AMA #13: Winter Months & Sickness, Wim Hof Breathing & Stressors

Andrew Huberman, who introduces himself as a professor of neurobiology and ophthalmology at Stanford School of Medicine, opens AMA #13 by explaining where it sits. It belongs to the Huberman Lab premium subscriber channel. He says that channel was set up to support the standard Monday podcast, which stays free on YouTube, Apple, Spotify and other feeds, and to fund human research on mental health, physical health and performance at Stanford and elsewhere.

He also says the Tiny Foundation has agreed to match every dollar the premium channel raises for research studies, which doubles the total funding for that work. The rest of this section covers two questions: why colds and flus are more common in winter, and whether cyclic hyperventilation (Wim Hof-style breathing), deliberate cold exposure and, by his own extension, exercise can help someone fend off or shorten an illness.

The listener asks whether more colds and flus in winter is a myth, or whether it comes from the outdoor temperature or from people spending more time inside. Huberman answers that the research "very clearly shows" more colds and flus in the winter months. He then breaks the phrase "winter months" into separate variables. Away from the equator, winter means shorter days and longer nights. The effect is most extreme far north: in Tromsø, Norway, close to the North Pole, winter days are very short and summer days very long. Day length varies less the closer you get to the equator.

He says that in most places on Earth, days get noticeably shorter, by at least an hour or two, during part of the year, and that shorter days generally go with colder temperatures wherever you live. So winter bundles at least three factors: less sunlight (meaning more darkness or more artificial light), colder outdoor temperatures, and, as a result of both, more time indoors. He points out that cold weather does not mean you are actually exposed to the cold, because people respond by staying inside.

He calls indoor crowding "one of the reasons, not the only" reason for more winter illness. People spend more time indoors and therefore closer together. He says this has prompted peer-reviewed research on how proximity relates to cold and flu transmission.

Huberman describes laboratory studies in which consenting participants who had colds or flus sneezed at different distances from other people. He reports "a very nice relationship" between physical distance and infection: the closer an uninfected person is to someone who is sneezing, coughing, wiping their nose or wiping their eyes, the more likely they are to catch the illness.

He admits this sounds obvious. Nobody expects to catch a cold from someone in the next room or across the street, but sharing a car, an airplane row, a bus or a classroom with someone who is sneezing and coughing raises the risk. What he says the studies add is resolution. They compared specific distances, such as one, three and six feet apart, and found what he calls "a very direct relationship": the closer the distance, the higher the probability of catching the illness.

He extends the point from airborne droplets to contact. Kissing, hugging and other skin or saliva contact further increase transmission. He also notes that the virus can sit on the skin. It "doesn't always survive terribly long" there, but if an infected person wipes their face or nose, or uses tissues and then doesn't wash their hands thoroughly, a handshake can pass the illness on. He adds, with some humor, that this information will justify hypochondriacs in keeping their distance from people who may be sick.

Huberman says he plans a full episode on colds, flus and how to avoid them. He previews one point now because he thinks it is too important to wait: people's own theories about whether they are contagious, such as claiming they are early or late enough in an illness to be safe, are "rarely substantiated by the actual data."

keep in mind that anytime someone is sneezing or coughing, they are in fact contagious.

He limits this a little in the next segment. He says the data point to people still being contagious when they sneeze and cough "if it's due to a cold or flu." He gives no specific studies here and defers the details to the planned episode.