Chemical Present in Clear Plastics Can Impair Learning and Cause Disease

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Chemical Present in Clear Plastics Can Impair Learning and Cause Disease

New Haven, Conn. — Low doses of the environmental contaminant

bisphenol–A (BPA), widely used to make many plastics found in food

storage containers, including feeding bottles for infants, can impair

brain function, leading to learning disabilities and age–related

neurodegenerative diseases, according to Yale researchers and

colleagues.

“These data heighten concerns about the potential long–term

consequences of human BPA exposure,” said Neil J. Macy of Helen

Hospital, who conducted the study with Csaba Leranth, M.D.,

professor in the Department of Obstetrics, Gynecology & Reproductive

Sciences and in the Department of Neurobiology at Yale School of

Medicine.

Leranth’s group, which also included Tibor Hajszan, M.D., a research

scientist at Yale, found that low doses of BPA in female rats inhibit

estrogen–induction of synaptic connections in the hippocampus, an area

of the brain involved with expression of sexually differentiated

behaviors, as well as with formation and retention of memory.

Although estrogen is best known as one of the principal hormone

products of the ovary, a number of studies over the last twenty years

have shown that estrogen is also synthesized in the brain, where it

contributes to the development and function of the hippocampus.

Macy said that high concentrations of BPA have been reported in the

blood of some pregnant women and that BPA contamination could adversely

affect human hippocampal development, with long–term effects on

children’s learning ability. Also, when the ability to make estrogen is

impaired, as in old age, exposure to BPA could adversely affect

hippocampal function and contribute to age–related neurodegenerative

diseases such as Alzheimer’s disease, in which hippocampal function is

impaired.

About two billion pounds of BPA are produced annually in the United

States. In addition to its use in plastics, BPA is found in dental

sealants and prostheses. BPA derivatives are used as flame–retardants

in adhesives, paper and textiles.

Citation: Environmental Health Perspectives, 10. 1289, Online Feb. 24,

2005.

http://www.yale.edu/opa/newsr/05-03-28-02.all.html