The association between organic food consumption and biomarkers of inflammation, C-reactive protein (CRP) and cystatin C (CysC) was explored in this cross-sectional analysis of older adults.

Dietary data and organic food consumption was collected in 2013 from a FFQ. Alternative Mediterranean diet score (A-MedDiet) was calculated as a measure of healthy eating. Biomarkers CRP and CysC were collected in serum or plasma in 2016. We used linear regression models to assess the associations between organic food consumption and CRP and CysC.

This cross-sectional analysis uses data from the nationally representative, longitudinal panel study of Americans over 50, the Health and Retirement Study.

The mean age of the analytic sample (n 3815) was 64·3 (se 0·3) years with 54·4 % being female.

Log CRP and log CysC were inversely associated with consuming organic food after adjusting for potential confounders (CRP: β = –0·096, 95 % CI 0·159, –0·033; CysC: β = –0·033, 95 % CI –0·051, –0·015). Log CRP maintained statistical significance (β = –0·080; 95 % CI –0·144, –0·016) after additional adjustments for the A-MedDiet, while log CysC lost statistical significance (β = –0·019; 95 % CI –0·039, 0·000). The association between organic food consumption and log CRP was driven primarily by milk, fruit, vegetables and cereals, while log CysC was primarily driven by milk, eggs and meat after adjustments for A-MedDiet.

These findings support the hypothesis that organic food consumption is inversely associated with biomarkers of inflammation CRP and CysC, although residual confounding by healthy eating and socioeconomic status cannot be ruled out.