The Call, Column 89 – It’s 2pm: Do You Know Where the Sun Is?

28 01 2018

(January 28, 2017)

The Urban Farmer

It’s 2pm: Do You Know Where the Sun Is?

Two columns ago, we talked about the “passive solar clock”, the fact that many of the things happening on Earth’s surface are driven by the amount of sunlight received. This creates a sort of weather clock, which varies periodically over the course of one day and one year.

Last column, we moved on to the idea of the “active solar clock”, the ability of certain things on Earth – namely animals, plants, fungi, and some microorganisms – to keep track of the Sun’s position over the day and the year, and adjust their behavior accordingly. This is called the circadian rhythm. It is a feature of so many organisms, from fungi to chickens to human beings; and drive behavior like (more obviously) sleep and wake cycles, hormone levels, and reproductive capacity, but also (less obviously) mood and metabolic health.

Today, let’s expand on this last concept. I want you to fully understand how important the circadian rhythm is – including your own – and the possible side-effects of circadian dysregulation, when an organism’s brain (or whatever regulates its circadian clock) can no longer accurately discern the time of day and year.

So last time, we discussed some examples of how organisms are able to use their circadian rhythms to regulate biological things. I want to make one side note here: in general, though my language kind of indicates otherwise, it isn’t organisms making the conscious choice to use their brain’s record of solar time of day and year to do things. Rather, it is their brain (or whatever) automatically regulating lots of biological mechanisms and processes according to its record of solar time.

There are some very obvious examples of this in the natural world. Plants use a series of biochemical reactions to maintain a circadian rhythm, which they use to “know” when to flower, set seed, and go dormant for the winter. Most animals reproduce best in the spring and summer, which is why birds’ nests are filled with eggs in the spring, baby deer and turkeys emerge sometime during the warm season, and even chickens take a break in their egg-laying during the winter. Much of the life in the soil goes dormant during the winter. Almost everything – including plants – sleeps at night and is awake during the day, with the curious exception of nocturnal animals. In general, animals tend to store fat more easily in the fall, and have more difficulty shedding it in the winter. This is an adaption that helps to prevent starvation during lean months…not that that fact makes me feel any better about the numbers on the scale as of late. But all of this is driven by the circadian rhythm, and therefore by sunlight!

Looking specifically at human beings, this is regulated by the human brain. It uses a combination of neuron activity, electrical charges, and hormones to accomplish this intricate timekeeping endeavor. For example, your brain produces melatonin when it believes bedtime is approaching, and cortisol when it believes it is time to get up; these are respectively responsible for feelings of sleepiness at night and wakefulness in the morning. That’s a pretty powerful hormonal drive, huh?

So what is circadian dysregulation? I’m glad you asked! Your brain has a central clock that it tries to maintain on a roughly 24-hour cycle and another roughly 365-day cycle, based on 1) the brightness of sunlight you’re exposed to; 2) the spectrum of that sunlight (more blue light indicates morning and noon, while more red/yellow light indicates evening), and 3) possibly, the position of the sun in the sky. If you go outside, and those data points match the time of day and year that your brain thinks it is, that’s a positive feedback which reinforces your circadian clock; if they don’t match, that is negative feedback, which forces your brain to readjust. Again, how cool is that?

But there are some very widespread behaviors that can actively throw off this regulation…and nighttime exposure to blue light is probably the most significant. When you look at basically any electronic screen, or even at certain light bulbs (some fluorescents and LEDs, unfortunately), the exorbitant level of blue light in their spectrum tricks your brain into thinking that it is morning/noontime. This is the reason that, for many people, staring at their phone right before bed can jolt them awake or make them less tired, even if they were ready to fall asleep right before.

But the problem is much broader. We live in a society where it is perfectly possible – even considered normal – to not see the sun most days each week, for a few months of the year. If you work in an office, it is entirely possible that during the winter, you will go to work while the sun is rising, and leave after it sets…and spend the entire day under (bluish) fluorescent lights, staring at a (bluish) computer screen, without seeing the sun at all. The shortest day of the year was just a few weeks ago, so this problem is particularly relevant right now.

On top of this, we look at a lot of brightly-lit screens at night, we generally don’t get as much sleep as we should, and we rely on coffee to keep us awake. With all of these biologically-abnormal stimuli, it’s no wonder that circadian dysregulation is rampant in the West! But what does it look like, for a human being’s circadian rhythm to be misaligned?

Seasonal Affective Disorder (SAD) is one of the most relevant manifestations of circadian dysregulation. Some peoples’ brains seem to be more reliant than others on exposure to sunlight, in order to keep their circadian rhythm aligned. During the winter, inadequate exposure to sunlight can lead to this form of acute depression, which (at least in my experience) creates feelings of bitterness, hopelessness, and resentment. The exact hormonal mechanism isn’t quite understood yet, but the link between SAD and exposure to adequate sunlight for circadian alignment is obvious.

Another common manifestation of (probably) circadian dysregulation is metabolic disease (i.e. obesity). There is far less scientific evidence linking these two, but early studies (and lots of anecdotal evidence) have shown correlation between circadian dysregulation and metabolic dysregulation, and causation between circadian dysregulation and hormonal problems…and the relationship between metabolic health and hormonal health is indisputable. This is one connection for which I’m anxiously awaiting on more concrete science.

There are things you can do to prevent the worst effects of circadian dysregulation. Avoid looking at screens and other blue-containing light sources when it’s dark outside. If this isn’t possible, invest in a pair of blue-blocking/amber-tinted glasses, which filter out most of the blue light, and as a result prevent much of the negative effect on your circadian alignment. I have a pair that cost me $10, so if you want recommendations, just shoot me an email.

Try to get adequate sleep. I know how hard this is in modern society, and my personal demon is the shear amount of interesting things I could be doing at 10 pm and midnight and 2 am, instead of sleeping…but join me in trying to sleep at least 7 hours each night (the optimal amount varies by person), because it helps to fine-tune and properly-align the melatonin and cortisol spikes that drive sleepiness and wakefulness. Also, keep in mind that coffee helps to create an artificial increase in cortisol. This is probably fine earlier in the day, but cortisol should be very, very low at night as melatonin and sleepiness start to kick in. This means coffee in the afternoon and night = no bueno.

Finally, and this is probably the most important recommendation (alongside reducing blue light at night): get some sunlight each and every day! Last winter, which the first one of my life where I was working fulltime instead of either in school or on Christmas break, I suffered a little SAD. It took me a few weeks to realize what it was. But as soon as I did, I began taking 15 minute walks most days, during my breaks or lunch at work, and the symptoms almost immediately evaporated. When I began feeling inklings of it late this past November, I took that same action and haven’t really felt it since.

Now like I mentioned earlier, the effects of circadian dysregulation on metabolic health are much more indirect and ill-defined, so it would be harder to relate the solution of that back to taking daily walks outside. But if the disappearance of my SAD symptoms is any indication of the effect of more sunlight exposure on proper circadian alignment, I have no doubt believing that this is great for long-term metabolic health as well. (Side note: I am not a psychiatrist. I am not a doctor. This is a solution which worked for me, for a specific type of acute depression that is very well-linked to sun exposure, and more likely in someone of my genetic/geological origin. If you are suffering depression symptoms of unknown cause, I urge you to seek medical help.)

Ending on a bit more of a lighter note, there is another aspect of this that I have been giving some thought to, and wanted to share. There are some…“less scientific”, shall we say…topics that may potentially be linked to the human circadian rhythm.

The first is the possibility of a greater conscious awareness of the circadian clock, beyond its background (hormonal and other biological) effects. I tend to believe that other animals – whose circadian rhythms aren’t boggled by blue lights, sub-optimal sleep, coffee and alcohol, and spending all day in climate- and light-controlled boxes – may be more consciously aware of what solar time it is, and deliberately perform actions or adjust their behavior accordingly. Do you know how, if you find yourself in a random place and the sun is not too far above the horizon, you can sort of “intuitively tell” whether it’s sunset or sunrise? Also, do you ever have those mornings where there is something very important that you need to be up for, and your brain seems to wake you up shortly before your alarm? I feel that these may be manifestations of this phenomenon – something that other animals use all the time, like when my chickens obviously know that nighttime is approaching even before dusk.

The second is astrology. I don’t actually subscribe much to it, but there have been some cases, in my experience, that the solar horoscope accurately describes behavior. If there is any underlying scientific reason at all, that the time of year that one was born may affect their behavior, I think it is probably due to circadian effects. It is entirely within the realm of possibility that there may be subtle differences in the way a mother’s body forms and nurtures an unborn baby, depending on the time of year that this is happening, because of hormones or expected availability of resources or whatever…and that this could somehow affect the baby’s long-term behaviors. Additionally, the initial circadian alignment that a newborn baby’s brain has to perform shortly after birth, and the information about the time of day and year that its life began, could conceivably affect the formation of its brain and therefore behavior as well.

This is all speculation and “thinking out loud” so-to-speak, but those are my final thoughts.

My column appears every other Sunday in The Woonsocket Call (also in areas where The Pawtucket Times is available). The above article is the property of The Woonsocket Call and The Pawtucket Times, and is reprinted here with permission from these publications. These are excellent newspapers, covering important local news topics with voices out of our own communities, and skillfully addressing statewide and national news. Click these links to subscribe to The Woonsocket Call or to The Pawtucket Times. To subscribe to the online editions, click here for The Call and here for The Times. They can also be found on Twitter, @WoonsocketCall and @Pawtuckettimes.

Advertisements

Actions

Information

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s




%d bloggers like this: