Hannah Fry

Welcome to ZOE Science and Nutrition, where world-leading scientists explain how their research can improve your health.

Welcome back to part two of our 2025 highlights, the moments that changed how we think about our health and give us practical tools to feel better every day.

Today, you'll hear what happened when I put my own breakfast under the microscope, how arthritis symptoms were reversed in a groundbreaking trial, and we finally get a scientific answer to the question, does cheese really cause nightmares?

But first, a person who has arguably pushed the boundaries more than anyone, Brian Johnson.

Brian has dedicated his life and his body to testing cutting-edge health interventions to slow down aging.

His meticulous approach to sleep, diet, and exercise has sparked global debate and raises a question that matters for all of us.

How much should we experiment with our own health?

I began by asking him how he developed his unique way of living.

And Brian, when you say the best possible markers, do you mean the best possible markers for someone of your age?

Or are you saying that they're better than my 16-year-old son?

If I understand right, you are saying that, yes, you are better than my 16-year-old son, basically, on all of these markers.

That's amazing.

Listening to Brian, I was struck by the contrast between his extreme routine and the much smaller health experiments most of us might want to try.

My Zoe co-founder, Professor Tim Spector, Brian and I shared a really honest, useful exchange about what's safe, what isn't, and where to start.

One question I think a lot of listeners will have listening to this is, is it safe to experiment on my health?

So how should people, if you were going to advise anyone listening to this, thinking about experimenting with their health but wanting to do it safely, what would you be saying, Tim?

That idea of simply paying attention, noticing how you feel after you eat, move, or change your routine has really stayed with me.

It's such a low-effort habit, and yet it can tell us more about our health than we realize.

And it doesn't just apply to food.

Brian told us that sleep was one of the biggest levers he's found for improving his overall well-being.