Your circadian rhythm regulates your sleep cycle by telling your body when it’s time to sleep and when it’s time to be awake. This system can be disrupted by many external factors, including light exposure, food consumption, physical activity and certain medications. It’s well-known that caffeine can provide an energy boost, but is caffeine consumption another environmental factor that could affect your internal clock?
The Importance of a Regular Sleep-Wake Cycle
An irregular circadian rhythm can significantly effect your health and quality of life. Circadian rhythm disturbance can lead to an increased incidence of medical problems, such as:
- Cardiovascular disease
Caffeine’s Effect on Cellular Timekeeping
In past years, scientists have studied bread mold, green algae and fruit flies to discover that caffeine can alter the way certain cells keep time. This led one group of researchers to question whether caffeine has the same effect on human cells.
The study was conducted by a research team at the University of Colorado, Boulder. They conducted a 49-day double-blind, placebo-controlled sleep study. Participants were either exposed to caffeine, bright light or both 3 hours before bedtime. The caffeine dosage was equivalent to the amount in a double espresso.
Results of the study indicated that the caffeine dosage taken 3 hours before bedtime delayed circadian rhythm in the patients by approximately 40 minutes. Researchers also found that exposure to bright light before bedtime had a double effect of caffeine on participants.
There’s no denying that both caffeine and bright light have a significant impact on humans’ circadian rhythm.
Maintaining a Regular Circadian Rhythm
As this study suggests, it’s best to avoid caffeine at least 3 hours prior to regular bedtime. In addition to coffee, caffeine is also found in some teas, soda and chocolate.
When your internal clock is continually misaligned with your normal sleep schedule, it can put unnecessary stress on your body.
The effect of caffeine can vary from person to person based on a variety of factors, including genetics. Anyone who is sensitive to caffeine should be especially vigilant about the foods and beverages they consume later in the day.