Caffeine is a natural psychoactive substance widely used in foods and beverages across the world. Caffeine is found in many plants, including coffee beans, tea leaves, cacao pods, and kola nuts. Caffeine is also synthetically produced and used in medications and energy drinks for its energizing and alertness-promoting effects.
Caffeine is most often consumed in drinks. Since there are so many variations in caffeinated products, it can be hard to know exactly how much caffeine is in a particular drink, especially a fresh-brewed cup of tea or coffee that has no label. Generally speaking though, coffee is the most potent and most consumed caffeinated beverage. A single eight ounce cup of coffee contains between 95-200mg of caffeine. For comparison, a 12 ounce soda contains 35-45mg, about half the amount of a weaker cup of coffee.
| Beverage | Caffeine |
|---|
| 8 ounce cup of coffee | 95 – 200mg |
| 8 ounce energy drink | 70 – 100mg |
| 12 ounce soda | 35 – 45mg |
| 8 ounce cup of tea | 14 – 60mg |
How Caffeine Affects the Brain
When we consume caffeinated drinks and foods, our stomachs and small intestines quickly absorb the caffeine. The maximum effects of caffeine usually occur between 30-60 minutes within consumption, although this timing can vary widely among individuals. After being absorbed, caffeine is efficiently distributed throughout the whole body, and it crosses the blood-brain barrier.
Inside the brain, caffeine blocks adenosine receptors. Adenosine is a sleep-promoting chemical that is produced in the brain during our waking hours. Normally, adenosine builds up in the brain the longer we’re awake. The more it builds up, the sleepier we become. When caffeine blocks this process, we remain alert and vigilant.
Research has also shown that caffeine interferes with circadian melatonin rhythms, delaying the onset of sleep if consumed close to bedtime. Circadian rhythms are physiological patterns, like our sleep-wake cycle, that operate on a 24-hour clock. They are held in check by the external cycle of day and night, and by internal cellular processes. The buildup of adenosine contributes to this process, and caffeine’s interference with this process may explain its impact on circadian rhythm.
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SleepFoundation.org's Scientific Advisor
How Long Does Caffeine Lasts
The effects of caffeine are measured by its half-life, which typically ranges from 4-6 hours. The half-life means the time that your body has metabolized, or processed through, half the caffeine you consumed. As a result, the six-hour half-life of a caffeinated beverage you consume in the afternoon could keep you up at night.
Some factors can slow or speed up the metabolism of caffeine. Nicotine use can reduce the half-life of caffeine by up to 50%, so frequent smokers process through caffeine much quicker, with a half-life as short as two hours. By contrast, pregnant women experience slower caffeine metabolism. It is recommended that those who are pregnant or breastfeeding should avoid coffee, or limit intake to 16 ounces or less per day (about two cups of coffee).
During pregnancy, caffeine can be passed to the baby through the placenta. A trace amount of caffeine can also be found in breast milk. If you are pregnant or breastfeeding and concerned about your caffeine intake, talk to your health care provider about what steps you should take to ensure optimum health for you and your baby.
How Does Caffeine Affect Sleep?
Caffeine can impact the onset of sleep and reduce sleep time, efficiency, and satisfaction levels. Older adults may also be more susceptible to caffeine-induced sleep troubles. Caffeine notably reduces the time of slow-wave sleep, which is the stage of deep, restful sleep that leaves us feeling refreshed and alert in the morning. Caffeine-interrupted sleep can lead to sleep deprivation the following day, which is characterized by fatigue and problems with learning, memory, problem-solving, and emotion regulation.
One study examined the effects of caffeine intake zero, three, and six hours before bedtime, and found that even caffeine consumed six hours before bed could reduce sleep time by one hour. In addition, study participants reported sleeping problems when consuming caffeine 0-3 hours before bed, but they did not realize their sleep was also disrupted when consuming caffeine six hours before bed. If you have difficulty sleeping, consider limiting any caffeine intake six hours before bed.
Can Caffeine Keep Me Awake?
Caffeine can cause a burst of energy as it stimulates the central nervous system . Most people drink coffee in the morning to help them wake up, but caffeine consumed at night can cause more harm than good. While caffeine can boost cognitive function in the severely fatigued, it cannot permanently ward off sleep or fix the effects of long-term sleep loss. Even though caffeine can marginally boost performance, it is no substitute for a restful, restorative night of sleep.
It is also proposed that the effectiveness of caffeine varies depending on the dose and the state of the individual. For example, the arousing effects of caffeine may benefit someone who feels foggy and tired. For someone who is already alert and aroused, however, caffeine may cause over-arousal and lead to anxiety, restlessness, and dependency.
Can Caffeine Cause Insomnia?
While there are short-term performance benefits to caffeine consumption, overuse can lead to insomnia symptoms or worsen pre-existing insomnia. Consuming caffeine to stay awake at night may lead to sleeplessness, anxiety, frequent nighttime awakenings, and overall poorer sleep quality.
In addition, caffeine from sodas has been linked to increased severity of sleep-disordered breathing (SDB), which is the primary characteristic of obstructive sleep apnea (OSA). Notably, this association was only found with caffeinated sodas, but not with coffee or tea, although it is unclear why. Regardless, those who suffer from sleep-disordered breathing may not know about their sleep disruption and find themselves attributing excessive daytime sleepiness to other causes. If you struggle with sleepiness during the day, it might be helpful to reevaluate your caffeine consumption, especially from sodas.
Does Caffeine Make Some People Sleepy?
Yes. It may seem counterintuitive, but some people feel like caffeine makes them tired instead of more alert. The disruptive effects of regular caffeine use on sleep can create a vicious cycle. Caffeine use causes sleep deprivation, and sleep deprivation causes sleepiness the subsequent day, which in turn causes an increased need to consume more caffeine in order to cope with the sleepiness. Even with increased caffeine consumption, sleep deprivation catches up. People may be especially aware of their long-term sleep loss after they consume caffeine because they do not experience the pick-me-up they expected, and instead feel sleepy.
Sleepiness can also be a symptom of abstinence from caffeine, which is why regular caffeine users may feel overly sleepy in the morning when they have gone all night without caffeine.
How Much Caffeine Is Safe To Drink?
Since caffeine can be both beneficial and harmful depending on the dose, it is important to find a level of consumption that is healthy for you. The Food and Drug Administration (FDA) recommendation for safe daily caffeine consumption sits around 400mg, or 4-5 cups of coffee per day. A large cup of coffee can have up to 470 mg of caffeine content which is more than the daily recommended caffeine content. It is essential to read the fine print about what you’re drinking. Since there can be a lot of variation in the way people respond to and metabolize caffeine, talk to your doctor if you are unsure if your caffeine consumption is recommended.
How Many Hours Before Bedtime Should I Have Caffeine?
The recommended cut-off time for caffeine use is a minimum of six hours before bedtime. For example, if you typically go to bed at 10pm, avoiding caffeine after 4pm can help minimize sleep problems. If you find the six-hour recommendation is not enough, make note of the times you consume caffeine and how you sleep the subsequent night. You may find you sleep better with a longer period of caffeine abstinence before bed.
How Can I Tell if Caffeine Is Affecting My Sleep?
Are you struggling with insomnia, headaches, or anxiety during the day? This could be a sign of caffeine overuse and dependence. Troubles during the night, like frequent awakenings, inability to fall asleep, and nighttime anxiety may also be a sign caffeine is interfering with your sleep14. If you find yourself excessively sleepy during the day and caffeine isn’t helping, it could be a sign you are sleep deprived from extended caffeine use. In that case, it may be time to put down the coffee and catch up on some much-needed rest.
How Else Can I Improve My Sleep?
Monitoring your caffeine use is just one way you can help yourself get regular, restorative sleep. Other lifestyle choices, like a healthy diet and exercise regimen, can contribute to healthy sleep. Good sleep hygiene is comprised of all the habits and routines that optimize your sleep quality:
- Sleep environment: Cool, comfy, quiet, and dark. Give your body and mind a peaceful and relaxing environment to rest.
- Lifestyle: Moderate alcohol and caffeine consumption within recommended guidelines, exercise regularly, and don’t smoke!
- Routine: Make a regular bedtime, including scheduled time beforehand to wind down, dim the lights, and put away electronics and other stimulating activities.
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FAQs
Negative Effects of Caffeine
The most obvious effect of the stimulant is that it can make it hard for you to fall asleep. One study also found that caffeine can delay the timing of your body clock. These effects will reduce your total sleep time. Caffeine also can reduce the amount of deep sleep that you enjoy.
What level of caffeine disrupts sleep? ›
The results of this study suggest that 400 mg of caffeine taken 0, 3, or even 6 hours prior to bedtime significantly disrupts sleep. Even at 6 hours, caffeine reduced sleep by more than 1 hour. This degree of sleep loss, if experienced over multiple nights, may have detrimental effects on daytime function.
Can caffeine cause sleep disorders? ›
While there are short-term performance benefits to caffeine consumption, overuse can lead to insomnia symptoms14 or worsen pre-existing insomnia. Consuming caffeine to stay awake at night may lead to sleeplessness, anxiety, frequent nighttime awakenings, and overall poorer sleep quality.
Does caffeine affect sleep apnea? ›
One study showed that caffeinated soda use may be associated with more severe sleep-disordered breathing, such as OSA . But tea or coffee use didn't appear to be associated with more severe sleep-disordered breathing.
Does coffee affect REM sleep? ›
As expected, caffeine had no effect on REM sleep for any time of administration. There were no significant differences in percentage of sleep stage distributions between caffeine conditions.
Which coffee is best to avoid sleep? ›
A double espresso three hours before bedtime delayed the production of the sleep hormone melatonin by about 40 minutes, making it harder to nod off.
How much sleep do you need by age? ›
How Much Sleep Do I Need?
| Age Group | Recommended Hours of Sleep Per Day |
|---|
| Newborn | 0–3 months | 14–17 hours (National Sleep Foundation)1 No recommendation (American Academy of Sleep Medicine)2 |
|---|
| School Age | 6–12 years | 9–12 hours per 24 hours2 |
| Teen | 13–18 years | 8–10 hours per 24 hours2 |
| Adult | 18–60 years | 7 or more hours per night3 |
5 more rowsSep 14, 2022
"But in general, our guideline is eight hours before going to bed, you should eliminate all caffeinated products." Dr. Conroy recommends avoiding it at least three hours before bed. "It's sedating at first, so it can help you fall asleep, but can interfere with staying asleep.
How long does it take for caffeine to exit the body? ›
The level of caffeine in your blood peaks about one hour later and stays at this level for several hours for most people. Six hours after caffeine is consumed, half of it is still in your body. It can take up to 10 hours to completely clear caffeine from your bloodstream.
How do you fall asleep when you can't sleep? ›
How to Fall Asleep FAST When You CAN'T Sleep! 10 Sleep Life Hacks!
Common causes of chronic insomnia include: Stress. Concerns about work, school, health, finances or family can keep your mind active at night, making it difficult to sleep. Stressful life events or trauma — such as the death or illness of a loved one, divorce, or a job loss — also may lead to insomnia.
Why do people get insomnia? ›
It's not always clear what triggers insomnia, but it's often associated with: stress and anxiety. a poor sleeping environment – such as an uncomfortable bed, or a bedroom that's too light, noisy, hot or cold. lifestyle factors – such as jet lag, shift work, or drinking alcohol or caffeine before going to bed.
Does sleeping without a pillow help sleep apnea? ›
Potential Drawbacks of Sleeping Without a Pillow
Pillows may be helpful for people with conditions such as heartburn or obstructive sleep apnea. They also help many sleepers maintain a healthier sleep posture and reduce back and neck pain.
Do naps help sleep apnea? ›
If you have sleep apnea or another sleep disorder, it's best to forgo that afternoon power nap. The primary reason why naps aren't recommended for sleep apnea patients is that they make it harder to embrace continuous positive airway pressure (CPAP) treatment.
What foods are good for sleep apnea? ›
Foods That Help
Asparagus, corn, cherries, grapes, broccoli, and cucumbers all contain this sleepy hormone. And, many recommend tart cherry juice as the best natural source of melatonin. Just make sure to brush your teeth after drinking juice, especially before bed.
How long before bed should you stop drinking water? ›
It's important to drink enough water during the day, however, it can be disruptive if you drink directly before bed. Avoid drinking water or any other fluids at least two hours before sleeping to prevent waking up at night.
Is tea before bed good for you? ›
Drinking tea before bed has been shown to help aid in a better night's sleep and high quality of sleep. This is pretty significant because so many Americans struggle with sleep issues like insomnia. Additionally, sleep issues can become worsened when you've had too much screen time and not enough exercise.
Does tea affect sleep? ›
Some people experience a calming effect after drinking a warm, cup of tea before bedtime. At the same time, it's important to choose a tea that is free of sleep-disrupting caffeine. You should also avoid adding sugar to your tea before bedtime, since sugar can promote wakefulness.
What should I drink in the morning to wake up? ›
9 energizing drinks that will wake you up better than coffee
- Chai tea. Credit: Reviewed / Danielle DeSiato. ...
- Green tea. Credit: Reviewed / Danielle DeSiato. ...
- Matcha. Credit: Getty Images. ...
- Yerba mate. Credit: Reviewed / Danielle DeSiato. ...
- Kombucha. ...
- Dandelion root tea. ...
- Hot Water with Lemon and Honey. ...
- Apple cider vinegar.
Green Tea
Green Tea is the best substitute for coffee. It contains less caffeine than coffee; it is calories less and keeps you awake and active. It is considered a superfood because, besides other benefits, it has fat-burning properties and boosts brain function.
Because of this effect, caffeinated foods and beverages, including soda, coffee, caffeinated tea, and caffeinated chocolate products may negatively affect sleep and keep you awake at night. In fact, research shows that consuming coffee, even many hours before bedtime, can affect sleep.
Why do I keep waking up at 4am? ›
For those of us who are waking up at odd times in the morning, more often than not, it's at the same time every day - sometime around 4am or 5am. This could be because of the simultaneous rise in cortisol levels and the brain's processing of emotional material early in the morning.
How much sleep does an 80 year old need? ›
Older adults need about the same amount of sleep as all adults—7 to 9 hours each night. But, older people tend to go to sleep earlier and get up earlier than they did when they were younger.
What time should I go to bed if I wake up at 5? ›
Sleep calculator
| Wake-up time | Bedtime: 7.5 hours of sleep (5 cycles) | Bedtime: 9 hours of sleep (6 cycles) |
|---|
| 5 a.m. | 9:15 p.m. | 7:45 p.m. |
| 5:15 a.m. | 9:30 p.m. | 8 p.m. |
| 5:30 a.m. | 9:45 p.m. | 8:15 p.m. |
| 5:45 a.m. | 10 p.m. | 8:30 p.m. |
17 more rowsGoing for a brisk daily walk won't just trim you down, it will also keep you up less often at night. Exercise boosts the effect of natural sleep hormones such as melatonin.
How can I improve my sleep habits? ›
Tips for Better Sleep
- Be consistent. ...
- Make sure your bedroom is quiet, dark, relaxing, and at a comfortable temperature.
- Remove electronic devices, such as TVs, computers, and smart phones, from the bedroom.
- Avoid large meals, caffeine, and alcohol before bedtime.
- Get some exercise.
Benefits of Quitting Caffeine
These speak for themselves, but cutting down on your caffeine consumption can lead to less anxiety, better sleep, more efficient nutrient absorption, whiter teeth, balanced hormones, improved brain chemistry, and fewer headaches.
Does water flush out caffeine? ›
An effective way to get rid of your jitters is to flush out your system with water. Drinking water will decrease the effects of caffeine in a relatively short time.
How can I flush caffeine out of my system fast? ›
Besides waiting it out and avoiding caffeine, there isn't any effective home remedy to clear caffeine from your system. All the same, you can reduce its side effects by staying hydrated, going for a walk, and eating fiber-rich foods.
Why do I keep waking up at 3am? ›
You wake up at 3am because this is the time you shift from a deep sleep into a lighter sleep. If you turn in at 11pm, by three in the morning you're mostly out of deep sleep and shifting into longer periods of lighter sleep, known as REM.
If you wake up at 3 a.m. or another time and can't fall right back asleep, it may be for several reasons. These include lighter sleep cycles, stress, or underlying health conditions. Your 3 a.m. awakenings may occur infrequently and be nothing serious, but regular nights like this could be a sign of insomnia.
How can I stop waking up at 3am? ›
Keep the bedroom dark and quiet: Environmental disturbances, like noise and light, can wake a person from nighttime sleep. If darkness and quiet are not possible, wearing a sleep mask30 to block out light and earplugs to block out sound can help.
How can I solve my sleeping problem naturally? ›
Five tips for better sleep
- Drink up. No, not alcohol, which can interfere with sleep. ...
- Exercise . Physical activity can improve sleep, though researchers aren't completely sure why. ...
- Use melatonin supplements . ...
- Keep cool. ...
- Go dark.
Anxiety or depression
Stress can make it hard to get to sleep in the first place (that's called sleep-onset insomnia). But anxiety can also cause you to wake up in the middle of the night and have trouble getting back to sleep (called middle insomnia, or sleep-maintenance insomnia).
How do you break the insomnia cycle? ›
Tips for Better Sleep
- Avoid electronics at night. And if possible, keep your phone or other devices out of the room you're sleeping in.
- Keep cool. ...
- Exercise. ...
- Get plenty of natural light during the day. ...
- Avoid caffeine, alcohol, and cigarettes. ...
- Use soothing sounds.
Insomnia is rarely an isolated medical or mental illness but rather a symptom of another illness to be investigated by a person and their medical doctors. In other people, insomnia can be a result of a person's lifestyle or work schedule.
Why do I wake up every 2 hours? ›
Reasons this might happen include drinking caffeine or alcohol late in the day, a poor sleep environment, a sleep disorder, or another health condition. When you can't get back to sleep quickly, you won't get enough quality sleep to keep you refreshed and healthy.
What is the best sleep position for sleep apnea? ›
Mayo Clinic Minute - What's the best sleeping position? - YouTube
What is the healthiest sleeping position? ›
The Best Sleep Position For Your Health - YouTube
What position makes sleep apnea worse? ›
Sleep apnea is worse when sleeping on your back (supine position) because of the effects of gravity on the body. The tongue falls back and blocks the airway increasing the duration and the number of apneas during sleep.
ResMed - How is obstructive sleep apnea treated? - YouTube
What are the long term effects of using a CPAP machine? ›
What are the long-term effects of using a CPAP machine?
- dry or runny nose.
- sore throat.
- dry mouth.
- dry eyes.
- nasal congestion.
- nosebleeds.
- facial irritation.
- air leaks around the mask.
How Often You Should Replace Your CPAP Supplies - YouTube
What is the main cause of sleep apnea? ›
In adults, the most common cause of obstructive sleep apnea is excess weight and obesity, which is associated with the soft tissue of the mouth and throat. During sleep, when throat and tongue muscles are more relaxed, this soft tissue can cause the airway to become blocked.
How can I reverse sleep apnea? ›
Treatment
- Lose weight if you're overweight.
- Exercise regularly.
- Drink alcohol moderately, if at all. Don't drink in the hours before bedtime.
- Quit smoking.
- Use a nasal decongestant or allergy medications.
- Don't sleep on your back.
- Avoid taking sedative medications such as anti-anxiety drugs or sleeping pills.
For years, the most common treatment for millions of people with sleep apnea involved wearing a continuous positive airway pressure (CPAP) mask. That is, until the U.S. Food and Drug Administration recently approved a new, maskless treatment option -- the Inspire upper airway stimulation device.
How does alcohol affect sleep? ›
Alcohol And Sleep - What Is The Connection? - YouTube
How long before bed should you stop drinking caffeine? ›
"But in general, our guideline is eight hours before going to bed, you should eliminate all caffeinated products." Dr. Conroy recommends avoiding it at least three hours before bed. "It's sedating at first, so it can help you fall asleep, but can interfere with staying asleep.
Why does Red Bull make me sleepy? ›
Your blood sugar levels will spike shortly after drinking a high-sugar energy drink, but the boost in energy will only last 30 to 60 minutes. After this, your blood sugar — and energy levels — will crash, leaving you feeling more tired than before. Symptoms of a sugar crash include: Tiredness.
How much caffeine should you have before bed? ›
For most people, caffeine should be avoided for four to six hours before bedtime, as this is how long it takes the body to metabolize half of your (caffeine) consumption. 2 If you are highly sensitive to the stimulant, you might consider cutting it out after noon (or perhaps entirely).
According to the findings, alcohol does allow healthy people to fall asleep quicker and sleep more deeply for a while, but it reduces rapid eye movement (REM) sleep. And the more you drink before bed, the more pronounced these effects. REM sleep happens about 90 minutes after we fall asleep.
Do you sleep better without alcohol? ›
Sleep is better without alcohol
Alcohol has sedative effects, so it may not immediately look like a culprit for poor sleep. People might find it easier to fall asleep – or even nod off when they don't mean to – if they've been drinking alcohol.
Why do alcoholics sleep a lot? ›
Alcohol may aid with sleep onset due to its sedative properties, allowing you to fall asleep more quickly. However, people who drink before bed often experience disruptions later in their sleep cycle as liver enzymes metabolize alcohol.
How much sleep do older adults need? ›
Older adults need about the same amount of sleep as all adults—7 to 9 hours each night. But, older people tend to go to sleep earlier and get up earlier than they did when they were younger. There are many reasons why older people may not get enough sleep at night.
How much sleep do you need by age? ›
How Much Sleep Do I Need?
| Age Group | Recommended Hours of Sleep Per Day |
|---|
| Newborn | 0–3 months | 14–17 hours (National Sleep Foundation)1 No recommendation (American Academy of Sleep Medicine)2 |
|---|
| School Age | 6–12 years | 9–12 hours per 24 hours2 |
| Teen | 13–18 years | 8–10 hours per 24 hours2 |
| Adult | 18–60 years | 7 or more hours per night3 |
5 more rowsSep 14, 2022
You may be too exhausted even to manage your daily affairs. In most cases, there's a reason for the fatigue. It might be allergic rhinitis, anemia, depression, fibromyalgia, chronic kidney disease, liver disease, lung disease (COPD), a bacterial or viral infection, or some other health condition.
What can help you stay awake? ›
How to Stay Awake Naturally
- Get up and move around to feel awake. ...
- Take a nap to take the edge off sleepiness. ...
- Give your eyes a break to avoid fatigue. ...
- Eat a healthy snack to boost energy. ...
- Start a conversation to wake up your mind. ...
- Turn up the lights to ease fatigue. ...
- Take a breather to feel alert.
Avoid drinking water or any other fluids at least two hours before sleeping to prevent waking up at night. If drinking water before bed has caused you to experience irregular symptoms, talk with your doctor or dietitian. They can help you determine what amount of water is best for your diet and your overall health.
When should you stop eating before bed? ›
Experts recommend waiting at least three hours after you've eaten to go to bed. This allows your body time to digest your food so you're not up at night with an upset stomach, indigestion, or acid reflux. And it helps you stay asleep.
What time should you stop eating? ›
If you want to maintain or lose weight, then you shouldn't eat after 7 p.m. There are myriad reasons why people might not want to eat after a certain time in the evening, especially if it's close to when they go to sleep, says Cara Harbstreet, M.S., R.D., L.D., owner of Street Smart Nutrition..
