Exposure to chemicals commonly found in plastic changes the way fat is stored in the cells, scientists say. This could in turn increase individuals' risk of developing obesity.

In the past, a number of studies have looked at how chemicals called phthalates – found in everything from home products to soap and nail polish – impact human health. Exposure to phthalates was subsequently associated with a wide range of diseases. "Phthalate exposure can be closely associated with the rise of different types of disease development", Lei Yin, researcher at UGA College of Public Health pointed out.

However, no link was established up to now with obesity. In her recent research, published in the journal Toxicology in Vitro, Yin investigates how benzyl butyl phthalate (BBP) affects the good functioning of the cells, in particular when it comes to the processing of fats and oils.

Mouse model

The scientists used mouse cells to create in vitro models, in order to analyse how lipids accumulated within the cells, when said cells were exposed to BBP. The cells were observed via two methods. The first one was a classic staining approach, during which cells as coloured to be more visible under a microscope, the second one consisted in a "celomics high-content analysis". This screening technique involves an automated quantification of lipid droplets.

Thanks to both methods, the researchers were able to quantify the extent of lipid accumulation in the cells. Then, the results of BBP's effects were compared with bisphenol A (BPA) an environmental endocrine active substance known to influence how fat cells develop.

The scientists noted that BBP and BPA exposures induced similar responses: both led to an accumulation of lipid droplets. The only notable difference was the droplets from BBP-treated cells were larger.

Although more research needs to be done, because findings on mouse models cannot directly be replicated to humans, this is a first clear indication that BBP exposure may further increase the risk of obesity.