No one looks forward to old age, but are the problems we dread inevitable? Why do they happen? And can we do anything to avoid them?
A widely-held theory is that our cells are under constant attack from harmful molecules. Some are a byproduct of normal metabolism such as free radicals
, while others arise from our environment. These damage the DNA, fats and proteins in our cells, which over time become less able to repair themselves.
Other research suggests internal processes cause our cells to age. This may be part of the same process that triggers our development from children to adults. Our cells constantly multiply to replace damaged cells, but they can only reproduce a certain number of times. At each reproduction, the telomeres at the ends of our chromosomes get shorter, which is also a marker for aging.
But, why do some people age “better” than others?