Do we think caffeine is something good for our brain or bad or neutral?
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?
What coffee seems to increase is a 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 found 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 of the antioxidant-rich foods will have the same effect.
When people talk about the coffee benefits, they tell half-truth 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 beans. For example, cocoa beans have caffeine too but much more of the 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 using misleading science to justify our habit. It is the same story as alcohol, finding some benefit that we can also find in other food items without any unique special ability to just coffee bean 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 brain. Adenosine binds to the receptors and in time slows our brain activity down. The longer we are awake, the more adenosine accumulates, 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 the 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 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 feeling 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 brain is even more sensitive.
The lethal dose of caffeine is 150mg per kg of the 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 (1). 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. The limit is around 400 mg of caffeine a day. Drinking more than that will have vasoconstrictive effects even in the 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 became 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 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 (2). When we do a 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 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 the 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 as 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.
Passages selected from a book: “Go Vegan? Review of Science: Part 1” [Milos Pokimica]
- Separating neural and vascular effects of caffeine using simultaneous EEG-FMRI: differential effects of caffeine on cognitive and sensorimotor brain responses. doi: 10.1016/j.neuroimage.2012.04.041
- Caffeine impairs myocardial blood flow response to physical exercise in patients with coronary artery disease as well as in age-matched controls doi: 10.1371/journal.pone.0005665.
- Coffee and Its Consumption: Benefits and Risks doi: 10.1080/10408390903586412.