Recap: The hidden clock controlling your health | Professor Russell Foster

Hello, and welcome to Zoe recap, where each week we find the best bits from one of our podcast episodes to help you improve your health. Today, we're exploring circadian rhythms. Did you know that you could eat the exact same meal at two different times of day and your body would respond dramatically differently? It sounds like a riddle, but it actually comes down to your body clock. Every cell in your body has one. A tiny internal ticker shaped by evolution over millions of years to keep you in sync with the phases of the day. So how can we ensure we're doing the right thing at the right time? I'm joined by professor Russell Foster to help us all stay in time with our natural rhythm. Circadian rhythms, you know, the body clock as it's called, what are they and and why do they matter to us? Let's start with why do they matter. If you think about our biology, what it has to achieve is the right substances at the right concentration delivered to the right tissues and organs at the right time of day. And it's the, sort of temporal time structure that is delivered by our circadian system, our body clocks, that allow us to do this, that allow us to essentially optimize our biology. So they're incredibly important. Essentially, they influence every aspect of our physiology and behavior. What they are has turned out to be really fascinating. We sort of known about rhythmicity for a very long period of time. The first sort of description of a circadian rhythm goes back to about 1729 in plants with a rhythmic opening and closing of leaves under constant conditions, under constant darkness. In fact, this, French astronomer hopped a plant in a cupboard and would peek in from time to time. Is that right? I never knew that. I assumed it was only the light that caused the flowers to move. That was the assumption. You know, the light dark cycle drives this rhythmic behavior. But in fact and and he was completely puzzled by this. Like, there must be some internal mechanism, and he was dead right. And it took us quite some time to try and understand what that mechanism was. I mean, in the early days, we knew that there was a master clock within the brain in the hypothalamus, an area called the suprachiasmatic nuclei, mercifully abbreviated to s c nuclei, mercifully abbreviated to SCN, and it comprises about 50,000 cells. And when I started in the business, it was assumed that circadian rhythms were the product of cell cell interactions, a sort of a circuit property that would generate a twenty four hour oscillation in electrical activity. And then, I mean, it was so exciting because people had isolated individual SCN neurons and shown that they would tick away in a dish on their own in terms of electrical activity and and indeed turning on and off of of …