Healthy volunteers spent days being deliberately sneezed on, swabbed and injected with the fluids of sick people. Hardly any of them fell ill, and that one stubborn result sent a researcher back to the original records.
- Weigh over two hundred human trials before treating catching a cold as settled.
- Test any germ claim against the rulebook medicine wrote for itself.
- See how plain saltwater alone can bring on cold symptoms in some people.
- Read mood, weather and season as forces that shape the very same symptoms.
- Hold a charged health question calmly, as a live inquiry rather than a fixed belief.
The person asking is Daniel Roytas, a naturopath who lectures in naturopathic and nutritional medicine. He had taught the management of infectious disease for years, so the claim that germs do not cause illness struck him as easy to bat away. Instead of dismissing it in 2020, he went to the primary literature and stayed there for eighteen months, working through more than a thousand cited papers. The result became his book Can You Catch a Cold?. My aim in this piece is not to hand you a verdict. It is to walk that same evidence at a calm pace, so the contagion question stays yours to weigh.
What earns the material a careful hearing is its method. There is no lone dramatic study and very little anecdote. Instead it gathers the published transmission trials, the older medical record and the laboratory steps of virology into one catalogued whole. Learning to sit with a subject that unsettles you, without rushing to a side, is itself a skill. The free course on settling yourself before you weigh a big question is a gentle place to practise it.
Why one illness after another feels like solid proof
Your own reasoning is more trustworthy here than the habit suggests. Almost everyone treats colds as catching because the order of events looks conclusive. A friend gets sick, you are near them, then you get sick too. Roytas simply asks you to notice the join in that chain. Two events in a row do not prove that the first produced the second. Winter and coughing arrive together every year, yet nobody says the cold weather was passed from person to person.
That distinction is the whole discipline of the book. It sets aside how illness feels day to day and asks one narrow thing. Has any controlled study ever taken a well person, exposed them on purpose to a sick one, and reliably made them ill? You come away with a cleaner habit of mind, testing a health claim by its evidence rather than by how convincing the surrounding story feels.
The centuries when weather, not germs, explained a cold
The picture you inherited is younger than the one it replaced. Through most of medical history, doctors traced colds and flu to the air, the damp and the changing seasons, not to something passed between people. A specialist field even tracked how pressure and temperature lined up with each outbreak. By the mid-1800s the medical mainstream in Britain and America had largely set contagion aside for these particular illnesses. After polling scores of doctors during an epidemic in 1800, one physician reported the great majority calling influenza non-contagious and declared the matter closed.
All of that turned within a generation. The shift followed Louis Pasteur, the French chemist now remembered as germ theory's founder, publishing his account around 1861. Roytas is careful about the cause of the reversal. No fresh finding had overturned the older weather explanations. A rival framework had simply gathered institutional weight and won the room. Seeing that lets you hold today's consensus as one move in a long argument.
A founding quarrel ran underneath it too. Pasteur's contemporary Antoine Béchamp argued that tiny living particles inside us shift into microbial forms according to the state of the tissue around them. On his reading, microbes gather where tissue is already damaged, a bit like maggots arriving at decay they did not cause. Far from a fringe idea, several respected surgeons reached something similar on their own. Battlefield surgery in the First World War seemed to back them, since wounds healed in step with how well dead tissue was cleared, not with how many bacteria were counted.
What is the actual test for blaming a germ?
Any confident talk of a proven viral cause can be held up against germ theory's own founding checklist. That checklist is Koch's postulates, four steps meant to pin one specific microbe to one specific disease. Robert Koch, a father of modern bacteriology, drew them up in the 1880s. The awkward part is that he could not pass his own test. The germ he named kept turning up in healthy people, and the illness he produced in animals looked nothing like the one in patients. When bacteria kept failing this bar, science reached for a smaller unseen culprit, the virus.
Thomas Rivers wrote a virus version of the rules in 1937. In that very paper he conceded that nobody, himself included, had yet laid eyes on a virus directly, and he noted tensions inside his own scheme. Today's isolation step does not resolve it. A patient's filtered fluid is added to a broth of animal cells, antibiotics and serum, and when those cells start dying that death is read as a virus at work. The snag Roytas presses is that the same dying appears in dishes that never received any patient sample. What you gain is a sharper question to put to any pathogen story, which is whether its proof clears the bar the field set for itself.
Years of helping people think calmly about their health have taught me that the facts are rarely the hard part. The hard part is staying settled enough to look at an unsettling claim without either panic or flat refusal. That composure is exactly what the short daily practice for steadying your reactions is built to grow.
What more than two hundred human trials actually showed
The most direct evidence is the transmission trials themselves. Roytas catalogues 203 of them, spread across the years from 1906 to 2020, and one result repeats. More often than any particular success, the outcome was that nobody got sick. The largest effort ran during the 1918 influenza pandemic. American naval and public health teams staged twenty-five separate trials on 161 well volunteers, exposing them by swab, by injection and by coughing at close range. Around one in fifty showed any illness at all, and none resembled the devastating flu then killing people in their millions.
A British unit later spent more than forty years trying to give paid volunteers colds under near-perfect conditions. By its own account, one of its steepest challenges was simply managing to infect anyone. Bringing that same patient weighing to a decision you are stuck on is often the real work. It is the kind of knot we can unpick together in a one-to-one session, whatever the subject turns out to be.
A trial from 1920 makes the puzzle vivid. Plain salt water, carrying nothing living at all, brought on colds in almost one in five of the people given it. That beat the rate in the same researcher's trials using genuine mucus from flu patients.
In another study, volunteers were kept on a lonely Scottish island for ten weeks, then exposed on purpose to people with laboratory-induced colds through shared air, shared objects and touch. Nobody caught anything across four different exposure formats. Yet one guest arriving with a natural cold did pass it to three of four in one small group, while giving nothing to a near-identical group beside it. Sitting with both facts at once is the honest ground the book keeps returning you to.
Can fear and belief alone produce a real cold?
You hold more sway over your own body than the germ account tends to grant. One of the plainest alternatives on offer is the nocebo effect, where fear or expectation alone produces real illness with no physical trigger. In a study from 1930, a volunteer was told he had just been given mucus from a sick person. He had in truth received nothing but sterile broth. By evening a heavy cold had set in. The next morning, once the deception was revealed, it lifted within the hour. A much larger survey in 1960 traced the same pull. People who doubted they would fall ill proved less likely to, regardless of the group they had been sorted into.
Scaled up, the same effect becomes what the book calls social contagion, physical states rippling through a group by watching and shared belief rather than any agent passing between bodies. A yawn spreading round a room is the everyday version. The extreme version is mass psychogenic illness, real symptoms sweeping a crowd while no toxin or germ is ever found. One episode in 1962 started with a handful of schoolgirls in what is now Tanzania. It grew to touch over a thousand people across many villages over a year and a half. No biological cause was ever pinned down. That widens your map of how illness seems to travel, making room for the mind alongside the microbe.
How the seasons shape the very same symptoms
A large stack of environmental research points the same direction. Respiratory illness can be forecast, and in the lab reproduced, through routes that involve no infectious agent. Consider absolute humidity, meaning the real water content of the air whatever the temperature. When it falls past a certain point, flu risk climbs by more than half, and agencies can predict outbreaks from that measure alone. Cold air by itself, with no virus given, lifted cold rates across several controlled trials. In two large wartime tests, soldiers left out in cold and wet for days sickened at four times the rate of sheltered ones.
Dirty air adds a separate route. Fine particles, now sitting at unsafe levels across almost the entire planet, have been shown to turn the thin fluid lining the airways more acidic. Past a certain acidity the lining cells start dying and shedding, which sets off the cough, mucus and inflammation that define a cold. Roytas pushes one step further, wondering whether some flare-ups are the body actively clearing built-up toxins and worn cells. A tree letting its leaves fall each autumn is his image for it, a healthy shedding rather than a sickness.
None of this asks you to deny that germs exist or ever play a part. The book is emphatic that it makes no medical claims and argues against no ordinary care. It presses one modest request, that your certainty about catching colds should match the evidence actually in hand. Reaching that is a matter of unhurried judgement, not a ready-made verdict pressed on you.
Turn an unsettling question into steady, clear thinking
The real prize in this material is not a fresh belief to trade for the old one. It is the poise to hold a charged health question while fear stops yanking you toward either extreme. You practise separating what a study actually showed from what a familiar story implies, and you notice the moment certainty runs ahead of proof. That steadiness reaches well past colds and flu, into every claim about your body you will meet across a lifetime.
If a health decision or a stuck situation would be easier to face with calm, unhurried company, you can bring that question to a personal session with me. And if you would rather start quietly on your own, put a plain question in and pull an answer drawn from this source alongside others. In seconds you have something to reason through at your own pace.