Surprising Effects of Caffeine on the Brain and Nervous System

Coffee: 85% of US adults drink it.

Tea: ¾ of the world’s population drinks it daily.

Combine that with energy drinks, chocolate, and herbal sources of caffeine, just about everyone on the planet consumes caffeine at least once per week – most once per day.

Some sources call caffeine most abused stimulant in the world.

caffeine brain effects

What we want to cover today is the health effects of caffeine, the positives, and the negatives, and what are safe as sources so that you can enjoy life and reap the benefits.

What is Caffeine?

Caffeine is a rather simple molecule. The molecular formula is C8H10N4O2. Compared to some of the other vital nutrients and vitamins that we talked about on this site, it’s very small. Yet, it is mighty.

Caffeine stimulates the central nervous system of the human body. It is technically classified as a psychoactive drug. However, this one is legal and unregulated just about everywhere in the world. It is highly addictive.

It’s structurally similar to the protein adenosine and primarily blocks the same receptors. By blocking this receptor, caffeine prevents drowsiness. And, caffeine readily crosses the blood-brain barrier to stimulate the neurons of the brain directly.

Caffeine comes from many different herbs and seeds. Plants use it as a pesticide for several predator insects. It also helps to prevent the germination of seeds. As a little side note, many gardeners use spent coffee grounds in their garden. Most of the caffeine from the grounds moved into the liquid, leaving very little to interfere with plants. Your garden is safe from caffeine when you use spent coffee grounds.

Caffeine is most well known for being found in the coffee bean and tea. Small amounts exist in the cacao bean, from which we get chocolate. It also has been added to sodas, energy drinks, nootropics, and processed foods.

Some of the positive effects of caffeine include the famous wakeful properties and stimulating effects. It also could help reduce anxiety, the symptoms of Parkinson's disease, and breathing disorders.

Unfortunately, some of the adverse side effects of caffeine include sleepiness, headache, and irritability, especially after you stopped taking it and experience withdrawal. In concentrated amounts, it has been known to cause death.

caffeine effects on brain infographic

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Caffeine in the Body

There are many effects of caffeine on the body, and it’s not all in the brain. One of the things caffeine does to the body helps increase aerobic and anaerobic metabolism, which can improve athletic performance. The stimulating properties of the caffeine help improve performance most during endurance activities. Caffeine affects the body by increasing basal metabolic rate, promoting wakefulness, and stimulating nerves.

Caffeine can also affect your heart, increasing beats per minute and your blood pressure. It’s one of the reasons why coffee is not recommended for people with high blood pressure. However, some studies have found that coffee drinkers have a slightly reduced risk of death from heart disease.

What happens when you drink coffee is that within 20 minutes, the caffeine has absorbed into your bloodstream and is already blocking the adenosine receptors in a central nervous system. This helps keep you from feeling fatigued. It stimulates the nerves in your body and increases your blood pressure.

For people who don't like coffee, tea, caffeine pills, synthetic caffeine, and less concentrated forms caffeine including chocolate and tea have similar effects.

caffeine effects on body

Caffeine and the Brain

Caffeine’s effect on the brain can be felt right away. Within 20 minutes, most people feel more awake and alert. As the caffeine binds to the adenosine receptors in the brain, it helps fight off fatigue. The stimulating effect of the caffeine on the central nervous system gives a boost of energy.

Caffeine enters the brain rather quickly. As it crosses the blood-brain barrier, the caffeine begins affecting your brain chemistry almost immediately. It can stimulate hormone production, especially endorphin production and cortisol. In the short-term, this is not a problem. However, repeated and prolonged hormone production of endorphins and cortisol can lead to weight gain and high blood pressure.

Fortunately, caffeine's effect on the brain is short-lived. Most of the caffeine clears out of your system in 6 hours. After that, caffeine can make you feel sleepy as the adenosine receptors are now functioning normally.

The short-term effects of caffeine are easily seen. But, as people consume caffeine regularly, the body creates more adenosine receptors. This means it takes more caffeine to produce the same effects of wakefulness. You see this most in people who are addicted to coffee, that they need 4 to 6 cups per day to achieve the same results some people get with one.

The long-term effects of caffeine tend to be this addiction and increased need. The body also adjusts the hormone production to overcome the problems created by the caffeine. It can adapt to testosterone and estrogen levels, increasing estrogen. As estrogen increases in the body, it can cause breast cancer and decreased sexual drive.

Due to the increased hormone production to offset the caffeine’s effect on the body, it leads to weight gain. For people who do not consume caffeine, coffee can help reduce weight in the short-term. On the other hand, the way your body adjust to continuous exposure to caffeine is to gain weight.

Some people also experience headaches when exposed to caffeine. Generally, this is a short-term problem that usually resolves itself quickly. People with migraines often take up drinking small amounts of coffee on a regular basis to ward off the pain.

For people who have exposed themselves to caffeine in the long-term, withdrawal headaches are much more common. These can feel quite severe, although they are not life-threatening.

Fun Facts about Caffeine

Most adults drink coffee, and the most ardent coffee drinkers welcome joke about having a caffeine IV drip to get their fix. Of course, we know they are joking. Introducing caffeine or coffee directly into your bloodstream can prove quite disastrous.

When coffee was introduced into Europe in the late 1500s, it caused such an uproar among the elite; it was almost classified as crisis worse than opium. As people realize they could stay up late and sit through elaborate religious ceremonies that would last all day and night, coffee was slowly woven into the fabric of society as a staple drink. It’s now a welcome respite after a large meal to ward off fatigue.

Caffeine’s Effect on Health

Caffeine and Children

It's recommended that children not be exposed to very much caffeine at all. It is an addictive substance and often considered one of the most highly abused drugs in the world.

Just about all sources of caffeine that kids have easy access to and drink regularly are beverages with high amounts of sugar. These include sodas and energy drinks. Some energy bars and other processed foods contain added caffeine. These can add up, so you need to be careful eating these food-like substances.

caffeine and kids

Unfortunately, because of the high amounts of caffeine and the inability of a young body to process the caffeine appropriately, there have been deaths linked to overdoses of caffeine.

That being said, there are a few uses of caffeine for kids, as we show below.

Caffeine and ADD

When it comes to caffeine and the kids, the most prominent use is for attention deficit disorder (ADD). Caffeine acts as a stimulant, very similar to the prescription Adderall. In children, stimulants have an opposite effect, causing mental depression, which will allow them to think clearer and control their actions better.

There have been a few studies to see how caffeine can help control the symptoms of ADHD. However, the results are not precise. Caffeine often raises dopamine levels in the brain, which can be extremely helpful for kids who have learning difficulties.

The biggest downside is the studies recommend using 400 mg of caffeine. This amount of caffeine in children has been known to cause migraine headaches, insomnia, irritability, and upset stomach. Also, it was found much less effective than prescription medications such as Ritalin. At 400mg, the chances of caffeine toxicity in those younger than 18 is significantly higher.

Because of the side effects of having headaches and insomnia, it is not recommended you give your children caffeine to help control ADHD, especially if they’re already using prescription medications. If your children with ADHD already have difficulty sleeping, this can make things worse.

The American Academy of Pediatrics also recommends that no children or teenagers should be allowed to have energy drinks at all. This includes supplements or candy with caffeine. They also recommend avoiding packaged food products that contain caffeine.

Caffeine and the Elderly

The multiple mixed reviews of whether caffeine, especially coffee, made an impact on the rise of mental disorders in the elderly or if it can be a protective factor.

In some studies, long-term exposure to caffeine worsened the symptoms of Alzheimer’s and Parkinson’s in various populations. It has been linked to mild cognitive impairment and the weakening of the myelin sheath around the nerves.

However, in various studies explicitly targeting Alzheimer's and Parkinson's diseases, there were also studies that show that caffeine levels in the blood directly correspond to the risk of developing dementia symptoms. People who did not produce the symptoms had twice the amount of caffeine in their system as those who did. Confusing, isn’t it?

The answer might be caffeine’s relation to adenosine. One of the reactions of adenosine receptor interactions is the increase in inflammation; caffeine may block this inflammation by preventing the adenosine from reaching the receptor. This would account for the protective factor.

On the opposite side of that, many people with dementia symptoms have difficulty sleeping. Because caffeine’s stimulating ability, it could cause further difficulty sleeping. This may account for the caffeine being a detriment to those already with dementia issues.

Caffeine and Brain Fog

can caffeine withdrawal cause brain fog

One of the greatest feelings in the morning can be the caffeine driving away brain fog. Once the caffeine begins working in your system, your body is stimulated through the central nervous system interaction, and it blocks the adenosine receptors which cause you to feel fatigued. Thus, you feel more awake.

But, like everything else, it can wear off, and the lack of caffeine can cause brain fog. Also, caffeine withdrawal causes brain fog. Generally, the withdrawal symptoms come from the long-term use of caffeine, but you may feel it after your first cup of coffee. If your consumption of caffeine is moderate, and you take regular breaks to allow your body to detoxify, you should not suffer through withdrawal.

The periodic breaks from the caffeine will also improve your sleep, which will also reduce the brain fog in the morning. If you are experiencing brain fog, other factors in your life need to be examined. Brain fog can be a symptom of further diseases and a poor diet. Several medications have a depressing effect on the brain that causes brain fog.

Caffeine and Fibroids

Fortunately, caffeine has no direct effect on the formation of fibroids. Yet, it can affect many of the systems that keep your body in check, and thus can contribute to the causes of the fibroids.

Much of the caffeine detoxify in the liver and having a consistent and high amount of this caffeine within your system interferes with hormonal control. Having excessive amounts of certain hormones in your system may contribute to the formation of uterine fibroids.

The caffeine will depress the liver’s ability to process medications, making them last longer in your body. This can cause your medicine to work too well or create unintended interactions.

Occasionally, a small amount of caffeine has not shown to increase the risk of fibroids, however consistent and high amounts of caffeine have.

Caffeine and Migraines

can caffeine cause headaches

For people who drink coffee on a consistent basis, they have a double edge appreciation of caffeine migraines. Like many other stimulants, too much caffeine can give you a headache. And if you are addicted to the caffeine, withdrawal can also give you a headache.

On the opposite side of that, because of caffeine’s ability to act as a stimulant and increase blood pressure, it can help with the flow of blood and oxygen to the brain, which can relieve headaches and migraines. It also can dilate blood vessels and capillaries, which one cause of headaches and migraines. Caffeine has the ability to both cause and cures headaches and migraines of different types.

Many people have experienced relief from headaches and migraines by sipping on coffee. Although coffee can cause headaches in some people, those who suffer migraines find relief with an occasional cup. Fortunately, for people who do not enjoy the taste of coffee, often the scent alone will help reduce the symptoms.

Caffeine and MS

ms and caffeine

In 2015, a fantastic presentation was held at the American Academy of Neurology annual meeting. In it, the research showed that moderate caffeine consumption might have a slight side benefit of lowering the risk of developing multiple sclerosis (MS).

The same neuroprotective properties that caffeine confers to Parkinson's and Alzheimer's disease indicates that caffeine may also protect against MS.

It is not significant protection, however. In one single study, they found that moderate coffee drinkers had approximately a one and a half times smaller risk of developing MS versus people who do not drink any coffee. It's enough to indicate that further research is needed, not that it is conclusive that coffee will protect against this disease.

Caffeine and Blood Pressure

caffeine and blood pressure

One of the side effects of caffeine is increased blood pressure. The stimulating effects of the caffeine cause the blood vessels to contract. Because of the decreased amount of room within your blood vessels, your blood pressure rises. I can also increase your heart rate and the pressure at which your heart beats, both of which will increase your blood pressure.

The effect of caffeine on your blood pressure happens within 20 minutes. Generally, within 4 hours, the caffeine in your system will have cleared out enough that your blood pressure decreases. However, people who drink caffeine drinks on a regular basis may not see a decrease in their blood pressure at all. Over time, the increased blood pressure can lead to heart disease.

Because of the rise in blood pressure, people who consume energy drinks, especially in excessive amounts, risk severe heart problems, which has contributed to the number of deaths due to energy drinks.

Caffeine and Liver Protection

caffeine sensitivity liver

The ability of caffeine, and especially coffee, to protect the liver is a bit mixed. Multiple studies have shown that caffeine is detoxified in the liver and continuous exposure to this drug can cause liver damage. However, there have also been numerous studies that have shown that moderate coffee intake leads to a significant reduction in hepatocellular carcinoma, a type of liver cancer.

The healthier person is, the more protection caffeine may confer. Also, people who have adequate intakes of the majority of the B vitamins, potassium, and manganese also show that caffeine is more protective.

People who are overweight and already have existing liver issues do not show the same protection. Many of the studies used plain, black coffee. The addition of sugars, dairy, and/or creamers significantly changes the results to the negative.

Caffeine and Diabetes

caffeine and diabetes

Caffeine and diabetes have a curious relationship. First, most people obtain their caffeine through coffee. Unfortunately, many people add sugar to their coffee, which adds nothing and can raise blood sugar levels significantly. For people with diabetes, it is recommended that they skip coffee if they can’t drink it without sugar.

For people with diabetes who can drink plain, black coffee, there have been studies that show that caffeine can help reduce blood sugar. One of the investigations by the Harvard School of Public Health shows people have an 11% lower risk of type 2 diabetes when they drink one cup of coffee each day over a four-year period.

The same study found that people who decrease their coffee consumption over the investigation, from 3-4 cups per day to one, increase the risk of type 2 diabetes by 17%.

Other studies have shown that it may be the coffee itself, not the caffeine that has the beneficial properties. Both caffeinated and decaffeinated coffee demonstrate the ability to lower the risk of type 2 diabetes. It may be the polyphenols that act as antioxidants that come from the coffee. This helps the body to decrease insulin resistance.

There is one small study, of just 33 people, showed that 100 milligrams of caffeine supplements have an adverse effect on blood sugar control in healthy men. We don’t think it should put you off coffee, but we lean towards recommending against caffeine supplements for this reason.

Because of the mixed reviews, we recommend that you take your coffee black, and keep it to moderate consumption. Don’t rely on it too help control your diabetes; that should be done with proper diet.

Caffeine and Sleep

caffeine makes me sleepy

Caffeine keeps us awake. It is not meant to help people sleep well, however using it may help you sleep better.

When the caffeine rush wears off, your body experiences the fatigue it had prior. You no longer have the artificial stimulation. When combined with extra activity, it can cause you to feel more tired than you were previously. In some cases, this can help you sleep, especially if you’re on a cycle that allows you to be awake early and rest later on.

However, if you drink coffee too late, you could experience the opposite effect. The caffeine could keep you up longer and impair proper sleep throughout the night. It takes time for our body to clear out the caffeine from our system, primarily when it has built up multiple times during the day. Drinking coffee within 6 to 8 hours or less before rest does not allow the body enough time to clear the caffeine from your system.

The detoxication ability of the liver is impaired by caffeine, which could alter the hormones necessary for proper sleep, like melatonin *. This will not allow you proper restful sleep.

Caffeine and Ulcers

caffeine stomach ulcer

Some studies show that caffeine can help reduce ulcer formation and others that show that it increases it. The most significant caveat of dealing with caffeine and ulcers is that most of the research has been done using soda and coffee as the primary sources of caffeine. Both of these are highly acidic drinks that are well known to irritate current ulcers and could adjust the natural production of stomach acids.

However, studies have not found caffeine itself will cause stomach ulcers. Generally, it is recommended that you avoid the coffee and caffeinated beverages when you have stomach problems. It's not it may not be the caffeine that irritates your stomach, but the drink might.

Caffeine and Kidney Stones

caffeine kidney stones

It’s generally accepted that people with who are prone to kidney stones should avoid caffeinated beverages. However, in the American Journal of Clinical Nutrition of December 2014, an analysis of three larger studies show that the people who consume the most caffeine, or caffeinated beverages, are 25% less likely to develop kidney stones.

This may be due to the high amounts of coffee these people were drinking. It’s suspected that some of the antioxidant and anti-inflammatory properties of the coffee play a role in the lack of formation of kidney stones. It’s also believed that these people consume a diet lower in calcium to magnesium, which reduces the risk of kidney stones.

Remember, a diet lower in calcium and magnesium * leads to other health problems. We do not recommend limiting your intake in these essential nutrients.

Caffeine and Inflammation

caffeine and inflammation

The triggering of the adenosine receptors in the body are the precursors to inflammation. When caffeine blocks these receptors, the body does not receive the signal to produce the inflammation. It’s one of the reasons why some of the studies have focused in on caffeine and its anti-inflammatory properties.

Additionally, coffee has anti-inflammatory properties due to its high antioxidant content when compared to other caffeine drinks, like soda. In another study, inflammation was shown to increase as coffee consumption increased, especially about cardiovascular health.

The study focused in on the human peripheral blood mononuclear cells and the relation to immune deficiency syndromes. The researchers were able to correlate that caffeine may be reducing these conditions, warranting that more research is needed in this area before conclusions could be drawn.

Since there is inconclusive science had to prove or disprove whether caffeine will help with inflammation, we do not recommend starting to drink coffee for the sole purpose of reducing inflammation. However, if you are already drinking coffee, let us know if you experience any inflammation assistance through the coffee.

Caffeine and Allergy

caffeine allergy

Generally, caffeine has no relation to allergy symptoms. People may experience worse symptoms of the allergies due to the increased cardiac function and the constriction of the blood vessels. However, any experience should be minimal.

There is a specific caffeine allergy and people with this allergy are recommend to avoid any food or drink that contains caffeine.

Caffeine and Asthma

However, the opposite occurs when it comes to asthma. Because caffeine is similar to drug theophylline, a prescription medication used to improve breathing in asthma patients, it may help to open constricted airways in people suffering from asthma attacks.

It must be noted that caffeine in food and beverages is not consistent and cannot be relied on during an asthma attack. Also, because of the stimulating effect on the central nervous system and the heart, it could accelerate an asthma attack, lessening the time to get proper help.

Caffeine and Detoxification

caffeine cleanse

Coffee should not be used during a detox. The properties of the caffeine can accelerate the heart and promote sensitivity to various toxins released into the body. Additionally, because of the restricted food intake, your blood sugars could be variable, and the stimulation could trigger severe blood sugar drop.

Caffeine is also processed in the liver, resulting in various hormones being altered. It could cause sluggishness in the liver, which defeats the purpose of the detoxification.

Caffeine and Weight Loss

caffeine and weight loss

Many people find that if they start drinking coffee at the beginning of a weight loss program, in the short-term, it aids their weight loss. It is an excellent stimulant and increases the metabolism for a few hours.

However, if you are drinking coffee on a daily basis, you will experience no change in your metabolism or weight loss. Your body will be used to the stimulation, and it is not enough of a difference to be significant for the body.

The weight loss that caffeine will help with is during exercise. Some studies show that when a person exercises and takes caffeine within the hour before a workout, the weight loss potential increases. People also feel more energy and more stamina when taking caffeine. In the area of sports nutrition, caffeine is a popular supplement used before endurance events.

If you are not drinking coffee before weight loss or exercise, a small cup of coffee or caffeine supplement will aid in weight loss. But if you are a regular coffee drinker, you’re not going to see much of a change.

Caffeine and Pain Reduction

caffeine and pain

Caffeine is a pretty good painkiller. It stimulates the body to exerting peripheral action, or relief at the site of an injury. It acts directly on the muscle tissue and aids repairing the tissue damage, reducing inflammation. Since caffeine works on the central nervous system, it can also help the body process pain signals differently and increases the effectiveness of pain-killing hormones.

It is incredibly effective at reducing headache and migraine. The reason why it's added too many painkillers, especially those used for migraines.

In specific studies, as little as 200 milligrams of caffeine has been found to reduce pain in the muscles.

A study in 2001 was conducted on people who experienced tension headaches. They compared the actions of caffeine versus Ibuprofen. In the study, two-thirds of the participants experience complete relief of their head headaches using 200 mg of caffeine alone. The participants also found the caffeine worked faster, ending the headache a half hour before the Ibuprofen took effect. Curiously, the same study showed that a combination of caffeine and Ibuprofen stop the headaches in ¾ the participants, lasted longer than either caffeine or Ibuprofen alone, and took effect within a half hour.

Caffeine and Regrowing Hair

caffeine and hair loss

Surprisingly, there have been studies to show that caffeine helps aid regrowth of hair in people who are experiencing hair loss. Unfortunately, the scientist found that it would take nearly 60 cups of coffee per day to achieve the same amount of hair growth they found in their studies. It takes almost 6,000 mg of caffeine to stimulates follicle regrowth. That is more than enough to stop your heart.

Fortunately, there are some shampoos on the market that deliver caffeine directly to your scalp. These are formulated to stop the direct absorption of caffeine into your bloodstream, which could provide a dangerous overdose of caffeine to your system.

Yes, caffeine will help regrow hair, but it is not yet to the point that it is safe to take that much internally.

Caffeine’s Effect on Erectile Dysfunction

caffeine erectile dysfunction

There are mixed reviews of whether caffeine can help with the blood flow to sustain an erection. Caffeine increases blood pressure, which can either help or harm the blood flow to the penis.

The difficulty in studying this phenomenon is that the vast majority of adults with erectile dysfunction already drink coffee. They already obtain caffeine in large amounts and still experiencing the problem. It is thought that the caffeine will help stimulate the nerves and blood vessels to sustain an erection, and the coffee will provide antioxidants that are known to help strengthen blood vessels.

While more study needs to be done, one study in 2015 showed that two to three cups of coffee daily might reduce the risk of erectile dysfunction.

Caffeine and Brain Damage

caffeine brain damage

No, caffeine is not going to kill your brain cells unless you drink an awful lot of it. However, as we said earlier, caffeine does change your brain. The stimulating effects of the caffeine on the adenosine receptors helps you to be more alert and helps avoid fatigue.

In the long-term, caffeine can permanently alter your brain. Aside from the addiction factor, people who are exposed to caffeine on a regular basis, produce more adenosine receptors. When withdrawal from caffeine does happen, it increases fatigue and overall tiredness.

In excessive amounts, for more than what is healthy in a day, the caffeine can cause brain damage. Like any other drug, overdosing is harmful to your health.

Caffeine and Cancer

caffeine and cancer

Caffeine, coffee, in particular, seems not to affect cancer. In people with healthier diets, coffee may help decrease the risk of cancer.

Except for lung cancer. There are some studies on the show drinking coffee may reduce lung cancer, while other studies show a small risk of increasing lung cancer with coffee consumption.

The antioxidants in high-quality coffee might aid in reducing the risk of cancer. Especially in tea, the antioxidants provide strong protective factors that have been shown in studies individually to help prevent cancer.

It is the additives in the coffee that increases many of the risk factors. Artificial chemicals used for flavorings, such as creamers, substantially increase the risk of cancer. The high amounts of sugar also increase the cancer risk, along with diabetes.

For people who are experiencing cancer currently, you should talk to your doctor as to whether coffee and caffeine will interfere with any treatment you are going through. Specific chemotherapy treatments require a restriction of caffeine.

Side Effects of Caffeine

Relatively speaking, caffeine safety is one of the highest of all the drugs. It takes a significant amount of caffeine to cause serious side effects.

But the side effects of too much caffeine are quite distinct. The most common ones are increased heart rate, high blood pressure, jitteriness, racing thoughts, and liver damage.

too much caffeine side effects

When people consume too much caffeine, especially with the emergence of energy drinks, people can experience heart rates that far exceed normal tolerance, blood pressure spikes that cause an aneurysm, and death. The CDC reports over 100 deaths from energy drinks, attributed to overdose in caffeine.

Over time, too much caffeine is bad for you and your brain. It is an addictive substance, and the withdrawal symptoms are pretty severe. Taken repeatedly, caffeine can alter your hormone cycle, making menopause worse, and inducing higher estrogen levels in men.

Most of the time people get the side effects of drinking too much coffee. However, energy drinks are becoming quite a problem, too.

In the short-term, caffeine is a laxative. It can help increase peristalsis and help evacuate the intestine of any food. It’s most potent effects are experienced when a person has not eaten for a day or two. It is the reason why most detoxification programs ban coffee.

Caffeine is also a diuretic. It is one of the most commonly used diuretics, and attributed, at least partially, to the surge in people who experience chronic dehydration. The liquid in the coffee or energy drink is not enough to offset the diuretic effect. Therefore, drinking coffee or energy drinks, and especially soda, have an adverse impact on your hydration level.

Fortunately, other than experiencing withdrawal, you should experience no side effects from caffeine. Generally, the side effects of withdrawal are a headache, fatigue, and nervousness. There have been no reported deaths by caffeine withdrawal.

Daily Dose of Caffeine

The recommended caffeine dosage for a healthy adult is 400 mg per day. The amount of caffeine for a young adult or teenager is half this amount or 200 mg per day. It is not recommended for children consume caffeine in any amount, including from soda.

how much caffeine is safe

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For people who are sensitive to caffeine, or obtain their caffeine from processed drinks and food, there is no safe amount of caffeine. The caffeine high that people receive from these drinks is far too concentrated, and the body is not able to process them quickly.

In many people, the lethal dose of caffeine has been listed as 1000mg. However, young adults have been identified as having 400 mg or less in their system at the time of death. So the maximum caffeine dose is not listed as how much caffeine can be consumed in one day, but how much caffeine should be consumed over a period of time.

Most health officials recommend how much caffeine is safe over 1 hour period at less than 50 mg. In this manner, adults could drink many cups of coffee or soda throughout the day without experiencing adverse side effects. The safety factor comes as a result that 100% of the caffeine you consume is in your bloodstream within 45 minutes. Nearly half was absorbed in the first 20 minutes.

The liver will generally detoxify the caffeine from your system in 4 to 6 hours, which is the half-life of caffeine. For people who drink tea or coffee, one cup per hour is handled by the body safely and the maximum amount of daily caffeine is reached slowly.

Now, if you look at the caffeine levels and energy drinks, and know that nearly all of the caffeine is absorbed within 45 minutes, you'll see that you can reach your maximum daily dose in 1 hour. It will take all day to detoxify that amount of caffeine.

And in younger people, it takes longer for the caffeine to be detoxified. This is why lethal doses of caffeine can build up over several days in young people. It is why we don’t recommend energy drinks or processed energy products for youth.

Good and Bad Sources of Caffeine

If you’re interested in getting some of the positive effects of caffeine, we do have particular sources to recommend. Coffee and tea are the safest and healthiest sources of caffeine. They are the most accessible and most reliable. Both coffee and tea provide numerous antioxidants that are known to increase health, reduce the risk of cancer, and benefit the heart.

Following that, we recommend chocolate. There’s not a lot of caffeine in chocolate, but it is an incredibly delicious way to get caffeine. The darker the chocolate, the more caffeine, so make sure you get high-quality dark chocolate for your caffeine rush. You'll also get a boost of resveratrol.

dark chocolate for brain health infographic

Otherwise, we recommend you avoid other sources. Soda and energy drinks are two of the worst sources of caffeine, but some of the most common. Soda consumption beats out coffee consumption worldwide. There is no nutritional value to either soda or energy drinks. Both of these drain your body of healthy nutrients and contribute to weight gain. Excess of soda consumption, and especially energy drink consumption, has been linked to multiple health problems, including death.

Many supplements have caffeine or its substitute guarana. You have to be careful with supplements. In the short-term, using a caffeine supplement will help give you a boost of energy and athletic performance. It will clear your head and help you concentrate.

It is not recommended you take the supplements repeatedly or long-term. You also need to be very sure you know the source of your supplements and is a high-quality manufacturer. There have been reports of certain supplements containing either far too much or far too little caffeine compared to the label requirements.

Amount of Caffeine in Drinks and Food

There are a surprising amount of food items that contain caffeine. We really haven’t talked about them that much so far because many of them are low levels of caffeine. Natural foods, like fruits and vegetables, usually contain zero caffeine.

But, if you consume them with things like soda and coffee, you can get much more than the recommended dose of caffeine in a day. In a teenager, one energy bar and an energy drink exceed the maximum amount of caffeine for one day.

The caffeine content of many foods is minimal. Generally 5 to 30 mg of caffeine. Other things that contain caffeine can be much higher. Some protein and energy bars can provide as much as 100 mg of caffeine. This is half of your daily recommended dosage.

Combine that with the caffeine per cup of coffee, which is 95 mg; you can see that with just one cup of coffee and one energy bar, you can be your limit.

Not all coffees are the same, however. Decaffeinated coffee contains just a few milligrams of caffeine. Removing it all is impossible. Be sure to go with methods of decaffeination that avoid the use of benzene, toluene, and methylene chloride. All of these are potent carcinogens.

You can compare that minuscule amount of caffeine to the BioHazard brand of coffee, which comes in at 928 milligrams of caffeine. It's the most caffeinated coffee in the world, as of this writing. (Although rumor has it a coffee shop in NYC has one that boasts over 1000mg of caffeine in 1 cup, we just can’t verify this rumor).

The caffeine in a cup of tea can vary widely. Generally, black tea has the highest amount of caffeine at 60 to 90 mg per cup. Green tea has just 35 to 40 mg of caffeine. Oolong and chai teas have various other amounts, between the green and black tea ranges.

The level of caffeine will depend on the amount of oxidation (fermentation in some places) the tea leaves have gone through. The process takes green tea leaves to black tea leaves, liberating caffeine. Oolong tea is partially oxidized and generally has 40 to 50mg of caffeine. White tea, a very young tea, has 10 to 30mg of caffeine.

The caffeine in green tea might not affect many people, because there are specific proteins in phytonutrients that neutralize the caffeine and prevent it from acting in your system.

However, if you are worried about the caffeine content in tea, we recommend drinking herbal teas which have zero caffeine.

Soda has a significant amount of caffeine. Many of the different varieties of soda does have anywhere from 35 to 60 mg of caffeine in 8 oz. However, caffeine-free sodas have zero.

Surprisingly, the sodas that have the most caffeine tend to be diet sodas. They make up the sugar content with caffeine. Most diet sodas have between 60 and 100 mg of caffeine. On the other end of the spectrum, Sprite is caffeine free.

Soda, Pop, or Cola, the caffeine content of these drinks is within the recommended limit if you stick to 8 oz per day. This is the recommended amount, even by the manufacturer. You will not get a rush of caffeine with this amount.

However, because of the high acid content, so does tend to be very dehydrating and contribute nothing nutritionally to your system. They can significantly dehydrate you if you drink more than the recommended amount. Also, cans of soda tend to be 12 oz or a serving and a half. Yes, they expect you to share or waste that amount if you follow the serving size. However, very few people do.

If you look at energy drinks, you’ll find that the caffeine content isn’t much different than soda. The caffeine in the Monster Energy Drink is only 86 mg per serving. Red Bull has 111 mg per serving. This is just a little bit more than a soda, equivalent to a coffee. Do you remember I was telling you that there have been deaths attributed to energy drinks? What makes these drinks so different?

In coffee and tea, the caffeine is bound up with other phytonutrients which help mitigate the effects of the caffeine. Plus, coffee and tea are often consumed over a lengthier period, allowing the body to be able to assimilate the caffeine and process it more manageable.

Energy drinks use a distilled and concentrated powder of caffeine which moves into a person’s system much faster. There are no mitigating factors of vital nutrients and other co-factors. Also, many types of energy drinks are sold in much larger quantities than a cup of coffee. When we combine this with the tendency for younger people to consume an energy drink within a 15-minute time span, it leads to a severe spike of caffeine.

Since many energy drinks market to young teenagers and young adults, their systems are not fully developed enough to handle this caffeine. In a brief amount of time, these young kids can consume enough caffeine to push them into a fatal overdose level without realizing the danger.

Caffeine Alternatives

Many drugs and stimulants replicate the effects of caffeine. Most of them are illegal.

An herbal supplement often used because it gives us stimulation similar to caffeine is guarana. This herb has about 50mg of caffeine per gram. Supplements often use a concentrated extract and listed on the label as guarana. It is used in many supplements so the manufacturer can claim the supplement is without caffeine.

Fortunately, although caffeine is found in many teas, it is in a smaller quantity, and the antioxidants within tea generally offset the effects of caffeine. In green tea, there is a protein, L- theanine * that binds to the caffeine and slows the absorption and effect of it. Even for people who are sensitive to caffeine, they generally can drink green tea without experiencing any caffeine effects.

Vitamins, like B1 and niacin, help provide the body energy. Ginseng * and cayenne stimulate the body, giving alertness and energy. They can be used in place of caffeine.

As you are looking to replace caffeine and your diet, you can also turn to herbal teas. Many of them give abundant vitamins, minerals, and phytonutrients that provide a natural stimulation without caffeine side effect.

How to Quit Caffeine

Many call quitting caffeine one of the most challenging things they’ve had to do. People who have stopped smoking and quit caffeine health and say that quitting smoking is a lot easier.

Most sources give two ways to quit caffeine, cold turkey and long-term.

If you quit cold turkey, you will need to cut out all sources of caffeine from your life. This includes coffee, energy drinks, chocolate, teas, and any foods that may have caffeine added. It is also recommended you remain away from any sources of guarana.

Most people who quit cold turkey experience withdrawal symptoms including a headache, nausea, shakiness, and fatigue. Depending on the level of addiction, these effects can last a few days to a few weeks. It's successful, people can resume normal activities and standard biological functions reasonably quickly and can keep up the avoidance of caffeine fairly easy.

For people who are quitting using a gradual method, it is recommended that you begin substituting some of the drinks and foods that contain caffeine in lesser quantities. For example, if you were drinking 4 to 5 cups of coffee per day, replacing one of those cups of coffee with tea is recommended. As your body becomes used to this reduce amount, more and more cups of coffee are replaced with tea.

Other people reduce the quantity they drink at any one of time. Instead of a full cup of coffee, they get a ¾ cup of coffee. Ordering at one of the fashionable coffee Baristas can mean switching from a large cup to a medium cup. Many people have great success by stepping down. They’re able to avoid many of the side effects of caffeine withdrawal. However, some of the people who use the step-down method tend to drag it out much longer and can revert or stop reducing altogether. If you're looking to quit caffeine, you have to be dedicated.


Caffeine * in smaller, appropriate amounts occasionally will give you a boost to your mental and physical routine. There are a few side effects, and people react well to the energy boost.

Drinking coffee on a regular basis may have some health benefits, but many of them are poorly understood. Excess amounts of caffeine are discouraged.

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Christina Major

Christina Major is a holistic nutritionist, traditional naturopath, and herbalist. She has a Master’s degree in Holistic Nutrition and an advanced degree in Traditional Naturopathy. Further certifications in herbalism and metabolic typing. She owns and operates Crystal Holistic Health Consulting based in PA, the USA since 2010.