DEAR DOCTOR K: I see advertisements about various treatments that stop your cells from aging. Is there anything to that? What happens to our cells as we age?
DEAR READER: There are no treatments that can stop our cells from aging. But in the past 10 years scientists have made giant steps in understanding what causes cells to age. That knowledge could lead to true “anti-aging” treatments.
As for what happens to our cells as we age, I’d rephrase the question: What happens to us as our cells age?
Our bodies are made up of trillions of cells. As we get older, so too do our cells. And like us, our cells do not live forever. Most of the cells in our bodies today were not with us when we were born.
From birth through adulthood, new cells are constantly forming; that’s how our bodies grow larger. Cells “grow” not by getting bigger, but by dividing in two. This process is called mitosis.
Once we reach adulthood, our cells don’t need to divide to help our bodies grow bigger. They divide only to replace cells that have died or been damaged.
Each time a cell divides, a little bit of the telomere – DNA at the tip of each chromosome – is lost. Thus, telomeres of young cells are longer than the telomeres of middle-aged cells or old cells. When the telomeres become very short, the cell can no longer divide, and it dies.
Along with telomeres that get shorter, older cells also suffer increasing damage to their DNA. In addition, the mitochondria – the little “batteries” inside each cell that supply its energy – start to become less efficient.
The bottom line is this: We get older because our cells get older. What makes a cell age, and what could help keep a cell young, were nearly total mysteries just 25 years ago. Since then, medical research has provided many answers. Because of that research, I believe that someday we will be able to slow aging.