Bisphenol en uw gezondheid*
Eerdere studies hebben al aangetoond dat bisphenol-A een stof die o.m. wordt aangetroffen in plastic producten en in de bekleding van blik door migratie in de voeding terecht komt. Nu twee studies waarvan uit de ene blijkt dat bisphenol veel meer migreert bij hoge temperaturen en een andere studie die doet vermoeden dat bisphenol een verhoogde kans geeft op metabool syndroom, een combinatie van vier frequent voorkomende aandoeningen, een hoge bloeddruk, suikerziekte, verhoogd cholesterol en overgewicht.
In een plastic fles met water van kamertemperatuur migreert ongeveer 0,2 tot 0,8 ng bisphenol per uur terwijl bij kokend water 8 tot 32 ng migreert, oftewel 40x meer. En natuurlijk zijn deze waarden op zich zeer klein doch heel wat hormonen in het menselijk lichaam werken met deze kleine hoeveelheden. Van bisphenol is al langer bekend dat dit in het lichaam reageert als het hormoon oestrogeen en daardoor ontwikkelingsproblemen kan veroorzaken en een verhoogd risico geeft voor borst- en prostaatkanker. Zelfs een zeer lage dosis van bisphenol kan de ontwikkeling van hersenen zowel bij een foetus als de eerste jaren van een baby danig verstoren. In de tweede, laboratoriumstudie met menselijk weefsels blijkt dat bisphenol de werking van het
peptidehormoon adiponectine doet onderdrukken waardoor de kans op metabool syndroom groter wordt.
Adiponectine speelt een rol bij het vet- en koolhydraatmetabolisme in het
lichaam.
Heat Accelerates Release of Toxic Plastics Chemicals From Baby Bottles, Food Packaging
Plastic water bottles release the toxic chemical bisphenol A at a rate 55 times greater when filled with boiling water than when filled with room temperature water, according to a study conducted by researchers from the University of Cincinnati College of Medicine and published in the journal Toxicology Letters.
"Previous studies have shown that if you repeatedly scrub, dish-wash and boil polycarbonate baby bottles, they release bisphenol A," said researcher Scott Belcher. "But we wanted to know if 'normal' use caused increased release."
Bisphenol A is used to make the hard, transparent polycarbonate plastics that are used in a wide variety of consumer products, including water and baby bottles. But concerns have been raised that the chemical might leach into water or infant bottles from the normal use of such bottles.
"There are a lot of concerns surrounding bisphenol A," said David Santillo a scientist at the Greenpeace research laboratory in Exeter, England. "It is a hormone disrupter able to mimic and interfere with hormone systems in animals. Newborn babies are at a very sensitive stage of their development and the last thing you want to be doing is dosing them with a very potent hormone disruptor."
Hormone disruptors can interfere with the development of infants, as well as causing reproductive problems and cancers in adults.
Researchers tested reusable polycarbonate water bottles for seven days with room temperature water and then with boiling water. The bottles were shaken in such a way as to simulate regular outdoor activities such as backpacking.
When filled with room temperature water, bisphenol A leached from the bottles at a rate of 0.2 to 0.8 nanograms per hour. After being exposed to boiling water, the bottles leached the chemical at a rate of 8 to 32 nanograms per
hour.
"A nanogram is a fairly small amount, but given that a lot of hormones work at levels far below that ... you are in the range there which could be contributing to adverse effects," Santillo said.
Bisphenol A Linked to Metabolic Syndrome in Humans
CINCINNATI—New research from the University of Cincinnati (UC) implicates the primary chemical used to produce hard plastics—bisphenol A (BPA)—as a risk factor for the metabolic syndrome and its
consequences.
In a laboratory study, using fresh human fat tissues, the UC team found that BPA suppresses a key hormone, adiponectin, which is responsible for regulating insulin sensitivity in the body and puts people at a substantially higher risk for metabolic syndrome.
Metabolic syndrome is a combination of risk factors that include lower responsiveness to insulin and higher blood levels of sugar and lipids. According to the American Heart Association, about 25 percent of Americans have metabolic syndrome. Left untreated, the disorder can lead to life-threatening health problems such as coronary artery disease, stroke and type 2 diabetes.
Nira Ben-Jonathan, PhD, and her team are the first to report scientific evidence on the health effects of BPA at environmentally relevant doses equal to “average” human exposure. Previous studies have primarily focused on animal studies and high doses of BPA.
“People have serious concerns about the potential health effects of BPA. As the scientific evidence continues to mount against the chemical, it should be given serious attention to minimize future harm,” says Ben-Jonathan, a professor of cancer and cell biology at UC who has studied BPA for more than 10
years.
“Experimenting with human tissue is the closest we can come to testing the effects of BPA in humans. It’s a very exciting breakthrough because epidemiological studies looking at BPA effects on humans are difficult since most people have already been exposed to it,” she adds.
Scientists estimate that over 80 percent of people tested have measurable BPA in their bloodstream. The UC study was designed to mimic a realistic human exposure (between 0.1 and 10 nanomolar) so that a more direct correlation between human exposure and health effects could be drawn.
To conduct this study, the UC team collected fresh fat tissue from Cincinnati patients undergoing several types of breast or abdominal surgery. These samples included three types of fat tissue: breast, subcutaneous and visceral (around the
organs).
Tissue was immediately taken to the laboratory and incubated with different concentrations of BPA or estrogen for six hours to observe how the varied amounts of BPA affected adiponectin levels. The effects of BPA were then compared to those of estradiol, a natural form of human estrogen.
They found that exposing human tissues to BPA levels within the range of common human exposure resulted in suppression of a hormone that protects people from metabolic
syndrome.
“These results are especially powerful because we didn’t use a single patient, a single tissue source or a single occurrence,” she adds. “We used different fat tissues from multiple patients and got the same negative response to BPA.”
UC’s Eric Hugo, PhD, Terry Brandebourg, PhD, Jessica Woo, PhD, J. Wesley Alexander, MD, and Christ Hospital surgeon Jean Loftus, MD, participated in this study. The study was funded by grants from the National Institute of Environmental Health
Sciences. (Oktober
2008)
U zult zelf moeten zorgen dat u geen Bisphenol binnenkrijgt want overheden in Amerika en Europa doen niets om de stof te verbieden door gewoon te zeggen dat het veilig is. Mede gelet op de grotere migratie bij hoge temperaturen gebruik zeker geen babyflessen met daarin bisphenol.