EDINBURGH, Scotland — Coffee just may be what you need to get your day moving, but a recent study finds too much caffeine consumption later in the day can have an unpleasant effect on your sleep cycle.
Researchers from the Sleep Medicine Department at the University of Edinburgh add coffee’s impact on sleep can last for up to six hours before someone is ready for bed. Lead author of the study, Reneta Riha, says decreasing caffeine intake starting six hours prior to bedtime may help reduce the impact on a person’s sleep-wake cycle.
Thankfully, the news is much better for people who can’t function without that morning cup of Joe. Study authors find drinking coffee after waking up can help aid concentration and alertness. This is especially true for shift workers who have to adjust quite often to a new sleep cycle.
The study notes that people have a sleep-wake cycle called the circadian rhythm, which regulates body functions according to a 24-hour cycle. This rhythm syncs up with light and dark cycles of the planet, which is why changing time zones or changes in a work schedule can throw people off.
A previous study discovered that consuming 300 mg of caffeine per day (equivalent to three cups of coffee) can help improve the cognitive responses of the brain during the first three days of poor sleep. For those with an abnormal sleep cycle, like working a night shift, regular coffee intake can help alleviate short-term cognitive impairment due to lack of sleep. Although this may help night shift workers right away, researchers say it will likely have a negative impact on sleep quality and duration later.
Some people may be more sensitive to caffeine’s effects
The amount of caffeine one consumes also provides different results. Study authors find 75 mg of caffeine increases attention, concentration, and alertness. However, coffee drinkers can still enjoy up to 400 mg as part of a healthy balanced diet while remaining active.
“Caffeine is consumed daily by roughly 80% of the world’s population, often for its benefits in promoting wakefulness and concentration,” says Riha in a media release. “Its effects can last for several hours, depending on how quickly or slowly it is metabolized by the body.”
Caffeine sensitivity is vital to the daily amount of coffee one should consider drinking. This will also have an effect on the sleep and wake cycles, researchers report. The team notes that the amount of caffeine consumed throughout the day will likely determine a person’s sleep quality and duration.
“Those who find that drinking coffee later in the day disrupts their sleep patterns may wish to swap to low caffeine drinks, or decaffeinated coffee during the afternoon and evening,” Riha concludes.
The Institute for Scientific Information on Coffee published their findings in the report, Coffee and sleep in everyday lives.