Feeding Canned Food? This Can Happen After Just 2 Weeks

Analysis by Dr. Karen Shaw Becker

bpa in canned pet food

Story at-a-glance

  • A 2017 study concluded that even short-term feeding of canned dog food dramatically increases dogs’ exposure to Bisphenol A (BPA), an industrial chemical
  • BPA is an endocrine disruptor that is associated with a range of health problems in both humans and animals
  • After just two weeks eating two different brands of widely available canned dog food, BPA levels tripled in the dogs in the study
  • BPA exposure also caused metabolic changes and alterations in the gut microbiome of the dogs
  • It’s impossible to know if canned dog food labeled “BPA-free” really is, other than to ask companies for third party validation

This is a watch-out for all of you parents out there who feed your canine companion canned dog food. A study published in 2017 in the journal Science of the Total Environment, conducted by researchers at the University of Missouri, indicates that even short-term feeding of canned dog food results in a significant increase of BPA (Bisphenol A) in dogs.1

Serious Health Problems Linked to Bisphenol A

Bisphenol A is found in a wide range of household products, including hard plastic water and baby bottles, consumer electronic and sports equipment, DVDs and CDs, medical and dental devices, eyeglass lenses, dental sealants and fillings, and thermal paper, including store receipts. It's also found in the epoxy resins used as coatings inside food and drink cans.

Bisphenol A is an endocrine disruptor. It's an industrial chemical that according to Medical News Today "… interferes with the production, secretion, transport, action, function and elimination of natural hormones."2

BPA has the ability to imitate the body's hormones, especially estrogen, in ways that are damaging to the health of both humans and animals. In humans, exposure to BPA has been linked to:3

  • Reproductive disorders and breast cancer in women and impotence in men
  • Heart disease, diabetes, and liver-enzyme abnormalities
  • Problems in brain function, memory, and learning
  • Reduced effectiveness of chemotherapy treatment
  • Asthma

After 2 Weeks Eating Canned Dog Food, BPA Levels Tripled

For most animals, including humans, exposure to BPA occurs primarily through diet. Since there's been very little investigation into BPA in commercial dog food and its potential influence on the health of dogs, researchers at the University of Missouri wanted to determine if short-term feeding of widely available commercial canned food could alter blood concentrations of BPA in dogs.

The research team also looked at whether BPA exposure from the canned food affected the dogs' gut bacteria or caused metabolic changes.

The two-week study included 14 healthy pet dogs who were normally fed kibble. The dogs' guardians were instructed not to use plastic serving utensils or bowls (that might contain BPA) for the two weeks, and to refrain from offering treats stored in plastic containers.

Blood and stool samples (used for microbiome assessments) were taken before and after the two-week period, during which the dogs were fed one of two widely available canned dog foods, one of which claimed to be BPA-free. The cans and the food in them were also analyzed for BPA levels.

According to study author Cheryl Rosenfeld, an associate professor of biomedical sciences in the MU College of Veterinary Medicine and an investigator in the Bond Life Sciences Center:

"The dogs in the study did have minimal circulating BPA in their blood when it was drawn for the baseline. However, BPA increased nearly three-fold after being on 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."4

In other words, the dogs had low levels of BPA in their blood at the start of the study, but those levels tripled during the two-week period when they were eating the canned foods – including the one that claimed to be BPA-free. Upon analysis, that food did indeed contain BPA. Neither of the pet foods used in the study was identified. More about that shortly.

BPA Exposure Also Triggered Changes in the Gut Microbiome

In addition to the increased levels of BPA in their blood, the dogs also underwent metabolic changes and alterations in their gut bacteria. The researchers theorize the BPA may have depleted a bacteria strain that helps metabolize BPA and related environmental chemicals.

dietary exposure to BPA

Rosenfeld and her team assessed BPA contained within pet food cans. They also analyzed whether disturbances in bacteria found in the gut and metabolic changes could be associated with exposure to BPA from the canned food. Credit: Cheryl Rosenfeld

The study authors concluded:

"Dogs, who share our internal and external environments with us, are likely excellent indicators of potential human health concerns to BPA and other environmental chemicals. These findings may also have relevance to aquatic and terrestrial wildlife."5

BPA-Free Canned Dog Food: Myth or Reality?

A few years ago, my colleague Susan Thixton, a pet food activist and founder of TruthAboutPetFood.com, published a list of pet food manufacturers who claim their cans are BPA-free. Her list was linked in the University of Missouri study, so we can narrow down the possibilities of which "BPA-free" canned dog food was used in the study to the following 10 manufacturers:6

Chicken Soup

Petropics

Merrick

Nutro

Weruva

Purina

Blue Buffalo

Iams/Eukanuba

Canidae/Felidae

Fromm

If you're feeding your dog a canned food made by one of these companies, at least now you know the cans may or may not be BPA-free. Unfortunately, there's no way tell for certain which are, and which aren't. Per Susan:

"When pet food manufacturers learn what consumers do not want in their pet food (in this case BPA in the can lining), some of these companies will lie. There is little we can do about it, unless there is sound evidence of a lie (sound evidence would be test results.)

If someone out there wins the lottery, they could start a pet food testing fund (and a legal defense fund because certainly those that are caught lying will fight back). But until this happens, we are left with having to trust our pet food manufacturer is telling us the truth."7

If you're concerned about Bisphenol A in your dog's canned food, my suggestion is to consider transitioning your pet to a nutritionally optimal, fresh food diet, either homemade or commercially available. Many transparent pet food companies are now doing preemptive third-party testing for contaminants and endocrine disruptors, including heavy metals, mycotoxins, glyphosate and BPA; ask your pet food company for their results.

I absolutely don't recommend switching from a canned diet to a dry dog food. I believe pets do better with a moisture-rich diet, so consider freeze-dried or dehydrated pet food you reconstitute with water or broth.

These foods are manufactured at lower temperatures than kibble and canned diets, so they introduce fewer carcinogens into your pet's body on a daily basis, and considerably less than high-heat processed foods made from non-fresh, dry ingredients.

If you're feeding your dog a processed diet, also consider an intermittent detoxification protocol. I also recommend using stainless steel, glass, or ceramic food and water bowls instead of bowls made of plastic.