While our bodies age, scientists believe that our DNA at least remains constant.
New research, however, reveals that, even though its sequence remains constant, subtle chemical changes occur to our DNA as we age—and it could explain why the risk of developing disease increases as we get older.
DNA is made up of four basic chemical building blocks, called adenine, thymine, guanine, and cytosine. It's the sequences of those chemicals in a strand of DNA that determines what function a gene has, and one of the ways the resulting genes are controlled is a process called methylation. That just means that a methyl group — one carbon atom and three hydrogen atom—bonds to part of the DNA and subtly change its function.
