15. Toxic Exposure Can Be Transmitted to Future Generations on a “Second Genetic Code”

Source:

Rachel’s Democracy & Health News, October 12, 2006
Title: “Some Chemicals are More Harmful Than Anyone Ever Suspected”
Author: Peter Montague
http://www.precaution.org/lib/06/ht061012.htm

Student Researchers: Kristen Kebler and Michael Januleski
Faculty Evaluator: Gary Evans, M.D.

Research suggests that, contrary to previous belief, our behavior and our environmental conditions may program sections of our children’s DNA. New evidence about how genes interact with the environment suggests that many industrial chemicals may be more ominously dangerous than previously thought. It is increasingly clear that the effects of toxic exposure may be passed on through generations, in ways that are still not fully understood. “This introduces the concept of responsibility into genetics and inheritance,” said Dr. Moshe Szyf, a researcher at McGill University in Montreal, “This may revolutionize medicine. You aren’t eating and exercising just for yourself, but for your lineage.”1

The new field of genetic research, called epigenetics, involves what scientists are referring to as a “second genetic code” which influences how genes act in the body. If DNA is the hardware of inheritance, the epigenetic system is the software. The epigenetic system determines which genes get turned “off” or “on” and how much of a certain protein they produce.

It is this switching system that allows the genetic material in each cell to influence the creation of proteins—which ones are manufactured, in what sequence, and how many. Proteins are the building blocks of our bodies. The chemicals and hormones in our bodies are proteins. They determine, in large part, how we look, how we feel, even how we act.1

Now, it seems that this chemical switching system may also act in reverse. In most cases, epigenetic changes (changes to DNA from current environmental conditions) are not passed from parents to their offspring. Scientists are still not sure how—but genes seem to be “wiped clean” after a sperm fertilizes an egg. Based on the recent data, however, researchers are intrigued by the notion that some of the genetic changes influenced by our diet, our behaviors, or our environment, may be passed on from generation to generation.

On average, 1,800 new chemicals are registered with the federal government each year and about 750 of these find their way into products, all with hardly any testing for health or environmental effects. The bad news about chemical contamination is steadily mounting, while the number of new chemicals is steadily increasing. Many critics of the chemical and pharmaceutical industries are renewing their admonitions that government agencies practice the “precautionary principle”—the rule of “do no harm first” in the approval of new drugs and chemicals.

In 2005, the European Union responded to this situation by trying to enact a new law called Registration, Evaluation and Authorization of Chemicals (REACH), which requires that chemicals be tested before they are sold—not after. As they say in Europe, “No data, no market.” At the same time, US and European chemical industries—and the White House—began working overtime to subvert the European effort to enact REACH. Their efforts failed, however, and the REACH act was adopted by the European Union in December, 2006.2 Chemical companies throughout the US and Europe are still struggling with how they will respond to the new requirements.

Citations

1. Anne McIlroy, “Chemicals and Stress Cause Gene Changes That Can Be Inherited,” Globe & Mail, March 11, 2006. See http://www.precaution.org/lib/06/prn_code_2.060311.htm.
2. “European Parliament OKs World’s Toughest Law on Toxic Chemicals,” San Francisco Chronicle, December 14, 2006.

UPDATE BY PETER MONTAGUE

Basically this story tells us that environmental influences (like our mother’s diet and her exposure to toxic chemicals) are far more important to us than anyone suspected just a decade ago.

It turns out that environmental influences shape us from the moment of conception onward, and the earliest months and years of life are the most important ones. It is called “fetal programming” and it means our first environment (the womb) can determine what sorts of diseases will afflict us later in life. Furthermore, some of these early influences can be inherited by our offspring and even by their offspring. So your personal pattern of disease may have been set by your grandmother’s diet, or by her exposure to toxicants.

These findings imply that keeping toxic industrial chemicals out of the environment is far more urgent than anyone has previously thought. With more than 1,000 chemicals presently entering commercial channels each year with almost no health or safety testing, this is not welcome news.

In May 2007, a group of two hundred scientists from five continents issued strongly worded consensus statement (the “Faroes Statement”) saying that early exposure to common chemicals leaves babies more likely to develop serious diseases later in life, including diabetes, attention deficits, certain cancers, thyroid disorders, and obesity, among others.

Notably, the scientists urged governments not to wait for more scientific certainty but to take precautionary action now to protect fetuses and children from toxic exposures.

Most of the mainstream press continued to tiptoe around this story, with a few important exceptions, until May 2007 when the Faroes statement blew the story open. Now that it is out in the open, we’ll have to see if the mainstream press has what it takes to explain the far-reaching ramifications of these findings.

The best source of information on this topic (and many others) is http://www.environmentalhealthnews.org. Search for “epigenetics,” “fetal programming,” or “gene expression.”