Caffeine messes up your circadian rhythm, study suggests

It may not be an uncommon thing to drink a cup of coffee just after the dinner or right before the sleep. And some people may or may not experience the changes in their sleep after that late coffee. Well, the recent study suggests that caffeine, coffee’s main active substance, does more to your circadian rhythm than you can ever imagine.

A late cup of coffee can mess your sleep in more than a single way: Caffeine doesn’t only keep you awake, but it also messes up the internal body clock. This basically means that caffeine changes the way your body decides to sleep or wake up.

Kenneth P. Wright Jr., a co-author of recently published study and director of Sleep and Chronobiology Laboratory at the University of Colorado, says that caffeine “affects our physiology in a way we hadn’t really considered in the past”. Such discovery may affect night owls who’d like to get up earlier, or those who experience a jet lag after a long and tiresome travel between the time zones.

In the published study, five healthy individuals have spent a night in a laboratory, where the researchers have monitored their melatonin levels, a hormone responsible for our circadian rhythm. Melatonin is a natural indicator of circadian rhythm, where high levels suggest that body needs to rest and go to sleep.

Three hours before the sleep, the participants would take either a caffeine pill which contained an amount of caffeine worth of two espresso shorts, or a placebo pill. The participants who had taken a caffeine pill previously would take the placebo pill the night after, and vice versa.

The study has shown that the caffeine pill delays the release of melatonin for at least 40 minutes. This basically means that caffeine affects the body’s internal clock, pushing the biological night later.  It is widely known that caffeine releases the chemicals which promote arousal and wakefulness, but the recent study suggests that circadian rhythm is affected as well.

A delay of melatonin’s release could have a huge impact on a person’s body. For example, if an individual is exposed to a bright light just before the bedtime, such factor could delay the release of melatonin by 85 minutes. Further research of caffeine’s effects on circadian rhythm may be available anytime soon, as this study creates a good base for later examinations.

The study was published on Sept. 16, in journal Science Translational Medicine.

Melatonin and insomnia

Insomnia is defined as difficulty falling asleep or difficulty in staying asleep. Generally, people with insomnia sleep less or inadequate, even though they have plenty of time available. Poor sleep leads to poor functioning during the day. Insomnia is defined by the number of hours we were asleep because it may vary significantly from one person to another. In many cases, insomnia is associated with problems such as stress, for example, or medical conditions such as pain. 

It is a serious medical condition. Insomnia additionally varies in however long it lasts and the way it typically happens. It may be short insomnia (acute) or it can last a protracted time (chronic insomnia). Acute sleep disorder will last from one night to a couple of weeks of sleep disorder. People with chronic insomnia have sleep disorder a minimum of three nights every week for a period of month or longer.

There are two types of insomnia: primary insomnia and secondary insomnia. Primary insomnia implies that someone has sleep issues that aren't directly related to the other health condition or drawback. Secondary insomnia implies that someone has sleep issues thanks to one thing else, like a health condition (such as bronchial asthma, depression, arthritis, cancer or heartburn), pain; medications they're taking, or a substance they're mistreating (like alcohol).

Melatonin is a hormone of the pineal gland, which is located in the center of the brain. The pineal gland produces melatonin from serotonin only during the night and this process stops during the day. Its most important role is to maintain the cycle of sleep and wakefulness - the daily rhythm of a healthy body.

The hormone melatonin improves sleep quality necessary for optimal functioning of the body and helps with the regulation of day-night rhythms. It is a powerful antioxidant that protects against the harmful effects of free radicals and supports the activities of glutathione in neuronal tissues. It is believed that melatonin prevents heart attack caused by stress and provides protection from the effects of aging of the organism. It is important in the treatment of Alzheimer's and Parkinson's diseases, which are caused by the free radicals.

For example, athletes are known for using some amount of melatonin periodically. The main purpose for which athletes use melatonin is its ability to induce the formation of a deep sleep. The athletes often have trouble sleeping and suffer from insomnia, especially after a heavy workout when central nervous system is agitated. 

Experienced professionals want to avoid such situations for all cost and resort to various measures. Athletes, who often travel from one end of the world to another, changing the number of time zones, often suffer from unpleasant disorder that is called the "jet lag". Many competitors, including most professional tennis players, confirmed the great effectiveness of melatonin in the fight against the inconvenience caused by sudden changes in a large number of time zones.