Roxanne Khamsi

And I kind of have to shift their thinking because I am interested in epigenetics.

I write about epigenetics, but I really wanted to focus on the actual sequence changes that happen.

So epigenetic markers sit on top of the DNA.

But what I'm talking about here are actual changes to those three billion nucleotides that make up the human genome in each of our cells.

Yes, definitely.

This is one of the reasons I had to write this book because I was shocked.

I learned about this about eight years ago when I read that in the New England Journal of Medicine, they had a brand new paper suggesting that mutant blood cells were not only linked to cancer, but in some people that had no cancer were doubling the risk of heart disease, stroke, all these cardiovascular diseases.

And I was just shocked because I'd never thought about mutation as causing these kind of

diseases.

It was completely new to me.

So some of it happens to just be time.

Like over the course of our lives, we are more likely to pick up mutations that cause these

large populations of mutant blood cells to start growing within us.

And so by the time somebody is 70 years old, there's about a 10 to 20% chance that you have a substantial number of these mutant blood cells in your body.

But there's also some interesting research looking at how things like getting good sleep might reduce your risk of these mutant blood cells rising in your body.

And they've actually also tried to study what happens to astronauts in space, whether that extra radiation that they're

exposed to might also contribute to their risk of these mutant blood cells.

I think this is one of the most provocative things I've learned.

So we tend to think about mutation as something bad, right?

We've talked about cancer.