In the last decade, epigenetics has become one of the hottest topics in science. Epigenetics is the study of how genes are up- or down-regulated without modifying the actual DNA itself. Before the discovery of epigenetic marks, it was thought that a person’s genetics were set in stone at birth. Now we realize that there are a broad range of epigenetic marks that can be added to the DNA strand and alter gene expression.
Our cells have so much DNA that it must be wound around itself in order to fit in the cell. The cellular machinery must unwind a section of the DNA to use a gene as a template to make a protein. The presence of certain epigenetic marks determines how tightly sections of the DNA are wound, thereby influencing how easily a gene can be expressed.
The environment largely determines the epigenetic marks present on the DNA. The epigenetic marks improve the body’s ability to adapt to an environment
For example, the body has a set of machinery for processing carbohydrates and different a set of machinery for processing fat. If a person eats mostly carbohydrates, the carbohydrate-processing machinery will be up-regulated and the fat-processing machinery will be down-regulated. If the person switched to a high fat, low carbohydrate diet, they would likely feel sluggish for a few days. They might feel sugar cravings because their body is not yet adapted for using fat as the main fuel source. After a few days, their body would up-regulate the fat-processing machinery and down-regulate the carbohydrate-processing machinery. At that point, they would have adapted to new diet and become efficient at processing fat for fuel.
We are beginning to understand that diet has a big impact on which genes are up- or down-regulated, and this, in turn, has a big impact on our health. A poor diet doesn’t make us unhealthy simply from the consequences of being malnourished or overweight, the diet actually affects the expression of our genes. Certain diets could up-regulate cancer-causing genes and other diets may up-regulate cancer-resistance genes. This is the exactly what I’m studying for my dissertation research.
Now that we’ve covered the basics of epigenetics, next I will write about a new study investigating the epigenetic effects of a ketogenic diet.