Do daily lifestyle decisions result in lasting and multigenerational effects on our genetic code? Said differently, can our environment and behavior change our genes in ways that will affect future generations? Research in epigenetics—the science of heritable changes in gene expression—not only tells us this is possible but that it is continuously happening to all of us.
One way to explain epigenetic changes in the human body is to think of a software program running in a computer system. Our physical characteristics are determined by the genes in our DNA that we inherited from our parents. Just as a computer program tells the computer what to display, so there are mechanisms outside our DNA that control whether certain traits are expressed. In primarily two ways, “DNA methylation” and “histone modification,” genes are switched on or off without altering the DNA sequence itself. An example of this process is seen in the development of blood, muscle, bone, nerve, and other cells in a human embryo. The DNA contained in every embryonic cell is the same, but epigenetic mechanisms determine whether individual cells receive instructions to become blood, muscle or nerve.
Some of the major breakthroughs in this field are still relatively new, so we’re just beginning to understand the profound impact of day-to-day activities on our genes and how this carries on to future generations. In the BMC Medicine paper “Multigenerational Epigenetic Effects of Nicotine on Lung Function,” Frances M. Leslie, professor of pharmacology at the University of California–Irvine School of Medicine, writes that “not only maternal smoking but also grandmaternal smoking is associated with elevated pediatric asthma risk.” Other compelling studies in epigenetics demonstrate that our diet, exposure to certain toxins, and even obesity can change how our genes express certain traits that increase risk of developing diabetes and heart disease. It is then possible to pass this elevated risk to future generations through lasting changes in gene expression.
Another recent study by the Karolinska Institute in Stockholm, published in the journal Epigenetics, showed that regular moderate exercise not only produced positive physical changes in the human body but also made changes in the DNA methylation that resulted in greater muscle health and regeneration. Helpful changes in gene expression like these can also be heritable. Ultimately, both negative and positive lifestyle behaviors—including those that may be considered interpersonal, such as abusive or supportive behaviors—affect DNA expression in a way that has implications for our mental and physical health, and the health of future generations that inherit our genes.
Isn’t it interesting that, thousands of years before anyone understood the concept of epigenetics, the Bible explained the principle of behavior having a multigenerational effect? In the book of Exodus, God describes himself to Moses as “the Lord God, merciful and gracious, longsuffering, and abounding in goodness and truth, keeping mercy for thousands, forgiving iniquity and transgression and sin, by no means clearing the guilty, visiting the iniquity of the fathers upon the children and the children’s children to the third and the fourth generation” (Exodus 34:6–7).
The most encouraging thing about epigenetics as a field of research is that, with positive changes in behavior, not only do we benefit, but so do the generations after us. Like the epigenetic principle itself, the standards for such behavioral changes are found in the pages of the Bible.
T. BRANDON SEXTON