Happily, except for playgrounds, outdoor public spaces are still open where I live.
The outdoors and sunshine are such strong factors in fighting viral infections that a 2009 study of the extraordinary success of outdoor hospitals during the 1918 influenza epidemic suggested that during the next pandemic (I guess this one!) we should encourage “the public to spend as much time outdoors as possible,” as a public-health measure.
I make an effort to get out into nature as often as possible. With our little prairie and woods nearby, it’s possible almost every day. Larger natural areas—Forest Glen, Fox Ridge, Spitler Woods, etc.—are within easy driving distance.
Trunk of fallen tree conforming to the contour of the ground in Forest Glen.
With my focus having been on nature for a long time, I was interested to read this piece in The Guardian:
In recent years, stressed-out urbanites have been seeking refuge in green spaces, for which the proven positive impacts on physical and mental health are often cited in arguments for more inner-city parks and accessible woodlands. The benefits of “blue space” – the sea and coastline, but also rivers, lakes, canals, waterfalls, even fountains – are less well publicised, yet the science has been consistent for at least a decade: being by water is good for body and mind.
We do have some water right here where we live. There’s the little creek that runs behind Winfield Village and a couple of little detention ponds, and they do have some wildlife. I often see turtles, snakes, groundhogs, and many sorts of birds. I’ve occasionally seen mink, coyotes, and bald eagles.
I do feel the lack of a beach. The closest is Indiana Dunes, but it’s nearly 3 hours away. I’ve done it as a day trip, but it makes for kind of a long day.
Great Blue Heron departing detention pond near Lake Park Woods.
The article makes for a good reminder to be sure to include blue when you’re making sure you get out into the green.
Here’s a report on a study which measured vitamin D levels of Hadzabe and Maasai individuals living traditional hunter-gatherer or pastoral lifestyles, the data having been collected with an eye toward learning something about what would have been typical during our evolution as a species.
For the Hadzabe the mean was 109 nmol/l and for the Massai 119 nmol/l. These levels are not outside the reference range, but are way above the minimums.
[T]he mean vitamin D concentration of traditional Africans is indicative of the level that would have been typical throughout much of our evolution, and hence, the level that the human physiology would have grown accustomed to over millions of years. Hence, it’s not unreasonable to speculate that such a level may indeed represent optimality…
People not living traditional lifestyles can get enough sun to see similar levels, but probably not if they work in an office, and probably not at all in the winter (unless they live in the tropics).
I had my own vitamin D level measured once. It was 38.5 ng/mL (equivalent to 96 nmol/l) versus a reference range of 30.0 – 100.0 ng/mL (75 – 250 nmol/l). That was in February though, and that level was produced with vitamin D supplementation.
As I was observing just a few days ago, when exposed to sunlight, your skin does a lot more than just make vitamin D. I’m pretty sure that high vitamin D levels are just a marker for adequate sun exposure. Taking vitamin D supplements in sufficient quantity to raise your blood levels high enough to mimic those of people who get enough sun will produce no more benefit than gaming any metric does.
I’d be interested to know what my vitamin D levels are right now, after a long summer of getting plenty of sun. But not interested enough to go to the effort of convincing my doctor that it’s worth testing again, nor interested enough to pay for the test.
I observed years ago that the more sunlight I got the better I felt. Although “it’s the vitamin D” seemed like a reasonable hypothesis, I’ve been pretty careful not to just assume that—whenever I’ve written about this I’ve gone ahead and listed some of the other “active ingredients” that tend to come along with sun exposure—exercise, time in nature, etc. As I look into the matter more, I find there’s a growing body of evidence that sunlight itself does provide benefits, but it’s not just the UV light—the other frequencies of light are also actinic in all kinds of ways.
We’ve long known that blue light (especially, but not exclusively, a specific frequency of blue-green light absorbed by a pigment in the eye called melanopsin) was critical for establishing and maintaining an appropriate circadian rhythm. Very recently we’ve discovered that adipose tissue expresses the genes that produce the same pigment and use it to vary how the cell acts. In particular, after exposure to an amount of blue-green light that might shine through skin exposed to full sun, fat cells reduce the amount of fat they store, and also produce less leptin (a hormone that affects feelings of satiety).
Red light
As I discussed a few weeks ago, there’s been a lot of research on the effects of red and near-infrared light exposure. Here’s a page with links to a bunch of studies that suggest that red and near-infrared light boosts collagen synthesis, speeds healing of burns, incisions and broken bones, reduces inflammation, and generally reduces the effects of aging on your skin.
I guess that leaves us with orange and yellow light unaccounted for, but I don’t doubt that they’ll turn out to be actinic as well.
I am a little too prone to use black humor to distance myself from the depressing effects of the long, cold darkness of winter, which sometimes leaves people worrying about me unnecessarily. So I thought I’d mention that despite a bit of anxiety over the inevitable turn of the seasons, my mood is currently pretty great.
Beyond just feeling good right now, I’m hopeful. Over the past decade I’ve been handling winters better and better.
The biggest factor, I think, is that I no longer have a job to lose, so I no longer get into the spiral where seasonal depression makes me less productive, making me anxious about losing my job, making me more depressed, making me even less productivity. Sadly, advising others to take advantage of this strategy is not very useful (although I do and will continue to support and advocate for either a citizen wage or a guaranteed job).
Putting early retirement aside as impractical for most people, I thought I’d briefly summarize my other current practices—mostly ordinary coping strategies—both as a reference for myself any time I start to feel my brain chemicals coming on, and perhaps as a resource for other people. Here’s what’s working for me:
Spending time in nature. I do that all summer, and it may be part of the reason that my mood is generally great in the summer. But I can do it in the winter too. (I don’t seem to have a post on this topic. I’ll be sure to write one this winter. In the meantime you can find various mentions by clicking on the vitamin N tag over on the sidebar.)
Light therapy. I’ve used my HappyLight™ for years, and it does seem to help. Getting outdoors anytime in the first couple of hours after dawn is probably even better—another thing I find easy to do in the summer that would probably help just as much in the winter.
Taking Vitamin D through the winter. The evidence for any benefit is scant, but even if it only helps through the placebo effect, it is at least a safe, cheap placebo. (There’s good evidence that people with high levels of vitamin D are healthier, but very little evidence that supplementing vitamin D makes people healthier. It could easily be purely associational—maybe more time spent outdoors both boosts vitamin D levels and makes people healthier and happier.)
Anything that boosts neurogenesis. That’s most of the things listed above, but lots of other things too, such as engaging in creative work. Also on the list are calorie restriction and adequate consumption of omega-3 fatty acids.
I have a few new possibilities up my sleeve:
There’s recent evidence that sauna bathing is dramatically effective at treating depression, probably through many mechanisms including the activation of heat-shock proteins. (One thing on my to-do list is finding a local fitness center or spa with a sauna and investigating the cost of a three or four month membership.)
Related to heat exposure is cold exposure, which activates many of the same protective proteins that heat exposure does. Cold exposure, of course, is trivially easy to achieve in the winter—just wear a coat or jacket one notch less warm than would be most comfortable.
Obviously sleep is very important, and with my Oura ring I’m tracking my own sleep carefully. This has already been helpful, and I’m hoping to be able to do more to improve my sleep (and thereby my mood) in the winter as well.
That’s what I’ve got at the moment, but I’m always on the lookout for things to alleviate seasonal depression.
For most of my adult life I carefully limited my sun exposure. More recently—after discovering that the more sun exposure I got the better I felt—I’ve been trying to get as much as I could without getting burned. Just lately I’ve been groping towards something more nuanced.
Back in maybe the 1980s I briefly tried to follow the advice of dermatologists to never go out without sunblock. That didn’t work well—inevitably there would come the day when I was out in the sun longer than anticipated, and (not having built up a protective tan) I’d end up burned.
After that, for a decade or two, I came up with some simple rules: Unlimited sun before 8:00 AM and after 5:00 PM, but I’d aim to get 20 minutes of mid-day sun. If I was going to get more than that, I’d wear sunblock, but I tried to get that much sun every sunny day. That worked pretty well—I’d get enough of a tan to provide some protection on those days that I was unexpectedly out in the sun.
That schedule, of course, fell out pretty much automatically from working at a regular job. I stuck with it even after I wasn’t working at a regular job because it worked pretty well.
For various reasons, such as needing to take very long walks to train for our big Kal-Haven trail walk, I started spending more time out in the sun, and began to observe that the more time I spent in the sun the better I felt, leading me to get what was probably more sun than is really wise.
Since recently running into the idea that certain frequencies of red and near-infrared light are good for your skin and deeper tissues, I’ve been prompted to think about all this in a more systematic way, and have been trying to come up with a plan that maximizes the benefits while reducing the harm caused by sun exposure.
I’m still in the research stage, but here are the early changes that I’m making:
First, I’m reducing the amount of mid-day sun I’m getting. I’ve been going for around 40 minutes (as much as I can get without risk of burning), but I’m bringing that back to around 20 minutes. Still enough time to make plenty of vitamin D.
Having gotten the amount of mid-day (2:27 PM) sun exposure I wanted, I moved the rest of my walk into the woods.
Second, I’m replacing that 20 minutes of mid-day sun with 20 (or more) minutes of sunlight during the period that the UV index is between 1 and 3. (This time of year, where I live, that’s maybe 7:30 AM until 9:00 AM.) My hope is that part of the reason more sun makes me feel better is the red light (rather than the UV), and that morning and evening sun can provide those frequencies.
Taken during at 8:59 AM during a walk in the prairie.
Third, I’m trying to get some very early (dawn) sun exposure. This is specifically for the effect early morning light has on the circadian rhythm.
Early morning (6:53 AM) sun over the Lake Park/Winfield Village prairie.
Only in the middle of writing this did I realize the extent to which I’ve come back to what I did for most of my working years—except that instead of having to squeeze my morning sun exposure into the time I spent crossing the parking lot, now I can extend it to 20 minutes or longer, and combine it with a proper walk in nature for some sweet, sweet vitamin N.
I went for a long-for-me, 7.22-mile run this morning, and listened to a podcast about light therapy.
(I go back and forth on listening to podcasts during runs. When I listen I feel like I miss out on being fully embodied in my physical activity. When I don’t listen I fall behind on stuff I really want to listen to. Today I listened.)
The podcast had Paleo Magazineʼs Ashleigh Van Houten interviewing Scott Nelson, the founder of Joovv, talking about the health benefits of exposing your skin to red and near-infrared light. I’d heard about this, but had assumed it was some woo-woo new-agey thing. Turns out it’s probably not. There’s been a huge amount of research on the benefits of exposing your skin to red light in the 660-nanometer and near-infrared light in 850-nanometer range.
(There was apparently a lot of research funded by NASA back in the 1990s when they had to use lasers to get light of just the right frequency. Nowadays LEDs make it easy to get the intensity and frequency of light that you want.)
So, I’m out on my run, listening to Ashleigh and Scott talk about all the health benefits to your skin (of the red light) and to deeper connective tissues (of the near-infrared) and thinking that it all sounds really cool, but knowing that I’m probably never going to want to spend even hundreds, let alone thousands, of dollars to buy a device that will shine bright red light on my skin.
At around the mid-point, maybe 4 miles into my run, I paused for a drink of water out of the fountain in Morrissey Park, thinking it was pretty hot for just 8:40 AM . Which made me think of this giant glowing orb in the sky, which was shining down on me with pretty intense light at a wide range of frequencies, most definitely including red and near-infrared.
Turns out, sure enough—the energy in the red and near-infrared frequencies of sunlight is right in the range of therapeutic doses shown to have health benefits.
Of course, full sunlight is full of other frequencies of light, including blue (prone to mess up your circadian rhythm if you’re exposed too close to bedtime, but just what you want to get your circadian rhythm set correctly if you get your exposure in the early morning like I was doing), and ultraviolet (dangerous in excess, but the UV index was zero when I started my run at 7:40 AM and probably didn’t reach 5 before I was safely back indoors). So you need to treat sunlight with respect. But I already knew that.
I have mentioned before that I feel better when I spend a lot of time outdoors, and have speculated that sun exposure is part of the reason. (Along with time in nature, moving more, appropriate quantities of community and solitude, etc.) The information about red and near-infrared light exposure seems to lean a bit in the sunlight direction—but with the welcome news that it’s not just the vitamin D that helps make me feel better, which means maybe I can feel great without having to expose myself so much to the deadly actinic rays of the sun.
From 11:56 AM until 12:12 PM today, the sun will be high enough in the sky that its powerful actinic rays will reach the earth with enough energy for exposed skin to produce vitamin D.
Of course, the temperature around noon will be about 12℉, so I’m not expecting to have much exposed skin, but it is still nice to know that vitamin D production will be possible.
There might be an unseasonably warm and sunny day at any time this month or next, giving me a chance to make some vitamin D. And soon enough spring will come.
(Ephemeris data valid for where I live. The opening of the vitamin D window will likely be different for you.)
I shared a link to this article by Rowan Jacobsen, with the comment “This article falls so squarely in the sweet spot of reinforcing my own preconceptions, I almost hesitate to tweet it.” But I did, with a few brief quotes.
Freed of the limitations of twitter, here’s a more extended excerpt:
Lindqvist tracked the sunbathing habits of nearly 30,000 women in Sweden over 20 years. Originally, he was studying blood clots, which he found occurred less frequently in women who spent more time in the sun—and less frequently during the summer. Lindqvist looked at diabetes next. Sure enough, the sun worshippers had much lower rates. Melanoma? True, the sun worshippers had a higher incidence of it—but they were eight times less likely to die from it.
So Lindqvist decided to look at overall mortality rates, and the results were shocking. Over the 20 years of the study, sun avoiders were twice as likely to die as sun worshippers.
There are not many daily lifestyle choices that double your risk of dying. In a 2016 study published in the Journal of Internal Medicine, Lindqvist’s team put it in perspective: “Avoidance of sun exposure is a risk factor of a similar magnitude as smoking, in terms of life expectancy.”
Jacobsen later mentions the app dminder, which I’ve been using for several years now. It helps you optimize your sun exposure (getting maximum vitamin D production without getting sunburned, based on time of year, time of day, location, and skin pigmentation). I just checked the app, which tells me that it’s just 8 days until the vitamin D window reopens here in Savoy, Illinois!
I concluded my little tweet storm with this: Pretty much every nice day of the spring, summer, and fall, I announce to my wife around midday that “I’m going out to expose my integument to the deadly actinic rays of the sun.” And then I do. I feel so much better since I started doing this.
I have always enjoyed exercising in the heat. In this I seem to be different from most people.
I originally took note of this fondness back in the early 1980s when I was living in Ft. Lauderdale. A ritzy local tennis club—way too expensive for me—offered summer memberships for just $100. I just got access to the outdoor courts and not to the indoor amenities, but all I wanted was a place where I could reserve a court and know that it would be available when I met someone there. The only downside was that you were playing tennis outdoors, in the summer, in Ft. Lauderdale. And it turned out I was okay with that.
I’m pretty careful not to be stupid about it. (And successfully so, it seems—I’ve never gotten heat exhaustion or heat stroke.) If I start feeling tired, thirsty, or overheated, I slow down, move to the shade, and drink some cold water.
Over the years I’ve had a variety of theories about why I didn’t mind exercising in the heat when other people hate it so much. I like to imagine that I’m just better at tolerating the heat than the average person: Everyone slows down in the heat, but maybe I slow down slightly less; at some high temperature, maybe I’d become competitive! More likely, since I’m not competitive I’m not making unfavorable comparisons between my speed in the heat versus my speed in cool weather, so the fact that I slow down doesn’t make me unhappy.
Recent research has given me a new, much more likely reason why I like exercising in the heat. On Rhonda Patrick’s Found My Fitness podcast, I heard an interview with Dr. Charles Raison, in which he described the results of a study suggesting that Whole-Body Hyperthermia was an effective treatment for depression. The experiment used infrared lights to heat people up to a core body temperature of 38.5℃ (101.3℉), but Raison is convinced that there is nothing special about the device used, and that a sauna, hot spring, sweat lodge, hot yoga—or just exercising in the heat—would have the same antidepressant effect.
Dr. Raison is studying further to try to elucidate the mechanism by which hyperthermia boosts mood in depressed people. (It seems to reduce inflammation, perhaps by boosting IL-6 which activates IL-10. Heat Shock Proteins might also be involved, since they do all sorts of things.)
I have always been inclined to blame a lack of daylight for the seasonal depression that I’m prone to suffer from during the winter—both too short of a photo-period (which I address with a HappyLight™) and too little vitamin D (which I address with vitamin D supplements), but it now occurs to me that a lack of opportunity to exercise in the heat (and thereby raise my core body temperature high enough to trigger whatever it is that reduces depression) may be an independent factor.
It seems very likely that, just like my desire to spend time outdoors in daylight is probably self-medicating to boost my vitamin D and regulate my circadian rhythm, my desire to exercise in the heat is probably self-medicating to boost my mood.
I hesitate to rejoin a fitness center just to get access to a sauna, but I’ll have to investigate options for access to winter whole-body hyperthermia.
