Centre for Sleep and Human Performance: Changes in Clocks and Amount of Light Affect Sleep and Health

CALGARY, AB--(Marketwired - October 28, 2014) - The clocks go back an hour at 0200 AM Sunday morning, providing an extra hour of much needed sleep. "As many as 30 percent of people in society are chronically sleep deprived," says Dr. Charles Samuels, the Medical Director of Calgary's Centre for Sleep and Human Performance. 

"We need to get 7-9 hours of sleep a night to function properly, and many of us try to get by on far less." Dr. Samuels says a big part of the problem is we work too much and do not devote enough time to recovery and rest. "I see a lot of people who are causing significant harm to their health with too much work and not enough sleep."

Another common problem this time of year is Seasonal Affective Disorder (or SAD). Dr. Samuels says as many as 5-10 per cent of North Americans suffer from the disorder and it is more common in northern regions. "The shorter days and extended periods of darkness mess up the body's natural circadian rhythms," he says. "We need sunlight or other bright light to help adjust those rhythms -- or body clocks -- in order to stay awake and alert." Disturbances in melatonin and serotonin due to longer hours of darkness are believed to play a role in sleep and winter depression.

Also known as the "Winter Blues," SAD means a person who is normally very alert can become overly tired as their body struggles to cope with a lack of sunlight. 

Dr. Samuels says light therapy has been effective in treating people with SAD. The patient is exposed to bright light (as much as 20 times brighter than household lighting) for at least 30 minutes a day, usually in the morning. This light affects the brain's biological clock which has an important role in maintaining the sleep/awake cycle. Light inhibits the secretion of melatonin, which scientists think may have an important role in regulating the body's circadian rhythm. 

Dr. Samuels -- an expert on the effect of sleep deprivation and disruption on human health and performance -- says there is ongoing research into SAD and how best to treat it. 

He says problems with sleep are among the most common complaints patients bring to their physicians. Chronic sleep deprivation can contribute to obesity, diabetes, high blood pressure, heart attack, stroke, and other serious medical conditions.