First study to evaluate mycoestrogens in young girls

Puberty is a time in a girl's life considered highly sensitive to stimulation by the hormone estrogen and a critical window during which estrogen exposure could greatly influence the risk of breast cancer later in life. An early onset of puberty also has been consistently shown in studies to increase the risk of breast cancer. The Jersey Girl Study, which aims to examine factors affecting puberty in girls and is based at The Cancer Institute of New Jersey (CINJ), has shown that estrogen-like substances produced by fungi may act as a hormone disrupter. CINJ is a Center of Excellence of UMDNJ-Robert Wood Johnson Medical School.

Led by CINJ epidemiologist Elisa Bandera, MD, PhD, a multidisciplinary team of investigators recently found detectable levels of these fungal compounds, known as mycoestrogens, in urine samples donated by girls participating in the Jersey Girl Study. The findings suggest that the presence of these mycoestrogens may delay height growth and the onset of breast development in young girls. The findings are scheduled to be published in the November 15 print edition of the journal Science of the Total Environment (doi:10.1016/j.scitotenv.2011.09.029).

Mycoestrogens are produced by fungi that are present in grains through contamination. They are also present in such foods as meat, eggs and dairy through contaminated animal feed or deliberate introduction of the synthetic mycoestrogen zeranol into livestock for the purpose of improved meat production. Zeranol is a non-steroid agent approved the by U.S. Food and Drug Administration to promote animal growth in beef production, but is banned for such use in the European Union and other countries.

The investigators measured zearalenone mycoestrogens and zeranol in the urine of 163 girls participating in the Jersey Girl Study and found detectable levels in 78 percent of the girls. More specifically, high levels of zearalenone mycoestrogens were found in 55 percent of the samples, while low levels of zeranol were found in more than 20 percent of the samples. Researchers also evaluated food sources for these mycoestrogens, and found that beef and popcorn intakes were strong predictors of detectable levels in urine. When researchers evaluated the association with growth and development, they found that girls with detectable urinary mycoestrogen levels tended to be shorter and less likely to have reached the onset of breast development.

"Because zearalenone mycoestrogens are widely distributed in the food supply, it is critical that we have a better understanding of their levels, their food sources and their effects on the development of young girls, which ultimately has important implications for their future breast cancer risk." said Dr. Bandera, who is the lead author of the research and an associate professor of epidemiology at UMDNJ-Robert Wood Johnson Medical School. "To our knowledge this is the first study evaluating mycoestrogens in healthy girls. More studies are needed in this very important research area. This is just the beginning."

Source: The Cancer Institute of New Jersey