Inflammatory potential of diet and risk of mortality in normal-weight adults with central obesity

The role of dietary inflammatory index in metabolic diseases: the associations, mechanisms, and treatments

In recent years, the prevalence of metabolic diseases has increased significantly, posing a serious threat to global health. Chronic low-grade inflammation is implicated in the development of most metabolic diseases, such as type 2 diabetes mellitus (T2DM), obesity, dyslipidemia, and cardiovascular disease, serving as a link between diet and these conditions. Increasing attention has been directly toward dietary inflammatory patterns that may prevent or ameliorate metabolic diseases. The Dietary Inflammatory Index (DII) was developed to assess the inflammatory potential of dietary intake. Consequently, a growing body of research has examined the associations between the DII and the risk of several metabolic diseases. In this review, we explore the current scientific literature on the relationships between the DII, T2DM, obesity, and dyslipidemia. It summarizes recent findings and explore potential underlying mechanisms from two aspects: the interaction between diet and inflammation, and the link between inflammation and metabolic diseases. Furthermore, this review discusses the therapeutic strategies, including dietary modifications, prebiotics, and probiotics, and discusses the application of the DII in metabolic diseases, as well as future research directions.

Association of dietary inflammatory index on all-cause and cardiovascular mortality in U.S. adults with metabolic dysfunction associated steatotic liver disease

Backgrounds

An inflammatory diet is pivotal in metabolic dysfunction-associated steatotic liver disease (MASLD) development. However, it remains unclear whether Dietary Inflammatory Index (DII), which serves as a reliable indicator to assess pro-inflammatory diet, have associative effects on mortality outcomes of MASLD.

Methods

Participants in the National Health and Nutrition Examination Survey (NHANES) database from 1999 to 2018 years were included. Kaplan-Meier (KM) curves were used to estimate survival probabilities, while Cox regression analysis and restricted cubic splines (RCS) were employed to assess the association between DII and mortality outcomes. The concordance index (C-index) evaluated the accuracy of multivariate-adjusted DII for mortality among MASLD participants.

Results

The cohort consisted of 4,510 men and 4,323 women with a median age of 52 years. Multivariate-adjusted Cox regression analysis revealed that high levels of DII were significantly associated with the all-cause mortality of participants with MASLD (multivariable-adjusted hazard ratio (aHR) = 1.28, 95% confidence interval (CI) 1.10-1.49, p = 0.002, DII aHR for cardiovascular mortality = 1.28, 95% CI 1.07-1.53, p = 0.006). The C-index for the multivariate model, integrating DII and other clinical variables, was 0.837 for all-cause mortality and 0.860 for cardiovascular mortality. RCS analysis showed a positive linear relationship between DII and all-cause mortality rate (p for nonlinearity = 0.057), with no significant nonlinearity for cardiovascular mortality (p = 0.953). Subgroup analyses indicated stronger associations in participants <65 years, married, with a college education, non-smokers, non-drinkers, and those without hypertension.

Conclusion

Elevated DII levels are linked to higher mortality in adults with MASLD, underscoring the index's utility in predicting mortality risks. These findings shows that dietary interventions targeted inflammation may be helpful in this population.

The relationship between dietary inflammatory index and all-cause and cardiovascular disease-related mortality in adults with metabolic syndrome: a cohort study of NHANES

Objective

This study aims to investigate the correlation between dietary inflammatory index (DII) and mortality resulting from all-cause and cardiovascular diseases (CVD) in adults affected by metabolic syndrome (MetS).

Methods

The focus of this study was to analyze the information of 13,751 adults who had been diagnosed with MetS. DII scores were computed based on a 24-hour dietary intake at the start of the study. By implementing both the Cox regression analysis and restricted cubic spline(RCS) analysis, we examined the correlation between DII score and mortality.

Results

After a mean follow-up duration of 114 months, a total of 2,343 individuals (representing 13.45% of the sample) died, with 639 fatalities attributed to CVD. The degrees of dietary inflammation were classified into three groups based on DII scores: low, medium, and high-grade. The mortality rates for each tertile of DII were 11.55%, 13.96%, and 15.05%, respectively. In comparison to participants with T1, the multivariate-adjusted hazard ratios (HR) and 95% confidence intervals (CI) for participants with T3 were 1.16 (95% CI: 1.01-1.34) regarding mortality caused by any reason, and 1.26 (95% CI: 0.95-1.68) for mortality related to CVD. Through the use of the Kaplan-Meier survival curve and RCS, it was observed that individuals in the high DII tertile had an increased likelihood of death compared to those in the low DII tertile.

Conclusion

Our findings provide validation of the theory that diets high in inflammatory substances contribute to elevated mortality rates for all causes and CVD-related deaths in individuals diagnosed with MetS.

The Relationship of Certain Diseases and Dietary Inflammatory Index in Older Adults: A Narrative Review

PURPOSE OF REVIEW

One of the important markers affecting aging processes is the increase in inflammatory markers. Many chronic diseases are associated with inflammation and chronic inflammation increases with aging. Inflammation can change with dietary components. Foods, compounds and nutrients that have anti-inflammatory or proinflammatory properties attract attention. According to the Dietary Inflammatory Index, positive scores are obtained if the nutrient has a proinflammatory effect on cytokines, and negative scores are obtained if it has an anti-inflammatory effect.

RECENT FINDINGS

A higher proinflammatory diet is associated with cardiometabolic diseases, neurodegenerative disease, cancers and musculoskeletal health and related mortality. In this study, its relationship with type 2 diabetes mellitus, obesity, metabolic syndrome, musculoskeletal diseases, dementia, depression and cancer, which are more common in older adults and known to be associated with inflammation, was examined. Although studies involving under 65 years old are more prevalent, research involving older adults and Dietary Inflammatory Index (DII) is more limited. It is known that chronic inflammation increases with aging. Diet is one of the factors affecting inflammation. In the light of these investigations, the topics of anti-inflammatory nutrition and DII for the treatment of inflammation-related diseases in older adults are strong and open to development topics of discussion. Despite the significant interest in the potential positive effects of anti-inflammatory nutrition on diseases, contributing to clearer evidence of its protective effects on health necessitates further randomized controlled trials, in vivo, in vitro, cell, animal, human and case-control studies for better risk assessment.

Association between the dietary inflammatory index and serum perfluoroalkyl and polyfluoroalkyl substance concentrations: evidence from NANHES 2007-2018

Diet is an important source of perfluoroalkyl and polyfluoroalkyl substance (PFAS) exposure, and the dietary inflammatory index (DII) is a tool used to assess the inflammatory potential of an individual's diet. However, limited research has explored the association between the DII and PFAS exposure in humans. This study is the first to analyze the association between the five PFASs and DII using the National Health and Nutrition Examination Survey (NHANES) 2007-2018 database. Additionally, we assessed the interaction between the DII and PFASs regarding oxidative stress and inflammatory markers, including alkaline phosphatase, albumin, neutrophil count, lymphocyte count, total bilirubin, and serum iron based on a previous study. A series of covariates were included in the analysis to reduce the confounding bias. The study included 7773 and 5933 participants based on the different models. The DII was significantly associated with serum perfluorooctanoic acid, perfluorononanoic acid, perfluorooctane sulfonic acid, and sum-PFAS. Some of the food parameters used to calculate the DII also showed associations with special PFAS serum concentrations. Specifically, dietary fiber, n-3 polyunsaturated fatty acids, energy intake, and vitamin D were associated with more than three PFASs. Higher DII levels in participants were linked to a more significant association between bilirubin (the interaction P-value is not significant), alkaline phosphatase, serum iron, neutrophil counts, and some PFASs. In conclusion, this study clarified the association between the three PFASs and DII, highlighting the diverse effects of PFASs on oxidative stress and inflammatory markers across different DII levels.

Exploring the association between dietary Inflammatory Index and chronic pain in US adults using NHANES 1999-2004

Chronic pain, a substantial public health issue, may be influenced by dietary patterns through systemic inflammation. This cross-sectional study explored the association between Dietary Inflammatory Index (DII) and chronic pain among 2581 American adults from NHANES data. The DII, ranging from - 4.98 to 4.69, reflects the inflammatory potential of the diet, with higher scores indicating greater pro-inflammatory capacity. Our findings showed no significant association between the continuous DII score and chronic pain prevalence. However, a nonlinear relationship emerged. When the DII was categorized, a significant association between higher DII scores (DII ≥ 2.5) and chronic pain prevalence was observed. The analysis uncovered a U-shaped pattern, with an inflection point at a DII score of - 0.9, indicating an association between both low and high levels of dietary inflammation are associated with higher pain prevalence. This nuanced interaction between dietary inflammation and chronic pain indicates the possibility of incorporating dietary modification into pain management strategies and underscores the need for further research into the long-term effects of diet on chronic pain.

Dietary inflammatory index in relation to salivary cytokine concentrations and periodontitis: A cross-sectional analysis

AIM

To examine the associations of dietary inflammatory index (DII) with salivary cytokine concentrations and periodontitis after controlling for body mass index (BMI), socio-demographic factors and lifestyle.

MATERIALS AND METHODS

Subgroups from two Finnish surveys, DILGOM 2007 and Health 2000, were included (total n = 727). The DII scores were calculated based on a food frequency questionnaire. Periodontal status was assessed with a cumulative risk score in DILGOM 2007 and by pocket depth measurement in Health 2000. From saliva, interleukin (IL)-1β, IL-1 receptor antagonist, IL-6, IL-8, IL-10 and tumour necrosis factor (TNF)-α concentrations were measured.

RESULTS

The DII scores did not differ between non-periodontitis and periodontitis participants in pairwise comparison. After adjusting for energy intake, periodontal status, BMI, age, education level, smoking habit and physical activity, DII was not associated with salivary cytokine concentrations. After adjusting for salivary cytokine levels and other confounding factors, DII was associated with periodontitis in the Health 2000 subgroup but not in the DILGOM 2007 subgroup.

CONCLUSIONS

The current data support the evidence that diet is not associated with salivary cytokine levels but may be associated with periodontitis. The association observed between diet and periodontitis is related to factors other than diet-dependent inflammatory tendency in the oral cavity.

Association of dietary inflammatory index with helicobacter pylori infection and mortality among US population

BACKGROUND

Limited research has been conducted on the potential relationship between the dietary inflammation index (DII) and mortality, particularly in individuals with Helicobacter pylori (H. pylori) infection. This study aimed to investigate the association between the DII and H. pylori infection, as well as their respective impacts on all-cause mortality in a cohort of individuals with or without H. pylori infection.

METHODS

Data from the 1999-2018 National Health and Nutrition Examination Survey (NHANES) were utilized for this study, with a final of 4370 participants included. Both univariable and multivariable-adjusted logistic regression analyses were employed to explore the relationship between H. pylori infection and pertinent covariates. Cox regression analysis, as well as restricted regression cubic spline analysis, were utilized to assess the association between DII and all-cause mortality among individuals with or without H. pylori infection.

RESULTS

The findings demonstrated a positive correlation between DII scores and H. pylori infection, even after adjusting for potential confounding factors. Moreover, higher DII scores were significantly associated with an elevated risk of mortality exclusively in individuals with H. pylori infection, while no such association was observed in the uninfected population. Additional analysis using restricted cubic spline modeling revealed a positive linear relationship between DII scores as a continuous variable and the adjusted risk of all-cause mortality specifically in H. pylori-infected patients.

CONCLUSION

The results of this study indicated that DII was positively correlated with an increased risk of H. pylori infection and was associated with a heightened risk of all-cause mortality solely in individuals with H. pylori infection. Consequently, DII might serve as a useful tool for risk stratification in the H. pylori-infected population among U.S. adults. Further research is warranted to elucidate the underlying mechanisms and potential clinical implications of these findings.

The relationship of dietary inflammatory index and dietary patterns with premenstrual syndrome among women in Kermanshah: An analytical cross-sectional study

Premenstrual syndrome (PMS) is a common psychological condition that occurs continuously during the luteal phase of the menstrual cycle. Potential factors in this syndrome comprise the central nervous system, hormones, genetic background, and nutritional indicators. Little is known about foods or eating patterns that may be associated with this syndrome, yet nutritional factors can be considered in strategies for the management of PMS. The current study purposed to investigate the relationship between PMS and dietary inflammation index as well as PMS and food patterns. The present cross-sectional study was conducted on 125 women and girls aged 20-46 years who experienced symptoms of PMS. The inclusion criteria included cooperation and consent to enter the study, a body mass index of 18.5-25 kg/m², no underlying disease, no use of contraceptives or antidepressants, and no use of multivitamin or mineral supplements. In the first stage of this study, participants' height, weight, waist circumference, and hip circumference were measured. In the second stage, eating habits were examined using a semiquantitative Food Frequency Questionnaire. This study found a significant correlation between glycemic load quintiles as well as between energy and macronutrient intake and the dietary inflammatory index; however, it revealed a direct correlation between PMS and both Western-mixed dietary and high-salt-high-sugar dietary patterns. Moreover, the Western food pattern was found to have a direct correlation with dietary inflammatory index, and the healthy food pattern had an inverse correlation with this index. This study showed that PMS symptoms are more severe with the consumption of high-salt-high-sugar or a Western-mixed food dietary pattern. It seems that an imbalance in hormones and neurotransmitters can affect the metabolism of proteins, carbohydrates, and fats. Also, some foods, such as vegetables, and low-fat and high-fiber diets reduce plasma estrogen levels and the duration of PMS symptoms.