I have heard a little about "epigenetics" and how the genes of even great-grandparents can affect their descendants. But it seems complicated — can you explain the basics? -Leona
Transgenerational epigenetic inheritance — or epigenetics, for short — doesn't exactly roll off the tongue. Yet this idea that environmental factors (such as diet, lifestyle choices and behaviors, and stress) can change the health not only of the people who are exposed to them, but also the health of their descendants, is something we'll be hearing more and more about.
Epigenetic experts believe that the environmental conditions and life experiences of parents, grandparents, and even great-grandparents can, in a way, flip "on/off switches" on the genes in their eggs and sperm, or the genes of developing fetuses in pregnant women, thus changing the genetic code of their offspring and descendants. In this way, new genetic traits can appear in a single generation, and be passed on to kids, grandkids, and beyond.
For instance, evidence suggests that smoking and overeating can affect genes, causing those affecting obesity to become "switched on" and those carrying messages for longevity to become "switched off." That means that in addition to the self-harm that can come from eating too much or smoking, these lifestyle choices may predispose a person's offspring (and even future descendants) to disease and premature death.
In the past, understanding of diseases focused on the interaction among the genes we inherit (for diabetes, as an example) and our environment (like eating and exercise habits). But researchers have long puzzled about how the risks for, and frequency of, some conditions seem to change as quickly as from one generation to the next. After all, according to traditional genetics, major changes in the structure of the human genome only occurred over many generations or even thousands of years. But now, the concept of epigenetics is shedding new light on how such changes can occur much faster.
What This Means for Families
So is epigenetics just a topic of interest to scientists, or should it have an impact on the way we live now? Growing research seems to support the role of parental lifestyles and their (possibly permanent) effects on the health of their children, grandchildren, and beyond.
While you may not be able to undo the genetic "on/off switch" changes you've passed on to the kids you already have, living healthier now could be invaluable to the health of your future offspring — and their kids. Epigenetics doesn't just apply to passing on potentially negative traits or health risks, but also to the benefits of inheriting healthy factors.
Scientists also are using the concept of epigenetics to develop new approaches to diseases with genetic roots. Drugs are now being produced that act by switching on or off faulty genes in epigenetic fashion. This type of genetic "quick fix" could be a very valuable strategy in the fight to prevent, treat, or cure a number of conditions, such as cancer, diabetes, and Alzheimer's disease.