Genes play important role in our health, as well as our lifestyle, environment, our diet and how active we are. Epigenetics is the study of how the above factors can cause changes that affect the function of our genes. In contrast to genetic changes, epigenetics are reversible and do not change the DNA sequence, however can change the way DNA is read. Thus, all the genetic information in our DNA is not the only determinant of a quality long life. Everyone, depending on their lifestyle, their eating habits, their body weight, smoking, exercise, can affect the activity in the relevant genes. Indicatively, common diseases due to epigenetic changes are cancer, heart attack, stroke, inflammation, oxidative stress, aging, diabetes, hypertension and autoimmune diseases.