Exposure to a widespread environmental chemical could cause changes to chemical tags on DNA, which can impact the expression of genes and potentially increase the risk for disease. Researchers studied one of our closest companions – dogs – and the epigenetic effect of bisphenol-A (BPA) found in canned dog food. Since these animals share our environment more closely than any other species, they offer us valuable insight into the exposure of this toxic chemical and its potential epigenetic influence.
Extensive research has connected BPA to breast cancer, obesity, diabetes, and other serious medical problems, including reproductive issues shown to compromise fertility. For example, epigenetic research has recently shown that BPA can affect fetal development and a similar chemical may even “tip the epigenetic balance”, programming a person for obesity.
BPA has been known to seep into food from containers lined with a sealant containing the chemical. Only recently did the FDA ban BPA from baby bottles and sippy cups. Yet, it is still found in food and drink packaging and elsewhere in the environment to this day.
In this study, a team of researchers looked at circulating concentrations of BPA in dogs that ate canned food from two different manufacturers over a 2 week period. Both types of canned dog food were found to contain BPA, although one was initially verified as BPA-free. Surprisingly, the researchers found that serum BPA concentrations increased by almost 3-fold as a result of both diets.
In order to investigate a potential epigenetic effect of short-term exposure to BPA, they used EpiGentek’s MethylFlash Global DNA Methylation (5-mC) ELISA Easy Kit to quantitate global DNA methylation with a one-step ELISA method. Not only did the levels of BPA in the dogs rise, but the team detected hypomethylation, or an overall loss of methylation, in the circulating lymphocytes of the dogs that ate one type of canned food. Specifically, they found lowered levels of 5-mC, suggesting a potential impact from the chemical on the epigenome.
Although additional research is required to tease out this possible epigenetic effect of BPA, the evidence offers interesting preliminary insight, especially because dogs may be a good biological sensor for hazards to human health, according to the researchers.
“It could be speculated that this epigenetic shift could lead to detrimental gene expression changes, such as increased expression of proto-oncogenes,” the researchers added.
There is much more to be investigated regarding the epigenetic effects of BPA on DNA methylation and the development of disease. BPA will likely continue to be a chemical of great interest, considering its widespread presence and newly discovered epigenetic role.
Source: Koestel, Z.L., et al., (2016). Bisphenol A (BPA) in the serum of pet dogs following short-term consumption of canned dog food and potential health consequences of exposure to BPA, Sci Total Environ.