I wish I hadn’t drunk strong coffee, tea, cola, or energy drinks during the evening. It’s never a good feeling to lie awake at night, staring at the walls and ceiling, lamenting that late-night caffeine stimulant.
Even though it’s late and you need to get up early, you don’t feel tired and wonder if you’ll ever sleep.
Caffeine reaches maximum efficacy about 45 minutes after consumption but slowly loses potency. After 5-6 hours, about 50% of the caffeine will have left your body.
What Are the Effects of Caffeine?
Caffeine is a central nervous system stimulant. In the short term, caffeine increases blood pressure and the heart rate constricts the blood vessels. This tells the liver to release more sugar into the bloodstream.
Caffeine doesn’t give the body energy but creates the same sensation. Consuming caffeine too soon before bed can stop you from feeling tired, which is why you can’t sleep after an energy drink.
Caffeine is a diuretic, meaning it dehydrates you. Consuming caffeine causes the body to release water, so you’ll urinate more at night. Drinking more fluids is vital to compensate for water loss.
Don’t consume caffeine regularly because it can result in physical dependency. Taking away caffeine once you’re addicted causes withdrawal symptoms.
The most well-known caffeine withdrawal symptoms are headaches, irritability, drowsiness, and nausea. Caffeine can lead to anxiety, insomnia, tremors, and stomach problems in the long term. Caffeine also strains the cardiovascular system.
Caffeine is an antioxidant that may help prevent certain cancers and heart disease. Caffeine consumption is also associated with a lower risk of developing type 2 diabetes.
How Long Does Caffeine Affect The Body?
When you drink coffee, the caffeine enters the bloodstream through the lining of the mouth and seeps into the blood through your esophagus and stomach when you swallow.
This means that 45 minutes after drinking coffee, 99% of the caffeine has been absorbed.
Once absorbed, the liver metabolizes the caffeine, turning it into theobromine, paraxanthine, and theophylline. These chemicals travel around the body, affecting various organs and bodily functions.
Now that the caffeine is in the body, how long will it take to leave the system?
The average half-life of caffeine is 5-6 hours. Imagine you drink a small cup of coffee (100 mg of caffeine) at 9 AM. At 2 PM, about 50 mg would be left in your system.
The more you consume, the longer your body takes to clear it. A Starbucks Venti Cold Brew Latte contains 276 mg of caffeine. If you drank one midday, you’d still have 138 mg in your system at 5 PM.
How long does it take for caffeine to leave the system entirely? It takes 27.6 hours for no trace of caffeine to be left in your system.
Does Caffeine Affect Everybody the Same?
Caffeine makes most people feel energized and awake. Even though caffeine doesn’t give the body energy, it creates the same sensation as if you’d had extra sleep.
Why is this? When the brain recognizes the need to sleep, it creates the neurotransmitter adenosine. Adenosine binds to receptors in nerve cells, slowing the cell’s activity and making you feel tired.
If caffeine is in the system, it binds to the adenosine receptors instead.
It doesn’t slow down cell activity. The body still lacks energy but feels awake and alert because the adenosine can’t communicate this to your nerve cells.
Caffeine doesn’t affect everybody the same way. Scientists have identified a gene called CYP1A2, which has two different variants. If you have the 1F allele, you metabolize caffeine slowly.
This means it affects you longer and takes a long time for the caffeine to leave your system.
If you have the 1A allele, you metabolize caffeine faster. People with this allele may not feel any effects of caffeine because their bodies get rid of it before they consciously experience it.
It’s possible to become caffeine-tolerant. If you drink caffeine regularly, you’ll need more to feel awake. Interestingly, younger people are less sensitive to caffeine than older people.
Does Black Tea Affect Sleep?
There’s more caffeine in black tea than in coffee. On average, there are around 30 mg of caffeine per gram of black tea. In contrast, 1 gram of coffee grounds has roughly 12 mg of caffeine.
When you make a cup of tea, water is added to dilute the taste of the leaves (which are then discarded). Coffee isn’t diluted as much as tea, so a cup of coffee contains more caffeine than a cup of tea.
On average, a cup of tea contains about half the caffeine of a cup of coffee, as long as the cups are the same size. However, each cup of tea is different. The longer you steep the tea, the more caffeine is infused into the water.
If your tea is weak, you’ll probably be okay before bed. However, drinking two cups of strong tea will have the same effect as a cup of coffee.
Does Decaffeinated Coffee Cause Sleeplessness?
Manufacturers use substances like water, activated charcoal, and carbon dioxide to remove the caffeine from coffee beans.
Decaffeinated coffee isn’t caffeine-free. As hard as they try to remove all the caffeine, some remains left over. Decaffeination removes 94-98% of the caffeine from coffee.
While a regular cup of coffee may contain 100 mg of caffeine, decaffeinated coffee contains around 5 mg.
Scientists found that drinking 5 cups of decaf coffee could be enough to feel the effects of caffeine. If you drank 10 cups, it would be equivalent to consuming a small cup of regular coffee.
Of course, you won’t drink 10 cups of decaffeinated coffee before bed. In most circumstances, you can have 1-2 cups of decaf before bed and be unaffected.
What Is The Latest Time to Drink Coffee Before Bed?
Many people drink coffee as soon as they get up in the morning. If you frequently feel groggy when you wake up, this could be you.
Caffeine gives you the buzz of alertness you need in the morning. Fortunately, most of the effects of your coffee over breakfast will wear off before bedtime.
If you indulge in a Starbucks during the afternoon, it could still affect you at nighttime.
A study by sleep scientists tested how caffeine affects sleep when consumed at different times. They found that caffeine consumed up to 6 hours before bedtime significantly affected sleep quality.
Participants who drank caffeine 6 hours before bed spent lots of time awake at night. When they did get some sleep, it was low quality.
Is Caffeine Causing Sleeplessness?
Caffeine continues affecting the body long after you stop feeling it. Your coffee habit could still influence your sleep even once the buzz has worn off.
It’s time to examine your caffeine habits to see if they affect your sleep. Start by listing every food and drink you consume after lunchtime and check if any contain caffeine. Check for the following:
- Coffee and coffee-flavored foods.
- Black, green, and white tea.
- Energy drinks and sodas, even diet or sugar-free versions.
- Chocolate and chocolate-flavored foods or drinks.
- Candies, including some breath mints.
- Protein and energy bars.
Also, check any medications. Some, particularly painkillers and migraine medications, contain caffeine because it works as a vasoconstrictor, narrowing the blood vessels.
Headaches and migraines occur when the blood vessels in the brain widen. Avoid medications containing caffeine after 2 PM. Ask a pharmacist for an alternative that doesn’t have caffeine.
How Does Caffeine Affect Sleep Quality?
Caffeine resembles adenosine, the chemical your brain releases to tell your body it’s tired. However, when caffeine has bound itself to adenosine receptors, adenosine can’t enter.
Even though you’re low on energy, you don’t feel tired and can’t switch off when you try to fall asleep. This means you’ll get less sleep and feel tired in the morning.
When you finally manage to fall asleep, caffeine can impact you. If caffeine remains in your system while you sleep, you’ll likely wake up at night.
Caffeine has a detrimental effect on your sleep cycle. The brain naturally cycles through light sleep, deep sleep, and REM sleep. If you keep waking up, the cycle resets.
For this reason, there’s a link between caffeine and REM sleep and caffeine and deep sleep. Drinking caffeine before bed involves missing out on these two vital sleep stages.
Missing out on deep sleep and REM sleep can adversely affect your health. You may wake up feeling groggy, sleepy, and disoriented most days.
You may also have problems with concentrating and thinking. Tasks that should be easy will feel harder than they should. You may even experience mood changes or mild hallucinations.
How To Drink Coffee And Sleep Well
Getting at least 7-8 hours of quality sleep per night can increase the length of your life. However, if you’re a coffee lover, you probably won’t like giving it up altogether.
What’s the best way to drink coffee and sleep well at night? Maintain a proper sleep schedule. Go to bed and wake up at the same time each day, including weekends.
Avoid caffeine after 2 PM, which isn’t always easy if you’ve formed a habit.
Switching to a different hot drink is one way to make it easier. Certain teas, like fruit teas, contain little caffeine. Hot chocolate is another option because it has only 5–15 mg of caffeine per cup.
If you crave the coffee flavor, try switching to decaffeinated coffee. Most quality brands taste similar to regular coffee. Although they aren’t entirely caffeine-free, having 1-2 cups won’t harm you.
Limit your intake to 400 mg of caffeine per day, no matter what time you consume it.
You’ll soon recognize which foods and drinks contain caffeine and know to avoid them after 2 PM. You should also understand how to create a good sleeping environment and schedule.
