Recent Study Shows Link Between Light And Mood
A study from Ohio State University that was published in the Journal of Neuroscience in August 2013 has shown that the blue-white light of electronic devices can have a negative impact on mood. Red-orange wavelength lighting may reduce those effects. The abstract is available here: http://www.jneurosci.org/content/33/32/13081.abstract
Tracy Bedrosian is a post-doctoral researcher at the Salk Institute in San Diego, CA. She conducted a study that looked at the effects of light exposure at night while she was a doctoral student in neuroscience at Ohio State University.
“People are being exposed to light at different times of day,” Bedrosian said. “We’ve created sort of a twenty-four hour society. And some converging evidence from different fields of science and medicine have started to suggest that having light exposure at the wrong time of day can actually have negative effects on your health. Some epidemiological studies have suggested that mood disorders can be exacerbated by exposure to light at night.”
Hamsters were used to look at the effects of chronic exposure to dim light at night, which people might be exposed to in their homes from televisions, computers or e-readers. The hamsters were divided into four groups. They were kept in environments lighted by white, blue or red light, while a control group kept in darkness. After four weeks of exposure to those lighting conditions, the hamsters were given tests for depressive-like responses. One was a test of sucrose preference.
“We let the hamsters have a choice of drinking their normal tap water or a sweetened solution of sugar-water. Usually they love to drink the sugar water, they’ll drink it at much higher levels than their standard tap water. But in our case, hamsters that were exposed to white light or blue light at night, tended to drink much less of the sugar water,” Bedrosian said.
The hamsters chose sugar water half of the time when there was a choice between the two.
“To us, that suggests something that looks sort of like depression symptoms in humans would look,” Bedrosian said. “Anhedonia is one major symptom, which is the loss of pleasure in something one used to enjoy.”
The hamsters are nocturnal, so the light manipulation took place during their normal waking hours. However, Bedrosian says that for humans, excessive exposure to light at night can affect health and mood, cause weight gain, as well as disrupt sleep and metabolism. Though the red light did not have a positive affect on the hamsters, it did not produce the negative effects caused by the blue and white light.
“The cells in the retina that project to the circadian rhythm center in the brain, your body’s biological clock, are highly sensitive to blue light but are much less sensitive to red light,” Bedrosian said.
Jim Flynn enjoys the look of red light. Flynn is the owner of the Elbow Room, a tavern on Cervantes Street in Pensacola. Its interior as looked the same since the day it opened on October 3, 1963, including its characteristic red lighting.
“I was in the Navy and I was stationed on board ship, and our home port was Villa, France, which is between Nice and Monte Carlo on the French Riviera,” Flynn said. “There was a nightclub in Nice called Le Guerille, or The Gorilla Club. It was a cellar club. It didn’t have red lights, but it had red walls and carpet and tablecloth and stuff like that. And probably how I fell in love with that.”
Flynn believes that red light has benefits.
“Years later, I found out that that red is the most complementary color to the human complexion. It covers up wrinkles, it covers up freckles, it makes you look younger. So, where blue makes you look ghosty. A lot of people like red, it’s a warm, fuzzy color. I read somewhere where it makes some people mad, wanna fight or something, but I’ve never found anybody that felt like that,” Flynn said.
Again, researcher Tracy Bedrosian says there are ways to reduce the effects of exposure to blue and white light.
“It’s possible that people who are shift-workers and people who are just exposed to a lot of light at night might be able to manipulate the wavelengths they’re exposed to, by using red-orange tinted bulbs, or using glasses to block out the blue wavelengths,” Bedrosian said.
The free software “f.lux” was designed to make the light emitted from computer screens look warmer and change to match the time of day. More information is available here: http://justgetflux.com/
Taking breaks from computer use throughout the day and limiting use at night can also help minimize the negative effects on mood and sleep.
Katya Ivanov, WUWF News