Turn On or Turn Off? Chemicals Sending Mixed Signals to Our Genes

Our Mission: We ignite the movement that empowers parents to protect children from harmful chemicals. Donate »

Blog

Turn On or Turn Off? Chemicals Sending Mixed Signals to Our Genes

Janelle Sorensen

Monday, August 17, 2009

Have you ever seen a picture of DNA? The double helix that looks like a twisted ladder? DNA is the fundamental building block of life and contains the instructions for the development and functioning of all living organisms. A section of DNA that has the potential to perform a specific function is called a gene. From the moment of conception our body’s roughly 30,000 genes are determining everything from whether a cell will be a brain cell or a bone cell to the color of our eyes and shape of our nose.

Throughout life genes turn on and off as needed. Some are needed for basic daily functioning – dubbed “housekeeping genes” and are on almost all the time. Some play a role in early development and then are turned off forever. In a healthy body, the cells turn on the genes they need, precisely when they need them, and actively keep the rest turned off. It is complicated, to say the least.

What happens if they turn on or off at the wrong time? What happens if during development, a brain cell is accidentally told to be a bladder cell? Scientists don’t know yet, but a growing body of evidence is showing that synthetic chemicals may be sending subtle signals to our genes that turn them on or off at the wrong times.

Bette Hileman of Environmental Health News describes the most recent developments:

Last week, several dozen researchers and experts convened by the National Academies tackled this complicated topic, called epigenetics, at a two-day workshop in Washington, D.C. They discussed new findings that suggest chemicals in our environment and in our food can alter genes, leaving people vulnerable to a variety of diseases and disorders, including diabetes, asthma, cancer and obesity. They also considered whether regulatory agencies and industry should start testing the thousands of chemicals in use today for these effects.

“There is little doubt these epigenetic effects are important. The next question is how we test for effects," said William H. Farland, professor of environmental and radiological health sciences at Colorado State University.

Exposure to gene-altering substances, particularly in the womb and shortly after birth, “can lead to increased susceptibility to disease,” said Linda S. Birnbaum, who was named director of the National Institute of Environmental Health Sciences and of the National Toxicology Program in December. “The susceptibility persists long after the exposure is gone, even decades later. Glands, organs, and systems can be permanently altered.”

“There is a huge potential impact from these exposures, partly because the changes may be inherited across generations. You may be affected by what your mother and grandmother were exposed to during pregnancy,” Birnbaum said.

The scientists at the workshop said it’s important to understand epigenetics not only to figure out which chemicals might endanger public health, but to find new ways to prevent or treat diseases.

The next steps for furthering our understanding of this new scientific arena is to begin performing rapid tests of the 80,000 chemicals registered for commercial use and finding which ones have the potential to send mixed signals to our genes. Then scientists will need to study exactly what the epigenetic impacts of those chemicals are. Birnbaum sounds ready to lead the charge. Read “How to Green Your Genes” to learn more about this issue as well as tips for protecting yourself.