Epigenetics

Why your cancer-creating habits can affect your children (and we’re not talking about second-hand smoke).

It’s hard enough being a parent.  There are no “Parenting for Idiots” books out there.  We just bumble along, trying our best to inoculate our children from our worst selves and influence them with our best.

But like many humans, we may hit the potato chips a bit hard, make exercise the last task on our ever-lengthening “to do” list, and find ourselves doing things we know may not be good for us.

But the science of epigenetics is now telling us that we’re not only influencing our own health but those of our children – genetically.

Here’s how it works.  Epigenetics looks at the way genes express or don’t express themselves as we age.  Those gene changes are thought to be influenced directly as a result of our nutrition and behavior, as well as exposure to toxins in our environment.  In a sense, it’s a hybrid of hereditary disease and lifestyle choices.

An experimental study was done by Stanford University scientist Anne Brunet and colleagues. They noticed that nematodes (a type of worm) had varying lifespans.  Some were exceptionally long-lived and passed that trait through three generations.  Others lived much shorter lives. Yet all the worms, both the old sages and the early departers, were genetically identical.

How is this possible?

The answer lies in epigenetics.  Some of the worms had experienced a change during their lifetimes that affected certain gene expressions that regulated lifespan.  They passed that gene expression through reproduction, even though it had not been part of their initial DNA makeup.

A human version of this can be found in the cases involving the synthetic estrogen compound  diethylstilbestrol (DES).  This was given to women in the 1950’s to prevent miscarriages.  Later it was discovered that DES mothers gave birth to DES affected daughters, increasing their risks for vaginal, breast, and ovarian cancers. Ironically, it also made DES daughters more prone to miscarriage.  The mechanism for this phenomenon is now believed to be epigenetics which facilitated the altered maternal DNA to be passed down to their daughters.

It must be noted the study of epigenetics is in its infancy.  Clear-cut examples of it, like noted above, are rare.  But scientists now have a new understanding that our lifestyle choices and exposure to environmental toxins can affect sperm and egg DNA, and thereby set up new generations for cancer risk in ways that cannot be explained through traditional genetic pathways.


Sources:

https://blogs.scientificamerican.com/guest-blog/epigenetics-a-turning-point-in-our-understanding-of-heredity/

http://www.bu.edu/news/2014/09/15/epigenetic-drugs-a-hope-to-treat-cancer-resistance-and-reduce-cancer-relapse/