Daylight Savings & the Circadian Rhythm

One of those topics that I just love writing on is that of the human body clock, or as I like to refer to it, “my wacked up circadian rhythm”. The term circadian rhythm essentially refers to the 24 hour period that the human body has evolutionarily adjusted too. And scientists are saying that, due to daylight savings, there are some nasty surprises awaiting us.

Now most people work the normal 9-5 job, waking up a little before 9 and going to bed a few hours after 5. It’s not that far off from the evolutionary journey our ancestors would have been accustomed too. Waking up with the sunrise, working the fields, finishing when the sun goes down, having some dinner, then a bit of a sleep.

So you can see that, when people are forced to adjust to waking in the dark each morning, there could be some problems.

At least, that is the theory being posited by Dr. David Avery, a psychiatrist at the University of Washington. "Morning light is the most important light for synchronizing our circadian rhythms," he says, a specialist in the field of light, sleep and their connections to depression. "It's not natural to wake up in the dark," he adds. "What our ancestors did was wake up at dawn, whenever dawn came."

So when we head to bed the night daylight savings turns off (or on), and turn our clocks back (or forth), our bodies aren’'t just going to go along with it. They’.re confused, bewildered, and not ready to take any buzz from you “Mr. Snazzy Alarm Clock!”

"From a biological point of view, it really doesn't make any sense to do daylight-saving time," agreed Horacio de la Iglesia, a UW neurobiologist

But, that’s the point. Daylight savings is not a biologically backed idea, but rather a sociological reason. Whether it be for increased work days, increased play time, saving energy, or simply to baffle the nation in to submission, daylight savings is not going to be dictated by biology.

De la Iglesia, in his research on how the brain governs the rest of the body, has discovered that there are a whole range of body clocks. "There are biological clocks in the liver, lungs and other organs as well," he said. "We have these circadian rhythms because they allow the body to anticipate cyclical events."

One example he puts forth is the actions of the adrenal gland before you wake each morning. He explains that it releases the stress hormone cortisol prior to you waking up, to move the stored sugar, glucose, from the cells into the bloodstream. "That helps get you going," de la Iglesia said.

With the Earth’s tilted 23.5 degree angle, the northern hemisphere attracts more light during summer, but loses out during winter. Hence the need for day light savings time, to essentially steal the last hour somewhere.

But there are those of us who just wish that daylight savings would go away and stop interrupting with our lives. And it isn’t just crackpots like me. Woodruff Sullivan, a UW astronomer, believes that clock time is nothing more than “hardly natural”.

Considering that clock time didn’t actually exist until the early 19th century, it’s not surprising. The sun dial was everyone’s time keeping device, and it relied on the sun. As with our past ancestors, they got up with the sun and finished with the sunset.

But the reality is that if you don’t like clock time, it generally doesn’t matter to you. Thus, one more manipulation to the whole thing doesn’t really matter. For those who don’t mind it though, you get an extra hours sleep once a year (an unearned extra hour…) and you have to go through a reset process at another point in the year.

All in all, not too much to give up for that extra hour of sunlight. Wherever it ends up!

Posted by Josh Hill.

Story links:

http://seattlepi.nwsource.com/local/337944_timeclock03.html

Comments

[CSM Engineer]

I think the idea of realying on the sun died with the invention of the lightbulb...

I dont wake up to dark... I wake up to 46 watts of Compact Fluorescent Light...

After a week of waking and sleeping at similar times to the same light, I wake up without the need of an alarm clock... Isn't that my body adjusting to the change?...

[Teca Arantes]

I just hate daylight savings - I hate to see my daughter and all small children waking up and going out in the dark to catch a bus go to school - so that companies can save on what? lightbulbs? it's not fair! Let's end it now and forever!!