For years, the chemical bisphenol A (BPA) – commonly found in plastic bottles, can linings and other products – has been linked to a number of negative health consequences, and now a new study has indicated that even in small doses BPA can cause significant changes in metabolism as well as affect the reproductive and nervous systems.
Researchers from the National Food Institute, Technical University of Denmark found "reduced sperm count, obesity and changes to breast development and behaviour" in rats who were given small amounts of BPA, and believe that similar effects may occur in humans.
These effects were observed in low doses – in roughly equivalent levels to what humans are exposed to on a daily basis.
From a university press release accompanying the study:
The results show that particularly low doses of bisphenol A affect the development of the animals. The female rats that were exposed to the lowest dose weighed more as adults, and their behaviour had changed in a direction that resembled male behaviour. This could indicate masculinization of the females' brains. Male rats that were exposed to the lowest dose had increased growth of mammary gland tissue, and decreased sperm count as adults.Numerous serious health risks associated with BPA
These effects were not observed at the higher bisphenol A doses.
Mammary gland changes that could be indicative of an early stage of breast cancer were observed in aging rats exposed to the second lowest dose of bisphenol A.
The results support previous studies, which show that particularly low doses of bisphenol A can affect the animals' development, while higher doses have different effects.
Previous studies have linked bisphenol A to obesity, breast cancer, infertility in both males and females, early puberty, heart disease and nervous system damage. BPA disrupts the endocrine system, mimicking the hormone estrogen.
Endocrine disruptors are the link between human health hazards and plastic. ... In the human body, endocrine disruptors mimic the actions of the hormone estrogen. They upset the hormonal balance and can stimulate the growth of tumors in the breast, uterus or prostate. They can affect fertility, pregnancy, and worse, can affect the fetus by interfering with testosterone, disrupting normal sexual development. This disruption is not often apparent until adulthood and includes the increased risk of cancer.The EPA has done little to address the issue. It briefly considered a ban in 2012, but the only real action the agency has taken was to ban its use in baby products – two of every three canned goods still contain BPA in their linings.
Avoiding exposure to BPA
In our modern world, it's not easy to avoid contact with plastic, but you can take steps to minimize your exposure to BPA and other toxins found in plastic products.
Don't microwave or heat food in plastic containers, stop using plastic wrap, use glass or metal food dishes and utensils, and don't buy disposable plastic bottles.
Does "BPA-free" mean "toxin-free"?
Look for BPA-free labels if you purchase plastic bottles or canned goods, but keep in mind that BPA is not the only toxin found in plastic.
In fact, some of the "analog" chemicals used to replace BPA are highly suspect themselves - a pair of recent studies indicate that BPA substitutes "affect cells and animals in much the same ways."
Pascal Coumailleau of INSERM's Research Institute for Environmental and Occupational Health and the University of Rennes in France and colleagues measured the effects of four bisphenols on the brains of zebrafish.Clearly, it's best to avoid using plastic products as much as possible, even those labeled BPA-free. It may be virtually impossible to completely eliminate plastics from your life, but, armed with an awareness of the dangers, you can take action to minimize exposure to its toxic effects.
Exposing the animals to higher concentrations of these chemicals than humans would typically encounter, the team found that three of four BPA analogs—BPS, BPF, and BPAF—are estrogenic, causing an upregulation in the brain of the enzyme aromatase, which converts androgens—such as testosterone—to estrogens. Overall, these chemicals are similar to BPA in their effects....