Roxanne Khamsi

The bulk of new mutations that occur in the reproductive cells that form our kids, 80% are actually traced to the sperm, not the egg.

Yeah.

And that's because, in part, sperm are not quite as good at defending against mutations as egg cells, it seems, from what scientists have kind of uncovered.

So, I mean, at the risk of sounding like the doctors who talk to me about my age and my fertility, the sperm of a 25-year-old man is the result of around...

350 cell divisions.

And in contrast, the sperm of a 45-year-old man traced back to more than 750 cell divisions.

So it's like more than twice the number of cell divisions.

And every time there's a cell division, there's opportunity again for those mistakes to happen.

So the end story is the older a man is, the more chance that he has all those mutations.

So I think it's more just shifting...

The focus not just from women and just kind of placing on everybody to say, look, everybody as they get older have more mutations in their reproductive cells.

Well, first of all, I want to mention again what I said earlier, which is like sleep seems to like slow down the rise of some mutant cells in our bodies.

Yeah, but like put that aside.

There are people who are looking at factors that contribute to longevity.

And how is mutation playing a role in that?

So interestingly, centenarians, so people who live...

100 years or more, have been found to have like certain variants of the SIRT6 gene, which is involved in DNA repair.

So there's companies now looking at all this data and actually trying to kind of explore the idea of slowing our mutation down.

I love the idea of having DNA that is repaired.

My concern is how specific can it be?