By Alice Oglethorpe, published on January 1, 2012 - last reviewed on March 13, 2012
Don't just sit there. Turn up the lights. The too-short days of winter might lead to the blues, but that's not the worst of it: they can also wreak havoc on your body and brain. Long nights disrupt the body's natural circadian rhythm, releasing hormones that can exacerbate pain and cloud the mind. Read on to see how human behavior goes haywire when daylight becomes scarce.
Candlelit dinners may be romantic, but they are not so good for your health—especially if you're trying to lose weight. Dieters who eat with the lamps turned low eat more than those who dine in bright light, according to a study in Personality and Individual Differences. Psychologist Joseph Kasof believes that darkness lowers self-awareness, which makes people less focused on their caloric intake and less concerned about their dieting goals. An easy fix: Switch the bulbs in your dining area to stronger ones.
The dimmer your domain, the more you feel pain. A study from the University of Pittsburgh examined people recovering from operations in different sections of a hospital. Patients on the shady side reported more physical suffering and needed 28 percent more pain medication than those on the sunny side. "We know that levels of serotonin, which is a natural antidepressant, go up with sunlight," says Bruce Rabin, a professor of psychiatry and pathology at the University of Pittsburgh. "A side effect is that the boost also reduces perception of pain." The benefits don't stop there—a study at Johns Hopkins University found that patients recuperating in bright rooms were ready to go home more than two days sooner than those in dimmer rooms.
Overcast days can certainly feel gloomy—they might even fog your brain. In a recent Environmental Health study, researchers used simple cognitive tasks like short-term recall to evaluate the mental effects of weather on men and women, some with symptoms of depression. The subjects were scattered across different climes. Those who were depression-free had sharp thinking no matter the weather. But among those who were already feeling down, less sunlight was associated with dulled thinking.
Seasonal affective disorder is already known to cause low mood in some people when the weather is dreary. New evidence suggests it may also take the edge off mental acuity, explains study author Shia Kent, a researcher at the University of Alabama. Light affects blood flow in the brain, and a sunny sky can influence levels of vitamin D, melatonin, and serotonin, all of which are tied to cognitive function. Kent's advice? Get outside—before the sun goes down.