How many of us have dealt with teenagers who can seemingly stay up endless hours? Partying, playing video games, or just “hanging around?” Well, some researchers decided that it couldn’t possibly be natural – so they looked into the causes. And here’s what they found:
When teenagers spend more time indoors, they miss out on morning light, which kind of “resets” the body’s natural sleep/wake cycle. These researchers did a study on 11 eighth grade students, who wore special glasses, preventing them from having a certain type of light (short wavelength light, or blue light) reach their eyes. By the end of a 5 day study, they experienced a 30-minute delay in sleep at the end of the day. They think that this is due to the decrease of melatonin, a hormone that regulates sleep patterns, with removal of the blue light. The study showed that melatonin was released about 6 minutes later each night they students were deprived of the blue light. About 2 hours after melatonin is released, sleep typically occurs. These findings were published in Neuroendocronology Letters.
Whew, that was a mouthful. I would again like to give a shout out to Inditop.com for the findings of this study. And now, the explanation – for the rest of us.
First of all, the “study” results. I found them VERY interesting – until I got to the size of the “study.” There are several types of studies, some are called case studies, some are randomized controlled studies, and there are still others, but I’ll leave that for another time. Case studies involve a few people, and an observation about these people. What seems to happen. These can be very biased, meaning that there are factors that affect the outcome of the study that the researcher doesn’t intend. For example, I could do a case study on the number of cases of diabetes in the American population. I choose 20 people for my study, and I get a whopping 95% of those ended up having diabetes. Does this mean that 95% of the population will have diabetes? Of course not – the 20 people that I chose were all severely overweight, did not exercise, and ate fast food all the time. That introduces bias, and so the results cannot be trusted.
A randomized controlled study is a type of study where the participants are chosen at random, from a similar population. There are a couple of different types of these studies, but they all involve larger groups of people, so the information can be more trusted.
This study is a type of case study. It cannot prove that lack of morning light turns teenagers into night owls. It can say there might be a link, however, which is what is interesting about this study. More needs to be done in order to make a decision as to whether we need more morning light in order to get to bed on time.
Finally, a little bit about the hormone melatonin. Melatonin (in the case that we are talking about) is produced by the pineal gland, a small gland in your brain. It releases hormone in reaction to light levels, with the highest levels being released during the night. It was once thought that this hormone actually controlled sleep; it is now known that although melatonin promotes sleep, it doesn’t actually send you to sleep – your higher brain functions do that on their own. Some people who are having trouble sleeping can wear blue-blocking glasses a few hours before bedtime – this raises melatonin levels and helps promote sleep.
This being said, does lack of MORNING light hold back melatonin production at NIGHT? Like I said before, further study is needed – especially since it would make sense (to me) that artifical light at night (especially fluorescent daylight lighting, as it contains a higher amount of blue light) would be more important than simply not having enough light when you wake up. What are your thoughts on this? Any questions?