Caffeine is perhaps the most popular drug worldwide. Found in many products, including tea, cocoa, energy drinks, and of course the coffee bean, many people use it in the morning after waking up. However, because caffeine is a stimulant, and it sometimes helps people to remain alert by blocking chemicals in the brain and increasing adrenaline production, what is important to know is how caffeine affects sleep. Although caffeine is safe to consume in moderation, heavy use may cause sleeping disruptions.

How Sleep Occurs

Sleep is regulated by two body systems, the circadian biological clock, and homeostasis. Homeostasis let us know when a need for sleep is accumulating, and that it’s time for us to sleep. This process is due to an inhibitory neurotransmitter that makes us sleepy (adenosine). It does so by reducing the neuronal firing rate, and inhibits the release of neurotransmitters that are responsible for wakefulness. On the other hand, our internal circadian biological clock regulates the timing of the sleep/wake pattern throughout the day.

How Caffeine Affects Sleep

Caffeine is an adenosine antagonist, meaning it blocks the adenosine receptors by inserting itself instead. Caffeine enters the system quickly and peaks within 30 to 75 minutes. When consumed, caffeine may improve attention/reaction time, and it gives us a quick boost in alertness. However, problems arise with processing the caffeine. The half-life, or the concentration of caffeine in the body to decrease by half from a single serving is three to seven hours, and the more you put into your system, the longer it takes to process.

Caffeine is metabolized to paraxanthine, a central nervous stimulant, and is used recreationally and medically to ward off drowsiness. More importantly, the more you consume, the more paraxanthine is produced, causing a caffeine accumulation to build up in your system. Depending on your consumption of caffeine, the half-life of caffeine can increase to anything from more than 10 hours up to four days. Caffeine causes you to have a reduction in total sleep time, have less deep sleep, and an increased sleep latency, meaning the time to get to sleep.

The Effects of Caffeine on Sleep

Caffeine intake resulting in poor sleep is a cycle easily repeated, if you drink too much coffee today, you’ll not sleep well tonight, and you’ll wake up tomorrow and feel worse. Other mild and chronic conditions may include;

1. Mild Sleep Disturbance

Studies have shown that caffeine intake even six hours before bedtime results in significantly diminished sleep quantity and sleep quality. Because it takes more than six hours for caffeine to leave the body, ingesting more caffeine within the six-hour period will extend its stimulatory effects, and reduces total nightly sleep amounts by more than one hour. Mild sleep disruption is one side effect of how caffeine affects sleep, including waking up late at night and difficulty returning to restful sleep.

2. Insomnia

Caffeine consumed in moderation is fine for many people, however, excessive caffeine can cause insomnia. People who drink more than 300 mg of caffeine daily are more likely than those who drank less daily to experience at least one symptom of insomnia at least a few nights each week. Caffeine-induced physiological arousal can have long term unintended consequences on the sleep/wake cycle leading to chronic insomnia. Chronic insomnia may include being unable to sleep, to stay asleep, or to get a restful sleep, and can cause daytime sleepiness, irritability and difficulty concentrating.

3. Polyuria

Another side effect of excessive caffeine intake is Polyuria, or excessive urination. Urinary frequency can be accompanied with an immediate need to urinate, and many people will notice Polyuria because they find themselves having to get up to urinate throughout the night (nocturia). Nocturia also occurs when people drink too much caffeine, close to bedtime. Not only does caffeine have an excitatory effect on the central nervous system, it’s a diuretic and can also have a negative effect on the bladder.

Drink It Smart

There is a connection between the daily consumption of caffeine, how caffeine affects sleep, and daytime sleepiness. However, the effects also depend on the total amount of caffeine consumed daily, when it is consumed, and can vary with the medical status of individuals. Try following these basic suggestions when consuming caffeine in a sleep friendly way;

• Commit to a 2 o’clock cut off: How late in the day is too late in the day to be consuming caffeine? Caffeine consumed even six hours before bedtime results in significantly diminished sleep quality and sleep quantity, even if you aren’t aware of it. A way to avoid any sleep problems is by restricting your caffeine intake to the morning hours. If you want  more caffeine at midday, make sure to consume it before 2 p.m.
• Taper caffeine intake: Begin the day with the more highly caffeinated beverages and taper off on the caffeine intake as the day progresses. Many people crave their caffeine the most in the mornings, when it can do the most good in terms of waking up from the effects of a good night’s sleep and boosting energy. Consider switching over to decaffeinated coffee or tea as the morning progresses, in order to manage overall daily amounts of caffeine so you’ll be relatively caffeine-free by late-afternoon.
• Avoid jumbo drinks: In this fast paced world, many people purchase their caffeinated products when commuting, and it’s easy to purchase caffeinated products "super sized.” From a 20-plus ounce caffeinated soda or latte to an energy drink that is caffeine-packed, many large sized caffeine products deliver way too much caffeine than is healthful. You’re better off sticking to the 8 oz serving.