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.