Decoding Epigenetics: The Impact of Lifestyle on Genes

Epigenetics: The Effects of Lifestyle Choices on Genetic Factors

Epigenetics can be defined through its own etymology: epi means on top of and genetic refers to our genes. Thus, epigenes are small chemical tags that sit on top of our DNA and chromatin with instructions for them. In order to best understand this concept, one must understand some fundamental truths about our DNA: Each person is born with a set strand of genes. What differentiates our cells from one another (say a blood cell from a neural cell) is actually the aforementioned instruction provided by epigenes, which prompt our DNA to essentially turn certain genes on or off, resulting in a differentiation of cells. What is interesting about the study of epigenetics is the promise

that we may be able to manipulate certain genetic factors through environmental changes. For example, Waterland and Jirtle (2003) conducted an experiment on mice carrying the Agouti gene. This gene makes mice fat, yellow, and sickly. The researchers found that this gene can actually be turned off by feeding a pregnant mouse a diet supplemented with epigenes that essentially crowd around the Agouti gene and silence it. The result was healthy, thin, gray offspring. The findings of this study have had profound implications on the way scientists think about and understand genetic predispositions. Furthermore, the study suggests that epigenetic marks on our genes are actually susceptible to environmental changes, insinuating a chance for our ability to silence those genes in our makeup that might carry inherited diseases. This ultimately seems like one of the most promising findings in recent genetic studies, as it deals with the genesis of disease, essentially focusing on how to completely prevent disease at its very origin rather than treating disease when it has already developed.
Recently, there have been extensive studies conducted on epigenetics using vermin, animals and plants. However, the more exciting part of epigenetic studies revolves around its application in human models. Olsson, Hultman, Dunoyer-Geindre, Curtis, Faull, Kruthof and Jern (2015) conducted a study to observe the effects of epigenetic mechanisms in the way that tissue-type plasminogen activator (t-PA) expresses itself in the human brain. To put it more simply, t-PA is a protein (serine protease) found in the lining of blood cells that has the potential to break down blood clots. The importance of how this protein expresses itself in the human brain is essential, as it dictates how the blood in the brain will behave after traumatic injuries, or even for the treatment of strokes. The study was conducted on two sets of human brain cells: neurons, astrocytes and endothelial cells as well as hepatoma and hepatocytes. These normally contain high and low basal cell expression, respectively. Ultimately, the study came to two conclusions, the first being that histone deacetylation inhibition can induce expression of t-PA in neurons and astrocytes and the second being that DNA methylation of brain tissues and cells showed significantly unmethylated stretch of t-PA. According to Olsson et al., (2015), “Taken together, these results suggest that epigenetic mechanisms are of significance for the regulation of t-PA gene in the human brain” (pg. 12). The implications of such this finding are far-reaching, as they indicate that epigenetic mechanisms can in fact influence the way our brain tissues and cells work to keep us healthy.
An important facet of epigenetics is trans generational epigenetic inheritance.

This asserts that like certain genetic factors are undoubtedly inherited through generations, epigenetic factors also have trans generational effects on our genetic predispositions. As discussed previously, epigenetic factors are subject to environmental changes. This means that despite their original genetic makeup, your ancestors’ environmental choices (for example smoking, diet and exercise, and lifestyle) also have a direct effect on your genetic makeup, as the changes caused by their lifestyle choices affect the chemical tags your epigenes turn on and off. This is interesting hen one examines their family history of disease. At its most basic, the study of epigenetics suggests that a simple family history workup should tell you relatively what major diseases you might be at genetic risk of developing. In light of my personal family history, the only obvious disease risk factors appear to be cancer in three grandparents and thyroid disease in five family members: one being a parent, another a grandparent, two aunts, and a cousin, all on the maternal side of the family. Based on the ideal promise of epigenetics, one might hope that scientific research might discover either a way to change environmental factors such as diet in a way that would cause epigenetic mechanisms to shut off the genetic markers in my makeup that might carry cancer and thyroid disease. On a more forward-thinking

platform, we may go back to the Agouti mice study, where these two genetic risk factors might be treated during pregnancy with the introduction of epigenetic marks in-vitro in order to effectively erase the chance of my children developing cancer or thyroid disease.
Epigenetics simply points to the fact that our lifestyle choices have a serious effect not only on our genetics, but also on the genetics that we pass on to our subsequent generations.

A life expectancy questionnaire is useful in loosely determining how your daily lifestyle choices affect the number of healthy years you will potentially live. According to the bluezones vitality compass, my current biological age is 26.4, which is my exact age. My life expectancy is 82.2 years, with 70.8 years of completely healthy life (free of cancer, heart disease, and diabetes). Due to my lifestyle habits, my life has accrued a total of -1.3 years. According to the website, I could add a total of 16.7 years to my life expectancy if I completely quit smoking, do more vigorous exercise regularly, attend a religious service at least once a month (spiritual in my case) and eat less salt and salty foods.

Ultimately, the study of epigenetics focuses on maintaining the healthiest lifestyle possible in order to attempt to avoid certain genetic markers that might result in disease. While healthy living is not necessarily always going to erase your predispositions to disease (there are countless cases of people who have never smoked in their life and still die of lung cancer), it does stand true that your lifestyle choices have a significant effect not only on your current genetic makeup, but on that of your subsequent

generations.