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
-
Vegan Christmas Day 4: Pesto Puff Pastry Trees
on December 4, 2025
-
From Side Dish to Superfood: White Potatoes Are Making a Comeback
on December 4, 2025
-
SPINS Data Finds The Plant-Based Sector Isn’t Dying, It’s Just Evolving
on December 4, 2025
-
Vegan Christmas Day 3: Easy Chocolate Ganache Tart
on December 3, 2025
-
Plant-Based Diets Could Help Prevent And Reverse CMD Heart Disease, Says Study
on December 3, 2025
-
Whistleblower Says The Meat Industry Paid Them To Discredit Veganism Online
on December 2, 2025
-
Vegan Christmas Day 2: Hummus Christmas Wreath
on December 2, 2025
Top Health News — ScienceDaily
- Daily coffee may slow biological aging in mental illnesson December 4, 2025
Researchers studying people with major psychiatric disorders found that drinking up to four cups of coffee a day is associated with longer telomeres. This suggests a potential slowing of biological aging by about five years. However, drinking five or more cups showed no benefit and may even contribute to cellular damage. Coffee’s antioxidant and anti-inflammatory properties may help explain the effect.
- Simple nutrient mix delivers surprising autism breakthrough in miceon December 4, 2025
A low-dose mix of zinc, serine, and branched-chain amino acids boosted neural function and social behavior in autism mouse models. The combination restored more typical synaptic protein patterns and reduced excessive amygdala activity. Individual supplements had no effect, showing that the nutrients must work together. The findings point toward a promising multi-nutrient strategy for influencing brain circuits involved in autism.
- Scientists capture flu viruses surfing into human cells in real timeon December 4, 2025
Scientists have captured a never-before-seen, high-resolution look at influenza’s stealthy invasion of human cells, revealing that the cells aren’t just helpless victims. Using a groundbreaking imaging technique, researchers discovered that our cells actually reach out and “grab” the virus as it searches for the perfect entry point, surfing along the membrane.
- Gas stoves are filling millions of homes with hidden toxic airon December 4, 2025
Stanford researchers found that gas stoves expose Americans to surprisingly high levels of nitrogen dioxide—often matching or exceeding outdoor pollution. For millions, cooking alone pushes NO2 over long-term safety thresholds. Smaller homes, renters, and rural households face the highest concentrations. Cleaner cooking technologies could substantially reduce the risks.
- A routine shingles shot may offer powerful defense against dementiaon December 3, 2025
A unique vaccine rollout in Wales gave researchers an accidental natural experiment that revealed a striking reduction in dementia among seniors who received the shingles vaccine. The protective effect held steady across multiple analyses and was even stronger in women. Evidence also suggests benefits for people who already have dementia, hinting at a therapeutic effect.
- A common constipation drug shows a surprising ability to protect kidneyson December 3, 2025
A surprising link between constipation and kidney decline led researchers to test lubiprostone, revealing that it can protect kidney function. The results point toward gut-based, mitochondria-boosting therapies as a promising new avenue for CKD care.
- Your sweat reveals health problems long before symptoms appearon December 3, 2025
Sweat carries a rich mix of biomarkers that advanced wearables can now track in real time. New AI-powered patches analyze biochemical patterns to detect disease risks, medication levels, or stress responses. Researchers are building ultra-sensitive microfluidic devices to read glucose, cortisol, and more—without needles or blood draws. The tech is still emerging, but its potential is huge.
PubMed, #vegan-diet –
- The VEGPREV study: effectiveness of four plant-based diets on weight loss, metabolic syndrome components and appetitive traits in overweight and obese individuals: a randomized controlled trialon December 4, 2025
CONCLUSION: Among plant-based dietary patterns differing in animal product content, the EAT and VG diets demonstrated the most pronounced effects on weight and body composition. These findings provide support for the notion that structured, plant-based dietary interventions can be effective strategies for managing body weight.
- A vegan diet signature from a multi-omics study on different European populations is related to favorable metabolic outcomeson December 4, 2025
Vegan and omnivorous diets differ markedly in composition, but their effects on the gut microbiome, metabolome, and lipidome across populations remain insufficiently characterized. While both diet and country of origin influence these molecular layers, the relative contribution of diet versus country-specific factors has not yet been systematically evaluated within a multi-omics framework.In this cross-sectional, bicentric, observational study, we profiled healthy vegans (n = 100) and […]
- Prevalence, motivations, lifestyle preferences, and basic health behavior among 1,350 vegan, vegetarian, and omnivorous Austrian school teachers and principalson December 4, 2025
CONCLUSION: This is the first study to investigate the potential differences in basic health behavior among refined dietary subgroups (omnivorous, ovo-lacto-vegetarian, and vegan) in school teachers and principals. The findings indicate that basic diet type differentiation is the first step towards fundamentally healthy behavior, however, further action must be taken to achieve better health among school teachers and principals in Austria (more physical activity, sports and exercise, and […]
- Appropriate Intervention Diets to Manage Type 2 Diabetes Mellitus Among Adults in Australia: A Systematic Reviewon December 3, 2025
Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder characterised by insulin resistance and hyperglycaemia, contributing to significant morbidity and mortality worldwide, including in Australia. This systematic review aimed to explore the most appropriate dietary interventions for managing T2DM among Australian adults. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, databases including PubMed, Medline, Embase, and Google […]
- Plant-based diet as a precursor to human gut diversityon November 28, 2025
The gut microbiome significantly influences human health with dietary patterns, a key factor that modulates the structure and function of microbiome consortia. Plant-based diets (PBDs), including vegan and vegetarian, are linked to positive alterations in gut microbiota by stimulating the bacterial growth necessary for producing short-chain fatty acids. These microbial alterations help reduce inflammation, enhance gut barrier integrity, and improve metabolic health. However, not all PBDs […]
Random Posts –
Featured Posts –

Latest from PubMed, #plant-based diet –
- A vegan diet signature from a multi-omics study on different European populations is related to favorable metabolic outcomesby Anna Ouradova on December 4, 2025
Vegan and omnivorous diets differ markedly in composition, but their effects on the gut microbiome, metabolome, and lipidome across populations remain insufficiently characterized. While both diet and country of origin influence these molecular layers, the relative contribution of diet versus country-specific factors has not yet been systematically evaluated within a multi-omics framework.In this cross-sectional, bicentric, observational study, we profiled healthy vegans (n = 100) and […]
- Inferring Endozoochory From Ingestion to Germination Through Biological Filters: Brown Bear Feces as a Case Studyby Grégoire Pauly on December 4, 2025
Diaspore (e.g., seed and spore) dispersal is recognized as a key mechanism in plant dynamics, including endozoochory, which can be a risky journey for diaspores. Endozoochory is achieved when diaspores are consumed and may germinate after the mastication, the gut and fecal matrix passage, all representing filters for diaspores. Nevertheless, endozoochory is a highly studied mechanism through numerous methods, notably based on the observation of frugivorous behavior, diaspores retrieved in […]
- The VEGPREV study: effectiveness of four plant-based diets on weight loss, metabolic syndrome components and appetitive traits in overweight and obese individuals: a randomized controlled trialby Klaudia Wiśniewska on December 4, 2025
CONCLUSION: Among plant-based dietary patterns differing in animal product content, the EAT and VG diets demonstrated the most pronounced effects on weight and body composition. These findings provide support for the notion that structured, plant-based dietary interventions can be effective strategies for managing body weight.
- Prevalence, motivations, lifestyle preferences, and basic health behavior among 1,350 vegan, vegetarian, and omnivorous Austrian school teachers and principalsby Katharina C Wirnitzer on December 4, 2025
CONCLUSION: This is the first study to investigate the potential differences in basic health behavior among refined dietary subgroups (omnivorous, ovo-lacto-vegetarian, and vegan) in school teachers and principals. The findings indicate that basic diet type differentiation is the first step towards fundamentally healthy behavior, however, further action must be taken to achieve better health among school teachers and principals in Austria (more physical activity, sports and exercise, and […]
- A High-Fiber Plant-Based Diet in Myeloma Precursor Disorders – Results from the NUTRIVENTION Clinical Trial and Preclinical Vk*MYC Modelby Urvi A Shah on December 4, 2025
Consumption of a western diet and high body mass index (BMI) are risk factors for progression from pre-malignant phenotypes to multiple myeloma, a hematologic cancer. In the NUTRIVENTION trial (NCT04920084), we administered a high-fiber, plant-based diet (meals for 12 weeks, coaching for 24 weeks) to 23 participants with myeloma precursor states and elevated BMI. The intervention was feasible, improved quality of life and modifiable risk factors: metabolic (BMI, insulin resistance), […]
- Forage preference in two geographically co-occurring fungus gardening ants: A dietary DNA approachby Matthew Richards-Perhatch V on December 4, 2025
Traditional methods of forage identification are impractical with non-leafcutting fungus gardening ants, making diet-related ecological and life history questions difficult to study. To address this limitation, we utilized dietary DNA metabarcoding on excavated ant fungus gardens to generate forage diversity metrics for the two co-occurring species Trachymyrmex septentrionalis and Mycetomoellerius turrifex. Ten fungus garden samples from each species were collected from a 60×70 m plot in East…



















