PURPOSE: Higher ultra-processed food and drink (UPFD) consumption has been linked with increased risk of non-communicable diseases. Low-grade systemic inflammation may partly underlie this relationship, yet limited research on UPFDs exists in this context. We examined UPFD associations with inflammatory biomarkers and explored whether relationships are mediated by adiposity.

METHODS: This was a cross-sectional study of 1,986 middle- to older-aged men and women. Using the NOVA classification, UPFD weight ratios were calculated for each participant. Correlation and multivariate-adjusted linear regression analyses were used to test UPFD intake associations with a wide range of inflammatory biomarkers. Model 1 was age and sex-adjusted while Model 2 additionally adjusted for total energy intake. A third model also adjusted for education, lifestyle behaviours (smoking, alcohol use, physical activity), anti-inflammatory medication use, type 2 diabetes, cardiovascular disease history and cancer. Mediation analyses explored whether relationships were independent or mediated by adiposity, defined by body mass index (BMI) or waist-height ratio (WHtR).

RESULTS: Significant direct effects between UPFD consumption and higher levels of interleukin 6, tumour necrosis factor-alpha, white blood cell counts and constituent neutrophils, basophils, and the neutrophil-to-lymphocyte ratio, were observed in models which controlled for a range of potential confounders, and which additionally adjusted for BMI or WHtR. Higher levels of adiposity were found to mediate relationships between UPFD intake and biomarkers, with the percentage of total effect mediated ranging from 12.7 to 70.1% for models including BMI, and 13.5 to 64.5% for models including WHtR.

CONCLUSIONS: Consumption of UPFDs is associated with a less optimal inflammatory biomarker profile and the total effect of UPFD intake on biomarker concentrations is likely due both to higher levels of adiposity related to UPFD consumption and the pro-inflammatory potential of UPFD products.