CHICAGOFetal exposure to Bisphenol A (BPA), commonly used as an internal coating for soup and soft drink cans, can increase the risk for prostate cancer later in life, according to a new study published in the journal Endocrinology.
In children and adolescents, the chemical enters the body primarily through foods and liquids that have come into contact with materials containing BPA. The U.S. Food and Drug Administration (FDA) banned the use of BPA in sippy cup and baby bottles, but it is still commonly used in food packaging.
Previous studies have shown that people who avoided all contact with plastics or other BPA-containing objects for up to a month or more still had BPA in their urine, which means they must have come into contact with BPA in the last 24 to 48 hours," said lead author Gail Prins, professor of physiology and director of the andrology laboratory at the University of Illinois at Chicago.
Exposure of the fetus to BPA in utero is an area of particular concern because the chemical, which mimics the hormone estrogen, has been linked to several kinds of cancer in rodent models. The newest findings show that human prostate tissue is also susceptible.
Our research provides the first direct evidence that exposure to BPA during development, at the levels we see in our day-to-day lives, increases the risk for prostate cancer in human prostate tissue," Prins said. The findings of adverse effects of BPA in human tissue are highly relevant and should encourage agencies like the Food and Drug Administration to re-evaluate their policies in the near future."
Prins investigated the effect of BPA on human cells by implanting human prostate stem cells taken from deceased young-adult men into mice. Prostate stem cells are long-livedthey arise during early fetal development and produce and maintain a mans prostate tissue throughout his life.
To mimic exposure to BPA during embryonic development, the mice were fed BPA for two weeks following implantation in amounts proportional to those seen in pregnant American women.
After the tissue was allowed to mature for one month, the mice were given estrogen to mimic the naturally rising estrogen levels seen in aging men. This rise in estrogen later in life is one of the known drivers of prostate cancer.
Tissue was collected after two to four months and analyzed for prostate disease. Prins found one-third of tissue samples taken from mice fed BPA had either pre-cancerous lesions or prostate cancer, compared to only 12% in a control group. If the prostate stem cells were exposed to BPA before implantation, and again as they produced prostate tissue in the mice, 45% of the tissue samples had pre-cancerous lesions or cancer.
We believe that BPA actually reprograms the stem cells to be more sensitive to estrogen throughout life, leading to a life-long increased susceptibility to diseases including cancer," Prins said.
Previous research shows BPA exposure can also lead to serious health conditions such as cardiovascular disease, breast cancer, neurological disorders, diabetes and infertility. In addition, pregnant women exposed to BPA may have an increased risk of miscarriages.