For Science Geeks
The definition of epigenetics is a change in gene expression but no change to your actual DNA sequence. The body uses little compounds called methyl groups and inserts them into DNA grooves. These methyl groups can be on the DNA for a short period of time or they can get passed on to your children and grandchildren, depending on what types of cells had these methyl groups added to their DNA. Diet and environment can affect the amount of methyl groups we add to our DNA.
Histones are proteins that help fold the DNA into compact packages and impact gene activity. Depending on how tightly or loosely DNA is wound, the histone modifies the protein and thus affects DNA expression. As a result, different health effects can be seen with differing levels of histone modification. While histone research is still in its early years, a recent study found that mice who ate a ketogenic diet were able to help open chromatin (DNA and histone protein complex) in a certain part of the brain responsible for memory formation.
Methylation is the addition of a methyl group to DNA: a fancy way of saying a carbon with 3 hydrogens is added to DNA. When methyl groups are added to a particular gene, through DNA methyltransferase, that gene is turned off or silenced and no protein is formed by that gene. Depending on the needs of a particular cell or organ and where you are in your life cycle, it is in the body’s best interest to strategically turn genes on and off.
One of the most famous examples demonstrating the impact of methylation on health is the Agouti mouse study. These mice have the exact same DNA, but when a yellow mouse mother is fed a diet with added folic acid (a source of methyl groups), she produces brown, healthier looking mouse babies. The only difference between these two mice is one of their mothers ate a diet enriched with methyl groups while the other had standard mouse chow.