Plastics might be making us fat

An emerging view among scientists is that the rise of obesity may be associated to chemicals in modern life that disrupt the human metabolism, even at very low doses.

Some of these chemicals, known as “obesogens,” boost the production of specific cell types and fatty tissues related to obesity, reports The Washington Post.

But these chemicals are found across modern conveniences like plastic packaging, clothes and furniture, cosmetics, food additives, herbicides and pesticides.

“Obesogens are certainly a contributing factor to the obesity epidemic,” Bruce Blumberg, an expert on obesity and endocrine-disrupting chemicals from the University of California, Irvine, told The Washington Post.

“The difficulty is determining what fraction of obesity is related to chemical exposure.”

Much research on obesity focused on other factors like genetics, stress and diet.

But more and more research points to plastics as a key component of the worsening global obesity epidemic. The incidence of obesity worldwide has tripled since the 1970s, according to The Washington Post.  

Recent research found that obesogens are harmful in ways that traditional chemical toxicology misses, like how its effects may not appear in one’s lifetime but can be passed down to the next generation via epi-genetics.

For example, an experiment where mice were exposed to supposedly safe amounts of tribulytin, or TBT, a chemical used in wood preservatives, resulted in significantly increased fat accumulation for the next three generations of mice. 

Almost 1,000 obesogens that disrupt the normal biochemistry of the endocrine system, which regulates the body’s functions, have been documented in studies with animals or humans. Among these is Bisphenol A, a chemical widely used in plastics, and the phthalates – plasticizing agents used in paints, medicine and cosmetics, reports The Washington Post.

Alex Tabarokk of economics blog Marginal Revolution points out an important piece of supporting evidence – animals are also getting fatter. He cites a 2011 paper that found that cats, dogs and even control mice used for laboratory experiments – who are fed a very standard diet – have all gained weight on average over the past several decades.