Do we think coffee benefits we get when drinking it is something good for our brain or bad or neutral? What does the actual caffeine do and what are the risks?
Milos Pokimica
Written By: Milos Pokimica
Medically Reviewed by: Dr. Xiùying Wáng, M.D.
Updated May 29, 2023Do we think caffeine is something good for our brain or bad or neutral? There is much talk about coffee benefits but coffee benefits are also just one side of the coin. Coffee is also associated with some health risks that people usually just ignore. The real question is do we think that coffee benefits outweigh the associated risks?
So far research has no evidence to associate a link between coffee and an increased risk of heart disease or cancer. Some of the studies found decreased overall mortality by the same small amount, and some others found that it does the opposite. If we take an average conclusion from them, it will be approximately very small or no significant effect on longevity.
So are there any risks associated with the coffee benefits we so much desire?
Coffee seems to increase cognitive function and reduce the risk of depression. The potential coffee benefits also include protection against neurodegenerative diseases, improved asthma control, and lower risk of select gastrointestinal diseases. So did we find our amphetamine-like drug free of charge?
Coffee does have a high concentration of antioxidants providing cells protection from oxidative stress and inflammation. It is the bean after all. However, we can get other nontoxic beans to get all of the benefits that coffee bean has, and we should not confuse the coffee benefits as unique. Most antioxidant-rich foods will have the same effect.
When people talk about coffee benefits, they tell half-truths when insinuating that it is the benefit of that bean only and that we would not have similar benefits if we eat another type of bean. For example, cocoa beans have caffeine too but much more beneficial polyphenol antioxidants and much more health benefits so talking about the benefit of coffee is a little misleading.
To get to the truth, we should look into studies of pure caffeine and its effect on the body because that is the reason people drink coffee in the first place. We could get most of the coffee benefits with decaf too. It is caffeine that we need to investigate and not just use misleading science to justify our habit. It is the same story as alcohol, finding some benefits that we can also find in other food items without any unique special ability to just coffee beans so that we can justify our caffeine high.
What does the actual caffeine do?
We can take it in pills for example or in energy drinks. If we look at the chemical structure of caffeine, we will see that it is very similar to adenosine. Adenosine is a chemical in the brain that makes us sleepy. Whenever we are awake adenosine slowly accumulates in our brains. Adenosine binds to the receptors and in time slows our brain activity down. The longer we are awake, the more adenosine accumulates, and the more tired we feel. At some point, we will go to sleep. While sleeping concentration of adenosine declines and in the morning cycle begins again.
Because caffeine is similar to adenosine and acts as an adenosine receptor blocker in the brain, it will cancel natural brain chemistry making us feel more alert.
For individuals that regularly drink coffee in extensive amounts, our brains adjust by developing more adenosine receptors, so it takes more caffeine to elicit the same response. Having more adenosine receptors also means more adenosine makes its way into our brains so if we do not drink coffee, we will be more tired than in our regular normal state. In the morning, we will not be fully alert and during the day we will feel more tired if we did not drink our cup that day. It has a half-life of 6 hours meaning half of it will be gone in 6 hours so after 6 hours you will be feeling half of the effect. A couple of hours later it will be mostly gone, and we will need another cup.
Caffeine also stimulates the body to produce much more adrenaline than needed and that will end up in increased heart rate and anxiety.
Caffeine puts the body in a stressful state of fight and flight response leading to an increase in anxiety. People who are already overstressed and prone to panic attacks and other pro-anxiety conditions can have severe reactions with a tremor in their hands and cold sweats and heart palpitations from caffeine.
Caffeine also prevents dopamine from getting reabsorbed acting like cocaine in some sense leading to good feelings so by now we are in addictive behavior and have withdrawal symptoms. This dopamine effect is what makes coffee so addictive.
The reason why Coca-Cola puts caffeine in Coke is precisely because of this. Developing children’s brains is even more sensitive.
The lethal dose of caffeine is 150mg per kg of body mass. For a 70kg human, it is 14000mg caffeine. A cup of coffee on average has 150mg. This is not enough to kill but there is still one more fact that people tend to know little about. However, it is the one effect that is most important of them all. Adenosine also controls blood flow through the brain.
Caffeine produces cerebral vasoconstriction by antagonizing adenosine receptors.
Caffeine-induced cerebral vasoconstriction is well documented (Diukova et al., 2012). 250 mg of caffeine was found to be associated with significant reductions in cerebral perfusion thirty and ninety minutes later around. The value of decreased blood flow in the brain goes from 20% for one small cup of coffee to 40% for 2 or 3 cups. Chronic caffeine use results in an adaptation of the vascular adenosine receptor system presumably to compensate for the vasoconstrictive effects of caffeine. This entire adrenaline bump and stress in the form of I am suffocating and dying, help me, I am your brain without the oxygen is what actually wakes you up because you are about to die literally. That is what your alert state is. Fight or flight stress response. And that is the real job of caffeine, to be one more neurotoxic chemical for defense against pests. If you drink coffee every day, the brain adapts and tries to compensate.
Nevertheless, there is a deadline for what the brain can compensate for. The limit is around 400 mg of caffeine a day. Drinking more than that will have vasoconstrictive effects even in people who are chronic caffeine addicts. What happens is that in expectation of one more coffee cup the brain is going to raise its internal brain pressure. So when we drink coffee, the pressure will drop from vasoconstrictive effects and become normal. If you skip that cup in the morning and skip again in the afternoon the buildup of internal brain pressure is going to give you a migraine headache. That is the reason why people who are trying to quit usually suffer from headaches that can last for days before their brains start to adapt again to new normalized conditions. There is more.
Caffeine is also frequently utilized as a pre-workout supplement, but caffeine may adversely affect and limit bloodstream flow to heart muscle throughout the exercise (Namdar et al., 2009).
When we do physical exercise blood flow has to increase in order to match the increased need for oxygen and caffeine may adversely affect this mechanism too and not just the blood supply to the brain. It restricts the blood flow in the heart muscle, but interestingly enough it did not affect blood flow while the study subjects were at rest. When the subjects took caffeine tablets and exercised the blood flow was significantly lower than normal. Blood flow should increase when people exercise due to the more significant demand for energy, but caffeine blocks receptors for adenosine in the heart muscle and blocks specific receptors in the walls of blood vessels. I would not recommend that anyone take caffeine as a pre-workout supplement or for any athlete to drink caffeine before sports. In the upper mentioned study after oral administration of caffeine 200 mg bicycle exercise-induced myocardial blood flow decreased by 11% in regular individuals. In subjects who have coronary artery disease decrease was 18% and by 25% in stenotic subjects (with cholesterol deposit narrowing of coronary arteries). Caffeine is a pesticide that kills insects and other plants. Neurotoxic poison. It has the purpose of defending the coffee plant.
The coffee plant is one of the rare plants in nature that commits suicide. Unique coffee benefits, suicide. The leaves and beans that fall from the coffee tree have caffeine, and they start to poison the ground. At first, they kill everything that lives in topsoil but as time passes and more and more leaves fall, and more concentration of caffeine in soil raises more of the root system of the coffee plant itself gets affected. Investigations regarding the use of caffeine on plants demonstrated that when the concentration of caffeine gets high enough it begins to distort plant cells and if it gets even higher the result is the death of the plant.
People usually try to drink coffee when they are already stressed enough. They have a lot of work, or they need to study for the exam so that constant stressful response full of adrenalin and cortisol up and downs is going to give them adrenal fatigue and overall stressful condition. Adrenal fatigue is not a real disease just a made-up term. It is not an accepted medical diagnosis. There is a real medical condition called Addison disease which causes adrenal insufficiency. Adrenal fatigue does not cause inadequate production of one or more of these hormones as a result of an underlying disease. Adrenal fatigue is a light form of adrenal insufficiency caused by chronic stress with rapid hormonal ups and downs during the day. It is not as much the insufficiency of the adrenal glands as it is an overall fatigue state caused by constant hormonal fluctuations. Trying to take Valium to relax or because you are unable to sleep is just going to make things worse.
How many people are complaining about their stressful lives?
The valid question should be how many of them are caffeine addicts?
Keep that in mind the next time you are eyeing that 2nd (or 10th) cup of joe.
References:
- Diukova, A., Ware, J., Smith, J. E., Evans, C. J., Murphy, K., Rogers, P. J., & Wise, R. G. (2012). Separating neural and vascular effects of caffeine using simultaneous EEG-FMRI: differential effects of caffeine on cognitive and sensorimotor brain responses. NeuroImage, 62(1), 239–249. https://doi.org/10.1016/j.neuroimage.2012.04.041
- Namdar, M., Schepis, T., Koepfli, P., Gaemperli, O., Siegrist, P. T., Grathwohl, R., Valenta, I., Delaloye, R., Klainguti, M., Wyss, C. A., Lüscher, T. F., & Kaufmann, P. A. (2009). Caffeine impairs myocardial blood flow response to physical exercise in patients with coronary artery disease as well as in age-matched controls. PloS one, 4(5), e5665. https://doi.org/10.1371/journal.pone.0005665
- Butt, M. S., & Sultan, M. T. (2011). Coffee and its consumption: benefits and risks. Critical reviews in food science and nutrition, 51(4), 363–373. https://doi.org/10.1080/10408390903586412
Related Posts
Do you have any questions about nutrition and health?
I would love to hear from you and answer them in my next post. I appreciate your input and opinion and I look forward to hearing from you soon. I also invite you to follow us on Facebook, Instagram, and Pinterest for more diet, nutrition, and health content. You can leave a comment there and connect with other health enthusiasts, share your tips and experiences, and get support and encouragement from our team and community.
I hope that this post was informative and enjoyable for you and that you are prepared to apply the insights you learned. If you found this post helpful, please share it with your friends and family who might also benefit from it. You never know who might need some guidance and support on their health journey.
– You Might Also Like –

Learn About Nutrition
Milos Pokimica is a doctor of natural medicine, clinical nutritionist, medical health and nutrition writer, and nutritional science advisor. Author of the book series Go Vegan? Review of Science, he also operates the natural health website GoVeganWay.com
Medical Disclaimer
GoVeganWay.com brings you reviews of the latest nutrition and health-related research. The information provided represents the personal opinion of the author and is not intended nor implied to be a substitute for professional medical advice, diagnosis, or treatment. The information provided is for informational purposes only and is not intended to serve as a substitute for the consultation, diagnosis, and/or medical treatment of a qualified physician or healthcare provider.NEVER DISREGARD PROFESSIONAL MEDICAL ADVICE OR DELAY SEEKING MEDICAL TREATMENT BECAUSE OF SOMETHING YOU HAVE READ ON OR ACCESSED THROUGH GoVeganWay.com
NEVER APPLY ANY LIFESTYLE CHANGES OR ANY CHANGES AT ALL AS A CONSEQUENCE OF SOMETHING YOU HAVE READ IN GoVeganWay.com BEFORE CONSULTING LICENCED MEDICAL PRACTITIONER.
In the event of a medical emergency, call a doctor or 911 immediately. GoVeganWay.com does not recommend or endorse any specific groups, organizations, tests, physicians, products, procedures, opinions, or other information that may be mentioned inside.
Editor Picks –
Milos Pokimica is a doctor of natural medicine, clinical nutritionist, medical health and nutrition writer, and nutritional science advisor. Author of the book series Go Vegan? Review of Science, he also operates the natural health website GoVeganWay.com
Latest Articles –
Plant Based News
-
Some Dogs Can Sort Toys By Function, Says New Study On Canine ‘Label Extension’
on November 5, 2025
-
Courgette, Leek, White Bean And Kale Stew
on November 5, 2025
-
Precision Fermented Dairy Proteins Receive ‘No Questions’ Approval From FDA
on November 4, 2025
-
This One-Pan Ramen Is Ready In 30 Minutes
on November 4, 2025
-
How to Make Fresh Vanilla Hemp Milk at Home
on November 3, 2025
-
Animal Farming Is ‘World’s Biggest Cause Of Food Waste,’ Says Report
on November 3, 2025
-
Butter Bean And Sweet Papas Coconut Stew
on November 2, 2025
Top Health News — ScienceDaily
- Scientists uncover meditation’s hidden side effectson November 5, 2025
Meditation is widely praised for its mental health benefits, but new research shows that it can also produce unexpected side effects for some people—from anxiety and dissociation to functional impairment. Psychologist Nicholas Van Dam and his team found that nearly 60% of meditators experienced some kind of effect, and about a third found them distressing.
- Most Americans don’t know alcohol can cause canceron November 5, 2025
Most U.S. adults don’t realize alcohol raises cancer risk, and drinkers themselves are the least aware. Scientists say targeting these misbeliefs could significantly reduce alcohol-related cancer deaths.
- A breakthrough map reveals how the brain really workson November 5, 2025
Scientists have shown that brain connectivity patterns can predict mental functions across the entire brain. Each region has a unique “connectivity fingerprint” tied to its role in cognition, from language to memory. The strongest links were found in higher-level thinking skills that take years to develop. This work lays the groundwork for comparing healthy and disordered brains.
- A shapeshifting protein explains rabies’ deadly poweron November 5, 2025
Researchers discovered how rabies virus exerts massive control over host cells with very few genes. A key viral protein changes shape and binds RNA, allowing it to infiltrate different cellular systems. This adaptability could explain the power of other deadly viruses, including Nipah and Ebola. The breakthrough may lead to next-generation antivirals or vaccines.
- Cockroaches are secretly poisoning indoor airon November 5, 2025
Cockroach infestations don’t just bring creepy crawlers, they fill homes with allergens and bacterial toxins that can trigger asthma and allergies. NC State researchers found that larger infestations meant higher toxin levels, especially from female roaches. When extermination eliminated the pests, both allergens and endotoxins plummeted. The findings highlight how pest control is vital for cleaner, healthier air indoors.
- Scientists shocked to find E. coli spreads as fast as the swine fluon November 5, 2025
Researchers have, for the first time, estimated how quickly E. coli bacteria can spread between people — and one strain moves as fast as swine flu. Using genomic data from the UK and Norway, scientists modeled bacterial transmission rates and discovered key differences between strains. Their work offers a new way to monitor and control antibiotic-resistant bacteria in both communities and hospitals.
- Tiny molecules could stop glaucoma before it blindson November 5, 2025
Scientists at Mizzou have identified two small molecules, agmatine and thiamine, that could both reveal and fight glaucoma. Their research shows these compounds are lower in glaucoma patients, suggesting they may serve as early warning markers. Even better, they might help protect retinal cells from damage, potentially slowing or stopping vision loss. The discovery could revolutionize how the disease is detected and treated.
PubMed, #vegan-diet –
- Impact of in vitro digestion on the cytotoxicity and microbial viability of cholinesterase-inhibitor-rich vegan soups in human intestinal cell modelson November 1, 2025
Vegan lunch soups formulated with mushroom, asparagus, leek, and sea buckthorn were previously developed by our team to provide a consistent daily intake of dietary cholinesterase inhibitors. Considering the proposed continuous consumption of these functional soups, it is essential to examine any cytotoxic responses that may occur in the gastro-intestinal tract. This work starts this topic by investigating the effect of in vitro digested soups towards selected human intestinal cells and…
- A 6-Month, Prospective, Multi-arm Study for the Efficacy of Standardized Nutraceuticals to Improve Hair Fiber Thickness and Strengthon October 31, 2025
CONCLUSIONS: This study demonstrates that ingestion of these bio-specific HGNs are associated with significantly enhanced hair shaft diameter and decreased breakage, resulting in longer, stronger hair across their intended populations. These findings support the use of these HGNs for hair thinning, offering alternative options for various populations for improving hair growth and thickness.
- Consumer Acceptance of Sustainable Cat Diets: A Survey of 1380 Cat Guardianson October 29, 2025
There is increasing awareness about the adverse environmental and ‘food’ animal welfare impacts associated with the production of meat-based pet food. However, little is known about cat guardians’ acceptance of more sustainable food choices for the global population of approximately 476 million pet cats. By surveying 1380 cat guardians, this study explored feeding patterns used by guardians, determinants of their cat food choices, and their acceptance levels of more sustainable cat food…
- Consumer Acceptance of Sustainable Dog Diets: A Survey of 2639 Dog Guardianson October 29, 2025
Interest in more sustainable diets for the global population of 528 million companion dogs is steadily increasing, encompassing nutritionally sound cultivated meat, vegan, and microbial protein-based dog foods. Factors driving these alternative dog foods include lower impacts on the environment, fewer welfare problems related to intensively farmed animals and wild-caught fish, and potentially superior canine health outcomes, relative to conventional meat-based dog food. Through a […]
- Beliefs and behaviours associated with vegetarian, vegan, and gluten-free diets among Canadians capable of bearing childrenon October 29, 2025
There is increased interest in self-selected exclusionary diet patterns, specifically vegetarian, vegan, and gluten-free (GF) diets, but there is a lack of research exploring the beliefs and behaviours surrounding these diets in Canadians capable of bearing children (CCBC). The goal of this study was to explore the beliefs and behaviours of CCBC who follow vegetarian, vegan, and/or GF diets using mixed methods. A self-administered online Qualtrics™ survey containing 102 questions was […]
Random Posts –
Featured Posts –

Latest from PubMed, #plant-based diet –
- Diet quality scores and incidence of cardiovascular events: A 4-year prospective study of patients in cardiology secondary care (BALANCE Program Trial)by Aline Rosignoli da Conceição on November 5, 2025
As a modifiable determinant, dietary patterns are a crucial factor in the prevention of cardiovascular disease (CVD), as they account for more than half of all CVD-related deaths and disabilities. Thus, we aimed to assess whether changes in diet quality along with six a priori-defined diet scores were associated with the incidence of cardiovascular (CV) events during four years of follow-up of secondary care cardiology patients. We conducted a secondary prospective analysis of 1,704, 1,629 […]
- Dietary animal fat disrupts gut microbiota and aggravates Scl-cGVHD after allogeneic hematopoietic stem cell transferby Danielle D Millick on November 5, 2025
Allogeneic Hematopoietic Stem Cell Transplant (allo-HCT) is an effective treatment for high-risk or relapsed acute leukemia. However, the frequent occurrence of graft-versus-host disease (GVHD) poses significant complications. Modifiable factors such as the gut microbiome and dietary regimen have the potential to influence the frequency and severity of GVHD. Previous studies in mouse models have shown a direct link between obesity and increased severity of GVHD. Analysis of human data has not…
- Dose-response effects of a mixed condensed and hydrolyzable tannin extract on methane production and diet digestibility using the in vitro gas production techniqueby Jordan M Adams on November 5, 2025
Several studies have evaluated the impact of isolated condensed or hydrolyzable tannin extract (TE) supplementation for beef cattle on methane (CH4) mitigation and metabolic functions, but fewer have evaluated their combination. Our objective was to investigate changes in in vitro fermentation dynamics, CH4 production, neutral detergent fiber digestibility (ivNDFD), and ruminal volatile fatty acid (VFA) concentrations in response to the inclusion rate of a TE blend (Silvafeed ByPro; […]
- Discovery of urinary biomarkers of kiwifruit intake in a randomized intervention studyby Zilin Xiao on November 4, 2025
CONCLUSIONS: This study identified potential biomarkers of kiwifruit and developed a prediction model that may differentiate consumers. Further validation is necessary to confirm the reliability and generalizability of our findings.
- Nourishing the Skin: A Review of Diet’s Role in Hidradenitis Suppurativaby Jordan Beam on November 4, 2025
Hidradenitis suppurativa (HS) is a complex skin condition influenced by both genetic and environmental factors. Increasing evidence points to diet as a key contributor to disease severity through systemic inflammatory pathways. A review of recent literature was conducted to evaluate the relationship between dietary patterns and advancement of HS. Pro-inflammatory diets such as the Western diet, leucine-rich diets, and brewer’s yeast were associated with HS exacerbation through mTOR activation…
- Energy balance in cyclists on plant-based diets during a 30-day, 4300-km ride across Canada: Two case studiesby Sarah A Purcell on November 3, 2025
The popularity of ultra-endurance events and plant-based diets highlights the importance of understanding the energetics of athletes with diverse dietary preferences. This study examined energy balance in two recreational cyclists on plant-based diets (male, 41 years; female, 38 years) during a 30-day cross-Canada ride. Resting energy expenditure was measured via whole-room indirect calorimetry before and after the ride. Total energy expenditure (TEE) was assessed using doubly labeled water…



















