Caffeine Effects on the Brain

effects of caffeine

Caffeine is the most widely used drug on the market and consumed in a thousand different ways for generally the same reason. Caffeine can be enjoyed in your morning coffee, afternoon tea or nootropic stack. It does much more than arouse the body and awaken untapped energies, it is also an important cognitive enhancer.

Despite caffeine’s long history of fueling late night studies and professional pursuits, it is not, in fact, a nootropic. This is because the original definition of “nootropic” as opposed to other cognitive enhancers, as set forth by Dr. Giurgea, clearly include the “absence of negative rebound effects.”1 Further in the reading, we will delve into some important health cautions that must be observed when ingesting caffeine.

Nevertheless, caffeine does indeed boost cognitive function considerably and plays an important role in many nootropic stacks because of it. Caffeine is also a tonic to the central nervous system, an effective neuroprotective, and all around benefit to health that some experts say can help you live longer.

Sources of Caffeine

Caffeine is a naturally occurring compound that exist in just over 60 specific plants, primarily in the leaves and fruits. Some of the most well-known sources of caffeine include the kola nut, chocolate, cocoa, Camila Sinenesis (tea), guarana berries and of course the mighty coffee bean.2 It is hardly surprising that coffee is the single most popular drink in the world, and only surpassed by life giving water. It is estimated that over 2.25 billion cups of coffee are consumed each day internationally.3

Caffeine is also the hub of a multi-billion dollar industry that extracts this important drug from their natural sources to be applied in a wide range of products. Anhydrous caffeine can be dissolved in water easily. It can be consumed in capsule form or introduced into other foods and preparations.

Energy drinks, sodas, and many alcoholic beverages on the market contain caffeine. Medication for migraine headaches and hangovers also contain caffeine and nootropic stacks include caffeine for its cognitive enhancing benefits.

Effects on the Brain and Body

Caffeine is the most widely-distributed addictive substance on the market largely due to its stimulating effects on the central nervous system (CNS). Caffeine is produced by plants as a secondary metabolite for allelopathic or chemical defense against predatory animals or encroaching plants.4 But these repellent chemicals have an enticing and even addictive effect on humans.


In the brain, caffeine works to boost alertness by stimulating the brain and neurons of the body by antagonizing adenosine receptors. Adenosine is a neuromodulator created in the brain and is important for regulating a quality sleep cycle.

When adenosine binds to its adenosine receptors the individual begins to feel drowsy and maintaining concentration and focus is difficult (until you have your morning dose of caffeine that is).

When caffeine is introduced to the body and brain, it heads over to the adenosine receptors, which can’t distinguish between caffeine and the neuromodulator they typically respond to. This causes caffeine to bind rapidly to these receptors and effectively block adenosine from reaching their receptors.

Instead of reducing cellular activity, dilating the blood vessels, and preparing the body for sleep, the orders of action are suddenly changed. Neurons begin firing more rapidly, the blood vessels of the brain are constricted, and drowsiness is quickly banished.5


Caffeine also affects the function of the pituitary gland that begins releasing the energy-modulating hormone, adrenaline, in preparation for action. Adrenaline causes the pupils to dilate, muscles to tighten, and the airways of the lungs and throat to open for greater oxygen intake. All of these reactions are a part of the “fight or flight” response.6

But adenosine and adrenaline are not the only chemical processes affected by caffeine. Dopamine receptors encourage the release of the neurotransmitter dopamine when it is blocked by caffeine.

Dopamine is one of the more potent “feel-good” brain chemicals and activates the pleasure centers of the brain. It also improves focus and concentration. The release of this important neurotransmitter is part of what provides the feelings of satisfaction when enjoying your favorite caffeinated beverage.7

Benefits of Caffeine

Caffeine will produce just about the same effect no matter the forms in which it is ingested. As you will see, many of the reports made on the effects of caffeine on human health center around consumption of a hot cup of freshly-brewed coffee. This does not alter how a similar intake of caffeine in a cup of tea, chocolate bar or capsule form will affect the health for the better or worse, because nothing is good in excess!


Among the many benefits of caffeine, the capacity to bolster mental stamina and heighten alertness is by far the most renown. It is not uncommon for passionate coffee drinkers to express how a single cup of coffee can completely change the course of the day. This is especially true when enjoyed in a moment of mental fatigue.

Caffeine releases the neurotransmitters responsible for making one feel alert and alive to ensure optimal function, physically and mentally. Clinical evidence has shown the cognitive enhancement provided by caffeine has neuroprotective qualities. In addition to increasing the capacity to learn and apply knowledge, caffeine can prevent the Alzheimer’s disease.8


More clinical studies are being conducted on the role of caffeine in the treatment of Parkinson’s disease. This study is ongoing and more research is needed to confirm the symptomatic effects of caffeine on this condition. Nonetheless, recent research has suggested that non-coffee drinkers were five times more likely to develop Parkinson’s than those that drank 7 cups of coffee a day.9

While article recognizes the effects of caffeine in teas, chocolates or sodas, it also states that the effects from coffee are much stronger.10

Prevents Heart Disease

Studies show there is a link between the regular consumption of coffee and a reduced threat of coronary artery calcium and heart troubles. This study observed the effects of regular coffee consumption in men and women of good health.

Results show that regular coffee kept the blood vessels of the heart from narrowing and stiffening with a condition called atherosclerosis. This can prevent a specific variety of heart attacks.11

Can Lower the Risk of Potential Fatalities

Another study established an important connection between regular coffee consumption and the reduced potential for a variety of fatal conditions including kidney disease, diabetes and respiratory conditions.12 The exact causes of this are still unclear, nevertheless, many other studies support this connection.

Caffeine in coffee has been found to reduce insulin sensitivity.13 This evidence offers potential significance to preventing the onset of type-2 diabetes through the increased release of epinephrine.14 Epinephrine is released when blood glucose is too low.

Of course, anyone with diabetes or any conditions will want to consult their medical practitioner before attempting such a treatment. Also, a sugary mocha-latte frappuccino with whipped-cream and sprinkles is not exactly a healthy addition to any diet plan.

How Much Caffeine is Safe?

In 2017, a South Carolina teenager died from an overdose of caffeine. While dramatic incidents like this are extremely rare and no-doubt partially due to other extenuating conditions, it does beg an important question. How much caffeine did a 16-year-old ingest before succumbing to a caffeine-induced arrhythmia?

According to reports, the deadly mixture included an energy drink, a cappuccino, and a large caffeine-infused soda all consumed within the span of two-hours. This equated to over 500 mg of caffeine in various forms.15

According to the FDA, caffeine is on the list of substances “Generally Regarded As Safe” (GRAS). 400 mg of caffeine a day generally does not have toxic effects, but each person metabolizes and responds to caffeine differently.16 So, it is understandable that a youngster ingesting well above this limit in such a short amount of time could easily suffer a fatal cardiac condition.

Many factors play into an individual’s reaction to caffeine in various amounts. For example, the effects of caffeine are greatly reduced over time and it is not uncommon for a seasoned coffee enthusiast to drink anywhere from 10 to 20 cups of coffee in a single day, but this is not generally recommended.

Personal tolerance is an important consideration when using caffeine as a regular boost to cognitive function. Specific genes have been identified that can affect sensitivity to the effects of caffeine.17

Tolerance can be a problem for those taking caffeine as a part of a carefully planned nootropic stack. Cycling these products with other stimulant substances, like L-theanine, can help to maintain natural tolerance.

Mode of preparation is another important point for regular caffeine junkies. The best health benefits come from drinking fresh-brewed black coffee. Once other ingredients like creamer, sugar, and sprinkles are added to the equation, the health value dwindles. Consider swapping out processed creamers and sugars with almond milk if the robusticity of black coffee is not your cup of tea, so to speak.

Side-Effects and Risks

Caffeine would not be such a popular beverage among adults and children alike, if it were characterized by a series of serious health issues. Nevertheless, the dopaminergic action of caffeine is quite similar to that found in cocaine and heroin, albeit at a much reduced rate.

This means that caffeine can be highly addictive. Because it is easy to build a tolerance to the effects of caffeine, it is not uncommon for doses to be increased dramatically, sometimes to an unhealthy level. Some of the most common side effects of unhealthy or prolonged caffeine consumption are listed below.

 Effects of CaffeineDisrupted Sleep Cycles

Disrupting sleep cycles is what caffeine is all about. Adenosine is a big part of the body’s selection of sleepy-time chemicals that kick in when the day ends and the body feels exhausted.

Coffee is what helps the operator override this command and wring a few final drops of productivity from a fatigued mind and body.  As such, it should not be used excessively or for too long.

Caffeine can stay in the body providing its mind boosting benefits for as long as 6 hours. Someone with a low tolerance to the effects of caffeine, will probably not get much sleep until all the caffeine has been dispelled. This means an after-dinner cup of coffee, which is fine and common for many people, could keep others from going to sleep until the early hours of the morning.

The day after a troubled night’s sleep the body is not actually rested and a few more cups of coffee may be required to finish tasks, but can further disrupt the sleep cycle. A disrupted sleeping cycle can make it even more difficult for insomniacs to get proper rest.


Anyone suffering from high-blood pressure will want limit their coffee intake so as not exacerbate their condition. Caffeine has been studied to raise blood pressure for as long as three hours after consumption.

This is a consequence to the stimulating effects this substance has on the body. Hyperextension has been linked to the increased risk of strokes, kidney, and heart damage as well as heart attacks.18

Headacheseffects of caffeine

While caffeine is an important ingredient in a wide range of headache medicines, it can also be a cause of other types of headaches. These headaches come from having withdrawals after not drinking regular amounts of coffee, tea, or other forms of caffeine. If caffeine intake is leading to headaches, it is best to slowly reduce your intake or consult a qualified doctor.19

Increased Anxiety

Because coffee kicks the pituitary gland into action and initiates the “fight or flight” response, it can seriously aggravate stressful or anxious conditions. Caffeine makes the heart race and muscles tighten for action, which can contribute to the feeling of being “on edge.” Feeling jittery and nervous is a symptom of too much caffeine in the system.20

Review of Caffeine

The most important takeaway from this discussion on the various benefits and precautions surrounding caffeine is this: moderation. Caffeine in a wide variety of enjoyable servings is a potent potion of cognizance and stamina and should be used responsibly. If any of the side effects become noticeable or problematic, begin to reduce caffeine intake before it progresses into full blown conditions.

PhotoCredits: Multihobbit/, FlamingoImages/, Workdom/, TeroVesalainen/, LisaS./, goodluz/, portumen/

Taylor J.

By Taylor James

Taylor is an aromatherapy enthusiast who’s favorite use of essential oils is through a portable diffuser created by MONQ. In her spare time, you can find her enjoying nature whether it be on a lake or in a forest.

Favorite MONQ blend: Forest

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The above information relates to studies of specific individual essential oil ingredients, some of which are used in the essential oil blends for various MONQ diffusers. Please note, however, that while individual ingredients may have been shown to exhibit certain independent effects when used alone, the specific blends of ingredients contained in MONQ diffusers have not been tested. No specific claims are being made that use of any MONQ diffusers will lead to any of the effects discussed above.  Additionally, please note that MONQ diffusers have not been reviewed or approved by the U.S. Food and Drug Administration. MONQ diffusers are not intended to be used in the diagnosis, cure, mitigation, prevention, or treatment of any disease or medical condition. If you have a health condition or concern, please consult a physician or your alternative health care provider prior to using MONQ diffusers. MONQ blends should not be inhaled into the lungs.

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