Effects of Caffeine on Sleep and Mental Health


Caffeine intake in various forms (and tastes as well!) is a common practice all around the world, especially since past few decades. Though people are gradually realizing that it can affect their health and mental performance, but only a fraction of people around the globe are actually able to alter their caffeine intake for such reasons. The degree of influence of caffeine might be a debateable issue, but one thing is for sure; its daily intake is associated with sleep problems and daytime sleepiness. The effects of caffeine on your health not only depend on the amount of caffeine ingestion at bedtime, but also on total caffeine intake throughout the day. Studies provide a pile of tips for better sleep but still many people are unaware of them.

Effects of Caffeine

Caffeine Intake in relation to age
This subject is not taken very frequently for studies, but still the studies have produced some results:

  • Overall, the effects of caffeine appear same in young adults (20-30 years’ age group) and middle-aged (45-60 years’ age group) subjects. The middle-aged group was affected more only in a few EEG spectral frequency bins as compared to young adults.
  • Another recent study conducted by the same group revealed same tendencies of caffeine effects when investigated for daytime recovery sleep in subjects in the morning after wakefulness of 25 hours. Total sleep duration, sleep efficiency, slow wave sleep as well as REM sleep patterns during daytime recovery sleep were affected similarly in subjects from both age groups (young adults and middle-aged). However, the middle-aged group was observed with high decrements in total sleep duration as well as sleep efficiency compared to young adults’ group during daytime recovery under placebo, against nocturnal sleep. Middle-aged group showed increased difficulty overcoming circadian waking signal during their daytime sleep because of low brain synchronization in relation to age and caffeine intake. As a result, they experienced fragmented sleep during the day.

Caffeine abstinence

  • A systematic review conducted recently, including randomised trials, suggested improved sleep quality as a result of caffeine abstinence throughout the day, as a result, expected to be recommended by contemporary health practitioners as sleep hygiene advice.
  • Another trial showed lengthened sleep time as a result of caffeine abstinence, also reporting improvement in sleep quality.
  • One more trial revealed that subjects felt lower difficulty falling asleep when consumed decaffeinated coffee.

Caffeine intake in relation to jet lag and shift work
Jet lag and SWSD (shift work sleep disorder) can lead towards increased sleepiness and increased risks of injury. Results of another systematic review suggested that caffeine may prove effective in people working in shifts, for improving their performance. The same tendencies were also observed for people suffering from jet lag.

The studies conducted on how caffeine intake affects mental performance and sleep patterns are of initial level and need further exploration. However, one thing can be concluded for certain that caffeine consumption is capable of influencing not only sleep patterns in humans, but also their mental performances. So, if you are finding inconsistency in your sleeping patterns or cognitive functions, you better check your caffeine intake.

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