Association of urinary glyphosate levels with iron homeostasis among a representative sample of US adults: NHANES 2013–2018

Abstract

Purpose: Glyphosate and glyphosate-based herbicides (GBH), widely used globally, were initially considered harmless to humans. Experimental studies have suggested that these substances can disrupt iron homeostasis by interfering with iron uptake or triggering inflammatory responses. However, their potential impact on human iron homeostasis remains underexplored. Approach and results: We analyzed data from 5812 participants aged three and older from the 2013 to 2018 NHANES. We investigated the relationships between urinary glyphosate levels, oral iron intake, and markers of iron homeostasis, including serum iron, unsaturated iron-binding capacity (UIBC), total iron-binding capacity (TIBC), transferrin saturation, ferritin, and transferrin receptor. Higher urinary glyphosate levels were positively associated with oral iron intake (β = 1.310, S.E. = 0.382, P = 0.001). A one-unit increase in the natural logarithm (ln)-glyphosate was associated with lower serum iron (β = − 4.236, 95 % CI = − 6.432 to − 2.039, P < 0.001) and ferritin (β = − 9.994, 95 % CI = − 17.342 to − 2.647, P = 0.009), and higher UIBC (β = 5.431, 95 % CI = 1.061–9.800, P = 0.018) and transferrin receptor levels (β = 0.139, 95 % CI = 0.015–0.263, P = 0.029). Increasing glyphosate exposure was associated with significant decreases in serum iron and ferritin across exposure quintiles (trend P-values = 0.003 and 0.018, respectively). Conclusions: Higher glyphosate exposure is associated with reduced iron availability, suggesting potential disruptions in iron absorption. These findings underscore the need for further research into the health implications of glyphosate exposure on iron homeostasis.

Keywords

• Ferritin
• Glyphosate
• Glyphosate-based herbicides (GBH)
• Iron homeostasis
• National Health and Nutrition Examination Survey (NHANES)
• Serum iron