Assessing the (anti)-inflammatory potential of diets

Pro-inflammatory diet affects markers of iron metabolism in healthy older adults

BACKGROUND

Inflammation and inadequate nutrition are common in older age and known to affect iron homeostasis. However, it is not known whether a pro-inflammatory diet affects iron status in older adults. We investigated the diet quality of healthy older adults considering markers of iron homeostasis and inflammation compared to a younger control.

METHODS

Serum markers of iron metabolism (iron, transferrin, ferritin, hepcidin, soluble transferrin receptor [sTfR]) and inflammation (interleukin-6 [IL-6], IL-10 high-sensitive C- reactive protein [hsCRP]) were quantified using immunosorbent assays. Insulin resistance was determined by calculating the homeostasis model assessment index (HOMA-IR). The Dietary Inflammatory Index® (DII) was computed based on dietary intake and inflammatory (ID) or less inflammatory diet (LID) groups were created by using median DII score specific to age group and sex.

RESULTS

DII did not differ by age (p = 0.668, n = 80, F: 75 %, >65 years, n = 60, F: 72 %, ≤35 years). Iron and inflammation status were different between age groups in terms of higher transferrin saturation, sTfR, ferritin and IL-6 concentrations in the old (all p ≤ 0.001). Only in older adults, BMI, HOMA-IR, hsCRP, ferritin and hepcidin concentrations were significantly higher in ID compared to LID (all p < 0.01). In addition, a risk-factor adjusted regression analysis showed that ID was independently associated with higher ferritin and hepcidin concentrations in older adults.

CONCLUSION

In older age, a pro-inflammatory diet is associated with systemic inflammation and disturbed iron homeostasis.

Dietary inflammatory index is not associated with bone mineral density in functionally able community-dwelling older adults

BACKGROUND

Osteoporosis poses a significant health and quality-of-life burden on older adults, particularly with associated fractures after a fall. A notable increase in pro-inflammatory cytokines associated with aging contributes to a decline in bone mineral density (BMD). Certain food components have been shown to influence an individual's inflammatory state and may contribute to optimal bone health as a modifiable risk factor, particularly later in life. This study aims to explore the relationship between the dietary inflammatory index (DII) and dietary intake with BMD in community-dwelling older adults.

METHODS

Heathy community-dwelling older adults aged 65-85 years. DII scores were calculated using 24-h dietary recalls, and lumbar spine (L1-L4) and femoral neck (ward's triangle) BMD was assessed via dual-energy x-ray absorptiometry.

RESULTS

A total of 94 participants were recruited (72.9 ± 4.9 years, 76.6% female) with 61.7% identified having an anti-inflammatory diet (average DII = - 0.50 ± 1.6), 88.3% were physically active, 47.8% were osteopenic and 27.7% osteoporotic. There was no significant difference between DII scores, nutrient or food group intake in groups stratified by BMD T-Score except for lean meats and alternatives food group (p = 0.027). Multiple regression analysis found no associations between DII and lumbar spine (unadjusted model β = 0.020, p = 0.155) or femoral neck BMD (unadjusted model β = - 0.001, p = 0.866).

CONCLUSION

Most of this cohort of functionally able community-dwelling older adults followed an anti-inflammatory diet. DII and dietary intake were not associated with BMD. This research underlines the complex interplay between modifiable and non-modifiable risk factors on the BMD of older, physically active adults.

The association between empirical dietary inflammatory pattern and risk of cancer and cancer-specific mortality: a systematic review and meta-analysis of prospective cohort studies

Background/aim

Current evidence indicates a correlation between the inflammatory potential of diet and the risk of cancer and cancer-specific mortality. This study aimed to assess the association between empirical dietary inflammatory pattern (EDIP), which has recently been designed based on the inflammatory potential of the diet, and the risk of cancer and cancer-specific mortality.

Methods

A systematic literature search was conducted across the PubMed/Medline, Scopus, and Web of Science databases from January 2016 to March 2024. A random effects model was used to calculate the pooled effect size (ES) and 95% confidence intervals (95% CI). Heterogeneity between studies was assessed using the Cochran Q test and the I 2 statistic.

Results

From the initial 229 records, 24 prospective cohort studies with 2,683,350 participants and 37,091 cancer incidence cases, as well as 20,819 cancer-specific mortality, were included in our study. Pooled results indicated a significant association between higher adherence to the EDIP and an increased risk of total cancer (ES: 1.10; 95% CI: 1.05-1.15; I 2 = 41.1), colorectal cancer (ES: 1.19; 95% CI: 1.11-1.27; I 2 = 41.1), and liver cancer (ES: 1.48; 95% CI: 1.14-1.94; I 2 = 36.9). However, no significant association between increased adherence to the EDIP and an increased risk of ovarian or endometrial cancer was found. Furthermore, greater adherence to the EDIP was significantly associated with an increased risk of cancer-specific mortality (ES: 1.18; 95% CI: 1.05-1.33; I 2 = 45.4).

Conclusion

Our results showed that a diet with higher inflammatory properties is associated with an increased risk of cancer and cancer-specific mortality.

Systematic review registration

PROSPERO registration no. CRD42024496912.

Anti-inflammatory diets

ABSTRACT

This article reviews inflammatory versus anti-inflammatory foods, autoimmune and inflammatory disorders, the benefits of specific anti-inflammatory diets, and strategies for nurses to partner with individuals, while considering culture and food preferences, to promote healthy eating habits and prevent diseases.

The Association between Dietary Inflammatory Patterns and the Incidence of Frailty and Its Reversal in Older Adults: A Community-Based Longitudinal Follow-Up Study in Taiwan

Dietary patterns related to inflammation have garnered great interest in disease prevention. The aims of this study were to evaluate whether a proinflammatory diet affects the incidence of frailty and its reversal in a prospective follow-up study. Data were taken from 5663 community-dwelling individuals ≥ 55 years old in Taiwan. The energy-adjusted dietary inflammatory index (DII) and the Empirical Dietary Inflammatory Patterns-Healthy Aging Longitudinal Study in Taiwan (EDIP-HALT) at baseline were calculated using a food frequency questionnaire. Frailty was assessed with Fried's criteria in 2008-2013 and 2013-2020. Associations with changes in frailty status were assessed with multinominal logistic regressions and adjusted for major confounders. Higher EDIP-HALST scores (proinflammatory) were associated with higher odds of frailty among baseline robust participants in men (OR = 2.44, 95% CI = 1.42-4.21, p-trend < 0.01) and broadline associated in women (OR = 1.96, 95% CI = 0.96-3.98, p-trend = 0.05), but associated with lower odds of reversing back to robust among baseline prefrail participants. However, the later association was only observed in women, and the relationships were stronger in the middle tertile (second vs. first tertile, OR = 0.40, 95% CI = 0.25-0.65). A pro-inflammatory diet pattern was associated with higher odds of frailty onset in baseline robust participants and lower odds of reversal in baseline prefrail female participants.

Interventions for Pancreatitis-New Approaches, Knowledge Gaps, and Research Opportunities: Summary of a National Institute of Diabetes and Digestive and Kidney Diseases Workshop

ABSTRACT

There exists no cure for acute, recurrent acute or chronic pancreatitis and treatments to date have been focused on managing symptoms. A recent workshop held by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) focused on interventions that might disrupt or perhaps even reverse the natural course of this heterogenous disease, aiming to identify knowledge gaps and research opportunities that might inform future funding initiatives for NIDDK. The breadth and variety of identified active or planned clinical trials traverses the spectrum of the disease and was conceptually grouped for the workshop into behavioral, nutritional, pharmacologic and biologic, and mechanical interventions. Cognitive and other behavioral therapies are proven interventions for pain and addiction, but barriers exist to their use. Whilst a disease specific instrument quantifying pain is now validated, an equivalent is lacking for nutrition - and both face challenges in ease and frequency of administration. Multiple pharmacologic agents hold promise. Ongoing development of Patient Reported Outcome (PRO) measurements can satisfy Investigative New Drug (IND) regulatory assessments. Despite multiple randomized clinical trials demonstrating benefit, great uncertainty remains regarding patient selection, timing of intervention, and type of mechanical intervention (endoscopic versus surgery). Challenges and opportunities to establish beneficial interventions for patients were identified.

Association between Dietary Inflammatory Index and Bone Mineral Density Changes among Pregnant Women: A Prospective Study in China

OBJECTIVES

This study aims to examine the relationship between dietary inflammatory index (DII) and bone mineral density (BMD) changes among Chinese pregnant women, offering valuable insights for dietary guidance during pregnancy.

METHODS

289 pregnant women were enrolled in this cohort. Serum inflammatory factors and ultrasonic BMD were measured at the first, second, and the third trimesters. DII scores were calculated based on a semi-quantitative food frequency questionnaire (FFQ) and divided into tertiles. We compared the differences in inflammatory factors in serum across the tertiles of DII and changes in BMD at the second and third trimesters across the tertiles.

RESULTS

The participants with higher DII scores had higher total energy intakes than those with lower DII scores. The serum level of interleukin-6 (IL-6) was significantly different across the tertiles of the DII. Women who had lower DII scores had higher T-scores and Z-scores in the BMD assessment. In the test of trends, after adjusting potential covariates, including educational level, physical activity, body mass index, and calcium, vitamin D, or multivitamin supplements, DII values were determined to be positively related to the maternal BMD lost.

CONCLUSIONS

DII was positively associated with serum IL-6. Meanwhile, higher DII scores were associated with more bone mass loss in pregnant women. We recommend adhering to a lower-DII diet to preserve BMD during pregnancy.

The feasibility of an anti-inflammatory diet in endometriosis: barriers and facilitators perceived by endometriosis patients

RESEARCH QUESTION

What is the feasibility of an anti-inflammatory diet in women diagnosed with endometriosis?

DESIGN

Qualitative study using semi-structured focus groups and individual interviews among patients with endometriosis. Transcripts of the focus groups and interviews were thematically analysed using ATLAS.ti 9. To identify and structure the ideas and views from the focus groups and interviews, two behavioural change models were used. The Capability Opportunity Motivation Behaviour (COM-B) model and domains of the Theoretical Domains Framework (TDF) helped to identify factors that make adherence to an anti-inflammatory diet more or less feasible for women with endometriosis.

RESULTS

The study population consisted of 23 patients with endometriosis. Numerous perceived barriers and facilitators were identified from all COM-B components and 13 out of 15 TDF domains. Knowledge and social influences were the most prominent TDF domains. Key barriers were eating with others; disbelief in a patients' own capability regarding specific dietary guidelines; concerns about taste; lack of knowledge on how to follow the diet; lack of noticeable beneficial effect; and lack of intention to follow the diet to full extent. Key facilitators were receiving social support; general confidence in a participant's own capabilities; knowing how and why to follow the diet; noticing beneficial effect; and belief that the diet would alleviate symptoms.

CONCLUSION

Provision of knowledge, stimulating social support and enhancing self-efficacy should be emphasized. Overall, an anti-inflammatory diet in endometriosis patients, especially when identified barriers and facilitators are addressed in an intervention, is feasible.

Assessing the influence of preconception diet on female fertility: a systematic scoping review of observational studies

BACKGROUND

Preconception diet is a proposed modifiable risk factor for infertility. However, there is no official guidance for women in the preconception period as to which dietary approaches may improve fertility.

OBJECTIVE AND RATIONALE

A comprehensive synthesis of the relevant evidence is key to determine the potentially effective dietary patterns and components as well as evidence gaps, and to provide information for nutritional recommendations for couples planning a pregnancy.

SEARCH METHODS

In this systematic scoping review, four electronic databases (Medline and EMBASE via Ovid processing, CAB Direct, and CINAHL via EBSCO) were searched for observational studies (prospective and retrospective cohort, cross-sectional, and case-control studies) from inception to 27 September 2021. Eligible studies included women of reproductive age during the preconception period, and evaluated exposures related to preconception diet and outcomes related to fertility. Results were synthesized using a descriptive approach.

OUTCOMES

A total of 36 studies were eligible for inclusion (31 prospective, 3 cross-sectional, and 2 case-control studies) and were published between 2007 and 2022. Of the assessed dietary exposures, increased adherence to the Mediterranean diet displayed the strongest and most consistent association with improved clinical pregnancy rates. Reducing trans fatty acids (TFAs), saturated fatty acids, and discretionary food intake (fast food and sugar-sweetened beverages) were associated with improvements in live birth, clinical pregnancy rates, and related ART outcomes. The dietary components of seafood, dairy, and soy demonstrated inconsistent findings across the few included studies.

WIDER IMPLICATIONS

Due to heterogeneity and the limited available literature on most exposures, there is insufficient evidence to support any specific dietary approach for improving fertility. However, following some of the dietary approaches outlined in this review (anti-inflammatory diets, reducing TFA, and discretionary food intake) are consistent with broad healthy eating guidelines, have little to no associated risk, and offer a plausible set of possible benefits. This warrants further exploration in randomized controlled trials.

Dietary inflammatory patterns are associated with serum triglycerides and insulin in adults: A community-based study in Taiwan

BACKGROUND

Dietary patterns related to inflammation have become a focus of disease prevention but the patterns may vary among populations.

OBJECTIVE

The study was conducted to determine Taiwanese dietary inflammatory patterns and evaluate their associations with biomarkers of lipid and glucose METHODS: Data were taken from 5,664 community-dwelling individuals aged ≥55 years old recruited in 2009 - 2013 in the Healthy Aging Longitudinal Study in Taiwan (HALST). Dietary data were obtained from a food frequency questionnaire. An empirical dietary inflammatory pattern (EDIP) was derived from reduced rank regression models that explained the serum hsCRP, plasma IL-6, and TNFR1. Cross-sectional associations between dietary scores and biomarkers of total cholesterol (TC); high-density lipoprotein cholesterol (HDLC); low-density lipoprotein cholesterol, triglyceride (TG); and ratios of TG/HDLC, TG/TC, fasting glucose, insulin, and HbA1c were analyzed via multiple linear regression and adjusted for major confounders. The false discovery rate (FDR)-adjusted p <0.05 was considered statistically significant. Abdominal obesity was defined as a waist circumference of ≥90 cm for men and ≥80 cm for women.

RESULTS

Higher EDIP-HALST scores were associated with higher TG (per score increment: 1.62%, 95% CI: 0.58-2.76%; p_FDR=0.01), TG/HDLC (2.01%, 0.67-3.37%; p_FDR=0.01), and TG/TC (1.42%, 0.41-2.43%; p_FDR=0.01) and nonlinearly associated with insulin, with those in the middle tertile had the highest serum insulin concentrations (means: 5.12 μIU/mL, 4.78-5.78; p_FDR =0.04) in men, but not in women. No heterogeneity was detected between sexes. The associations with TG (1.23%, 0.19-2.23%; p_trend=0.02), TG/HDLC (1.62%, 0.30-2.96%; p_trend=0.02), and TG/TC (1.11%, 0.11-2.13%; p_trend=0.03) were stronger in participants with abdominal obesity, but were borderline associated in participants with normal abdominal circumferences (all p_trend=0.05).

CONCLUSIONS

Inflammatory diets, as measured via EDIP-HALST, were associated with serum TG concentration, particularly in participants with abdominal obesity. These findings may suggest that developing disease prevention strategies using dietary inflammatory patterns may be different by populations.

Dietary Inflammatory Index and Associations with Sarcopenia Symptomology in Community-Dwelling Older Adults

Low-grade systemic inflammation is a key driver of muscle degeneration in older adults, and diets with pro-inflammatory properties may further contribute to loss of muscle mass, strength and function. Therefore, this research aimed to explore the associations between the inflammatory potential of the diet and measures of sarcopenia symptomology in community-dwelling older adults. Upper (handgrip strength, HGS) and lower extremity (sit-to-stand) muscle strength, physical performance (timed-up-and-go, TUG) and appendicular skeletal muscle mass (ASM) was assessed according to the European Working Group on Sarcopenia in Older People version 2 (EWGSOP2) criteria. Multiple 24-hr dietary recalls were used to calculate the Dietary Inflammatory Index (DII), which was then used to group participants into anti- and pro-inflammatory dietary groups. Multiple linear regression investigated associations between DII, muscle strength, physical performance, and muscle quantity adjusted for age, gender, comorbidities, waist circumference and physical activity. Adults 65-85 years (n = 110, 72.1 ± 4.7 years, 76.4% female) were recruited. One participant was identified with sarcopenia, 35.2% were pre-frail, or frail. More participants with a pro-inflammatory DII score had low muscle quantity than those with anti-inflammatory DII (3.4% vs. 6.4%, x² = 4.537, p = 0.043) and DII was negatively associated with HGS (β = -0.157, p = 0.016) and ASM (β = -0.176, p = 0.002) which remained significant after adjusting for covariates. In this population, DII was associated with less favorable muscle strength, physical performance, and muscle quantity.

Anti-Inflammatory Diets in Fertility: An Evidence Review

Infertility is a global health concern affecting 48 million couples and 186 million individuals worldwide. Infertility creates a significant economic and social burden for couples who wish to conceive and has been associated with suboptimal lifestyle factors, including poor diet and physical inactivity. Modifying preconception nutrition to better adhere with Food-Based Dietary Guidelines (FBDGs) is a non-invasive and potentially effective means for improving fertility outcomes. While several dietary patterns have been associated with fertility outcomes, the mechanistic links between diet and infertility remain unclear. A key mechanism outlined in the literature relates to the adverse effects of inflammation on fertility, potentially contributing to irregular menstrual cyclicity, implantation failure, and other negative reproductive sequelae. Therefore, dietary interventions which act to reduce inflammation may improve fertility outcomes. This review consistently shows that adherence to anti-inflammatory diets such as the Mediterranean diet (specifically, increased intake of monounsaturated and n-3 polyunsaturated fatty acids, flavonoids, and reduced intake of red and processed meat) improves fertility, assisted reproductive technology (ART) success, and sperm quality in men. Therefore, integration of anti-inflammatory dietary patterns as low-risk adjunctive fertility treatments may improve fertility partially or fully and reduce the need for prolonged or intensive pharmacological or surgical interventions.

Dietary Inflammatory Index score and prodromal Parkinson's disease incidence: The HELIAD study

AIM

The aim of the present study was to investigate the association of the inflammatory potential of diet with prodromal Parkinson's disease (pPD) probability and incidence among community-dwelling older individuals without clinical features of parkinsonism at baseline.

METHODS

The sample consisted of 1,030 participants 65 years old or older, drawn from a population-based cohort study of older adults in Greece (Hellenic Longitudinal Investigation of Aging and Diet - HELIAD). We calculated pPD probability, according to International Parkinson and Movement Disorder Society research criteria. Dietary Inflammatory Index (DII) was used to measure the dietary inflammatory potential, with higher index score reflecting a more pro-inflammatory diet. Associations of baseline DII with pPD probability cross-sectionally, and with possible/probable pPD incidence (pPD probability ≥30%) during the follow-up period, were examined via general linear models and generalized estimating equations, respectively.

RESULTS

Cross-sectionally, one unit increase of DII score[DII (min, max) = -5.83, 6.01]was associated with 4.9% increased pPD probability [β=0.049, 95%CI (0.025-0.090), p<0.001]. Prospectively, 62 participants developed pPD during 3.1±0.9 (mean±SD) years of follow-up. One unit increase in DII was associated with 20.3% increased risk for developing pPD [RR=1.203, 95%CI (1.070-1.351), p=0.002]. Participants in the highest tertile of DII score were 2.6 times more likely to develop pPD [β=2.594, 95%CI (1.332-5.050), p=0.005], compared to those in the lowest tertile.

CONCLUSION

More pro-inflammatory diet was related with higher pPD probability and pPD incidence (pPD probability ≥30%) in a community-dwelling older adult population. Further studies are needed to confirm these findings.

Obesity: Treatments, Conceptualizations, and Future Directions for a Growing Problem

Interventions in obesity management include nutritional selection, diet restriction, and physical exercise, followed by cognitive behavioral strategies, pharmacology, and surgery towards the tapered treatment end of the obesity pyramid of interventions. Calorie restriction, regular exercise, and several weight reducing drugs, including probiotic and prebiotic use, are increasing in the market as potential anti-obesity treatments all over the world. Despite these efforts, obesity is increasing and is at epidemic levels. We propose here that there should be a multicomponent individual specific treatment approach for treating this multifactorial pathogenesis, incorporating psychological assessment as a first step that may help to reduce the prevalence of this alarming epidemic. We also believe that focusing on psychological screening may not be enough to control this epidemic without government and community cooperation and intervention. Additionally, we suggest that it is imperative to take advantage of the developments in web-based counseling and artificial intelligence expansion in combination with available anti-obesity treatments to make treatments feasible, accessible, and cost-effective for populations of all ages. The purpose of this paper is to increase awareness and stimulate debate in relation to this growing problem.

The Partitioning of Newly Assimilated Linoleic and α-Linolenic Acids Between Synthesis of Longer-Chain Polyunsaturated Fatty Acids and Hydroxyoctadecaenoic Acids Is a Putative Branch Point in T-Cell Essential Fatty Acid Metabolism

Longer-chain polyunsaturated fatty acids (LCPUFAs) ≥20 carbons long are required for leukocyte function. These can be obtained from the diet, but there is some evidence that leukocytes can convert essential fatty acids (EFAs) into LCPUFAs. We used stable isotope tracers to investigate LCPUFA biosynthesis and the effect of different EFA substrate ratios in human T lymphocytes. CD3⁺ T cells were incubated for up to 48 h with or without concanavalin A in media containing a 18:2n-6:18:3n-3 (EFA) ratio of either 5:1 or 8:1 and [¹³C]18:3n-3 plus [d₅]18:2n-6. Mitogen stimulation increased the amounts of 16:1n-7, 18:1n-9, 18:2n-6, 20:3n-6, 20:4n-6, 18:3n-3, and 20:5n-3 in T cells. Expression of the activation marker CD69 preceded increased FADS2 and FADS1 mRNA expression and increased amounts of [d₅]20:2n-6 and [¹³C]20:3n-3 at 48 h. In addition, 22-carbon n-6 or n-3 LCPUFA synthesis was not detected, consistent with the absence of ELOVL2 expression. An EFA ratio of 8:1 reduced 18:3n-3 conversion and enhanced 20:2n-6 synthesis compared to a 5:1 ratio. Here, [d₅]9- and [d₅]-13-hydroxyoctadecadienoic (HODE) and [¹³C]9- and [¹³C]13-hydroxyoctadecatrienoic acids (HOTrE) were the major labelled oxylipins in culture supernatants; labelled oxylipins ≥20 carbons were not detected. An EFA ratio of 8:1 suppressed 9- and 13-HOTrE synthesis, but there was no significant effect on 9- and 13-HODE synthesis. These findings suggest that partitioning of newly assimilated EFA between LCPUFA synthesis and hydroxyoctadecaenoic acid may be a metabolic branch point in T-cell EFA metabolism that has implications for understanding the effects of dietary fats on T lymphocyte function.