Exposure to Bisphenol A (BPA) associated wih high levels of anxiety
According to studies conducted by researchers at North Carolina State University, bisphenol A, a chemical found in plastic objects, drastically increases anxiety levels. They also have found that soy is a protective factor that mitigates the effects caused by bisphenol A. Bisphenol A is a chemical compound that is very slightly soluble in water and it is found in plastics, bottles and other objects. There was a big controversy regarding this compound due to its very little known adverse effects. It seems that exposure to bisphenol A affects growth and development in children. Therefore, bisphenol A is considered in some countries a toxic substance. It has also been banned in baby bottles use in many European countries.
The researchers wanted to know what are the effects of BPA on behavior. They conducted a study in which they used several groups of animals. The researchers studied four groups of rats: one group of rats fed only soy-free, one group of rats fed soy, one group that was fed with soya and the last group was not fed soy instead was not exposed to bisphenol. What the researchers found was that the level of bisphenol A found in rats exposed to this chemical compound was well within the normal range normally found in humans. Furthermore, rats that were fed soy genistein levels were well within the normal levels found in people with regularly intake of soy.
In addition, the researchers found that exposure to BPA is associated with behavioral disorders, such as anxiety. The study results showed that rats exposed to BPA and fed soy free diet had significantly higher levels of anxiety. In addition, they found that these behavioral disorders are caused by some changes in the amygdala, a region located in the brain nervous. The amygdala is a nerve formation, which is part of the limbic system, is located in the temporal lobes and has a role in regulating behavior. The amygdala is responsible for emotional reactions, fear, social behavior etc.. Also, the amygdala seems to have a role in the development and memory consolidation. Now researchers from North Carolina State University have found that BPA can cause some disturbances in the amygdala by gene changes. They noticed some changes in genes required for the release of oxytocin, ie estrogen receptor beta and the melanocortin receptor 4.
Oxytocin is a neurotransmitter secreted by the pituitary gland which has several roles. In addition to sexual reproduction-related functions (Labour, breastfeeding), oxytocin has a role in social behavior. It seems that the lack of oxytocin is associated with behavioral disorders. What is interesting is the fact that researchers found that rats on soy rich diets did not have high levels of anxiety. However, Dr. Heather Patisaul, associate professor of biology at year NC State and lead author, says that it is not known if soy photostrogens protects against the effects of BPA or it is other compound that offer protection. He added that he hopes to find the answer in a future research program.
Study abstract can be found here.