Epigenetics and Heredity
The emerging field of epigenetics is changing scientific thinking about the way our genes work and may have profound implications for our health and the health of our children and grandchildren.
The dramatic rise in diabetes, asthma, heart disease and obesity may at least partially be attributed to an epigenetic mechanism, predisposing succeeding generations to these diseases. Simply put, diet, stress, nurturing, our behavioral habits and even environmental exposures may change gene activity without altering the actual sequence of our genes. Epigenetics has already changed the way researchers think about how diseases arise and how doctors treat them. The implication is that lifestyle choices have the potential to change our heredity.
“Epi” means above the genome, the total genetic material of an individual or species. The epigenome literally sits over the genome. Chemical changes called “epigenetic marks” may switch genes on or off, leading to disease; these epigenetic changes can occur during fetal development or even later in life. Scientists use the analogy of a computer to illuminate the concept. Our genome (DNA sequence) is the computer’s hardware. The epigenome is the software that tells the computer when, where and how to work.
Medical experts believe that elements such as poor nutrition choices, pesticides and exposures to synthetic compounds can trigger a chemical change in the body that mobilizes molecules called a methyl group (a basic unit in organic chemistry). This methyl group attaches to the control segment of a gene and either silences or activates the gene, causing it to deviate from its intended purpose. The process is called methylation. Methylation has been likened to “putting gum on a light switch. The switch isn’t broken, but the gum blocks its function (Duke 2005).” Other epigenetic changes may occur as well.
The good news is that scientists currently believe that if you take away environmental stressors, methylation is potentially reversible. Methylated genes can be “demethylated,” which means a healthy lifestyle can pay big dividends for your clients and their children.
Rosalind Gray Davis
References
Duke University Medical Center Library Newsletter. 2005. www.dukehealth.org/health_library/news/9322; retrieved Apr. 5, 2010.