Prenatal Exposure to Butyl Paraben Is Associated With Fat Percentage in 7-Year-Old Boys

Abstract

Context Parabens are used as preservatives in consumer products but are suspected of having endocrine-disrupting properties. A recent study reported an association between in utero exposure to butyl paraben and overweight in childhood, with a stronger trend in girls. Objective We therefore studied the association between parabens in maternal urine in third trimester and fat percentage in children aged 7 years. Design, setting & Participants We used data from the Odense Child Cohort, a mother-child cohort with enrollment from 2010-2012, in which the children are followed. Paraben concentration was assessed in maternal urine at median gestational week 28.7 and body composition measured as total, gynoid, and android fat percentages assessed by Dual Xray Absorptiometry in their children at age 7 years. Main Outcome Measurements Total, Gynoid, and Android fat percentages and z-score for BMI. Interventions None Results Paraben exposure was low. In multivariate linear regressions, detection of butylparaben in maternal urine was associated with an increase of 17% (95% confidence intervals CI 3.0%;32%) in total body fat percentage and an increase of 23% (95% CI 5.1%;43%) in android fat percentage in boys, compared to boys whose mother had no detectable butylparaben in urine. No significant associations between in utero exposure to methyl-, ethyl- or propyl parabens and body composition were found, and no significant associations were seen in girls. Conclusion Our findings suggest that parabens, which are believed to have low toxicity, may affect obesity development at vulnerable time periods during development

Impact of Paraben Exposure on Adiposity-Related Measures: An Updated Literature Review of Population-Based Studies

“…The majority of these studies showed that parabens could cross the placental barrier [ 28 , 29 , 30 , 31 ]. Early life exposure to parabens is associated with increases in the gestational weight gain (GWG) rate [ 32 ], changes in height, head, hip, or arm circumference [ 28 , 30 , 33 , 34 ], z-scores of bodyweight [ 35 ], BMI or BMI z-scores [ 31 , 36 , 37 ], and overweight status in early childhood [ 38 ], although the direction of associations depends on the type of parabens and gender ( Table 1 ). However, results from one large-scale (n = 1015 mother–child pairs) and one small-scale study (n = 99 mother–newborn pairs) did not show any clear association.…”

“…Estrogens play a critical role in the development of obesity [ 46 , 47 ] and parabens interfere with the estrogen metabolism pathway [ 48 , 49 ]. In vitro maternal butylparaben (BuP) exposure increases the weight of female offspring, but not male offspring mice [ 37 ], which may support the observed gender-specific effects in some of the studies, although the latter has not been consistent ( Table 1 ) [ 30 , 33 , 34 , 35 , 36 , 37 , 41 ]. Both estrogen and androgen are critical in regulating adiposity and metabolism.…”

“…Paraben content can also vary substantially among different food products [ 51 ]. Furthermore, among the early-life adiposity-related measures (for example, gestational weight gain (GWG), GWG rates, length at birth, head, arm, hip, chest circumference, BMI, BMI z-score and percentage of fat), the most reliable predictor(s) for subsequent later-life health outcomes is yet to be determined [ 36 , 52 , 53 , 54 , 55 ].…”

“…Caution is also needed when interpreting data with a low detection rate of certain parabens in the biological samples used. In some studies, the concentrations of certain parabens in most samples were lower than the limit of detection (LOD); therefore, dichotomization (e.g., paraben levels were treated as a binary variable, either below LOD or above LOD) was used for data analysis [ 33 , 35 , 36 ], leading to the loss of information and statistical power [ 57 ]. Dichotomization may also increase the chance of false-positive findings [ 58 ].…”

“…Dichotomization may also increase the chance of false-positive findings [ 58 ]. In addition, the threshold effects and dose-dependent associations cannot be examined when dichotomization is applied [ 36 ]. A few studies used mixed-pollutant models to account for the complex exposure patterns of common endocrine disruptors while controlling for potential co-pollutant confounding [ 38 , 39 ].…”