Our Chemical Inheritance

In a half-hearted attempt to organize my internet bookmarks this morning I found, for some unexplainable reason, ten or so bookmarks for the same article. I don’t recall bookmarking the page more than once, but somehow it seems to be cloning itself. Since it’s trying so hard to get my attention, I think I’ll pay it some by summarizing it here, even though I’ve touched on the issues it discusses previously.

The article, entitled “The Toxins that Affected Your Great-Grandparents Could be in Your Genes," was published in Smithsonian magazine. It makes the following points:

• In 2005, a researcher who worked with biologist Michael Skinner botched an experiment. The two were studying the effects of a fungicide on fetal development in rats and the researcher accidentally bred the grandchildren of the original subjects.

• When the new rats (the fourth generation of the rats who were originally exposed to the chemical) were analyzed, it was discovered that the animals had sperm defects, but that this was not due to a change in their inherited DNA.

• The experiment was repeated many times with different rats, different chemicals, and different health effects. The pattern held that diseases related to chemical exposures showed up in the fourth and fifth generations. One pattern found was that subsequent generations of rats exposed to DDT were more likely to be obese.

• It has long been known that an altered DNA message can be passed on to future generations. In Skinner’s rats, however, the disease process was found to be related to altered patterns of molecules called methyl groups. The author notes, “like burrs stuck to a knit sweater, these methyl molecules interfered with the functioning of the DNA and rode it down through future generations, opening each new one to the same diseases.”

• The discovery spawned a new field, which has come to be called transgenerational epigenetics.

• The “burrs” apparently fasten themselves in a particular arrangement, so that the biological fingerprint of the chemical may be traceable. In the future, it may be possible for doctors to screen people for methylation patterns in order to determine the chemical exposures of previous generations.

• Skinner’s findings have been opposed by “moneyed interests” and by those still attached to the old genetic paradigm. Skinner responds by saying that “the best way to handle these things is to let the science speak for itself."

The science is speaking. Are we listening?

Red Alert: Generational Poisoning

A couple of months ago I wrote a post entitled Do It For the Grandkids discussing how epigenetic changes caused by chemical exposures can have effects that are transmitted for generations. I hadn't planned to revisit the topic so soon, but the issue keeps coming to my attention in various ways, and it's important enough that I feel inclined to address it again.

An article entitled Red Alert for Humanity: Chemical Damage Can be Inherited by Offspring Through Unlimited Generations highlights a study in which exposure to a common fungicide caused neurological and behavioral changes that were passed on indefinitely. I don’t consider myself much of an alarmist by nature, but the “Red Alert” label does seem to fit. This is serious business. The article makes the following points:

• People are being affected by chemicals to which they were never exposed. We are a product of our ancestors' exposures, and future generations will be affected by what we are encountering today.

• The conventional wisdom has been that damaging effects of chemical exposures are limited to the generation that experienced them. This is proving not to be the case.

• The transgenerational transference of the effects of chemical exposures appears to continue indefinitely. The human genetic code is being permanently altered.

• The study's lead researcher believes that cumulative effects of chemical toxins may be a key contributing factor to the rise of diseases and conditions like autism, obesity and infertility.

This study and many others link epigenetic changes not only to health, but to behavioral effects. When gene expression is altered by the environment, growth and activity of neurons in the brain can also be altered. This can, in turn, affect behavior. Some of the attributes that have been linked to epigenetic differences include impulsivity, risk-taking, disinhibition, anxiety levels, stress response, learning, attention, eating disorders, addiction risk, and memory. Failing to take the issue of chemical toxicity seriously can have wide-ranging and extremely long-lasting effects. The sirens are blaring and the red lights are flashing. Let's pay attention.

Do It for Your Future Grandkids

There are many reasons that the issue of chemical toxicity tends not to be taken very seriously by most people. Perhaps the most natural and common reason is that the issue doesn't feel personal. People don't associate their health symptoms with chemical exposures and generally assume they're handling everyday toxins just fine.

Yes, there are certainly biological differences in the way people's bodies process chemicals, and some people do have stronger detoxification systems than others. I truly believe, however, that everyone alive today is being affected by chemicals in the everyday environment to one degree or another. We're also evidently affecting the next couple of generations as well.

Chemicals can impact the human body in a number of different ways. They can directly affect organs and systems, they can mutate genes, or they can change the way genes express themselves. The latter are known as epigenetic changes and, like mutations, can be passed on to future generations.

A recent article entitled How Your Great Grandmother’s Chemical Exposures May Affect You discussed a study in which exposure to common chemicals was associated with ovarian diseases that lasted for three generations. We've long known that when a pregnant mother is exposed to certain chemicals that her child may be affected. It's becoming increasingly clear, however, that an exposure may not only affect her child, but her future grandchildren, and even their children as well. (There is also a growing awareness that a father's exposure to chemicals before a child is conceived can have significant implications. A World Health Organization publication, for instance, notes that "exposure of either father or mother to pesticides before conception . . . has been associated with an increased risk of fetal death, spontaneous abortion and early childhood cancer.")

An article entitled Epigenetics: Chemicals Turn Genes On and Off at the Wrong Times notes that epigenetic changes have been linked to a wide range of diseases and conditions, including heart disease, diabetes, obesity, breast cancer, Alzheimer's disease, prostate cancer, Parkinson's disease, learning disabilities and asthma. This is serious business. It's easy for those of us past childbearing age to think the issue isn't relevant for us, but the truth is that our product choices affect others.. The personal care products we choose and the cleaning supplies, bug sprays and other products we use in our homes and churches may cause significant harm to the people around us and to individuals yet unborn. We are interconnected. Our product choices matter.