ZOE Science & Nutrition

Today, we’re talking about plants.

For years, our diets have been guided by a simple three word slogan: ‘five a day’. While it’s well established that eating fruit and vegetables is good for us, some experts believe the ‘five a day’ message puts too much emphasis on quantity, and not enough on variety.

So, is time to adjust our guiding plant principle?

I’m joined by Professor Tim Spector and chef Hugh Fearnley-Whittingstall, who advocate for a new goal: eating 30 different plants each week. Together, we’ll explore why diversity is key for your microbiome and share some delicious ways to bring more plants onto your plate.

🌱 Try our new plant based wholefood supplement - Daily30+

*Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Free resources from ZOE

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Have feedback or a topic you'd like us to cover? Let us know here

Listen to the full episode here

Is your smartwatch just a fun gadget, or a serious medical device? 

In this episode, Jonathan Wolf is joined by Dr. Malcolm Findlay, a leading consultant cardiologist, to explore the powerful health data available on your wrist. They decode the most misunderstood metric, Heart Rate Variability (HRV), and reveal how your wearable can provide clinical-grade insights into your heart's health.

Dr. Findlay explains the counter-intuitive science behind HRV — why more ‘wobble’ in your heartbeat is a sign of good health — and breaks down the two opposing nervous systems that control it. He shares the latest on how these devices can accurately detect serious conditions like atrial fibrillation and why he, as a cardiologist, trusts the ECG function on a consumer smartwatch to make diagnoses.

For listeners who track their own data, this episode is a practical guide to what your numbers actually mean. Dr. Findlay explains how to interpret your personal HRV trends, what constitutes a significant change, and when you should use the ECG feature. He also debunks common myths about heart rate zones, revealing the level of exercise intensity that truly benefits your long-term health.

The episode concludes with an empowering look at how this technology is shifting control into our own hands. Can a simple alert from your watch really help prevent a catastrophic event like a stroke? Discover which metrics matter most and how to use them to guide your wellness journey.

🥑 Make smarter food choices. Become a member at zoe.com

Try our new plant based wholefood supplement - Daily 30+ *Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system.

Timecodes 

00:06 Quick-fire questions on heart health

01:45 What is heart rate variability (HRV)?

03:05 Is a steady heart rate a healthy sign?

05:15 Atrial fibrillation makes HRV an invalid measure

07:30 What controls our heart rate?

10:00 Your heart is much more than a pump

11:10 Your thoughts can directly affect your heart

13:45 What lifestyle factors influence your HRV score?

15:15 How does stress impact your HRV?

17:15 Your watch's ECG is a clinical-grade tool

20:20 Wearables can help diagnose serious heart conditions

23:45 Are expensive wearables more accurate?

26:20 Does diet impact your HRV score?

29:15 How to track your HRV score correctly

30:00 Don't panic about small HRV fluctuations

32:30 When to use your watch's ECG function

34:10 The truth about heart rate training zones

36:50 The minimum exercise for a healthy heart

37:40 Does sleep consistency matter?

39:50 What is VO2 max and does it matter?

41:10 Stop comparing your health data to others

41:50 Key takeaways from the episode

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Free resources from ZOE

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Studies referenced for today's episode Heart rate variability: standards of measurement, physiological interpretation and clinical use, 1996, European Heart Journal Diagnostic Accuracy of a Smartwatch App for the Detection of Atrial Fibrillation, 2019, The New England Journal of Medicine The Effects of Alcohol on Heart Rate Variability and Heart Rate, 2017, The American Journal of Cardiology The relationship between mental stress and heart rate variability, 2007, Journal of Psychosomatic Research

Have feedback or a topic you'd like us to cover? Let us know here. Episode transcripts are available here.

If you’re a regular listener of this podcast, you’ll know that our cholesterol level is closely linked to heart health. With that in mind, it’s easy to be drawn to foods labelled as ‘low fat’, ‘reduced fat’ or ‘fat free’ - all of which promise to keep our cholesterol low and heart strong. 

However, is it really that simple?

I’m joined by Professor Sarah Berry to break down the difference between good and bad cholesterol, bust some myths about low-fat foods, and explain how we can make smarter food choices that support our heart.

🥑 Make smarter food choices. Become a member a zoe.com - 10% off with code PODCAST

🌱 Try our new plant based wholefood supplement - Daily30+

*Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Free resources from ZOE

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Have feedback or a topic you'd like us to cover? Let us know here

Listen to the full episode here

We’ve all been there: tossing and turning, checking the clock, and stressing about not getting enough sleep. But what if the secret to a good night’s rest isn’t in a pill or a product, but in changing your mindset and daily habits?

In this episode, we’re joined by Dr. Sophie Bostock, a leading sleep scientist and founder of The Sleep Scientist. Sophie has dedicated her career to helping people understand the science of sleep and how to build lasting, healthy habits.

We dive into what really happens when we don’t get enough sleep, from the psychological effects on our willpower and relationships to the physiological impacts on our long-term health. Sophie debunks common myths about blue light, alcohol, and cheese, and explains the critical difference between occasional poor sleep and true insomnia. And introduces us to Cognitive Behavioral Therapy for Insomnia (CBT-I), explaining why it’s a more effective long-term solution than sleeping pills.

Finally, we walk through the simple, science-backed habits you can adopt right now to improve your sleep, starting the moment you wake up.

Unlock the science of sleep 👉  ⁠Get the ZOE app 

🌱 Try our new plant based wholefood supplement - Daily 30+

*Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system

Follow ZOE on Instagram.

Timecodes:

00:00 How to fix your sleep: what works and what doesn't

01:05 How a lack of sleep affects your willpower and mood

02:02 The evolutionary link between sleep deprivation and a threat response

04:26 How a lack of sleep can impact cognitive function

05:05 Is there a real scientific link between poor sleep and disease?

07:21 The surprising link between sleep and mental health

08:23 Why you can't try to have a good night's sleep

09:33 How to apply the "perfect is the enemy of good" rule to sleep

10:43 The number one reason for insomnia

11:12 The split between those who don't sleep enough and those who worry about it too much

12:12 Why are so many people dissatisfied with their sleep today?

13:00 Why technology is the biggest threat to our sleep

15:46 Why phones are making sleep harder

17:45 The science behind forest bathing

18:55 Can cognitive behavioral therapy help you sleep?

21:10 The surprising clinical definition of insomnia

21:40 Does alcohol help you fall asleep?

26:15 Are sleeping pills a good solution?

29:35 Can exercise help you get better sleep?

32:40 Can eating turkey help you get to sleep?

36:55 What about supplements like melatonin and magnesium?

41:38 What is good sleep hygiene?

44:18 The number one rule for your smartphone and your bedroom

45:32 How can wearables that track sleep help you?

47:34 The technique that will help you fall back to sleep

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Free resources from ZOE

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Today, we’re unwrapping the truth about chocolate.

For many of us, chocolate is a guilty pleasure. But what if I told you that you didn’t need to feel guilty?

Because it turns out that not all chocolate is created equal. And by changing the type of chocolate you eat, you can support your health instead of harming it.

In this episode, I’m joined by chocolate expert Spencer Hyman and Sarah Berry to show you how to enjoy chocolate with a clear conscience.

🌱 Try our new plant based wholefood supplement - Daily30+

*Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Free resources from ZOE

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Have feedback or a topic you'd like us to cover? Let us know here

Listen to the full episode here

There's an unseen world inside you, teeming with trillions of tiny inhabitants. Just like any ecosystem, some bugs inside your gut microbiome are beneficial, while others wreak havoc, quietly disrupting your health. What if these disruptive "invasive species" are silently driving the rise of cardiometabolic diseases, the leading cause of illness and death in Western countries?

This episode reveals groundbreaking new ZOE research, soon to be published in Nature, that maps this hidden world. We’re joined by Professor Nicola Segata, the study’s co-author and a pioneer of this new technology, alongside ZOE's scientific Co-Founder, Professor Tim Spector, one of the world's top 100 most-cited scientists.

Together, they reveal the top-ranked gut bacteria – both good and bad – that influence your health. Discover three powerful "good bugs" and how feeding them can suppress the "bad," transforming your gut ecosystem and paving the way for better health and potential therapeutic breakthroughs. Learn actionable tips for boosting your beneficial bacteria, starving the detrimental ones, and why gut testing is forever changed.

🥑 Make smarter food choices. Become a member at zoe.com - 10% off with code PODCAST

🌱 Try our new plant based wholefood supplement - Daily 30+

*Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system

Follow ZOE on Instagram.

Timecodes

00:00 Introduction 

01:05 The most common misconception about gut health

04:04 Your gut bacteria are like mini pharmacists

08:12 Why your gut microbes are as unique as your DNA

14:23 How ZOE is revolutionising health with a new research model

19:39 Groundbreaking research that featured in Nature 

22:21 The new, simpler way to measure your gut health

24:25 Meet newly discovered good bugs

28:06 The microbe that thrives when you eat nuts and seeds

32:40 Why only eating kale won't make you healthy

34:25 The 'ancient' gut bug discovered in mummies (and one of our scientists!)

36:37 The future of probiotics

39:17 The shocking truth about store-bought probiotics

42:17 What makes a 'bad' bug bad for your health?

43:45 Could your gut microbes be making you crave junk food?

46:29 The diet your bad bugs love the most

49:10 The future of personalised nutrition for your gut

52:22 How to 'pivot your ' to feed your good bugs

53:55 Is it okay to eat occasionally?

55:53 Tim Spector's simple 'fridge raid ferment' 

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Free resources from ZOE

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Mentioned in today's episode

Gut microbiome species indicative of cardiometabolic health are modulated by diet in large and interventional cohorts of over 34,000 individuals, forthcoming in Nature, (2025)

Gut microbiome species indicative of cardiometabolic health are modulated by diet in large and interventional cohorts of over 34,000 individuals, Published in Nature Microbiology (2025)

[3] Research progress of gut microbiota and obesity caused by high-fat diet, Published in Fronteirs in Cellular and Infection Microbiology (2023)

Have feedback or a topic you'd like us to cover? Let us know here.
Episode transcripts are available here.

Research continues to confirm how important the gut is for overall health. From energy to immunity and even mood, it all seems to start with the gut. It’s no surprise then that the hunt for the next gut boosting hack has exploded in recent years.

So, are probiotics really the answer? Or is the fix already sitting on our supermarket shelf?

In this episode, Dr. Karan Rajan helps us separate science from marketing hype and shares the simple, evidence-backed changes that can make a big difference to your gut.

🌱 Try our new plant based wholefood supplement - Daily30+

*Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Free resources from ZOE

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Have feedback or a topic you'd like us to cover? Let us know here

Listen to the full episode here

Many supplements claim to “boost” your immune system. Now, we all want to avoid getting sick during the winter months, but do any of these products really work? And is trying to “boost” your immune system even a good idea?

Jonathan speaks with Professor Daniel M. Davis, MBE — a leading expert on immunology and Head of Life Sciences at Imperial College London. Daniel has published 145 scientific papers, authored four best-selling science books, and spent 25 years researching how our immune system works. He even helped discover the immune synapse, a breakthrough that changed our understanding of immunity.

Daniel explains how your immune system really works, why it’s connected to mental health, and how it can even detect cancer cells. He also clears up common myths and shares what genuinely helps keep your immune system strong through the winter months — and what won’t make a difference.

By the end of the episode, you’ll know the practical, science-backed steps you can take to reduce your risk of colds and flu this winter without wasting money on products that don’t deliver.

Unwrap the truth about your food 👉 ⁠Get the ZOE app 

🌱 Try our new plant based wholefood supplement - Daily 30+

*Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system

Follow ZOE on Instagram.

Timecodes

00:00 Your body’s surprising, built-in cancer defense

02:07 What is the immune system?

03:55 Why ‘boosting’ your immune system can be dangerous

05:28 Are allergies a sign of an overactive immune system?

07:53 The 'hygiene hypothesis': Does being too clean make us sick?

11:05 The unintended global experiment of the COVID pandemic

12:40 How your immune system is constantly fighting cancer

14:20 The revolutionary new therapies that unleash your immune system on cancer

16:05 Is your immune system killing cancerous cells right now?

17:12 Your immune system is the most unique thing about you

19:25 Why you shouldn't blame yourself for getting sick

21:18 The myth of vitamin C and the Nobel prize winner who started it

23:55 The truth about vitamin C and colds

25:06 Does being cold actually give you a cold?

26:15 The powerful link between your immune health and mental health

28:06 Cytokines: The secret messengers you’re going to hear more about

29:00 Could inflammation predict teenage depression?

33:40 What is inflammation, really?

40:33 The double-edged sword of personal health data

42:06 Are there any immune supplements that actually work?

43:35 The one thing that directly harms your immune health

45:05 Why 'fight or flight' is bad for your immune system

47:08 How much exercise is best for your immune system?

48:16 The two most practical pieces of advice for a healthy immune system

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Free resources from ZOE

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Have feedback or a topic you'd like us to cover? Let us know here.
Episode transcripts are available here.

From Instagram reels to viral tweets, seed oils have become one of the latest nutrition villains. And the fear’s getting real. People are emptying their cupboards, terrified these everyday oils are silently wreaking havoc on their health.

So is this panic justified? Or does the science require further scrutiny? 

Well, ‘scrutiny’ is Professor Sarah Berry’s middle name! She’s going to cut through the confusion, dig into the data, and tell you whether it’s time to rethink your next stir-fry.

🌱 Try our new plant based wholefood supplement - Daily30+

*Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Free resources from ZOE

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Have feedback or a topic you'd like us to cover? Let us know here

Listen to the full episode here

We’re told vitamins are essential for our health. That they boost our immune systems, fight fatigue, and protect us from disease. But what if most of it isn’t true?

In the 20th century, vitamin supplements were hailed as a breakthrough, curing diseases like scurvy and rickets. But that success story took a turn. In the US, a law passed in 1994 — helped by a Hollywood ad campaign — removed almost all oversight from the supplement industry. Since then, a $40 billion business has grown in the shadows. One where marketing beats science, and health claims are made with barely any evidence.

Dr. David Seres is Director of Medical Nutrition and a Professor at Columbia University’s Institute of Human Nutrition. David is known for calling out pseudoscience and misinformation, and promoting critical thinking and an evidence-based approach to health. For over 25 years, he’s worked as a physician nutrition specialist, caring for critically ill patients who rely on life-saving nutrition support. He received the Excellence in Nutrition Education Award from the American Society for Nutrition. On this episode, he helps us debunk the vitamin supplement industry.

Unwrap the truth about your food 👉 ⁠Get the ZOE app 

🌱 Try our new plant based wholefood supplement - Daily 30+

*Naturally high in copper which contributes to normal energy yielding metabolism and the normal function of the immune system

Follow ZOE on Instagram.

Timecodes:

00:00 The marketing trick vitamin companies use to fool you

02:03 Did Mel Gibson really help deregulate vitamins?

03:57 How vitamins went from miracle cures to a $40 billion industry

06:06 The shocking story of the anti-regulation ad that beat the Vietnam War

07:40 The legal loophole that lets supplements claim they 'support heart health'

08:38 Why supplements don't need the same proof as drugs

11:10 In the US, there is no one checking supplement claims

12:14 Can you just make up a health claim and sell a pill?

14:42 How companies twist 'petri dish' science to sell you products

16:40 The vitamin that unexpectedly increased cancer risk by 18%

18:41 An easy way to understand why most health studies are wrong

20:30 How a memory supplement company manipulated its own study for 7 years

22:50 The only type of study you should trust for health advice

26:31 Why does scientific advice on health keep changing?

30:25 The popular diet advice I used to give that was completely wrong

32:14 The only time you should be taking a vitamin supplement

33:40 Does vitamin C actually do anything for you?

34:37 The truth behind vitamin D 'insufficiency'

36:29 Can taking too much vitamin D be dangerous?

37:50 Do vitamins help even the most critically ill patients?

42:42 What about taking a multivitamin when you get older?

45:35 Are probiotics a waste of money?

48:25 What is the single best way to eat for your health?

51:12 Why we still don't have perfect evidence for the 'best' diet

52:57 The one thing you should do tomorrow for your health

📚Books by our ZOE Scientists

The Food For Life Cookbook

Every Body Should Know This by Dr Federica Amati

Food For Life by Prof. Tim Spector

Ferment by Prof. Tim Spector

Free resources from ZOE

Live Healthier: Top 10 Tips From ZOE Science & Nutrition

Gut Guide - For a Healthier Microbiome in Weeks 

Better Breakfast Guide

Have feedback or a topic you'd like us to cover? Let us know here.