake in detail.

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 risk of gynecological cancers: a systematic review and meta-analysis of observational studies

OBJECTIVE

There has been growing body of literatures showing that chronic inflammation might play an important role in cancer development. This meta-analysis aimed to assess the association between the dietary inflammation index (DII) score and gynecological cancers.

METHODS

A systematic search of PubMed, EMBASE and Web of Science up until October 20, 2018 was carried out to retrieve all related cohort and case-control studies. The summary risk assessments were pooled using random-effects models. The dose-response relationship was estimated by linear relationship model.

RESULTS

Twelve case-control studies (10,774 cases/15,958 controls) and six prospective cohort studies (330,363 participants/23,133 incident cases) were included in this meta-analysis. The pooled adjusted relative risk (RR) of gynecological cancers for the highest DII category compared to the lowest category was 1.38, (95% confidence intervals [CIs], 1.21-1.56, p<0.001]. A positive dose-response relationship was also noticed. Stratified by study design indicated that, the pooled RRs was significantly higher for case-control studies than cohort studies (p for interaction<0.001), for studies conducted among participants with body mass index (BMI) ≥25 kg/m² than participants with BMI <25 kg/m² (p for interaction=0.026), among participants with ovarian cancer and endometrial cancer than participants with breast cancer (p for interaction = 0.038). Meta-regression analysis further confirmed that study design significantly contributed to inter-study heterogeneity (p<0.001).

CONCLUSION

This meta-analysis suggests that elevated DII is independently associated with a higher risk of gynecological cancers, especially patients with ovarian cancer and endometrial cancer and among obese participants.

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

BACKGROUND:

We hypothesized a pro-inflammatory diet would be associated with higher prostate cancer (PC) risk.

METHODS:

We prospectively recruited incident PC cases (n=254) and controls (n=328) at the Durham Veteran Affairs, from 2007–2018. From a self-completed 61-item Food Frequency Questionnaire, we calculated dietary inflammatory index (DII®) scores with and without supplements. We examined the association between DII scores with and without supplements and overall PC risk using logistic regression and risk of low-grade PC (grade group 1) and high-grade PC (grade group 2–5) with multinomial logistic regression.

RESULTS:

Cases were more likely to be Black (58% vs. 42%), had higher PSA (6.4 vs. 0.8 ng/ml), lower BMI (29.1 vs. 30.6 kg/m²) and were older (64 vs. 62 years) versus controls (all p<0.01). Both black controls and cases had higher DII scores with and without supplements, though the DII scores with supplements in controls was not significant. On multivariable analysis, there were no associations between DII with or without supplements and overall PC risk (p-trend=0.14, p-trend=0.09, respectively) or low-grade PC (p-trend=0.72, p-trend=0.47, respectively). Higher DII scores with (p-trend=0.04) and without supplements (p =0.08) were associated with high-grade PC, though the association for DII without supplements was not significant.

CONCLUSIONS:

A pro-inflammatory diet was more common among Black men and associated with high-grade PC in our case-control study. The degree to which a pro-inflammatory diet contributes to PC race disparities warrants further study. If confirmed, studies should test whether a low inflammatory diet can prevent high-grade PC, particularly among Black men.

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.

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.

Adiposity does not modify the effect of the dietary inflammatory potential on type 2 diabetes incidence among a prospective cohort of men

Purpose

Inflammatory contributions from diet and adiposity may interact with respect to the development of type 2 diabetes mellitus (T2DM). We investigated the degree to which adiposity modified the association between dietary inflammatory potential and incident T2DM.

Methods

Data from 6,016 US men in the Aerobics Center Longitudinal Study who completed a 3-day diet record were used. The inflammatory potential of diet was characterized by the Dietary Inflammatory Index (DII®), and adiposity was assessed with body mass index, waist circumference, body fat percentage (BF) and waist-to-height ratio. Inverse probability weights were used in modified Poisson regression models to examine whether adiposity modifies the relationship between the DII and T2DM, while accounting for selection bias from participants who were lost to follow-up.

Results

There were 336 incident cases of T2DM after a mean follow-up of 6.5 years. DII scores were not significantly associated with T2DM incidence in multivariable models, but point estimates were consistently elevated across increasing DII quartiles compared to the most anti-inflammatory DII quartile. In the model that evaluated BF, the term for overall effect modification was significant (p = 0.02), but there was no evidence of effect modification on the multiplicative and additive scales when examined further. Effect modification was not present for any other adiposity measures.

Conclusions

We did not observe evidence that a pro-inflammatory diet, as measured by the DII, is associated with incidence of T2DM, nor evidence that adiposity modifies a potential relationship. Further investigation is needed in larger cohorts with longer follow-up.

Impact of a 12-month Inflammation Management Intervention on the Dietary Inflammatory Index, inflammation, and lipids

BACKGROUND AND AIMS

The objective of this study was to assess the feasibility (ability to recruit participants and develop the 12-month intervention), acceptability (retention of participants in the intervention), and impact on systemic inflammation and Dietary Inflammatory Index (DII®) scores over a 12-month DII-based intervention.

METHODS

Adults were recruited to participate in a self-selection trial (intervention: n = 61, in-person classes; control: n = 34, newsletters). Classes included participatory cooking and dietary recommendations focused on consuming a plant-based diet rich in anti-inflammatory foods (spices, vegetables, etc.). Changes in markers of inflammation, lipids, and DII were analyzed using general linear models with repeated measurements.

RESULTS

At 3 months, intervention participants had significantly lower DII scores (-2.66 ± 2.44) compared to controls (-0.38 ± 2.56) (p < 0.01); but not at 12 months (P = 0.10). The only biomarker to approach a significant group effect or group-by-time interaction was CRP (P = 0.11 for the group-by-time interaction). CRP decreased by -0.65 mg/L (95%CI = 0.10-1.20, P = 0.02) at 12 months in the intervention group; no significant decrease was seen for the control group. With both groups combined at 3 months, those with the greatest decrease/improvement in DII score (tertile 1) compared with those whose scores increased (tertile 3) had greater reductions in CRP (-1.09 vs. +0.52 mg/L, P = 0.04), total cholesterol (-9.38 vs. +12.02 mg/dL, P = 0.01), and LDL cholesterol (-11.99 vs. +7.16 mg/dL, P = 0.01).

CONCLUSIONS

Although the intervention group had reductions in DII and CRP, main inflammation and lipid outcomes did not differ between groups. Overall, those participants with the largest reduction in DII scores had the largest reductions in CRP and LDL and total cholesterol. Future interventions may need to have more components in place to support maintenance and continued reductions in the DII. CLINICALTRIALS.

GOV IDENTIFIER

NCT02382458.

Longitudinal associations between dietary inflammatory index and musculoskeletal health in community-dwelling older adults

BACKGROUND & AIMS

Aging is characterized by progressive decline in physiologic reserves and functions as well as prolonged inflammation, increasing susceptibility to disease. Diet plays an important role in maintaining health, and reducing morbidity and mortality, especially in older populations. This study was designed to determine prospective associations between dietary inflammatory index (DII®) scores and bone health, sarcopenia-related outcomes, falls risk and incident fractures in community-dwelling Australian older adults.

METHODS

A total of 1098 [51% male; age (mean ± SD) 63.0 ± 7.5 years] non-institutionalized older adults who participated in the Tasmanian Older Adult Cohort Study (TASOAC) at baseline, 768 at 5 years, and 566 at 10 years follow-up were included in this analysis. Baseline energy-adjusted DII (E-DII) scores were calculated using a validated Food Frequency Questionnaire. Changes in bone mineral density (BMD) and appendicular lean mass (ALM) were measured over ten years using dual-energy x-ray absorptiometry. Ten-year changes in hand grip, knee extensor and whole lower-limb muscle strength and quality were assessed by dynamometers and change in falls risk score using the Physical Profile Assessment (PPA). Incident fractures at any site and non-vertebral fractures over 10 years were self-reported.

RESULTS

The E-DII range was -3.48 to +3.23 in men and -3.80 to +2.74 in women. Higher E-DII score (indicating a more pro-inflammatory diet) was associated with lower total hip (B: -0.009; 95% CI: -0.017, 0.000) and lumbar spine BMD (B: -0.013; 95% CI: -0.024, -0.002), and higher falls risk score (B: 0.040; 95% CI: 0.002, 0.078) over 10 years in men. Women with higher E-DII scores had higher whole lower-limb muscle quality over 10 years (B: 0.109; 95% CI: 0.002, 0.215). For every unit increase in E-DII score, incident fracture rates increased by 9.0% in men (IRR: 1.090; 95% CI: 1.011, 1.175) and decreased by 12.2% in women (IRR: 0.878; 95% CI: 0.800, 0.964) in a fully adjusted model.

CONCLUSION

Higher E-DII scores were associated with lower bone density, higher falls risk, and increased incidence of fractures in community-dwelling older men, but decreased fracture incidence in women, over 10 years. This suggests pro-inflammatory diets may be more detrimental to musculoskeletal health in older men than in women. Additional studies are warranted to elucidate these sex differences.

Dietary inflammatory index and cancer risk in the elderly: A pooled-analysis of Italian case-control studies

OBJECTIVES

The aim of this study was to evaluate whether the association between the inflammatory potential of one's diet and cancer risk varies across age groups in a population characterized by widespread use of the Mediterranean diet.

METHODS

We analyzed data from a network of case-control studies conducted in Italy between 1991 and 2014. The studies included cancers of the oral cavity (n = 509), pharynx (n = 436), nasopharynx (n = 198), larynx (n = 459), esophagus (n = 304), stomach (n = 230), colon (n = 1225), rectum (n = 728), liver (n = 184), pancreas (n = 326), breast (n = 2569), endometrium (n = 454), ovary (n = 1031), prostate (n = 1294), kidney (n = 767), and bladder (n = 690). Controls were 13 563 patients hospitalized for acute, non-neoplastic conditions. Dietary inflammatory index (DII) scores were computed based on 31 food parameters assessed using a reproducible and validated food frequency questionnaire. Odds ratios were estimated through logistic regression models adjusting for recognized confounding factors.

RESULTS

The DII increased with age, with lower scores among men than women, in individuals located in northern rather than in central or southern Italy, and in controls more than in cancer cases. After adjustment for cancer-specific potential confounders, an increasing DII score was directly associated with cancer risk for all considered cancer sites, except for liver and endometrium. Although the DII level varied across age groups, no heterogeneity in cancer risk emerged for any of the considered cancer sites.

CONCLUSIONS

In the Italian population, DII scores were higher in elderly than in middle-aged individuals. Although not directly affecting cancer risk, this finding may have important implications for the older population because elevated DII scores, indicating a proinflammatory diet, also have been associated with frailty.

Inflammation as a unique marker of suicide ideation distinct from depression syndrome among U.S. adults

BACKGROUND

Recent evidence suggests that pro-inflammatory states may be independently associated with the risk of suicidality, above and beyond depression. This study assesses whether four indicators of inflammation, circulating levels of C-reactive protein (CRP), white blood cell (WBC) count and immunoglobulin E (IgE), and dietary inflammatory potential, measured using the Dietary Inflammatory Index® (DII), distinguish suicidal ideation (SI) from major depression (MD).

METHODS

Data come from multiple cycles of the US National Health and Nutrition Examination Survey (NCRP&WBC = 13,912; NDII = 17,076; NIgE = 4,060). MD was measured using the Patient Health Questionnaire-9 (PHQ-9); SI was indicated by the last item of the PHQ-9. To assess SI independent from MD, participants were classified into four categories: SI with MD, SI without MD, MD without SI, and neither MD nor SI. Regression models were used to assess the relationship between indicators of inflammation and SI with and without MD.

RESULTS

None of the inflammatory indicators were able to distinguish SI status among MD cases. DII was associated with SI among individuals without MD. CRP, DII, and WBC were associated with MD. No associations were found for IgE.

LIMITATIONS

Cross-section data prevent drawing causal conclusions. Underreporting of MD and suicidal ideation and measurement of habitual diet using 24 h dietary recalls are also weaknesses.

CONCLUSION

Dietary inflammatory potential was associated with suicide ideation among US adults with and without depression. Diet may play a role in suicide ideation and more empirical evidence is needed to determine whether nutritional protocols could aid in the treatment of suicidal behaviors. Findings did not support inflammatory factors having a relationship with suicide ideation distinct from depression.

Dietary Inflammatory Index Positively Associated With High-Sensitivity C-Reactive Protein Level in Japanese From NIPPON DATA2010

Background

It has been reported that chronic inflammation may play an important role in the pathogenesis of several serious diseases and could be modulated by diet. Recently, the Dietary Inflammatory Index (DII^®) was developed to assess the inflammatory potential of the overall diet. The DII has been reported as relevant to various diseases but has not been validated in Japanese. Thus, in the present study, we analyzed the relationship between DII scores and high-sensitivity C-reactive protein (hs-CRP) levels in a Japanese population.

Methods

Data of the National Integrated Project for Prospective Observation of Non-communicable Disease and its Trends in the Aged 2010 (NIPPON DATA2010), which contained 2,898 participants aged 20 years or older from the National Health and Nutrition Survey of Japan (NHNS2010), were analyzed. Nutrient intakes derived from 1-day semi-weighing dietary records were used to calculate DII scores. Energy was adjusted using the residual method. Levels of hs-CRP were evaluated using nephelometric immunoassay. Multiple linear regression analyses were performed.

Results

After adjusting for age, sex, smoking status, BMI, and physical activity, a significant association was observed between DII scores and log(CRP+1) (standard regression coefficient = 0.05, P < 0.01). Although it was not statistically significant, the positive association was consistently observed in almost all age-sex subgroups and the non-smoker subgroup.

Conclusions

The current study confirmed that DII score was positively associated with hs-CRP in Japanese.

Association between dietary inflammatory index, and cause-specific mortality in the MONICA/KORA Augsburg Cohort Study

Background

Chronic diseases such as cancer and cardiovascular diseases (CVDs) are well-established causes of disability and premature death. Dietary components have been implicated in the etiology of these chronic diseases.

Methods

We examined the ability of the Dietary Inflammatory Index (DIITM) to predict all-cause, coronary heart disease (CHD), CVD and cancer mortality and incident CHD in the MONICA-KORA Cohort Studies. DII scores were computed from baseline 7-day dietary records in this cohort of 1297 men, who were aged 45-64 years when enrolled. During the follow-up period, 551 total (155 CHD, 244 CVD and 175 cancer-related deaths) and 213 validated incident CHD events were identified through mortality record linkage and active follow-up. Spearman correlation coefficients were calculated between DII scores and the inflammatory marker C-reactive protein (CRP). Cox proportional hazards regression was used to estimate hazard ratios (HR) for the endpoints described above.

Results

DII scores were significantly positively correlated with CRP (P value <0.0001). Positive associations were noted between DII and all-cause mortality (HRQ4vsQ1: 1.41; 95%CI 1.04-1.90; P-trend = 0.007) and incident CHD (HRQ4vsQ1: 1.83; 95%CI 1.12-3.01; P-trend = 0.008). These associations were attenuated after further adjustment for smoking status, but remained significant for all-cause mortality. When stratified by smoking status, DII was associated with all-cause and cancer mortality among ex-smokers, in the absence of significant heterogeneity.

Conclusion

These results indicate that a pro-inflammatory diet as expressed by higher DII scores is associated with all-cause mortality. This association was more pronounced among ex-smokers in whom a significant association with cancer mortality was observed.

Dietary inflammatory index and acute myocardial infarction in a large Italian case-control study

Background

Diet and inflammation have been implicated to play a role in the incidence of acute myocardial infarction (AMI).

Methods

In this Italian case-control study conducted between 1995 and 2003, we explored the association between the dietary inflammatory index (DIITM) and AMI. Cases were 760 patients, below age 79 years, with a first episode of nonfatal AMI and controls were 682 patients admitted to hospital for acute conditions unrelated to diet. The DII was computed based on dietary intake assessed using a reproducible and validated 78-item food frequency questionnaire. Odds ratios (OR) were estimated through logistic regression models adjusting for age, sex, total energy intake, tobacco, body mass index, hypertension, hyperlipidemia and other recognized confounding factors.

Results

Higher DII scores (i.e., indicating a more pro-inflammatory diet) were associated with increased likelihood of AMI when expressed both as continuous (ORcontinuous=1.14, 95% confidence interval, CI:1.05, 1.24; one-unit increase in DII score corresponding to ≈9% of the range of DII) and as quartiles (ORQuartile4vs1= 1.60, 95%, CI 1.06, 2.41; P-trend = 0.02). Stratified analyses produced slightly stronger associations between DII and AMI among women, ≥60 years, never smokers, subjects with history of hypertension and subjects with no family history of AMI, however, in the absence of heterogeneity across strata.

Conclusion

A pro-inflammatory diet as indicated by higher DII scores is associated with increased likelihood of AMI.

Assessment of Dietary Patterns Represents a Potential, Yet Variable, Measure of Inflammatory Status: A Review and Update

Chronic low-grade, systemic inflammation is a well-characterized risk factor in the development of chronic metabolic diseases, such as cardiovascular disease, type 2 diabetes, and metabolic syndrome. Diet could be an effective strategy for reducing inflammation associated with chronic disease. While anti-inflammatory properties of isolated dietary bioactive and functional foods have been routinely studied, the evaluation of dietary patterns on inflammation warrants further review-especially given the recent inclusion of dietary pattern recommendations into dietary guidelines and policies. Therefore, the objective of this narrative review is to examine current evidence linking diet to low-grade, systemic inflammation within the context of chronic disease. Specifically, we provide an update on the findings from human trials that have characterized anti-inflammatory properties of dietary patterns, defined by various methods and indexes. Given the complexity of interpreting results from dietary pattern analysis, we further present recent evidence on the anti-inflammatory roles of isolated bioactive nutrients and functional foods that are common components of distinct dietary patterns, in addition to considerations for interpreting dietary pattern research, population-specific dietary recommendations, and future studies. Overall, we observe a vast range of variability in the evidence from observational studies that have evaluated the relationships between healthy dietary patterns and inflammatory markers. These studies highlight the need for additional intervention studies with study designs that account for metabolic status, diversity in populations, breadth of inflammatory measurements, fasting vs. postprandial effects of diet, and control of confounding factors (e.g., genotype, microbiome profiles, and dietary adherence) in order to better understand the effect that diet has, as a whole, on inflammation. These strategies will help to strengthen diet recommendations aimed at reducing inflammation and chronic disease risk.

Dietary inflammatory index is associated with increased risk for prostate cancer among Vietnamese men

OBJECTIVE

Inflammatory potential of diet, as measured by the dietary inflammatory index (DII), has consistently been associated with an increased risk for prostate cancer (PCa). However, data has largely been reported in populations with more proinflammatory dietary patterns, whereas there is high diversity in dietary pattern worldwide. The aim of this study was to assess the association between DII scores and the risk for PCa in Vietnam.

METHODS

A case-control study of 652 participants (244 incident PCa patients, 64-75 y of age, and 408 controls, frequency matched for age) was conducted in Ho Chi Minh City, Vietnam, from 2013 to 2015. Habitual diet was ascertained using a validated food frequency questionnaire (FFQ), whereas other factors, including demographic and lifestyle characteristics, were assessed via face-to-face interviews. The daily intake of pro- and anti-inflammatory nutrients for each participant was calculated from the FFQ and used to estimate individuals' energy-adjusted DII (E-DII) scores. Multivariate-adjusted odds ratios (OR) and 95% confidence intervals (CIs) were estimated using unconditional logistic regression models.

RESULTS

Comparing the middle and highest versus lowest tertile of DII scores, there was an increased risk for overall PCa. The OR and associated 95% CI was 2.63 (1.61-4.37) and 3.35 (2.06-5.53), respectively (P_trend < 0.01). Similar results were found for low-moderate and high-grade PCa. The respective ORs (95% CI) were 3.34 (1.66-7.13) and 5.29 (2.69-11.18), P_trend < 0.001, and 2.51 (1.40-4.63) and 2.57 (1.43-4.73), P_trend 0.006.

CONCLUSION

A proinflammatory diet was associated with increased risk for PCa among Vietnamese men.

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.

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.

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 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 inflammatory potential of diet and risk of lung cancer among smokers in a prospective study in Singapore

BACKGROUND

Diet and inflammation have been suggested to be important risk factors for lung cancer. We examined the ability of the dietary inflammatory index (DII^®) to predict lung cancer in the Singapore Chinese Health Study (SCHS). The DII is a diet quality index based on the literature linking foods and nutrients with inflammatory biomarkers.

PATIENTS AND METHODS

Using data from the SCHS for 60,232 participants, including 1851 lung cancer cases, we investigated the associations of baseline DII scores calculated from a food frequency questionnaire with risk of developing lung cancer over an average of 17.6 years of follow-up. Hazard ratios (HR) were estimated using Cox regression, adjusting for smoking status and other risk factors.

RESULTS

After excluding cancers diagnosed in the first 2 years of follow-up, the DII was non-significantly associated with risk of lung cancer (HR_Q5vsQ1 = 1.13; 95% CI 0.94-1.35; P-trend = 0.24) after adjusting for age, dialect group, sex, interview year, education, body mass index, total calorie intake, physical activity and various smoking variables. In stratified analysis, stronger, statistically significant associations were evident in current smokers (HR 1.44; 95% CI 1.11-1.86; P_trend = 0.03, P for interaction = 0.003) and in male ever-smokers (HR_Q5vsQ1 = 1.37; 95% CI 1.07-1.77; P-trend = 0.03).

CONCLUSION

A pro-inflammatory diet, as shown by higher DII scores, is associated with an elevated risk of lung cancer for subjects with a history of smoking. Public health measures should be adopted to promote consumption of a healthy, anti-inflammatory diet to reduce the risk of lung cancer, especially in current and former smokers.

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.

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.

Dietary inflammatory index and cardiovascular risk factors in Spanish children and adolescents

Dietary inflammatory potential is an established risk factor for adverse cardiovascular events. In this study we analyzed the relation between the Dietary Inflammatory Index (DII) and cardiovascular risk factors, based on anthropometric, body composition, blood pressure, and heart rate parameters in children and adolescents. We conducted a cross-sectional study of 428 Spanish schoolchildren (mean age 12.32 ± 1.84), whose DII was calculated, based on a 24-hr diet recall over 3 days. Anthropometric measurements were taken, and body composition analyzed by bioelectrical impedance analysis. Blood pressure and heart rate parameters were assessed with an automatic monitor. Pubertal stage was assessed based on Tanner criteria. We analyzed the DII both as a continuous variable and as a category variable based on quartiles. Linear regression analysis revealed that the DII was significantly associated with waist to height ratio (WHtR) (p = .026; B = 0.128, 95% CI [.001-.016]) after adjusting for age, sex, total energy intake, and Tanner stage. All macro- and micronutrient intakes were found to be higher in the DII Q1 (anti-inflammatory diet) except for caffeine. This study provides preliminary evidence of a significant association between the DII and WHtR, an index of cardiovascular risk. The results obtained indicate that the inflammatory potential of the diet may play a role in children and adolescents becoming overweight or developing obesity. Future studies in young people should be conducted to validate and further explore these relationships.

The dietary inflammatory index and insulin resistance or metabolic syndrome in young adults

OBJECTIVE

The aim of this study was to assess the association between the inflammatory potential of diet, as measured by the dietary inflammatory index (DII) and insulin resistance (IR) or metabolic syndrome (MetS).

METHODS

A cross-sectional study (nested within a cohort) was conducted on 2017 adults 23 to 25 y of age in Ribeirão Preto, Brazil. Food consumption was assessed using a validated food frequency questionnaire. DII scores were calculated from 35 available food parameters. IR was determined from the classification of homeostatic model assessment (HOMA) values (≥2.7 uU mL-1). MetS was diagnosed based on the Joint Interim Statement (JIS) criterion. The association of DII score with IR or MetS was determined by Poisson regression analysis. The variables included in the multivariable model were selected from directed acyclic graphs.

RESULTS

The diet of the young adults studied showed a high inflammatory potential, with a mean DII score of +1.10 (range: -4.69 to +5.28). The prevalence of MetS was 12.2% and IR 12.3%; both were higher in men than in women. The correlation between DII and HOMA-IR values was -0.038 (P = 0.09). The DII was not associated with IR or MetS in either sex.

CONCLUSION

Although the association between DII and the outcomes was not detected in this sample, the study demonstrated that the diets of these young adult Brazilians had a high inflammatory potential when compared with other studies. Future studies, preferably using longitudinal designs, are recommended.

Dietary Inflammatory Index and Biomarkers of Lipoprotein Metabolism, Inflammation and Glucose Homeostasis in Adults

Accumulating evidence identifies diet and inflammation as potential mechanisms contributing to cardiometabolic risk. However, inconsistent reports regarding dietary inflammatory potential, biomarkers of cardiometabolic health and metabolic syndrome (MetS) risk exist. Our objective was to examine the relationships between a food frequency questionnaire (FFQ)-derived dietary inflammatory index (DII^®), biomarkers of lipoprotein metabolism, inflammation and glucose homeostasis and MetS risk in a cross-sectional sample of 1992 adults. Energy-adjusted DII (E-DII) scores derived from an FFQ were calculated. Lipoprotein particle size and subclass concentrations were measured using nuclear magnetic resonance (NMR) spectroscopy. Serum acute-phase reactants, adipocytokines, pro-inflammatory cytokines and white blood cell (WBC) counts were determined. Insulin resistance was calculated by homeostasis model assessment (HOMA-IR). Our data indicate that a more pro-inflammatory diet, reflected by higher E-DII scores, was associated with potentially pro-atherogenic lipoprotein profiles characterised by increased numbers of large very low density lipoprotein (VLDL), small dense low density lipoprotein (LDL) and high density lipoprotein (HDL) particles and less large LDL and HDL particles (all p < 0.001). Inflammatory profiling identified a range of adverse phenotypes among those with higher E-DII scores, including higher complement component C3 (C3), C-reactive protein (CRP), (both p < 0.05), interleukin 6 (IL-6) and tumour necrosis factor (TNF)-α concentrations, higher WBC counts and neutrophil to lymphocyte ratio (NLR) and lower adiponectin levels (all p < 0.001). MetS risk was increased among those with higher E-DII scores (OR 1.37, 95% CI (1.01, 1.88), p < 0.05), after adjusting for potential confounders. In conclusion, habitual intake of a more pro-inflammatory diet is associated with unfavourable lipoprotein and inflammatory profiles and increased MetS risk.

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.

Design, Development and Construct Validation of the Children's Dietary Inflammatory Index

OBJECTIVE

To design and validate a literature-derived, population-based Children's Dietary Inflammatory Index (C-DII)^TM.

DESIGN

The C-DII was developed based on a review of literature through 2010. Dietary data obtained from children in 16 different countries were used to create a reference database for computing C-DII scores based on consumption of macronutrients, vitamins, minerals, and whole foods. Construct validation was performed using quantile regression to assess the association between C-reactive protein (CRP) concentrations and C-DII scores.

DATA SOURCES

All data used for construct validation were obtained from children between six and 14 years of age (n = 3300) who participated in the U.S. National Health and Nutrition Examination Survey (NHANES) (2005⁻2010).

RESULTS

The C-DII was successfully validated with blood CRP concentrations in this heterogeneous sample of 3300 children from NHANES (52% male; 29% African American, 25% Mexican American; mean age 11 years). The final model was adjusted for sex, age, race, asthma, body mass index (BMI), and infections. Children in level 3 (i.e., quartiles 3 and 4 combined) of the C-DII (i.e., children with the most pro-inflammatory diets) had a CRP value 0.097 mg/dL higher than that in level 1 (i.e., quartile 1) for CRP values at the 75th percentile of CRP using quantile regression (p < 0.05).

CONCLUSION

The C-DII predicted blood CRP concentrations among children 6⁻14 years in the NHANES. Further construct validation with CRP and other inflammatory markers is required to deepen understanding of the relationship between the C-DII and markers of inflammation in children.

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.

Proinflammatory diet is associated with increased risk of squamous cell head and neck cancer

Diets high in fruits and vegetables and low in red meat intake have been associated with decreased risk of head and neck cancer. Additionally, chronic inflammation pathways and their association with cancer have been widely described. We hypothesized a proinflammatory diet, as measured by the dietary inflammatory index (DII^® ), is associated with increased risk of head and neck cancer. We used the Carolina Head and Neck Cancer (CHANCE) study, a population-based case-control study of head and neck squamous cell carcinoma. Cases were recruited from a 46-county region in central North Carolina. Controls, frequency-matched on age, race, and sex were identified through the North Carolina Department of Motor Vehicle records. The DII score, adjusted for energy using the density approach (E-DII), was calculated from a food frequency questionnaire and split into four quartiles based on the distribution among controls. Adjusted odds ratios (ORs) were estimated with unconditional logistic regression. Cases had higher E-DII scores (i.e., a more proinflammatory diet) compared with controls (mean: -0.14 vs. -1.50; p value < 0.001). When compared with the lowest quartile, the OR for the highest quartile was 2.91 (95% confidence interval (CI): 2.16-3.95), followed by 1.93 (95% CI: 1.43-2.62) for the third quartile, and 1.37 (95% CI: 1.00-1.89) for the second quartile. Both alcohol and smoking had a significant additive interaction with E-DII (smoking relative excess risk due to interaction (RERI): 2.83; 95% CI: 1.36-4.30 and alcohol RERI: 1.75; 95% CI: 0.77-2.75). These results provide additional evidence for the association between proinflammatory diet and head and neck cancer.

The association between the inflammatory potential of diet and risk of developing, and survival following, a diagnosis of ovarian cancer

PURPOSE

Inflammation has been implicated in ovarian carcinogenesis. This study evaluated two dietary indices: the Dietary Inflammatory Index (DII®) and the Empirical Dietary Inflammatory Pattern (EDIP), in relation to risk of developing, and survival following, a diagnosis of ovarian cancer.

METHODS

Data came from the Australian Ovarian Cancer Study (1375 cases, 1415 population controls). DII and EDIP scores were computed from dietary information obtained using a semiquantitative food-frequency questionnaire. Logistic regression was used to assess the association between DII and EDIP scores and risk of ovarian cancer and proportional hazards models were used for survival analysis.

RESULTS

A high DII score, reflecting a more pro-inflammatory diet, was associated with a modest increased risk of ovarian cancer [odds ratio (OR) DII score_{Q4 vs.Q1} = 1.31, 95% CI 1.06-1.63, p_trend = 0.014]. Likewise a high EDIP score was associated with an increase in risk of ovarian cancer [OR EDIP score_{Q4 vs.Q1} = 1.39, 95% confidence interval (CI) 1.12-1.73, p_trend = 0.002]. We found no association between DII or EDIP score and overall or ovarian cancer-specific survival.

CONCLUSION

In conclusion, our results suggest that a pro-inflammatory diet modestly increases the risk of developing ovarian cancer.

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.

Validation of a Dietary Inflammatory Index (DII) and Association with Risk of Gastric Cancer: a Case-Control Study

Background:

Gastric cancer (GC) is the fifth most common malignancy and the second leading cause of cancer-related deaths worldwide. Studies have shown that dietary components and inflammation are implicated in the etiology of GC.

Methods:

We examined the ability of a dietary inflammatory index (DII) to predict the odds of GC in a case-control study conducted from December 2014 to May 2016. The subjects were 82 cases and 95 controls who attended specialized centers in Tabriz, Iran. DII scores were computed from a validated 168-item food frequency questionnaire. Logistic regression models were used to estimate odds ratios (ORs) adjusted for age, sex, body mass index, education, smoking, alcohol, H.pylori infection, physical activity, aspirin/NSAID use and total caloric intake.

Results:

In the fully adjusted model, subjects with a DII score >-1.77 had nearly 3.5 times higher odds of having GC compared with subjects with DII≤-1.77, (ORDII>-1.77≤-1.77=3.39; 95%CI=1.59, 7.22). Also, for every one-unit increase in DII, there was a corresponding increase in hs-C-reactive protein, tumor necrosis factor-alpha, interleukin (IL)-6 and IL-1b: β=0.09, 0.16, 0.16 and 0.10, respectively; and a corresponding decrease in IL-10: β=-0.11.

Conclusion:

Subjects who consumed a more pro-inflammatory diet were at increased odds of GC compared to those who consumed a more anti-inflammatory diet.

Sex consideration in diet-biomarker-related indices: a systematic review

OBJECTIVE

An index of biomarkers derived from dietary factors (diet-biomarker-related index) identifies foods and nutrients that encompass physiological potentials and provides scientific evidence for dietary patterns that increase the risk of disease associated with specific biomarkers. Although men and women have different dietary patterns and physiological characteristics, sex is not often considered when investigators develop a diet-biomarker-related index. We aimed to review whether epidemiological studies developed diet-biomarker-related indices in a sex-specific way.

DESIGN

We systematically searched for epidemiological studies that developed diet-biomarker-related indices, including (i) biomarker prediction indices that include dietary factors as explanatory variables and (ii) dietary patterns to explain biomarker variations, in the PubMed and EMBASE databases. We qualitatively reviewed the sex consideration in index development.

RESULTS

We identified seventy-nine studies that developed a diet-biomarker-related index. We found that fifty-four studies included both men and women. Of these fifty-four studies, twenty-nine (53·7 %) did not consider sex, eleven (20·3 %) included sex in the development model, seven (13·0 %) considered sex but did not include sex in the development model, and seven (13·0 %) derived a diet-biomarker-related index for men and women separately. A list of selected dietary factors that explained levels of biomarkers generally differed by sex in the studies that developed a diet-biomarker-related index in a sex-specific way.

CONCLUSIONS

Most studies that included both men and women did not develop the diet-biomarker-related index in a sex-specific way. Further research is needed to identify whether a sex-specific diet-biomarker-related index is more predictive of the disease of interest than an index without sex consideration.

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.

Association between Dietary Inflammatory Index and Metabolic Syndrome in the General Korean Population

Inflammation is thought to be partly responsible for metabolic syndrome (MetS). Recently, dietary inflammatory index (DII) was developed to calculate the overall inflammatory potential of a diet. The objective of this study was to investigate the association between DII and MetS, as well as MetS components, using nationally representative survey data. The study sample consisted of 9291 Korean adults (aged 19⁻65 years, 3682 men and 5609 women) who participated in the sixth (2013⁻2015) Korea National Health and Nutrition Examination Survey. DII values were calculated using 24-h dietary recall data. Multivariable-adjusted logistic regression analysis was performed to identify the association between DII and MetS by sex. In the multivariate logistic regression model, the top DII quartile (Q4), was positively associated with MetS prevalence in men (Q4 vs. Q1, OR = 1.40; 95% CI = 1.06⁻1.85; p for linear trend = 0.008) and in postmenopausal women (Q4 vs. Q1, OR = 1.67; 95% CI = 1.15⁻2.44; p for linear trend = 0.008). The top DII quartile was also positively associated with the prevalence of hyperglycemia in men and the prevalence of central obesity in postmenopausal women. Further studies using prospective cohorts are needed to identify the causal relationship between DII and MetS.

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.

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.

The association between physical activity and dietary inflammatory index on mortality risk in U.S. adults

OBJECTIVE

Both diet and physical activity have been shown to be associated with reduced risk for mortality. The current study examined the individual and combined effects of the inflammatory quality of diet and physical activity levels on mortality risk.

METHODS

Data from the 1999-2004 National Health and Nutrition Examination Survey were used (N = 10,610 adults 20-85 years). Participants were followed through 2011, entailing a median follow-up time of 9.6 yrs. Dietary patterns were assessed using the Dietary Inflammatory Index (DII®), with a higher score indicative of greater diet-related inflammation. Habitual physical activity was assessed via a 30-day recall of leisure-time physical activity as well as objectively via up to seven days of accelerometry assessment. Four lifestyle groups were created: 1) unfavorable DII and inactive (referent); 2) unfavorable DII and active; 3) favorable DII and inactive; and 4) favorable DII and active.

RESULTS

Those who had a low DII score (favorable) and who self-reported being active had a 39% reduced hazard of all-cause mortality (HR = 0.61; 95% CI: 0.49-0.76) when compared to those with a higher DII and were inactive. Results based on accelerometer-assessed physical activity indicate a 65% reduced hazard (HR = 0.35; 95% CI: 0.17-0.74). DII and physical activity also were individually associated with mortality in the expected direction. Specifically, DII was positively associated (HR = 1.08; 95% CI: 1.04-1.13) and physical activity inversely associated (HR = 0.97; 95% CI: 0.94-0.99) with all-cause mortality risk.

CONCLUSION

The combination of consuming a more anti-inflammatory diet and having adequate levels of physical activity is associated with a reduced risk of mortality. Additional replicative work is warranted.

Associations of prenatal and early life dietary inflammatory potential with childhood adiposity and cardiometabolic risk in Project Viva

BACKGROUND

Limited information exists regarding the association between early-life diet and cardiometabolic risk.

OBJECTIVES

Examine associations of dietary inflammatory index (DII) in pregnancy and early childhood (3-5 years) with adiposity, blood pressure and metabolic markers in mid-childhood (6-10 years).

METHODS

Among 992 mother-child pairs from Project Viva, a pre-birth cohort, we examined associations of DII scores with outcomes using multivariable linear regression adjusted for child age and sex and maternal age, BMI, education, parity, smoking, race and income.

RESULTS

Mean (SD) maternal DII in pregnancy was -2.6(1.4) units and in child DII in early childhood was 0.3(0.7). Mean mid-childhood BMI z-score was 0.40(0.98) units. In boys only, DII in early childhood was associated with higher BMIz (adjusted β = 0.16 units per unit DII, 95%CI 0.02, 0.29), waist circumference (0.93 cm; -0.07, 1.92) and skin fold thicknesses (1.12 mm; 0.01, 2.23). Dietary inflammatory index in the highest quartiles during both pregnancy and in early childhood, compared to the lowest quartiles, was associated with higher waist circumference (2.4 cm; 0.14, 4.6) in all children, and BMIz in boys (0.78 units; 0.34, 1.22). Associations with BP and metabolic markers were null.

CONCLUSIONS

A pro-inflammatory diet in pregnancy and early childhood may promote the development of adiposity.

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.

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.

Association of proinflammatory diet with low-grade inflammation: results from the Moli-sani study

OBJECTIVES

The association between diet and inflammation is well documented. Yet, no evidence exists on the relationship between the inflammatory potential of the diet and low-grade inflammation (LGI) as measured by a composite score of plasma and cellular biomarkers. The aim of this study was to assess the association between the Dietary Inflammatory Index (DII^®) and LGI in a large population-based cohort.

METHODS

Cross-sectional analyses were conducted on data from 20 823 adults (age ≥35 y; 48% male) without acute inflammation, who were recruited within the general population of the Moli-sani study from 2005 to 2010. LGI was measured by using a composite score (INFLA-score) including platelet and leukocyte counts, the granulocyte to lymphocyte ratio, and C-reactive protein. DII scores were computed based on dietary intake assessed by the EPIC food frequency questionnaire. Multivariable linear regression models were fit to produce adjusted regression coefficients and 95% confidence intervals (CIs).

RESULTS

Higher DII scores were associated with increased LGI (β = 0.131; 95% CI, 0.089-0.174 for the highest versus lowest quintile of DII) after adjusting for age, sex, lifestyle, prevalence of chronic diseases, and health conditions. A higher DII score also was positively associated with each single biomarker of inflammation included in the INFLA-score, unhealthy behaviors (smoking, sedentary lifestyle), and insulin.

CONCLUSIONS

Higher DII scores, indicating greater inflammatory potential of the diet, were directly associated with LGI, as measured by a composite score of plasma and cellular biomarkers of inflammation. These findings are consistent with the contributing role of diet-mediated inflammation in increasing risk for inflammation-related chronic diseases.

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.

Dietary inflammatory potential and risk of mortality in metabolically healthy and unhealthy phenotypes among overweight and obese adults

BACKGROUND & AIMS

This study was designed to investigate the association between the dietary inflammatory index (DII^®) scores, metabolic phenotypes, and risk of mortality risk in overweight/obese individuals from a representative sample of the U.S.

POPULATION

METHODS

Data from 3733 overweight/obese adults (BMI ≥ 25 kg/m²) aged 20-90 years from the National Health and Nutrition Examination Survey III, 1988-1994 were analyzed; these participants were followed for mortality through December 31, 2011. DII scores were computed based on baseline dietary intake using 24-h dietary recalls. Metabolically unhealthy status was defined as having 2 or more of these metabolic abnormalities: high glucose, insulin resistance, elevated blood pressure, triglycerides, C-reactive protein levels, or low high-density lipoprotein-cholesterol values.

RESULTS

In metabolically unhealthy overweight/obese (MUO) individuals, DII score was associated with increased risk of all-cause mortality (HR_{Tertile 3 vs Tertile 1} 1.44; 95% CI 1.11-1.86 P_trend = 0.008; HR_{1SD increase} 1.08; 95% CI 0.99-1.18). Additionally, a stronger association with cardiovascular mortality was observed (HR_T3 vs T1 3.29; 95% CI 2.01-5.37 P_trend < 0.001; HR_{1SD increase} 1.40; 95% CI 1.18-1.66), after adjusting for potential confounders. Furthermore, when analyses were restricted to obese individuals (BMI ≥ 30 kg/m²), the association was more pronounced, especially for cardiovascular mortality (HR_T3 vs T1 5.55; 95% CI 2.11-14.57 P_trend = 0.006; HR_{1SD increase} 1.74; 95% CI 1.21-2.50). No association was observed between DII score and risk of mortality in individuals with metabolically healthy overweight/obese (MHO) phenotype, or for cancer mortality in either MHO or MUO phenotype.

CONCLUSIONS

A pro-inflammatory diet appears to increase risk of all-cause and cardiovascular mortality in the MUO phenotype, but not among the MHO phenotype.