The research finding of dogs having elevated levels of the endocrine disruptor bisphenol A (BPA) from eating canned food mirrors what is happening to humans - eating canned food raises BPA levels in a person. The study also found that elevated BPA levels resulted in changes in the gut microbiome (the community of microbes living in the gut). Specifically, they found the abundance of a number of bacteria species increased or decreased depending on BPA levels in the dogs. This is not good.
This is of concern because BPA is linked to a variety of health problems. [See all posts.] So it's best to minimize exposure to BPA, BPS, and other hormone disrupting chemicals, and also "BPA-free" products (which usually contain BPS). The BPA is in the lining of the cans used in canned food, and this leaches into the food. Unfortunately, dog food cans thought to be BPA-free in the study also contained BPA, which then leached into the dog food. From Futurity:
Researchers saw a three-fold increase in BPA levels in dogs who ate canned dog food for two weeks. They also saw changes in the dogs’ gut microbes. Bisphenol A (BPA) is a widely used industrial chemical found in many household items, including resins used to line metal storage containers, such as food cans. The chemical can disrupt hormones and is linked to a range of health problems. “Bisphenol A is a prevalent endocrine-disrupting chemical found in canned foods and beverages,” says Cheryl Rosenfeld, an associate professor of biomedical sciences in the University of Missouri College of Veterinary Medicine....
Dog owners volunteered their healthy pets for the study. Blood and fecal samples were collected prior to the dogs being placed on one of two commonly used, commercial canned food diets for two weeks; one diet was presumed to be BPA-free. Robert Backus, an associate professor in the veterinary medicine and surgery in the College of Veterinary Medicine, and other researchers on the team then analyzed the cans and the food contained in the cans for BPA levels and performed gut microbiome assessments.
“The dogs in the study did have minimal circulating BPA in their blood when it was drawn for the baseline,” Rosenfeld says.“However, BPA increased nearly three-fold after being on the either of the two canned diets for two weeks. We also found that increased serum BPA concentrations were correlated with gut microbiome and metabolic changes in the dogs analyzed. Increased BPA may also reduce one bacterium that has the ability to metabolize BPA and related environmental chemicals.”
“We share our homes with our dogs,” Rosenfeld says. “Thus, these findings could have implications and relevance to humans. Indeed, our canine companions may be the best bio-sentinels for human health concerns.”
A chemical frequently used in place of BPA called BPS (bisphenol S) and found in "BPA-free" products is also an endocrine disruptor. This also has negative health and behavioral effects. In this study the effects were seen in mice, but they are worrisome. Makes you wonder, what are all the effects in humans? From Science Daily: Plastics compound, BPS, often substituted for BPA, alters mouse moms' behavior and brain regions
In the first study of its kind, environmental health scientists and neuroscientists examined the effects of the compound bisphenol S (BPS) on maternal behavior and related brain regions in mice. They found subtle but striking behavior changes in nesting mothers exposed during pregnancy and lactation and in their daughters exposed in utero. BPS, found in baby bottles, personal care products and thermal receipts, is a replacement chemical for BPA and was introduced when concern was raised about possible health effects of that plastic compound.