Poly- and perfluoroalkyl substances (PFAS) in the first 1000 days reduce linear growth, lean body mass and bone mineral density at age 3 years.

Background And Aims: Poly- and perfluoroalkyl substances (PFAS) are non-degradable, man-made-chemicals. They are considered to be 'Endocrine Disrupting Chemicals' (EDCs), a group of chemicals which interfere with endocrine processes and cause adverse effects on perinatal, neurodevelopmental, metabolic and reproductive outcomes. Especially when exposure occurs during susceptible periods of development, such as early life. Infants who had exclusive breastfeeding (EBF) for at least 3 months, have persistently 3-times higher PFAS plasma levels compared to infants who had exclusive formula feeding (EFF) during the 'first 1000 days' of life. However their effects on growth and body composition outcomes are lacking. We investigated the associations between early life plasma PFAS levels and growth, body composition and metabolic outcomes at age 3 years. Secondly, we studied if the influence of PFAS was different for EBF- and EFF-children, in order to examine if PFAS exposure through human milk diminishes the known health benefits of breastfeeding.

Methods: In 237 healthy term-born infants (99 EBF, 57 EFF and 81 mix), included in Sophia Pluto birth cohort, we determined anthropometrics, blood pressure, body composition and total body bone mineral density (BMD) by Dual-energy-X-ray Absorptiometry (DXA) at age 3 years. The plasma levels of 5 PFAS were determined by liquid-chromatography-electrospray-ionization-tandem-mass-spectrometry (LC-ESI-MS/MS) in samples collected at age 3 months and 2 years. We studied the associations between plasma PFAS levels and outcomes at age 3 years using multiple regression models, corrected for confounders, such as feeding practices in early life.

Results: Higher PFAS levels at age 3 months and 2 years were associated with less linear growth from birth until age 3 years (B: -0.068, p = 0.004 and B:-0.105, p < 0.001) and with shorter height SDS (B: -0.063, p = 0.010 and B:-0.099,p < 0.001) at age 3 years. Additionally, higher PFAS levels at age 2 years were associated with lower lean body mass (LBM) SDS and lower BMD SDS at age 3 years (B: -0.064, p = 0.003 and B:-0.075, p = 0.018, respectively). In contrast, exclusive breastfeeding for at least 3 months was positively associated with the same outcomes (B: 0.204, p = 0.010 and B: 0.274, p = 0.019, respectively).

Conclusions: Higher plasma PFAS levels in 'the first 1000 days' of life were negatively associated with height, LBM and BMD SDS at age 3 years, while exclusive breastfeeding during the first 3 months of life was positively associated with these outcomes. This suggest that early life plasma PFAS levels could jeopardize breastfeeding's known health benefits, which warrants further research.