Scientists believe that our DNA will change as our bodies age. According to new research, even though the sequence remains constant, subtle chemical changes occur to our DNA as we age and that could explain why we are at risk of developing diseases as we get older.

To understand this, DNA is made up of four basic chemical building blocks, adenine, thymine, guanine and cytosine. The sequences of those chemicals in a strand of DNA will determine what function a gene has and one of the ways genes are controlled is a process called methylation. It means that one carbon atom and three hydrogen atom, bonds to a part of the DNA and subtly change its function.

The new research shows that as we age, our DNA's susceptibility to methylation changes as well. Researchers from Bellvitge Biomedical Research Institute in Barcelona Spain extracted DNA from white blood cells of twenty newborn babies and twenty people aged between 89 and 100 years old to compare their degrees of methylation.

Newborn babies had 80.5 percent of cytosine nucleotides were methylated, while older people had a figure that dropped to 73 percent. It's not clear why it happens, but the researchers speculate that it could be due to extremely subtle age-related changes to the DNA.

The researchers discovered that a third of the methylated groups which were in different positions in the elderly compared to the young are already known to be linked to cancer risk.

So could this lead to a research to help maintain that level of methylation? If so, we could possibly be at less risk for diseases. [PNAS via Science]