Bisphenol A (BPA; IUPAC name: 2,2-bis(4-hydroxyphenyl) propane) is an organic synthetic compound that has a dysfunctional effect on the endocrine system.
Bisphenol A (BPA) causes random and systemic effects in living things without tissue separation. They can block the binding of natural ligands to their respective receptors. For example;
- Changes in the activity of gonadal hormones.
- Disturbances in thyroid hormone function; It is structurally similar to thyroid hormones and acts as a thyroid hormone receptor antagonist.
- Differences in central nervous system function.
- Suppression of the immune system.
BPA is a chemical used in the manufacture of many household items. It is frequently used in food and beverage packaging materials; polycarbonate plastics (plastic bottles, storage containers…), and epoxy resins (metal cans, soft drink cans, aluminum containers, tin containers…). Today, the production volume of BPA in the world is expressed in trillions of dollars annually and this volume is increasing every year.
Due to the faulty production of containers containing BPA, BPA is migrated to the food and it is taken into the body with the consumption of this food. Considering its negative impact on living things and its widespread use, its importance emerges and it draws attention, especially in packaging products that come into contact with canned food. Due to its negative effects on human health, many countries, especially the United States, the European Union, and the Republic of Turkey (Turkish Food Codex Communiqué on Plastic Substances and Materials in Contact with Food; No: 2013/34), have limited the use of BPA and set migration limits. In addition, its use is completely prohibited, especially in some products; such as polycarbonate baby bottles, pacifiers, and bottle caps. It is seen that these legal regulations and many studies are completely focused on human health.
Bisphenol A and Pets
It is known that cats and dogs are mostly fed commercial foods. However, the BPA content of these foods is questionable. Regarding BPA exposure, studies on the packaging of pet foods (especially cans) and food migration, the level of BPA exposure in pet animals, and potential health consequences are limited.
In a study, different concentrations of BPA were detected in 15 different commercial cat foods and 11 different commercial dog foods (Kang and Kondo, 2002).
In a study comparing cats with hyperthyroidism and cats with normal thyroid function, it was determined that feeding canned food poses a higher risk for hyperthyroidism than feeding other types of packaged food. It has been hypothesized that this situation may be related to the BPA content of canned foods (especially aluminum-composition tin containers) (Edinboro et al., 2004; Köhler et al., 2016).
In a recent study on dogs (Koestel et al. 2017), the BPA content in commercial dog foods was determined and the effects on the exposure level and health status of animals were investigated after consumption of these foods in a short time period (two weeks). For this purpose, a two-week feeding program was applied, one using packaged commercial food specified as BPA-free and the other commercial food without such an indication. The serum BPA concentrations of the animals were compared with the hematological tests, serum biochemistry, cortisol, DNA methylation, and intestinal microbiome changes in the samples (blood, feces) taken before the diet and two weeks later. As a result of the study, it was determined that serum BPA concentrations increased 3 times in dogs fed with both foods. It was determined that this increase was accompanied by changes in serum biochemistry and microbiome. It has been determined that the increase in serum BPA level decreases the bacterial species in the microbiome. One of the interesting findings of the study was the detection of measurable levels of BPA, even in foods specified as BPA-free.
BPA can bioaccumulate in terrestrial and aquatic resources, thus posing the risk of continued exposure to animals and humans. In a world where humans and animals live together, we cannot separate human and animal health. The principle of “One Health” should always be adopted, the issue of BPA should be approached from this perspective and more studies on the subject are needed.
References
- Edinboro CH, Scott-Moncrieff JC, Janovitz E, Thacker HL, Glickman LT, (2004). Epidemiologic study of relationships between consumption of commercial canned food and risk of hyperthyroidism in cats. J Am Vet Med Assoc., 224(6):879-886. https://doi.org/10.2460/javma.2004.224.879
- Kang JH, Kondo F, (2002). Determination of bisphenol A in canned pet foods. Res Vet Sci., 73(2):177-182. https://doi.org/10.1016/s0034-5288(02)00102-9
- Koestel ZL, Backus RC, Tsuruta K, Spollen WG, Johnson SA, Javurek AB, Ellersieck MR, Wiedmeyer CE, Kannan K, Xue J, Bivens NJ, Givan SA, Rosenfeld CS, (2017). 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., 579:1804-1814. https://doi.org/10.1016/j.scitotenv.2016.11.162
- Köhler I, Ballhausen BD, Stockhaus C, Hartmann K, Wehner A, (2016). Prevalence of and risk factors for feline hyperthyroidism among a clinic population in Southern Germany. Tierarztl Prax Ausg K Kleintiere Heimtiere., 44(3):149-157. https://doi.org/10.15654/tpk-150590
- Er B, SarımehmetoğluB, (2011). Gıdalarda bisfenol A varlığının değerlendirilmesi. Vet. Hekim Der Derg., 82(1):69-74.
Edited on: 20 October 2022