Luke O'Neill: Can you control how long you live?

We pass on our genes, but also our healthy habits. Photo: Getty

Scientists love a good puzzle. And one of the biggest puzzles in science is how our bodies age.

Why, if we rule out accidental death, do some of us live to old age, while others die much younger? Why do some of us develop diseases like arthritis or cancer as we age, while others do not? And perhaps most importantly: can we do something about it?