Daylight Saving Time can negatively affect sleep cycles, health care professor says

Stevens said his research in the field of sleep predominantly revolves around the health effects of bright lights present in many households in the evening--what he refers to as “inappropriate electric lighting.” (File/The Daily Campus)

With Daylight Saving Time beginning this Sunday, one less hour of sleep, combined with the effects of artificial lighting, can lead to sleep deprivation and a difficult time adjusting for some, according to Dr. Richard Stevens, a professor in UConn’s Community Medicine and Health Care department.

Stevens explained that daylight saving time often results in problematic sleep patterns due to the body’s need to adapt to this change.

“As everyone knows from personal experience, it is harder in the spring to ‘spring forward’ and lose an hour, than in the fall when we gain an hour,” Stevens said in an email.

Stevens said this is because it is easier for the body to extend nighttime physiology, as we do in the fall, than to shorten it for daylight saving time in the spring. He added that the time change can negatively impact a person’s health in the first few days after its onset.

“It will take a couple of days, particularly in the spring time change, to feel normal again,” Stevens said. “For the first day or two, many people will feel as though they have a little jet lag, which can include some gastrointestinal issues and some cognitive impairment.”

Stevens said he would advise people to drive more slowly on their commute to work, and to be more cognizant of their physical health in the days that follow the March 11 time change.

One way to improve sleep quality after the time change is to stay away from harsh lighting at night, Stevens said.

Stevens said his research in the field of sleep predominantly revolves around the health effects of bright lights present in many households in the evening--what he refers to as “inappropriate electric lighting.”

“The term ‘inappropriate’ means too much bright light in the evening and night, and not enough bright full spectrum lighting, like from the sun, during the day,” Stevens said.

Stevens said that bright blue light, such as the light from a Compact Fluorescent bulb, has negative effects on the average person’s circadian rhythm, which is an individual’s normal sleep and waking cycle. 

Stevens brought up a recent sleep study done in Africa and South America in which three groups of people still do not use electric light. This study revealed that most people only actually sleep for about six hours when not under an artificial light cycle, Stevens said.

“The difference is that in these pre-electric societies, people only use wood fires for light during the night, and that kind of light does not interrupt our nighttime physiology the way bright electric light does,” Stevens said.

Stevens said that in this state, people naturally transition to nighttime physiology beginning at sunset.

“At about sunset, body temperature drops, metabolism slows, hunger abates, sleepiness increases and the hormone melatonin rises dramatically in the blood,” Stevens said. “This natural physiological transition to night is of ancient origin.”

If this innate shift is delayed by harsh lights, the average person’s quality of sleep declines, even if the the numeric amount of sleep remains the same, Stevens said. In order to get better quality sleep, Stevens encouraged people to use dimmer, low-wattage lights at night.

“Six hours of sleep embedded within 11 or 12 hours of circadian dark-- either total darkness, or a dim, long wavelength light as from a wood fire or candle-- is much more rejuvenating than six hours embedded within only six hours of circadian dark, because many people use bright light in the evening until they ‘go to bed,’” Stevens said.


Annie Stachura is a campus correspondent for The Daily Campus. She can be reached via email at annie.stachura@uconn.edu.