I eat some fruit every day, but not too much and almost no processed food. I stay away from sweets, except 80 per cent chocolate.

The hope is that if we can increase youthfulness, we can postpone age-related diseases.

Maybe one day we will be able to take a pill that keeps us young and healthy much longer. I believe in my heart that this will happen.

You could have two completely different careers if you could stay healthy to 90. How fascinating that would be.

Carbohydrates, and especially refined ones like sugar, make you produce lots of extra insulin. I've been keeping my intake really low ever since I discovered this. I've cut out all starch such as potatoes, noodles, rice, bread and pasta.

You would think that UV just causes mutations, but it doesn't, you need a gene to be active for it.

I loved the idea that biology was logical.