Life-Time Environmental Chemical Exposure and Obesity: Review of Epidemiological Studies Using Human Biomonitoring Methods

Abstract

The exponential global increase in the incidence of obesity may be partly attributable to environmental chemical (EC) exposure. Humans are constantly exposed to ECs, primarily through environmental components. This review compiled human epidemiological study findings of associations between blood and/or urinary exposure levels of ECs and anthropometric overweight and obesity indices. The findings reveal research gaps that should be addressed. We searched MEDLINE (PubMed) for full text English articles published in 2006–2020 using the keywords “environmental exposure” and “obesity”. A total of 821 articles were retrieved; 102 reported relationships between environmental exposure and obesity indices. ECs were the predominantly studied environmental exposure compounds. The ECs were grouped into phenols, phthalates, and persistent organic pollutants (POPs) to evaluate obesogenic roles. In total, 106 articles meeting the inclusion criteria were summarized after an additional search by each group of EC combined with obesity in the PubMed and Scopus databases. Dose-dependent positive associations between bisphenol A (BPA) and various obesity indices were revealed. Both individual and summed di(2-ethylhexyl) phthalate (DEHP) and non-DEHP metabolites showed inconsistent associations with overweight and obesity indices, although mono-butyl phthalate (MBP), mono-ethyl phthalate (MEP), and mono-benzyl phthalate (MBzP) seem to have obesogenic roles in adolescents, adults, and the elderly. Maternal exposure levels of individual POP metabolites or congeners showed inconsistent associations, whereas dichlorodiphenyldichloroethylene (DDE) and perfluorooctanoic acid (PFOA) were positively associated with obesity indices. There was insufficient evidence of associations between early childhood EC exposure and the subsequent development of overweight and obesity in late childhood. Overall, human evidence explicitly reveals the consistent obesogenic roles of BPA, DDE, and PFOA, but inconsistent roles of phthalate metabolites and other POPs. Further prospective studies may yield deeper insights into the overall scenario.

Association of environmental exposure to perchlorate, nitrate, and thiocyanate with overweight/obesity and central obesity among children and adolescents in the United States of America using data from the National Health and Nutrition Examination Survey (NHANES) 2005–2016

“…Throughout our lifetime, chronic exposure to obesogens is likely the primary cause of obesity and metabolic disorders (Trasande et al., 2016 ). Some obesogens (e.g., bisphenols and phthalates) are lipophilic, accumulating in the adipose tissue of obese women and changing their chromatin organization and structure to influence the development of obesity in their offspring (Mohanto et al., 2021 ). Microplastics can induce oxidative stress and affect adipocyte differentiation following accumulation in liver and kidney, altering the energy balance and lipid metabolism (Kannan et al., 2021 ).…”

“…Microplastics can induce oxidative stress and affect adipocyte differentiation following accumulation in liver and kidney, altering the energy balance and lipid metabolism (Kannan et al., 2021 ). Furthermore, additives and monomers cause indirect toxicity for humans by promoting adipogenesis and lipid accumulation (Mohanto et al., 2021 ). A previous study demonstrated that chlorophenol, another environmental pollutant, was positively associated with central obesity in Korean girls.…”

From a toxin to an obesogen: a review of potential obesogenic roles of acrylamide with a mechanistic approach

“… 22 , 140 , 142 , 143 , 160–162 The exposure levels of humans to environmental chemicals are generally estimated by biomonitoring of these chemical’s essential compounds or metabolites in human urine or blood as exposure biomarkers. 163 DNA adducts of acrylamide might be used as biomarkers for monitoring chronic internal exposure to acrylamide. 164 In addition, hemoglobin adducts of acrylamide (HbAA) and its metabolite glycidamide (HbGA) can also be considered as biomarkers of exposure.…”

The EU chemicals strategy for sustainability: an opportunity to develop new approaches for hazard and risk assessment

“…The WHO and others proposed that various sources of chemical exposure need to be associated with negative health outcomes (Naidu et al 2021 ; Prüss-Ustün et al 2011 ; WHO 2016 ). Potential human health effects due to exposure to chemicals have, for instance, been discussed for neurodevelopmental disorders (Bennett et al 2016 ), obesity (Mohanto et al 2021 ) or male reproductive health (Foresta et al 2018 ; Pollard et al 2019 ; Wu et al 2022 ).…”