What causes the body to age?!

What causes the body to age?

is it something in the dna which transmits at certain times our bodies must break down? i was under the impression i could prevent certain aging, like using spf lotion. now i see that is not true, because i have used spf since i was 15 every single day and i have a lot of wrinkles. it seems compared the my peer relatives i am only 6 months to one year behind with my facial wrinkles because of the constant application of spf. whoopdeedoo.

We age because of our DNA and the way it is programmed. Your DNA determines how often your cells can replicate (reproduce) and how many times they can replicate. Every time your cells reproduce a small part of one of the ends of the DNA is lost. The ends of the DNA strand (known as telomeres) shorten and eventually with enough replications the cell loses the ability to reproduce and then dies without having replaced itself. When this happens enough times with enough cells then you die. Some believe that the rate of cell replication is determined in some part by how many calories one intakes (more calories = faster cell replication) and thus try to lengthen their lives by significantly limiting calories. It is true that external causes can speed up the process of cell death (such as tanning) but the influence varies in different types of cells.