Adequate intake of plant protein foods and moderate intake of animal protein foods are inversely associated with C-reactive protein in US adults with diabetes: A cross-sectional study with National Health and Nutrition Examination Survey

Food-based indexes and their association with dietary inflammation

Chronic inflammation is associated with an increased risk of noncommunicable diseases, prompting an intensified interest in the diet-disease relationship for modulating inflammation. Diet quality indexes are widely used to quantify dietary patterns. However, the optimal tool for assessing dietary quality in relation to chronic inflammation remains unclear. The objective of this study was to synthesize the literature on food-based diet quality indexes and their association with chronic inflammation. A systematic scoping review of scientific databases was conducted from inception to March 2024. Studies describing the development and validation of original dietary inflammatory indexes or assessed associations between established indexes and inflammatory biomarkers were included. Studies that predominantly focused on nutrient-based indexes were excluded. Forty-three food-based indexes, evaluated across 65 studies, were categorized into 4 distinct groups based on dietary patterns (n = 18), dietary guidelines (n = 14), dietary inflammatory potential (n = 6), and therapeutic diets (n = 5). Established indexes based on the Mediterranean diet and dietary guidelines were the most extensively utilized, demonstrating inverse associations with several inflammatory biomarkers across diverse populations. The Anti-Inflammatory Diet Index, Dietary Inflammation Score, and Empirical Dietary Inflammatory Index were identified as robust, empirically derived indexes to assess diet quality based on their inflammatory potential. The dietary composition of the evaluated indexes ranged from 4 to 28 dietary components, with fruits, vegetables, whole grains, and legumes consistently classified as favorable, whereas red/processed meats and added sugars were unfavorable. This scoping review identified several promising food-based indexes for assessing inflammation-related diet quality. Methodological variations and inconsistencies in algorithms underscore the need for further validation across diverse populations. Future research should consider the scoring methods, dietary composition, and validated inflammatory biomarkers when selecting indexes to evaluate diet-inflammation associations. Understanding the characteristics that underpin these indexes informs their application in nutrition research and clinical practice.

High-protein diet scores, macronutrient substitution, and breast cancer risk: insights from substitution analysis

BACKGROUND

Evidence from recent studies suggested that variation in the quantity and quality of macronutrients in the diet may potentially play a role in predicting the risk of breast cancer (BC). In the current study, we aimed to assess the association of different high-protein diet scores and replacing fats and carbohydrate (CHO) with protein in the diet with the BC risk among Iranian women.

METHODS

The current hospital-based case-control study was conducted on 401 participants, aged ≥ 30 years old, including 134 women in the case group who had been diagnosed with histologically confirmed BC and 267 women in the control group. Dietary intake data was collected using a validated food frequency questionnaire, and high protein diet scores were determined. Logistic regression models were used to determine the odds ratios (OR) and 95% confidence interval (CI) of BC across tertiles of high protein diet scores. Also, we assessed how substituting protein with other macronutrients affected BC odds while adjusting for the various confounding variables.

RESULTS

Participants' mean ± SD of age and body mass index were 47.9 ± 10.3 years and 29.4 ± 5.5 kg/m2, respectively. The scores of high-protein-low-CHO and fat diet, high-protein and CHO-low-fat diet, and high-protein and fat-low-CHO diet in participants were 16.5 ± 3.8, 16.5 ± 6.7, and 16.4 ± 5.9, respectively. In the multivariable model, individuals in the highest tertile of high-protein-low-CHO and fat diet score (OR:0.71;95%CI:0.56-0.90) and high-protein and CHO-low-fat diet (OR:0.76;95%CI:0.60-0.97) had lower odds of BC compared to those in the lowest tertile (P < 0.05). However, no significant association was found between high-protein and fat-low-CHO diet and BC risk. Our results showed that replacing fat by protein (ORdifferences:-0.40;95%CI:-0.73,-0.07) and also replacing refined-CHO by plant protein (ORdifferences:-0.66;95%CI:-1.26,-0.07) in the diet are associated inversely with risk of BC(P < 0.05).

CONCLUSIONS

The results of our study suggested that higher adherence to a high-protein-low-CHO and fat diet, characterized by a higher intake of plant proteins and a lower intake of refined grains and saturated fat can play a protective role against the odds of BC.

The association between diet quality, plant-based diets, systemic inflammation, and mortality risk: findings from NHANES

PURPOSE

To our knowledge, no studies have examined the association of diet quality and plant-based diets (PBD) with inflammatory-related mortality in obesity. Therefore, this study aimed to determine the joint associations of Healthy Eating Index-2015 (HEI-2015), plant-based dietary index (PDI), healthy PDI (hPDI), unhealthy PDI (uPDI), pro-vegetarian dietary index (PVD), and systemic inflammation with all-cause, cardiovascular disease (CVD), and cancer mortality risks by obesity status.

METHODS

Participants from NHANES were included in cross-sectional (N = 27,915, cycle 1999-2010, 2015-2018) and longitudinal analysis (N = 11,939, cycle 1999-2008). HEI-2015, PDI, hPDI, uPDI, and PVD were constructed based on the 24-h recall dietary interview. The grade of inflammation (low, moderate, and high) was determined based on C-reactive protein (CRP) values and multivariable ordinal logistic regression was used to determine the association. Cox proportional hazard models were used to determine the joint associations of diet and inflammation with mortality.

RESULTS

In the fully adjusted model, HEI-2015 (ORT3vsT1 = 0.76, 95% CI 0.69-0.84; p-trend =  < 0.001), PDI (ORT3vsT1 = 0.83, 95% CI 0.75-0.91; p trend =  < 0.001), hPDI (ORT3vsT1 = 0.79, 95% CI 0.71-0.88; p trend =  < 0.001), and PVD (ORT3vsT1 = 0.85, 95% CI 0.75-0.97; p trend = 0.02) were associated with lower systemic inflammation. In contrast, uPDI was associated with higher systemic inflammation (ORT3vsT1 = 1.18, 95% CI 1.06-1.31; p-trend = 0.03). Severe inflammation was associated with a 25% increase in all-cause mortality (ORT3vsT1 = 1.25, 95% CI 1.03-1.53, p trend = 0.02). No association was found between PDI, hPDI, uPDI, and PVD with mortality. The joint association, between HEI-2015, levels of systemic inflammation, and all-cause, CVD and cancer mortality, was not significant. However, a greater reduction in mortality risk with an increase in HEI-2015 scores was observed in individuals with low and moderate inflammation, especially those with obesity.

CONCLUSION

Higher scores of HEI-2015 and increased intake of a healthy plant-based diet were associated with lower inflammation, while an unhealthy plant-based diet was associated with higher inflammation. A greater adherence to the 2015 dietary guidelines may reduce the risk of mortality associated with inflammation and may also benefit individuals with obesity who had low and moderate inflammation.