Prenatal exposure to large quantities of bisphenol A (BPA), even in levels considered "safe" by law, changes the circadian cycle. This is revealed by a study presented at the annual conference of the Endocrinology Society. According to the researchers, these changes could contribute to the hyperactivity of certain mice. The hypothalamus is an area susceptible to developmental problems caused by BPA.
Inside there is also the so-called biological clock, which regulates the daily rhythms of the whole organism. In utero exposure to the substance may hinder the correct development of the hypothalamus. This causes hyperactivity, probably due to an alteration in the circadian cycle. The researchers divided pregnant animals into two groups, one fed with normal food and the other with food contaminated with small doses of BPA. The young grew together for about 12 weeks, after which the researchers separated them and monitored their sleep-wake cycle for 4 months.
During this time, they measured their ability to adjust their pace based on the environment and stimuli. Babies exposed to bisphenol A were much more active than average, even during periods of time spent in the dark. Their circadian cycle soon disintegrated, as demonstrated by alterations in daily activities. This shows that it takes little BPA to alter the internal clock.