WHAT IS EPIGENETICS?

"The new field of "epigenetics" is rapidly revealing how people may start with a certain genetic code at conception, but the choice of which genes are "expressed," or activated, is strongly affected by environmental influences.

Epigenetics refers to DNA and chromatin modifications that persist from one cell division to the next despite a lack of change in the underlying DNA sequence. Some epigenetic changes can be passed from one generation to the next. The expression of genes can change quite rapidly over time.

WHAT IS EPIGENETICS?
Within our DNA, the development and maintenance of our body is orchestrated by a set of chemical reactions that switch parts of the genome OFF and ON at strategic times and locations. Epigenetics is the study of these reactions and the factors that influence them.

They can be influenced by external factors. We are more than just the sum of our genes, and biological complexity depends less on gene number, and more on how those genes are used (expressed), which is largely due to epigenetic mechanisms.

EPIGENETICS & THE ENVIRONMENT
The genome dynamically responds to the environment. Stress, diet, behavior, toxins and other factors activate chemical switches that regulate gene expression.

EPIGENETICS AND THE HUMAN BRAIN
Throughout our lives, the brain remains flexible and responsive to the outside world. In addition to receiving signals from the outside world, the brain allows us to form memories and learn from our experiences. Many brain functions are accompanied at the cellular level by changes in gene expression. Epigenetic mechanisms such as histone modification and DNA methylation stabilize gene expression, which is important for long-term storage of information.

NUTRITION AND THE EPIGENOME
Unlike behavior or stress, diet is one of the more easily studied, and therefore better understood, environmental factors in epigenetic change.

The nutrients we extract from food enter metabolic pathways where they are manipulated, modified and molded into molecules the body can use. One such pathway is responsible for making methyl groups - important epigenetic tags that silence genes.

Familiar nutrients like folic acid, B vitamins and SAM-e (S-Adenosyl methionine, a popular over-the-counter supplement) are key components of this methyl-making pathway. Diets high in these methyl-donating nutrients can rapidly alter gene expression, especially during early development when the epigenome is first being established."

This is edited from the "Learn Genetics" website of the University of Utah