Higher Dietary Inflammatory Index Score is Associated with a Greater Risk of High Allostatic Load in US Adults: National Health and Nutrition Examination Survey, 2017-2020.

Abstract

Background: Allostatic load (AL) is a comprehensive indicator of chronic stress. Foods with pro-inflammatory properties can increase the risk of elevated AL levels. However, no studies have explored the association between AL and dietary inflammation.

Objective: The aim of this study was to investigate the relationship between dietary inflammatory index (DII) scores and AL.

Design: This cross-sectional study examined dietary data from 24-hour dietary recalls and biomarkers associated with AL in adult participants aged ≥18 years from the National Health and Nutrition Examination Survey (NHANES) (2017-2020).

Participants/setting: NHANES examines a nationally representative sample of approximately 5,000 individuals each year. A total of 15,560 participants were surveyed during the 2017-2020 period, and 1,577 participants were ultimately included in this study.

Main outcome measures: Twenty-six dietary components were selected to calculate the DII, while 10 biomarkers representing the cardiovascular, metabolic, and immune systems were chosen to calculate the AL.

Statistical analyses performed: Logistic regression and linear regression analyses were employed to investigate the relationship between DII and AL, and between each biomarker. Subgroup analyses were conducted based on sociodemographic variables, including age, gender, race/ethnicity, and BMI.

Results: The risk of high AL was 1.53 times higher in those with DII scores in the highest quartile than in those with DII scores in the lowest quartile (OR: 1.53; 95% CI: 1.00, 2.36; P_trend=0.04). For each unit increase in DII, the probability of having high AL increased by 11% (OR: 1.11; 95% CI: 1.01, 1.21; P_trend=0.03). Higher DII scores were significantly associated with higher systolic blood pressure, diastolic blood pressure, pulse, waist-hip ratio, and high-sensitivity C-reactive protein levels. Higher DII scores were also significantly associated with lower total cholesterol and high-density lipoprotein cholesterol levels (P<0.05). The association between DII score and AL was more pronounced in women [(OR_Quartile3vs1:2.04; 95%CI: 1.15, 3.61); (OR_Quartile4vs1:2.07; 95%CI: 1.18, 3.62) P_trend=0.01] and in those with a BMI < 24.9 kg/m² (OR_Quartile3vs1:4.74; 95%CI: 1.21, 18.05; P_trend=0.03).

Conclusions: This study found that higher DII scores were associated with greater risk of high AL. Further research with more rigorous study designs is needed to build upon these results and evaluate the effect of diets with low inflammatory potential (low DII scores) on AL.