About the Book
"Utterly absorbing. Nearly every paragraph brings a revelation."--Bill Bryson - "Wise, and beautifully written. . . . It will change the way you think about your body and live your life."--Chris van Tulleken - "This great book from a world expert offers practical tips and dispels many myths."--Tim Spector A world-renowned scientist offers a much-needed analysis of what it takes to have good immune health--helping readers navigate what can really help, what is a complete myth, and why.
Does orange juice help ward off colds? And how does our age affect our ability to recover from one? When it comes to immunity, are we really what we eat? Or how much we eat? We are surrounded by big questions and big claims about enhancing our immune systems, so how do we tell the fiction from the facts? And, ultimately, what can we do to reduce our chances of getting sick?
World-leading immunologist Daniel M. Davis offers answers in this authoritative, highly accessible, myth-busting guide to the effects of stress, age, exercise, weight, nutrition, sleep, vaccines, and mental health on our immune health. Taking us to the cutting edge of immunology research and explaining both what we know and how we know it, Self-Defense helps readers spot phony claims and make informed choices. Davis shows us that everyone's immune system is entirely unique, and that's why we should be wary of one-size-fits-all "cures." We learn how exercise, for example, has all sorts of different, even opposing, short- and long-term effects on our immune health. And while our gut microbes are vitally important, it's unlikely that yogurt drinks can really boost your immune system to stop you getting ill.
An eye-opening window into some of the astonishing possibilities for the future, when it comes to distinguishing bogus and beneficial health claims about everything from vitamin D to inflammation and cancer therapies, Davis's book may be your best self-defense.
About the Author :
Daniel M. Davis is head of life sciences and professor of immunology at Imperial College London. He is the author of The Compatibility Gene, The Secret Body, and The Beautiful Cure, the last also published by the University of Chicago Press and named a Book of the Year in the Times, Telegraph, and New Scientist. His writing has appeared in the United Kingdom's leading newspapers, as well as in New Scientist, Wired, and Scientific American. In 2025, he was awarded an MBE in the King's New Year's Honors list for services to science communication.
Review :
"As renowned immunologist Davis argues, the immune system is extremely complicated and widely misunderstood. . . . This isn't a book for people seeking cheap tips about what to eat to boost your immune system--something Davis explains we don't always want to do anyway, as an overly proactive immune system can be dangerous--but it offers an illuminating picture of a fascinating area of science."
-- "Daily Mail, "9 Best Health Books of 2025""
"With the recent publication of his fourth book, Self Defense, Dan's work shines a light on how immunology can influence our health, demystify the science behind many diet and lifestyle claims, and helps his audiences understand just how complex our biological systems really are."-- "British Society for Immunology"
"After giving public lectures, the immunologist Davis usually finds himself being asked a 'series of seemingly simple but actually really difficult questions, mostly, if not exclusively, about how to achieve good immune health.' He is, of course, under pressure to provide snappy answers to his audience's enquiries: does orange juice ward off colds? Should we take vitamin D? How can I boost my immune system? Self-Defense is his longer, more considered answer to these questions, and it aims to bridge the gap between the scientific research of his day job and what people want to know about immunity. . . . Self-Defense is a reminder that there's a lot of research behind even our simplest questions about the immune system. Davis follows the twists and turns of the evidence and offers nuanced responses to immune health questions. . . . Above all, his friendly tone and clear writing give the reader a much deeper appreciation of the complexity of the human body."-- "Times Literary Supplement"
"Davis is a world-class scientist and one of the best science communicators of his generation. From the role of tobacco scientists in promoting stress to why astronauts take antihistamines, Self-Defense will answer every question you have about your immune system and many more. It is deeply absorbing, wise, and beautifully written. Packed with astounding science, compelling stories, and ideas, it will change the way you think about your body and live your life."--Chris van Tulleken, author of "Ultra-Processed People"
"In Self-Defense, immunologist Davis explains everything that we know about our immune systems with clear, concise, and engaging stories based in the latest science, not hype. So, if you're tired of all the people trying to sell you things that they swear will improve your immune function, but then never do, this book is for you. Davis walks us through the often complicated answers to all our questions and shows us that there is no such thing as a one-size-fits-all solution to immune health."--Theresa MacPhail, author of "Allergic"
"A masterful exploration of what we know (and don't know) about the workings of this most crucial of bodily functions. In a world of sales patter, soundbites, and social media videos, scientific rigor, clarity, and nuance is much needed. Self-Defense provides precisely that. Davis dissects claims and widely held beliefs surrounding the workings of our immune system, and shines a light on what is myth, hype, uncertainty, and scientific truth."--Guy Leschziner, author of "Seven Deadly Sins"
"There is so much misinformation in the health and science arena that it can be really challenging to pick the truth out of all that fiction. Self-Defense is a perfect antidote to so many of those assumed truths about immune health that have gone unchallenged for way too long. It is a refreshing, expert examination of health myths, beautifully written, packed with science but always accessible. I learned a lot."--Suzanne O'Sullivan, author of "The Age of Diagnosis"
"Why does weight-loss drug Ozempic reduce dementia risk, and what's the connection between the bacteria living in your gut and risk of allergies? The answer--as in so many parts of biology--is the immune system. Self-Defense takes us on a fascinating tour of our bodies, linking happenings inside our cells to everyday practical advice, and dealing with pervasive myths about vitamins, inflammation, and more along the way. This book will do more for your health than any bottle of vitamin C tablets!"--Andrew Steele, author of "Ageless"
"Self-Defense: A Myth-Busting Guide to Immune Health uncovers how curiosity-driven science can help you truly understand and optimize your immune system--free from hype, misconceptions, and the traps of mistaking coincidence for causation. From the surprising links between cytokines and mood to the effects of stress on immunity, this book reveals how our biology shapes us in unexpected ways. With stories like how a glowing jellyfish transformed medical research, it shows how simple discoveries can lead to profound insights. Dive in to see how thoughtful, evidence-based exploration can lead to better health, resilience, and self-awareness."--Roger Highfield, science director at the Science Museum Group (London) and coauthor "The Dance of Life"
"This book is a masterclass in science communication. Davis unravels one of the most complex and vital elements of human biology, our immune system. Self-Defense disentangles the science of immunity and addresses some of the key questions we all want answered. Does orange juice really help us fight off colds, prevent us getting cancer, or combat HIV? Do increased infections in early childhood protect against allergies, and is it true that children who grow up on farms are less likely to have asthma and hay fever? How might our genes or gut bacteria alter our vulnerability to infection? What is the link between obesity, stress, and sleep with our ability to fight infection? And does our immune system affect our mental health and the aging process? This is essential reading for anybody who wants to understand their health."--Russell Foster, neuroscientist and author of Sunday Times-bestselling "Life Time"
"As David Attenborough opens our goggling eyes to the natural world without, so Davis brings us face to face with the stunningly clever and, yes, beautiful world within. . . . One of those books that makes you look at everything human in a new, challenging, and thrilling way."--Stephen Fry, on "The Beautiful Cure"
