Dietary inflammatory index potentially increases blood pressure and markers of glucose homeostasis among adults: findings from an updated systematic review and meta-analysis

Association between dietary inflammation index with anemia in Americans: a cross-sectional study with U.S. National health and nutrition examination survey

OBJECTIVES

Dietary inflammatory index (DII) is utilized to determine the inflammatory effects of nutrients and foods on various diseases. Inflammation is a potential risk factor for anemia. We hypothesize that pro-inflammatory diets boost the incidence of anemia, as indicated by high DII.

METHODS

41, 360 Americans were included in this study from the U.S. National Health and Nutrition Survey (NHANES) from 2003-2018. Multivariable logistic regression models were employed to examine the association between DII and anemia.

RESULTS

After adjustment for all the covariates, the odds ratios (ORs) (95% CI) between the risk of anemia and DII across tertile 3 were 1.2556 (95% CI 1.0621, 1.4843; P = 0.0077), and the trend test was statistically significant (P for trend = 0.009). Furthermore, in the subgroup analysis stratified by gender. The ORs (95% CI) between the risk of anemia and DII across tertile 2 and 3 were 1.8071 (95% CI 1.1754, 2.7783; P = 0.0070) and 2.1591 (95% CI 1.4009, 3.3278; P = 0.0005) in men after multivariable adjustment. However, in women, this association was only significantly different (P < 0.05) across tertile 3 in the crude model. In the subgroup analysis stratified by race, this association was significant (P < 0.05) between the risk of anemia and DII for Non-Hispanic Whites/Blacks after adjustment.

DISCUSSION

Together, anemia was significantly associated with DII using logistic regression. In stratified analyses, higher DII scores were linked to an increased incidence of anemia in men, while no association was found in women after adjustment. Additionally, anemia may be associated with greater pro-inflammatory diets in Non-Hispanic Whites/Blacks.

CONCLUSION

In the present study, we evaluate the potential relationship between DII and anemia using data from NHANES. This cross-sectional study confirmed the hypothesis that the higher DII was significantly associated with a higher risk of anemia in the U.S. population.

Dietary inflammatory index and lower glomerular filtration rate in Mexican adults

We hypothesized that higher scores on the dietary inflammatory index (DII) would be associated with a lower glomerular filtration rate (GFR). This cross-sectional study included 2098 participants from Mexican Teachers Cohort Study, the Health Workers Cohort Study, and the Comitán Study belonging to the RenMex consortium. Energy-adjusted DII scores were estimated using a semi-quantitative food frequency questionnaire (FFQ). eGFR was estimated by the CKD Epidemiology Collaboration equation. Quantile regression models and ordered regression models were estimated to assess the associations of interest. Median age of study participants was 47 years, median eGFR was 102.9 mL/min/1.73m2, and the median energy-adjusted DII was 0.89 (range, -2.25, +4.86). The median eGFR was lower in participants in the highest percentile of DII compared to those in the lowest percentile (103.8 vs 101.4). We found that continuous and categorical energy-adjusted DII scores were associated with lower eGFR, especially at the lower percentiles. In adjusted ordered logistic regression, we found that the highest DII category was associated with 1.80 times the odds of belonging to the mildly decreased eGFR category or moderately decreased eGFR category compared lowest DII category (OR: 1.80, 95%CI 1.35, 2.40). A high DII score was associated with a lower eGFR among the Mexican population. Additional studies are crucial to validate these findings and explore potential strategies to reduce the consumption of pro-inflammatory foods as a preventive approach for chronic kidney disease (CKD).

Associations between dietary inflammatory index and stroke risk: based on NHANES 2005-2018

The dietary inflammatory index (DII) is a measure of the inflammatory potential of the diet and is closely associated with insulin resistance (IR) and stroke. And IR may play an important role in the development of stroke. Therefore, this study aimed to evaluate the relationship between DII and stroke risk while delving into the potential role of IR in this association. We analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018, performing weighted univariate analyses, logistic regression, and mediation analyses. At baseline, 3.89% of participants developed stroke, and we observed stroke patients exhibited higher DII scores. After adjusting for covariates, compared to participants in the first quartile of DII scores, those in the third quartile and fourth quartile had increased odds of experiencing a stroke (OR: 1.78, 95% CI: 1.18-2.68) and (OR: 1.70, 95% CI: 1.16-2.50), respectively. Moreover, a significant dose-response relationship was observed (P-trend < 0.05). However, there was no observed interaction between DII and homeostatic model assessment-IR (HOMA-IR) concerning stroke risk, and HOMA-IR did not mediate the association between DII and stroke. In summary, our study elucidated the significant association between DII and stroke risk, independent of IR. This insight suggests that an anti-inflammatory diet may serve as an effective strategy for stroke prevention.

The Role of Diet in the Prevention of Hypertension and Management of Blood Pressure: An Umbrella Review of Meta-Analyses of Interventional and Observational Studies

High blood pressure (BP) is a major pathological risk factor for the development of several cardiovascular diseases. Diet is a key modifier of BP, but the underlying relationships are not clearly demonstrated. This is an umbrella review of published meta-analyses to critically evaluate the wide range of dietary evidence from bioactive compounds to dietary patterns on BP and risk of hypertension. PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched from inception until October 31, 2021, for relevant meta-analyses of randomized controlled trials or meta-analyses of observational studies. A total of 175 publications reporting 341 meta-analyses of randomized controlled trials (145 publications) and 70 meta-analyses of observational studies (30 publications) were included in the review. The methodological quality of the included publications was assessed using Assessment of Multiple Systematic Reviews 2 and the evidence quality of each selected meta-analysis was assessed using NutriGrade. This umbrella review supports recommended public health guidelines for prevention and control of hypertension. Dietary patterns including the Dietary Approaches to Stop Hypertension and the Mediterranean-type diets that further restrict sodium, and moderate alcohol intake are advised. To produce high-quality evidence and substantiate strong recommendations, future research should address areas where the low quality of evidence was observed (for example, intake of dietary fiber, fish, egg, meat, dairy products, fruit juice, and nuts) and emphasize focus on dietary factors not yet conclusively investigated.

Dietary inflammatory index in relation to severe coronary artery disease in Iranian adults

Background

Limited findings are available on the relationship between dietary inflammation index (DII) and severe coronary artery disease (CAD). Considering the high prevalence of CAD and its complications, we examined the relationship between DII and CAD.

Methods

This cross-sectional study was conducted on 275 adults who underwent elective angiography. Severe coronary artery disease was measured by the gensini scoring system. DII was measured by a valid semi-quantitative 168-item food frequency questionnaire (FFQ). Blood samples were collected after 12 h of fasting to measure serum lipid profile and quantitative C-reactive protein (q-CRP) levels. Binary logistic regression was used to calculate the odds (OR) and 95% confidence interval (CI).

Results

People in the last tertile of the DII had a higher chance of suffering from severe coronary artery disease (OR: 3.71; 95% CI: 1.97-6.98), hypercholesterolemia (OR: 2.73; 95% CI: 5.03-1.48), reduced HDL-cholesterol levels (OR: 3.77; 95% CI: 9.34-1.52), and hypertension (OR: 1.93; 95% CI: 3.49-1.06) compared to people in the first tertile. After adjusting for confounding factors, the relationship remained significant. A direct and significant relationship was observed between the DII and increased q-CRP levels, which disappeared after adjusting for confounding factors in the adjusted model (OR: 2.02; 95% CI: 0.86-4.73).

Conclusion

This cross-sectional study showed a direct and linear relationship between following an anti-inflammatory diet and decreasing the chance of severe CAD. Therefore, it seems necessary to implement community-based educational programs to promote healthy nutrition in order to prevent CADs.

The dietary inflammatory index is positively associated with insulin resistance in underweight and healthy weight adults

The aim of this study was to explore the relationship between dietary inflammatory index (DII) and insulin resistance (IR) in underweight and healthy weight adults. This cross-sectional study involved 3205 participants from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018. All dietary data used to calculate the DII were obtained based on the average of two 24-h dietary recall interviews. Participants were divided into an anti-inflammatory diet group and a pro-inflammatory diet group based on DII < 0 and DII ≥ 0, respectively. Fasting blood glucose and fasting insulin data used to calculate IR index (HOMA-IR) were from laboratory data in the NHANES database. According to the linear regression analysis results of DII and HOMA-IR, we found that there was a positive relationship between DII and IR. A positive association between DII and HOMA-IR was seen in the following groups after stratification: by age in 20-39-year olds, by sex in males, by race in Non-Hispanic Whites, by family history of diabetes in those without a family history of diabetes, by education level in those with high school education, by smoking status in current smokers and non-smokers, by hypertension in those with hypertension, by BMI in those with a BMI of 18.5-24.99, by hypertriglyceridemia (HTG) in those without HTG, by poverty impact ratio (PIR) in those with PIR ≤ 1.3 and >1.3, and by physical activity in those with moderate recreational activities. In conclusion, in underweight and healthy weight adults, DII was positively correlated with the risk of IR.

Association of shift work and dietary inflammatory potential with all-cause death among us hypertensive population: national health and nutrition examination study, 2005-2010

BACKGROUND & AIMS

The individual effect of working schedule on survival in the hypertensive population has not been adequately studied. Shiftworkers are also prone to unhealthy lifestyles like pro-inflammatory diet. Therefore, we assessed the effect of shift work and its joint association with dietary inflammatory potential on mortality risk among the large US nationally representative sample of adult hypertensive population.

METHODS

Data were from a nationally representative prospective cohort among US hypertensive population (n = 3680; weighted population, 54,192,988). The participants were linked to the 2019 public-access linked mortality archives. The working schedule were self-reported using the Occupation Questionnaire Section. Dietary inflammatory index (DII) scores were equally calculated using the 24-hour dietary recall (24 h) interviews. Multivariable Cox proportional hazards regression models were used to estimate hazard ratio and 95% confidence intervals (95%CI) for survival of hypertension individuals by work schedule and dietary inflammatory potential. The joint effect of work schedule and dietary inflammatory potential was then examined.

RESULTS

Among the 3680 hypertension individuals (39.89% female [n = 1479] and 71.42% white [n = 1707]; weighted mean [SE] age, 47.35 [0.32] years), 592 individuals reported shift work status. 474 (10.76%) reported shift work status with pro-inflammatory dietary pattern (DII scores > 0). 118 (3.06%) reported shift work status with anti-inflammatory dietary pattern (DII scores < 0). 646 (19.64%) reported a non-shift working schedule with anti-inflammatory dietary pattern, while 2442 (66.54%) reported non-shift working schedule with pro-inflammatory dietary pattern. After a median follow-up of 11.67 years (140 months), 317 deaths (cardiovascular diseases (CVD), 65; cancer, 104) were registered. Cox regression analysis showed that shift work was associated with higher risk of all-cause mortality (hazard ratio [HR], 1.48; 95% CI, 1.07-2.06) compared with non-shift workers. In the joint analysis, shift work status combined with pro-inflammatory dietary pattern was associated with the highest all-cause mortality risk. Moreover, adopting the anti-inflammatory diet significantly attenuates the deleterious effect of shift work on mortality risk.

CONCLUSIONS

In this large representative sample of adults with hypertension in the U.S., the combination of shift work status with pro-inflammatory dietary pattern was highly prevalent and was associated with the highest risks of death from all causes.

Association of a pro-inflammatory diet and gestational diabetes mellitus with maternal anemia and hemoglobin levels during pregnancy: a prospective observational case-control study

Anemia is prevalent in pregnant women, and the causes include inadequate diet, increased demand for iron, and inflammation. We hypothesized that gestational diabetes mellitus (GDM) and hepcidin-related gene polymorphisms may contribute to maternal anemia and that an anti-inflammatory diet can alleviate this negative effect. The aim of this study was to investigate the association of an inflammatory diet, GDM, and single nucleotide polymorphisms (SNPs) in hepcidin-related genes, which are key regulators of iron, with maternal anemia. This was a secondary data analysis of a prospective prenatal diet and pregnancy outcome study in Japan. The Energy-Adjusted Dietary Inflammatory Index was calculated using a brief self-administered diet history questionnaire. We analyzed 121 SNPs in 4 genes: TMPRS6 (43 SNPs), TF (39 SNPs), HFE (15 SNPs), and MTHFR (24 SNPs). Multivariate regression analysis was conducted to determine the association between the first variable and maternal anemia. The prevalence of anemia in first, second, and third trimesters were 5.4%, 34.9%, and 45.8%, respectively. The pregnant women with GDM had a significantly higher incidence of moderate anemia than those without GDM (40.0% vs. 11.4%, P = .029). In multivariate regression analysis, Energy-adjusted Dietary Inflammatory Index (β = -0.057, P = .011) and GDM (β = -0.657, P = .037) were significantly associated with hemoglobin levels during the third trimester. Using Stata's qtlsnp command, TMPRSS6 rs2235321 was found to be associated with hemoglobin levels during the third trimester. These results indicate that inflammatory diets, GDM, and TMPRSS6 rs2235321 polymorphism are associated with maternal anemia. This result suggests that a pro-inflammatory diet and GDM are associated with maternal anemia.

The association between food desert severity, socioeconomic status, and metabolic state during pregnancy in a prospective longitudinal cohort

Poor metabolic health during pregnancy is associated with health concerns for pregnant individuals and their offspring. Lower socioeconomic status (SES) is one risk factor for poor metabolic health, and may be related to limited access to healthful and affordable foods (e.g., living in a food desert). This study evaluates the respective contributions of SES and food desert severity on metabolic health during pregnancy. The food desert severity of 302 pregnant individuals was determined using the United States Department of Agriculture Food Access Research Atlas. SES was measured using total household income adjusted for household size, years of education, and amount of reserve savings. Information about participants' glucose concentrations one hour following an oral glucose tolerance test during the second trimester was extracted from medical records and percent adiposity during the second trimester was assessed using air displacement plethysmography. Information about participants' nutritional intake during the second trimester was obtained by trained nutritionists via three unannounced 24-h dietary recalls. Structural equation models showed that lower SES predicted higher food desert severity (β = - 0.20, p = 0.008) and higher adiposity (β = - 0.27, p = 0.016) and consumption of a more pro-inflammatory diet (β = - 0.25, p = 0.003) during the second trimester of pregnancy. Higher food desert severity also predicted higher percent adiposity during the second trimester (β = 0.17, p = 0.013). Food desert severity significantly mediated the relationship between lower SES and higher percent adiposity during the second trimester (βindirect = - 0.03, 95% CI [- 0.079, - 0.004]). These findings indicate that access to healthful and affordable foods is a mechanism by which SES contributes to adiposity during pregnancy and may inform interventions intended to improve metabolic health during pregnancy.

The association between dietary inflammation index and depression

Objective

We aimed to evaluate whether depression is associated with increased risk of dietary inflammatory index (DII) or energy-adjusted DII (E-DII) and whether the association is partly explained by insulin resistance (IR).

Methods

Base on the National Health and Nutrition Examination Survey (NHANES) 2005-2018. Univariate analyses of continuous and categorical variables were performed using t-test, ANOVA, and χ ² test, respectively. Logistic regression was used to analyze the relationship between DII or E-DII and depression in three different models. Mediation analysis was used to assess the potential mediation effects of homeostatic model assessment-IR (HOMA-IR).

Results

A total of 70,190 participants were included, and the DII score was higher in the depressed group. DII score was related to all participant characteristics except age (p < 0.05). After being included in covariates (Model 3), participants in the highest quartile of DII score have increased odds of depression (OR: 1.82, 95% CI: 1.28-2.58) compared with those in the first quartile of DII score. And, a significant dose-response relationship was found (p-trend <0.05). No interaction between DII and HOMA-IR was observed in terms of the risk of depression, and HOMA-IR did not find to play a mediating role in the association between DII and depression. Similar results were obtained for the association between E-DII and depression.

Conclusion

Our results suggest that a higher pro-inflammatory diet increases the risk of depression in U.S. adults, while there was no evidence of a multiplicative effect of DII or E-DII and HOMA-IR on disease risk, nor of a mediating effect of HOMA-IR.

The Dietary Inflammatory Index is positively associated with cardiometabolic risk parameters in atherosclerosis patients

Inflammation is implicated in the development and progression of a variety of cardiovascular diseases. We hypothesized that the Dietary Inflammatory Index (DII) is associated with anthropometric indices and metabolic parameters in Iranian atherosclerosis patients. The present cross-sectional study was conducted on 320 Iranian atherosclerosis patients. The DII was estimated using a valid and reliable 168-item food frequency questionnaire. Odds ratios and 95% confidence intervals were evaluated for anthropometric indices and metabolic parameters according to the DII score. Linear regression was used to estimate the relationship between DII scores with atherosclerosis-related dependent variables. According to the continuous score of DII, there was no significant association between DII and odds of obesity, total cholesterol/high-density lipoprotein cholesterol ratio, and aspartate aminotransferase/alanine aminotransferase ratio in all 3 models (P ≥ .05). In linear regression analysis, we found a significant association between DII score and fasting blood sugar, lipid profile (except for high-density lipoprotein cholesterol), liver enzymes (except for alkaline phosphatase), and serum sodium in adjusted models (P < .05). In this study, patients with atherosclerosis consuming a pro-inflammatory diet was positively associated with fasting blood sugar, lipid, and liver enzymes measures. Future studies with prospective and interventional designs are required to clarify the association between this dietary index and cardiovascular disease risk factors among patients with atherosclerosis.

The Association Between Dietary Inflammatory Index (DII) and Risk of Hypertension: A Case-Control Study

INTRODUCTION

Hypertension (HTN) is a common risk factor for various medical diseases. Recently, there is growing evidence focusing on the potential inflammatory properties of food in the developing HTN risk. However, limited data are indicating the link between the dietary inflammatory index score (DII) and HTN risk.

AIM

This study aimed to investigate the relationship between DII score and HTN risk in middle-aged people.

METHODS

This case-control study was performed on 945 middle-aged participants (376 subjects with HTN and 569 control group). Usual dietary intakes were collected using a validated semi-quantitative food frequency questionnaire. The dietary inflammatory index (DII) for each participant was calculated with a standardized procedure, and the relationship between the risk of HTN and the DII score was investigated.

RESULTS

The multi-adjusted regression analysis showed that subjects with the higher DII score had a 1.61 times greater chance of developing HTN than individuals in the lowest ones (95% CI 1.07-2.65). Interestingly, after conducting a sex-based analysis, there was no significant relationship between DII score and risk of HTN in middle-aged women (95% CI 0.38-1.61). However, middle-aged men in the highest quartile of DII had greater (2.91 times) odds of HTN compared to the lowest quarter of DII (95% CI 1.52-5.23).

CONCLUSION

The findings of this study suggested that adherence to a diet with a high inflammatory index could increase the risk of HTN in middle-aged men by approximately 2.9 times. However, following a diet with a high DII score had no significant relationship with HTN risk in middle-aged women.

The Association Among Inflammatory Diet, Glycohemoglobin, and Cognitive Function Impairment in the Elderly: Based on the NHANES 2011–2014

Background: Dietary inflammatory index (DII) was associated with Type 2 diabetes mellitus and cognitive function impairment (CFI). Objective: The aim of this study was to explore whether the associations among DII, glycohemoglobin (HbA1c), and CFI were similar in the participants with or without diabetes. Methods: A total of 1,198 participants aged 60 and over from the National Health and Nutrition Examination Survey (NHANES) in 2011–2014 were involved in this study, dividing into subgroups as diabetes and non-diabetes for further analysis. Results: We found that participants with pro-inflammatory diet had higher proportion of CFI patients (p <  0.05). Pro-inflammatory diet and HbA1c were positively associated with the risk of CFI; participants with pro-inflammatory diet was 1.479 times on occurrence of CFI compared with anti-inflammatory diet group. The interaction between inflammatory diet and HbA1c was positive on the risk of CFI and was negative on the CERAD-immediate and CERAD-delayed, respectively. Among the participants without diabetes, the associations of Energy-adjusted DII (E-DII) with Animal Fluency test and Digit Symbol Substitution Test (DSST) were partially mediated by HbA1c, and the mediated proportion was 5.8% and 6.6%, respectively. However, there was no such mediation effect in the diabetes patients. Conclusion: In elderly participants without diabetes, there was an interaction between inflammatory diet and HbA1c on the association with CFI, especially for the dimension of CERAD-immediate and CERAD-delayed. Besides, the associations of E-DII with Animal Fluency test and DSST were partially mediated by HbA1c. For diabetic patients, HbA1c, rather than the inflammatory diet has a positive effect on the CFI risk.

Children-Dietary Inflammatory Index (C-DII), cardiometabolic risk, and inflammation in adolescents: a cross-sectional study

OBJECTIVES

There is limited evidence about the inflammatory potential of diet and cardiometabolic risk in children. The aim of this study was to evaluate the association between the Children's Dietary Inflammatory Index (C-DII) with cardiometabolic risk factors in Turkish adolescents from 10 to 17 years.

METHODS

Participants aged 10-17 years, who completed a 24-h dietary recall, from which C-DII scores were calculated, were include in this cross-sectional study. Lipid profile, glycemic parameters, high-sensitivity C-reactive protein (hs-CRP), liver enzymes, thyroid-stimulating hormone (TSH), and uric acid were analyzed in blood samples. Sociodemographic characteristics and sedentary behavior were assessed using a semi-structured questionnaire. We compared the distributions of anthropometric, biochemical, and blood pressure measurement levels associated with cardiometabolic risk factors by the median of C-DII with linear regression.

RESULTS

The mean sample C-DII was -0.16 ± 2.31 and ranged from -3.22 to +4.09. Higher median C-DII scores, indicating a more pro-inflammatory diet among children, were associated with higher blood pressure and body mass index (BMI). However, the C-DII was modestly directly associated with fasting insulin, fasting blood glucose, and waist circumference. The area under the receiver operating curve of C-DII in predicting hs-CRP was found to be quite high (0.864, 95% CI: 0.795-0.933).

CONCLUSIONS

Consuming a pro-inflammatory diet in adolescence was associated with alterations in cardiometabolic risk factors, especially with systolic blood pressure, diastolic blood pressure, and BMI.

Dietary Inflammatory Index in relation to Type 2 Diabetes: A Meta-Analysis

BACKGROUND AND AIMS

Epidemiologic studies show a strong association between chronic inflammation and type 2 diabetes (T2D). Diet may also affect the risk of T2D by modulating inflammation. This meta-analysis aimed to assess the relation of dietary inflammatory index (DII) and risk of T2D.

METHODS

PubMed and Scopus were systematically searched from their inception to September 2020 to identify relevant studies. Relative risks, hazard ratios, or odds ratios (OR), with their corresponding 95% confidence intervals (95% CI), were calculated and pooled using a random-effects model.

RESULTS

A total of 48 different studies, with a total sample size of 1,687,424 participants, were eligible to be included in this meta-analysis. In the overall analysis, no significant association was observed between DII and risk of T2D (OR = 1.03, 95% CI: 0.91 to 1.15), with significant evidence for heterogeneity (I ²  = 96.5%, P < 0.001); however, higher DII was identified as being significantly related to increased risk of T2D in high quality studies (OR = 1.58, 95% CI: 1.15 to 2.17). In the stratified analysis by the dietary assessment tool, background disease, and sex of participants, DII showed no significant association with T2D.

CONCLUSIONS

Higher DII might be associated with an increased risk of T2D. Additional well-designed studies are required to confirm this finding.

The inflammatory potential of the diet in childhood is associated with cardiometabolic risk in adolescence/young adulthood in the ALSPAC birth cohort

PURPOSE

This study examined the association between a Dietary Inflammatory Score adapted for children (cDIS) and Cardiometabolic Risk (CMR) score in adolescence/early adulthood in the Avon Longitudinal Study of Parents and Children (ALSPAC).

METHODS

The cDIS was calculated at 7, 10 and 13 years using diet diary data. Anthropometric and biochemical data at 17 (N = 1937) and 24 (N = 1957) years were used to calculate CMR scores at each age [mean sex-specific z-scores from triacylglycerol, HDL-cholesterol, LDL-cholesterol, mean arterial blood pressure (MAP), homeostatic model assessment of insulin resistance (HOMA-IR) and fat-mass index (FMI)]. Multivariable linear regression models examined associations between cDIS at 7, 10 and 13 years and a continuous CMR z-score and individual CMR markers at 17 and 24 years.

RESULTS

In fully adjusted models, a higher cDIS (more pro-inflammatory diet) at 7 years was associated with an increase in CMR z-score at 17 years (β 0.19; 95% CI 0.03-0.35 for third versus first cDIS tertile) and at 24 years (β 0.28; 95% CI 0.11,0.44 for third versus first cDIS tertile). There was a weak association between a higher cDIS at 10 years and an increase in CMR z-score at 17 years (β 0.16; 95% CI - 0.003, 0.32 for third versus first cDIS tertile). No other clear associations were evident. FMI, MAP and HOMA-IR were the main CMR factors contributing to these associations.

CONCLUSION

A more pro-inflammatory diet during childhood was associated with a worse cardiometabolic profile in late adolescence/early adulthood. A childhood diet abundant in nutrients with anti-inflammatory properties could help reduce development of CMR factors.

The dietary inflammatory index, obesity, type 2 diabetes, and cardiovascular risk factors and diseases

An unhealthy diet is a recognized risk factor in the pathophysiology of numerous chronic noncommunicable diseases (NCD), including obesity, type 2 diabetes (T2DM), and cardiovascular diseases (CVD). This is, at least in part, due to unhealthy diets causing chronic low-grade inflammation in the gut and systemically. To characterize the inflammatory potential of diet, we developed the Dietary Inflammatory Index (DII®). Following this development, around 500 papers have been published, which examined the association between the DII, energy-adjusted DII (E-DII™), and the children's DII (C-DII™) and many chronic NCDs including obesity and cardiometabolic diseases. Although a previous narrative review published in 2019 briefly summarized the evidence in this area, there was a significant increase in papers on this topic since 2020. Therefore, the purpose of this narrative review is to provide an in-depth updated review by including all papers until July 2021 on DII and its relationship with obesity, T2DM, and CVD. Furthermore, we aim to identify potential gaps in the literature and provide future directions for research. Most studies found that DII was associated with an increased risk of obesity, T2DM, and CVD with some relationships being sex-specific. However, we identified the paucity of papers describing associations between dietary inflammation and T2DM and its risk factors. Few studies used gold-standard measures of cardiometabolic risk factors. We also identified the lack of interventional studies designed to change the inflammatory potential of diets and study its effect on cardiometabolic risk factors and diseases. We recommend that such interventional studies are needed to assess if changes in DII, representing the inflammatory potential of diet, independently of changes in body composition can modulate cardiometabolic risk factors and diseases.

The Dietary Inflammatory Index and Human Health: An Umbrella Review of Meta-Analyses of Observational Studies

Numerous observational studies have investigated the role of the Dietary Inflammatory Index (DII®) in chronic disease risk. The aims of this umbrella review and integrated meta-analyses were to systematically synthesize the observational evidence reporting on the associations between the DII and health outcomes based on meta-analyses, and to assess the quality and strength of the evidence for each associated outcome. This umbrella review with integrated meta-analyses investigated the association between the DII and a range of health outcomes based on meta-analyses of observational data. A credibility assessment was conducted for each outcome using the following criteria: statistical heterogeneity, 95% prediction intervals, evidence for small-study effect and/or excess significance bias, as well as effect sizes and P values using calculated random effects meta-analyses. In total, 15 meta-analyses reporting on 38 chronic disease-related outcomes were included, incorporating a total population of 4,360,111 subjects. Outcomes (n = 38) were examined through various study designs including case-control (n = 8), cross-sectional (n = 5), prospective (n = 5), and combination (n = 20) study designs. Adherence to a pro-inflammatory dietary pattern had a significant positive association with 27 (71%) of the included health outcomes (P value < 0.05). Using the credibility assessment, Class I (Convincing) evidence was identified for myocardial infarction only, Class II (Highly suggestive) evidence was identified for increased risk of all-cause mortality, overall risk of incident cancer, and risk of incident site-specific cancers (colorectal, pancreatic, respiratory, and oral cancers) with increasing (more pro-inflammatory) DII score. Most outcomes (n = 31) presented Class III (Suggestive) or lower evidence (Weak or No association). Pro-inflammatory dietary patterns were nominally associated with an increased risk of many chronic disease outcomes. However, the strength of evidence for most outcomes was limited. Further prospective studies are required to improve the precision of the effect size.

Dietary inflammatory index and the risk of non-communicable chronic disease and mortality: an umbrella review of meta-analyses of observational studies

We aimed to perform an umbrella review of systematic reviews and meta-analyses (SRMAs) of observational studies of the association of the dietary inflammatory index (DII) with the risk of non-communicable chronic disease and mortality in the general population. We searched PubMed, Scopus, and ISI Web of Science to November 2020. For each outcome, the summary effect sizes with the corresponding 95%CIs were recalculated using a random-effects model. The certainty of the evidence and the quality of conduct of published SRMAs were rated using the GRADE and ASMTAR 2 tools, respectively. A total of 11 SRMAs of observational studies, reporting pooled effect sizes for 29 outcomes obtain from 60 prospective cohort and 67 case-control studies, were included. Our results demonstrated evidence of moderate certainty for a positive relation between DII and the risk cardiovascular disease, all-cause mortality, and colorectal cancer. Higher DII was also associated with site-specific cancer risk, but for cancers at most sites, existing evidence is derived from case-control studies with the certainty of evidence being rated low or very low. Our findings suggested that adherence to a diet with high inflammatory features might be associated with a higher risk of colorectal cancer, cardiovascular disease, and all-cause mortality.

Dietary Inflammatory Index and Health Outcomes: An Umbrella Review of Systematic Review and Meta-Analyses of Observational Studies

Background and Aims: The dietary inflammatory index (DII) is associated with non-communicable disease. We conducted an umbrella review to systematically evaluate meta-analyses of observational studies on DII and diverse health outcomes.

Methods: We comprehensively searched the PubMed, Web of Science, and Embase databases to identify related systematic reviews and meta-analyses of observational studies. Those investigating the association between DII and a wide range of health outcomes in humans were eligible for inclusion. For each meta-analysis, we estimated the summary effect size by using fixed and random effects models, the 95% confidence interval, and the 95% prediction interval. We assessed heterogeneity, evidence of small-study effects, and excess significance bias.

Results: The umbrella review identified 35 meta-analyses assessing associations between DII and various health outcomes: cancer (n = 24), mortality (n = 4), metabolic (n = 4), and other (n = 3). The methodological quality was high or moderate. Of the 35 meta-analyses, we observed highly suggestive evidence for harmful associations between digestive tract cancer, colorectal cancer, overall cancer, pharyngeal cancer, UADT cancer, and CVD mortality. Moreover, 11 harmful associations showed suggestive evidence: hormone-dependent cancer, rectal cancer, colon cancer, breast and prostate cancer, gynecological cancer, breast cancer, ovarian cancer, colorectal cancer, prostate cancer, all-cause mortality, and depression.

Conclusion: DII is likely to be associated with harmful effects in multiple health outcomes. Robust randomized controlled trials are warranted to understand whether the observed results are causal.

Systematic Review Registration: CRD42021218361

Dietary inflammatory index significantly affects lipids profile among adults: An updated systematic review and meta-analysis

Background: The available data on the relationship between dietary inflammatory index (DII^®) and serum lipids are controversial. This systematic review and meta-analysis aimed to investigate the relationship between DII^® and serum lipids, including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) in general populations. Methods: PubMed, Web of Science, SCOPUS, and Cochrane electronic databases were systematically searched from inception to December 2019. Case-control, cohort or cross-sectional studies that evaluated the relationship between DII^® and serum lipids were included. The random-effects model was applied to evaluate the pooled weighted mean difference (WMD) and 95% confidence intervals (CI). Results: In total, twenty-four cross-sectional and one case-control studies with a total sample size of 129,759 were included in the meta-analysis. The pooled results showed that the highest category of DII^® was associated with 5.16 mg/dl increase in TC (Pooled WMD: 5.16; 95% CI: 0.58-9.73, p = 0.02) and 3.99 mg/dl increase in LDL-C (Pooled WMD: 3.99; 95% CI: 1.16-6.81, p = 0.006). However, no significant association between DII^® scores, HDL-C and TG was found. In subgroup analysis, the geographical region, gender, and dietary assessment methods were potent sources of heterogeneity. Conclusion: This study showed that a higher level of DII^® was associated with higher levels of TC and LDL-C in apparently healthy populations. Since the included studies had observational designs, therefore, no conclusion of causality was possible. More studies with interventional designs are required to elucidate the causality of the observed association between DII^® and the risk of abnormal lipid profile.

Sugar-sweetened beverages increases the risk of hypertension among children and adolescence: a systematic review and dose-response meta-analysis

BACKGROUND

In the current systematic review and meta-analysis, we summarized the studies that evaluated the effects of sugar-sweetened beverages (SSBs) intake on blood pressure among children and adolescents.

METHODS

In a systematic search from PubMed, Scopus, Embase and Cochrane electronic databases up to 20 April 2020, the observational studies that evaluated the association between sugar-sweetened beverages intake and hypertension, systolic or diastolic blood pressure (SBP, DBP) were retrieved.

RESULTS

A total of 14 studies with 93873 participants were included in the current meta-analysis. High SSB consumption was associated with 1.67 mmHg increase in SBP in children and adolescents (WMD: 1.67; CI 1.021-2.321; P < 0.001). The difference in DBP was not significant (WMD: 0.313; CI -0.131- 0.757; P = 0.108). High SSB consumers were 1.36 times more likely to develop hypertension compared with low SSB consumers (OR: 1.365; CI 1.145-1.626; P = 0.001). In dose-response meta-analysis, no departure from linearity was observed between SSB intake and change in SBP (P-nonlinearity = 0.707) or DBP (P-nonlinearity = 0.180).

CONCLUSIONS

According to our finding, high SSB consumption increases SBP and hypertension in children and adolescents.