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?
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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
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Episode transcripts are available here.