Caffeine is stimulant that is used around the world to combat sleepiness. It is present in coffee, teas, sodas, and other supplements to help provide energy throughout the day. It is natural, but can also be synthetically produced. 

Caffeine normally affects the body within about 30-60 minutes of consumption. It is efficiently distributed throughout the whole body and can cross the blood-brain barrier. 

Inside the brain, it blocks a sleep-promoting chemical and can also interfere with the circadian melatonin rhythms. Caffeine has a half-life of 4-6 hours, which means that's how long it takes for approximately half of it to remain in your system. So, consuming caffeine in the evening could keep you up at night because of how long it takes your body to metabolize it.

Caffeine can have a significant impact on sleep, so it's important to understand how it works, and how you should be consuming it for optimal sleep health. 

How caffeine affects sleep

Caffeine can impact the onset of sleep, and reduce all aspects of sleep including sleep time, efficiency and satisfaction. Older individuals may be more susceptible to caffeine-induced sleep troubles. It can reduce the time of slow-wave, or deep, sleep which is important for feeling rested and restored after a night of sleep. 

Caffeine can also lead to feelings of sleep deprivation the following day because of how much it can interrupt sleep. Caffeine consumed even six hours before bed can lead to a total loss time of one hour of sleep. Caffeine causes this by causing a burst of energy as it stimulates the central nervous system. 

Caffeine can cause a boost to cognitive function, but it has such a drastic effect on restful sleep that the boost is insignificant. In fact, caffeine can lead to some insomnia symptoms, or worsen pre-existing insomnia. Consuming caffeine late at night can lead to anxiety, frequent nighttime awakenings and overall poorer sleep quality. Caffeine from sodas has also been linked to sleep disordered breathing. 

There are some individuals who feel sleepy after consuming caffeine, but regular caffeine use can lead to a vicious cycle of sleep deprivation that leads to sleepiness the next day which can then require additional caffeine to compensate. Too much caffeine use, followed by abstinence can also lead to sleepiness. 

Caffeine can affect individuals differently, which is why it's important to consume it in controlled amounts. It's important to remember the main job of caffeine is to keep the brain awake and alert. Therefore, it will inevitably lead to fractionated sleep. 

How much caffeine is safe to drink 

Finding the right level of caffeine is very important for you because it can be harmful. Also, coffees, teas, sodas, and supplements have varying levels of caffeine, which can make its consumption harder to monitor. 

The current FDA recommendation for safe consumption is around 400 mg, or 4-5 cups of coffee per day. A large cup can have upwards of 470 mg of caffeine which is over the recommendation. Having several of these cups can truly put you at risk for very high levels of caffeine consumption. 

The cut off time of drinking caffeine before bed should be a minimum of six hours. So, identify what time you usually go to bed, and make a note to not consume caffeine any time after that. If you find that you can sleep with a later cut off time, then customize your schedule for you. Just remember that caffeine may be affecting your sleep more than you realize, so try the six hours for a couple of weeks and see how you feel in the mornings, and then you can slowly move the time later until you start to experience symptoms of sleep deprivation. 

You'll be able to recognize that caffeine is affecting your sleep by identifying any common symptoms of sleep deprivation or insomnia. This can include trouble sleeping, daytime headaches, excessive daytime sleepiness, and feelings of anxiety or jitteriness. When caffeine stops helping with these issues, then it is probably the cause.  

How to improve sleep overall

The best way to improve your energy is to get regular, good quality sleep. No amount of caffeine can make up for poor sleep habits Healthy diet and exercise can also help boost your sleep quality.

Your sleep environment is important. It should be cool, dark, quiet, and clean. Maintaining a healthy lifestyle in terms of moderate alcohol use, limited consumption of processed foods, and a balanced diet can help your body feel good enough to get a good night's rest. And your nighttime routine is important to.

Go to sleep and wake up at the same time every day - even on the weekends. Before going to bed, try to do the same sequence of activities - getting ready for the next day, reading, cleaning up, showering, etc., before going to bed for the night. 

If you continue to struggle with sleeping, then there may be an underlying issue. Please click the orange button to take a free online sleep test and talk with one of our sleep health experts. 

https://www.sleepfoundation.org/nutrition/caffeine-and-sleep