This past few years, after a decade or two of research showing that the plastic BPA was likely causing estrogen like and other effects in humans, the FDA finally banned it from baby bottles. The good news was that, seeing a commercial opportunity, many companies that made plastic bottles made the switch to the safer plastic BPS (bisphenol S). Now new BPA free research is showing that BPS is just as bad!
BPA is the main ingredient for making polycarbonate plastics. Any leftover BPA that isn’t consumed in the reaction used to create a plastic container can leach. From there it can enter the body when the container is used. I’ve blogged in the past how BPA may be forcing stem cells to turn to fat instead of bone. BPS was thought to be a good replacement because it was thought to be leach less. If people consumed less of the chemical, the thought was that it would cause no or only minimal harm. However, BPS has now been found in humans based on a recent Chinese study that sampled urine. The overall levels of BPS in Americans has yet to be determined.
We have a few problems in the U.S. that likely involve female hormones that are well documented. First, our young girls are getting their first period earlier (in medical term called menarche). Second, our weight as a society is exploding. While the first is almost certainly due to hormone exposure in the environment, the second likely has many causes including hormones. The problem with many plastics is that they leach chemicals like BPA and BPS that have been shown to act like female hormones (estrogens) in the body by flipping the same receptor switch as the actual hormones.
The new research on BPS is broad. One brand new study showed that BPA and BPS may be involved in obesity by flipping certain receptor switches in cells. Another new study just showed that BPS actually binds more ferociously to a common protein in blood than BPA, meaning that once in the blood stream it’s likely to stay. Another new study shows that while BPS activates estrogen receptors less it messes with progesterone receptors more than BPA. Finally, another study of an animal model of a developing fetus showed that BPS reduced testosterone in males, and in both sexes the estrogen levels and thyroid levels were altered.
The upshot? I personally loved the fact that companies were producing bright, shiny new plastic bottles that were “BPA free”. That elation has now turned to continued disgust that we can put a man on the moon, but the FDA and big industry can’t create a plastic bottle that won’t mess with our hormones. More importantly, if you look at the morbidity and mortality due to the obesity explosion, if plastics are responsible for some of that, this is a legitimate public health crisis!