Study: Lack of morning light upsets body clocks

You may have seen a recent article on this site that warned about over-exposure to blue light before bedtime.  The reason is that blue light signals your body that it’s time to wake up.  In scientific terms, it shuts down the body’s production of melatonin, the substance in the body that tells us it’s time to sleep.  From the Associated Press this week, we have news of a very interesting study that looked at the role of blue light in keeping our body clocks set properly.

The study followed a small number of eighth graders to attend a school that features heavy use of skylights to help eliminate the cost of artificial lighting.  The students wore special glasses for five days that block blue light but allow other wavelengths to be seen.  After the five days, students found that their natural body clocks, the ones that tell them it’s time to go to bed, were off by a half hour.  Despite the small size of the study, the findings have real world applications:

Teens who trudge to the bus stop before dawn or spend their days in mostly windowless schools probably suffer the same effect, as daylight is the best source of those short-wavelength rays, said lead researcher Mariana Figueiro of Rensselaer’s Lighting Research Center in Troy, N.Y.

The study is actually part of a larger effort to understand the role of blue light.  Another portion of the study is looking at evening light exposure to see if it similarly disrupts the body’s circadian rhythms.

To read the entire AP story at the Miami Herald site, click here.