They controlled for exercise and the effect size decreased by 40 percent but was still significant. My biggest criticism is, as usual in epidemiology, there's a bunch of confounders that weren't controlled for and are very difficult to control for. Vitamin D levels, social life, psychiatric disorders for example.

However I'm sceptical that vitamin D deficiency explains the entire effect given it is quite large. If sunlight itself isn't relevant I expect other confounders to be stacking on top of vitamin D deficiency.

> Avoiding the outdoors won't shorten your lifespan if you take care of your health in general.

You write this as if you somehow know this for sure. It’s well known that indoor air is significantly more polluted in most cases than outdoor air, at least in the west. Fresh exposure to outdoor air is also important not just exposure to the sun. I would definitely not want to spend most of my life breathing indoor air, and opening windows only gets you so far.

> . It’s well known that indoor air is significantly more polluted in most cases than outdoor air, at least in the west

Source on that? It probably vastly depends on the "outdoor", because i highly doubt next to an American highway the air is cleaner than the average housing away from that highway, like i don't doubt a house next to the highway has worse air than a forest in the middle of nowhere.

I thought it was common knowledge. Here’s some information from the Environmental Protection Agency:

> Americans, on average, spend approximately 90 percent of their time indoors,1 where the concentrations of some pollutants are often 2 to 5 times higher than typical outdoor concentrations

There’s been so much research on this by so many different organizations around the world, as far as I’ve known almost everybody was aware of this as fact.

There is an extraordinary amount of data online about this, should be easy to find. On average, outdoor air is healthier than indoor air, often by a wide margin. The above is from the EPA site: https://www.epa.gov/report-environment/indoor-air-quality

Also https://www.cnbc.com/2016/04/22/indoor-air-can-be-deadlier-t...

> indoor air is significantly more polluted in MOST cases

> indoors [...] concentrations of SOME pollutants are OFTEN [...] higher

Those two statements don't seem to be the same to me?

Everyone can make their own decisions about how much time they want to spend outdoors versus indoors. I encourage you to do the research yourself if it’s important to you, and make appropriate lifestyle choices. From the second link:

> World Health Organization has said that household cooking with coal or biomass-burning stoves led to 4.3 million deaths in 2012, compared with 3.7 million deaths from outdoor air pollution.

And that’s just talking about one of many different sources of pollution. There are so many sources of pollution indoors, sources that are very close to you physically, that you should carefully consider these factors and the statistics surrounding them.

For example, I don't live in a country where "household cooking with coal or biomass-burning stoves" is even a thing. I have an induction stove. In fact the air outside of my house is almost certainly worse because of a nearby highway.

Again, you are focusing on one specific source as an example. Feel free to ignore a decade of research on this topic -- but it's worth getting informed IMO.

Seems an overreaching and incorrect statement. Lots of studies on the correlation of outdoor time and well-being. This study itself, though imperfect controls for some of those variables like exercise.

It might not be true for everybody (sounds like you're fine sitting inside, popping vitamins, and grinding on the Peloton or whatever -- good for you) but don't make the mistake of thinking your experiences are others'.

Clearly there are things about "the outdoors" that can't be replicated indoors. Smells, the sheer size and variety of environs, O2/CO2 levels, etc. Unless you are living in some kind of enormous, elaborate bio-dome.