2020-04-12 08:53

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.

Source: Closing the Parks Is Ineffective Pandemic Theater – The Atlantic

Spending time in nature in the winter

I find it super easy to spend time outdoors in the summer. Anytime the weather is nice, I’ll almost automatically get out for at least a couple of hours per day. I’m a lot less motivated to do so when it’s cold or wet. This post is largely here to help me remember how nice it is to get outside, even when the weather isn’t so pleasant.

How nice is it? Really, really nice. And yet, I forget, so I end up having to manipulate myself into getting outside in the winter.

I find it easy to manipulate myself with perceived health benefits, such as the well-documented benefits of spending time in nature. I’d find the self-manipulation thing even easier if we knew a bit more about what the “active ingredients” are with regard to time in nature.

Maybe it’s visual. Does the appearance of leaves and trees have some effect on the brain? (I have my own theory that dappled shade has soothing effects on the brain due to our evolution as forest-edge animals.)

Maybe it’s chemical. Trees release all sorts of chemicals into the air, as do bacteria and fungi that live in the soil. I imagine that these are reduced during the winter when the trees are dormant and the soil is covered with snow, but I don’t know of any relevant data.

Besides health benefits, the main ways I motivate myself is either by finding a way to perceive the activity as enjoyable (as being outside on a nice summer day) or else to find a way to smugly perceive the activity as so unpleasant that lesser beings could not bestir themselves to get out in such wretched weather. (One of my mottos: If the weather can’t be good, it should at least be bad enough to be interesting.)

One practical idea I used today: In winter the sunrise is late enough to not have to get up early to get see it. Take advantage of that. See the dawn. Watch the sun rise. Then go back inside where it’s warm.

About 12 minutes before sunrise

A little vitamin W

Since reading a couple of weeks ago about the importance of blue places for both physical and mental health, I’ve been trying to spend a little more time near water, and to pay attention when I’m there.

Today Jackie and I took a short walk along the little creek that runs just south of Winfield Village. It’s really a spectacular amenity that I don’t appreciate nearly as much as I should. (I spend a lot of time admiring our little prairie and our little woods, but I mostly just cross the creek itself with scant notice—nowhere near what it deserves.)

Perhaps you can help me catch up on appreciating our creek. Is it not admirable?

It got me some vitamin W for the water and some vitamin N for the nature, but sadly no vitamin D. The vitamin D window has closed, and won’t open again for 57 days.

Blue and green spaces

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.

Source: Blue spaces: why time spent near water is the secret of happiness

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.

Optimal Vitamin D Levels

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…

Source: The Vitamin D Levels of the Hadzabe and the Maasai: An Important Study That Flew Under the Radar

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

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.

Turns out ALL the rays are actinic!

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.

UV light

The UV light doesn’t just make vitamin D. It also has all sorts of other effects. In particular, it modulates your immune system in ways that reduce the risk of multiple sclerosis, and probably other autoimmune disorders and some cancers. It also reduces blood pressure. In mice it has been shown to limit diet-induced weight gain.

Blue light

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.