Obesity and endocrine-disrupting chemicals

Abstract

Obesity is now a worldwide pandemic. The usual explanation given for the prevalence of obesity is that it results from consumption of a calorie dense diet coupled with physical inactivity. However, this model inadequately explains rising obesity in adults and in children over the past few decades, indicating that other factors must be important contributors. An Endocrine-Disrupting Chemical (EDC) is an exogenous chemical, or mixture that interferes with any aspect of hormone action. EDCs have become pervasive in our environment, allowing humans to be exposed daily through ingestion, inhalation, and direct dermal contact. Exposure to EDCs has been causally linked with obesity in model organisms and associated with obesity occurrence in humans. Obesogens are chemicals, including some EDCs that promote adipogenesis and obesity, in vivo, by a variety of mechanisms. The environmental obesogen model holds that exposure to obesogens elicits a predisposition to obesity and that such exposures may be an important yet overlooked factor in the obesity pandemic. Effects produced by EDCs and obesogen exposure may be passed to subsequent, unexposed generations. This “generational toxicology” is not currently factored into risk assessment by regulators but may be another important factor in the obesity pandemic as well as in the worldwide increases in the incidence of noncommunicable diseases that plague populations everywhere. This review addresses the current evidence on how obesogens affect body mass, discusses long-known chemicals that have been more recently identified as obesogens, and how the accumulated knowledge can help identify EDCs hazards.

Adipogenic activity of chemicals used in plastic consumer products

“…In contrast, the other active samples contain very low levels of these chemicals (PS 2, PP 4, PUR 2, PUR 3). Interestingly, we did not detect organotin compounds or bisphenols (SI Appendix Excel Table S1) despite these are known MDCs and thought of as being common in PVC and other plastics (16,17).…”

“…Adipogenic activity of plastic consumer products. We hypothesized that plastic products contain MDCs based on the fact that a small set of compounds used in plastics is known to induce adipogenesis in vitro and in vivo (8,16,17). However, the current focus on few, individual plastic chemicals neglects the chemical complexity of plastic materials given that we know that thousands of compounds are either used in plastics or non-intentionally present (13,14).…”

“…We built a list of 120 know adipogenic chemicals (SI Appendix Tab. S3) by searching Web of Science (Core Collection) for studies investigating chemicals in the adipogenesis assay and complemented the search with chemicals reviewed by Amato et al (16). We cross-referenced the list with the tentatively identified compounds in the plastic samples to determine whether some of these compounds are MDCs (Tab.…”

“…Building on these results and the fact that bisphenols and phthalates are known metabolism disrupting chemicals (MDCs; 8, 16, 17 ), we hypothesized that MDCs are present in plastic consumer products and that metabolic disruption might represent a common but understudied toxicological property of plastic chemicals. To explore this, we used the same plastic consumer products we have extensively characterized previously ( 15 ), and investigated the extracts’ adipogenic activity in differentiation experiments with murine 3T3-L1 cells.…”

Obesogens: How They Are Identified and Molecular Mechanisms Underlying Their Action

“…While EDCs can affect multiple physiological systems, recent research has placed much needed focus on chemicals that might be associated with the rising rates of metabolic syndrome and obesity. A subset of EDCs act as obesogenschemicals that lead to increased fat storage, in vivo after exposure [reviewed in (22)(23)(24)]. The environmental obesogen model proposes that obesogens cause greater susceptibility to weight gain, lipid storage, and energy imbalances that lead to obesity (25).…”