If only I hadn’t drunk strong coffee, tea, cola, or energy drink 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 getting late and you have to get up early, you don’t feel tired and wonder if you’ll ever fall asleep.
Caffeine reaches maximum efficacy about 45 minutes after consumption but slowly loses potency. After 5-6 hours, approximately 50% of the caffeine will have left the body.
What Is Caffeine?
Caffeine is a psychoactive drug, meaning it’s a chemical that changes the function of the brain.
Although it might sound concerning, caffeine isn’t dangerous to most people if consumed in moderation; it’s a stimulant that affects the body’s energy levels.
Most people consume caffeine to stay awake. Much of the time, we consume caffeine without even knowing it. Caffeine is a natural substance found in many plants.
The most well-known source of caffeine is coffee. There are two main coffee plants: coffea arabica and coffea canephora, and both varieties contain caffeine in the seeds (coffee beans).
Also, caffeine is found in the leaves of the tea plant. The kola nut also contains caffeine and exotic plants like guarana and yerba mate.
Consume no more than 400 milligrams of caffeine a day for adults, which equates to around 4-5 regular cups of coffee.
Which Products Contain Caffeine?
Humans have been drinking coffee since the 15th century, and there are many different types of coffee (instant, filter, and espresso).
Along with coffee itself, most coffee-flavored products contain caffeine. This could include coffee cakes, coffee liqueurs, coffee-flavored candies, etc.
Tea leaves contain more caffeine than coffee beans. However, tea has to be diluted more than coffee before drinking, so tea contains less caffeine than coffee does per ounce.
There’s around 50-70 mg of caffeine per cup of tea, compared to 100-150 mg in coffee. Green tea isn’t caffeine-free, containing around 30 mg of caffeine per cup.
Many soft drinks contain caffeine, including Coke, Pepsi, and Mountain Dew. Along with sodas, energy drinks also contain a substantial amount of caffeine. Red Bull, Monster, NOS, and Rockstar are all well-known brands.
Chocolate is also a source of caffeine. The higher the cocoa content, the more caffeine it contains, with some bars of dark chocolate containing as much caffeine as a can of coke. Of course, this also means that most things flavored with chocolate contain caffeine, including chocolate ice cream.
You can also find caffeine in many different medications and supplements.
What Are the Effects of Caffeine?
Caffeine is a central nervous system stimulant. In the short term, caffeine increases blood pressure and heart rate, constricts the blood vessels, and tells the liver to release more sugar into the bloodstream. The main outcome of this stimulation is alertness.
Caffeine doesn’t give your body energy but creates the same sensation. So, if you ingest caffeine too soon before bed, it can stop you from feeling tired, which is why you can’t sleep after an energy drink.
Caffeine is a diuretic, meaning that it dehydrates you. Consuming caffeine causes the body to let go of water, so you’ll urinate more at night. Drinking more fluids is important to compensate for water loss.
Don’t consume caffeine regularly, as it can result in physical dependence. Taking away caffeine once you’re addicted can cause 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.
However, caffeine is an antioxidant that can prevent some cancers and heart disease. Caffeine consumption is also associated with a lower risk of developing type two 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. So, 45 minutes after drinking coffee, 99% of the caffeine has already 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 working through the body, how long will it be until it leaves 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 had one at midday, you’d still have 138 mg in your system at 5 pm.
How long does caffeine take for caffeine to leave your system entirely? It takes 27.6 hours for there to be no trace of caffeine 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 some extra sleep.
Why is this? Your brain creates the neurotransmitter adenosine when it recognizes the need to sleep. Adenosine binds to special 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. However, it doesn’t slow down cell activity. Your body still lacks energy, but you feel awake and alert because the adenosine can’t communicate this to your nerve cells.
However, 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 for longer and takes a long time for the caffeine to leave your system. However, if you have the 1A allele, you metabolize caffeine more quickly. People with this allele may not feel any effects of caffeine because their body gets rid of it before they consciously experience the effects.
It’s possible to become caffeine tolerant. If you drink caffeine regularly, you’ll need more to feel awake. Interestingly, younger people seem 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’s around 30 mg of caffeine per gram of black tea. By contrast, one gram of coffee grounds has roughly 12 mg of caffeine.
However, when you make a cup of tea, a lot of water is added to dilute the taste of the leaves (which are then discarded). Coffee isn’t diluted as much as tea, which is why 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 very weak, you’ll probably be ok 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 such as water, activated charcoal, and carbon dioxide to remove the caffeine from coffee beans.
However, decaffeinated coffee isn’t caffeine-free. As hard as they try to remove all of the caffeine, some remains left over. Decaffeination removes 94-98% of the caffeine from coffee.
So, while a normal cup of coffee may contain 100 mg of caffeine, a cup of decaf coffee contains around 5 mg. It’s not much, but it’s not zero.
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 drinking a small cup of normal coffee.
Of course, you’re unlikely to drink 10 cups of decaffeinated coffee before bed. So, in most circumstances, you can have a cup or two of decaf before bed and not be affected.
What is the Latest Time to Drink Coffee Before Bed?
Many people drink coffee in the morning as soon as they get up. If you frequently feel groggy when you wake up, this could be you.
Caffeine gives you the buzz of alertness that you need in the morning. Fortunately, most of the effects of the coffee you drank over breakfast will wear off before bedtime.
However, if you indulge in a Starbucks during the afternoon, you could be cutting it fine. A study conducted 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. So, your coffee habit could still affect 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. So, avoid medications containing caffeine after 2 pm. Ask a pharmacist for an alternative that doesn’t contain caffeine.
How Does Caffeine Affect Sleep Quality?
Caffeine poses as adenosine, the chemical your brain releases to tell your body it’s tired. 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 have an effect. If caffeine remains in your system while you sleep, you’re more likely to wake up at night.
Caffeine has a detrimental effect on your sleep cycle. When you sleep, your brain naturally cycles through light sleep, deep sleep, and REM sleep. If you’re always 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 7.5 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 the idea of giving it up altogether.
So, 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 every day, including on weekends.
You should avoid caffeine after 2 pm. Sometimes, it’s not that easy, especially if you’ve formed a habit. One way to make it easier is to switch to a different hot drink. Certain teas, like fruit teas, contain little caffeine. Hot chocolate is another good option, as there’s only around 5–15 mg of caffeine per cup.
If you crave the coffee flavor, try switching to decaffeinated coffee. Most good-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.
If you follow the above advice, you’ll recognize which foods and drinks contain caffeine and know to avoid them after 2 pm. You should also know how to create a good sleeping environment and schedule.
