You have around 10,000 cancer cells in your body right now, but most never become dangerous. The science suggests cancer risk is not just about genetics, but how your body responds to these cells. So what can you do, day to day, to support your body’s natural defences? In this episode, Dr William Li, a world-renowned physician, scientist, speaker, and two-time NYT Bestselling author, explains how everyday foods can fuel cancer growth or help your body keep it under control. We explore how cancer starts, why it is part of normal biology, and explain why lifestyle and environment are more important than genetics when managing your cancer risk. Dr Li shares simple guidance on eating patterns that support your body’s defences, including increasing plant-rich foods and reducing ultra-processed foods. He also highlights everyday habits such as staying active, supporting gut health, and limiting toxin exposure as ways to tip the balance in your favour. If your body is already managing cancer cells every day, what small changes could help it do that job better? 🌱 Try our science-backed and tasty wholefood supplement Daily30 Get our brand-new app and Gut Health Test designed by world-leading gut health and nutrition scientists to build healthy eating habits 👉 Join ZOE Follow ZOE on Instagram. Timecodes 00:00 Intro 02:26 Almost everyone has microscopic tumours 08:15 We all have cancer right now? 10:45 Why most cancer cells stay harmless 13:40 The hidden trigger that fuels cancer growth 14:35 What makes cancer turn deadly 16:35 Cancer cells behave like seeds 19:05 How sunburn can lead to cancer 20:55 What smoking really does inside your body 22:20 The new way to fight cancer 24:20 Why genes matter less than you think 26:00 Is vaping worse than smoking? 27:05 The drinking habit that raises cancer risk 29:25 The environmental risk we can’t ignore 33:47 The diet pattern linked to cancer risk 35:10 Why processed meat is a class 1 carcinogen 37:25 How processed meat affects your gut 41:50 A simple way to reduce BBQ toxins 43:40 Does sugar really feed cancer? 45:51 The truth about soy and cancer 47:25 The soy study that shocked scientists 49:05 How tomatoes may lower cancer risk 51:00 Why berries are more powerful than you think 54:40 How tea and coffee support your defences 56:05 The gut link to cancer risk 57:40 Dr Li’s simplest rules to reduce risk 📚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 Good Mood Food (preorder) by Prof. Tim Spector Free resources from ZOE The Hormone Harmony Guide: Tuning Your Body’s Internal Orchestra Eating for Better Brain Health: Your brain-gut blueprint How to eat in 2026 - Discover ZOE’s 8 nutrition principles for long-term health 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 Eat to Beat Disease: The Body’s Five Defence Systems and the Foods that Could Save Your Life by Dr William Li Eat to Beat Your Diet by Dr William Li Huge microbiome breakthrough from ZOE, thanks to community science Shanghai Breast Cancer Study, JAMA (2009) The Anti-Cancer Activity of Lycopene, Nutrients (2022) Health Professionals Follow-Up Study Have feedback or a topic you'd like us to cover? Let us know here. Episode transcripts are available here.