Recent articles on line have made a big deal out of the findings that caffeine can reduce cerebral blood flow (CBF). This is a topic that’s gotten traction lately and understandably, has resulted in questions and concerns regarding the wisdom and safety of daily coffee consumption.
First, if the reader takes one thing away from this article, it’s that caffeine and coffee are not interchangeable terms, full stop. Many people, including scientists, medical professionals, and nutritional advisors, all of whom should know better, regularly make that mistake, and it creates unneeded confusion. Even when they don’t say it directly, there’s language used to suggest caffeine and coffee are interchangeable, and that’s simply not the case. Obviously there’s overlap between them due to the caffeine content of coffee, they are not interchangeable terms. That’s the short version, let’s explore the topic a bit more. I do explore some of the differences between coffee and caffeine in a prior article HERE worth a read and will be quoting from that article going forward.
First things first: while studies have found synthetic caffeine – usually in the form of caffeine anhydrous – appears to reduce cerebral CBF, the impact of that effect remains unclear. However, studies consistently find caffeine positively impacts memory, performance, mood, endurance, coordination and increases arousal, vigilance, while reducing fatigue, to name a few beneficial effects. The military has studied caffeine extensively also, and finds the above benefits, as well as improvements in marksmanship. That is not what one would expect from a brain experiencing reduced CBF.
While it’s understandable that data finding caffeine appears to have a negative effect on CBF would be concerning, the net effect remains unclear and does not appear supported as a negative by other data that exists. Be that as it may, per usual, moderation appears key to experiencing the benefits while mitigating the potential negatives, and nothing on this planet does not involve risk/benefit. What we can say is, this effect on CBF by caffeine requires more research as to its real world relevance. Synthetic caffeine is what you find in energy drinks, pills, etc. See article linked above for additional info on that topic.
So let’s talk coffee…
As most are aware, study after study after study after… well, you get the point, finds regular coffee ingestion associated with a long list of benefits and reduced risk of various diseases, including brain specific benefits, which is the topic of this article. That has been a robust and consistent finding. From my article linked above:
“Coffee is a complex biological substance with literally hundreds of compounds that are dissolved along with caffeine during the brewing process, all of which ends up in your coffee mug. Some of these compounds have effects completely separate from caffeine, and more important to this article, effects that appear to counteract the effects of caffeine, which is a positive or a negative depending on how you view it. Besides the more obvious stuff found in coffee (e.g., lipids, carbohydrates, and proteins) you find compounds of potential metabolic importance, such as nicotinic acid, opiate-receptor antagonists, and cholinomimetics (agents that exert an effect “opposite” to adrenaline). Interestingly one group of researchers isolated a cholinomimetic compound from both regular and decaffeinated coffees that, when injected into rats, resulted in decreases in heart rate and blood pressure. Thus, a compound that has direct counter regulatory effects to that of caffeine (and adrenaline).”
What follows is the abstract to a lengthy review (Chapter 46 – “Coffee and its Active Compounds are Neuroprotective” Coffee in Health and Disease Prevention 2015, Pages 423-427) that summarizes coffee ingestion specific to brain health and disease:
“Epidemiological studies suggest that both caffeinated coffee and decaffeinated coffee are neuroprotective. Data obtained from in vitro, in vivo, and human clinical trials have indicated that coffee exhibits protective effects against Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis. Thus, the active coffee compounds that underlie these effects are under investigation. To date, studies of coffee on brain health have primarily focused on the role of its well-known component caffeine as an antagonist of adenosine receptors. Apart from caffeine, chlorogenic acid, caffeic acid, and kahweol have also been shown to contribute the neuropharmacological activities of coffee, by virtue of their antioxidant and anti-inflammatory properties. Because neurodegenerative disorders are strongly associated with oxidative stress and inflammation, negation of these pathological phenomena by coffee components likely contributes to their neuroprotective activities. Trigonelline, a compound present in coffee beans, has regenerative activity on dendrites and axons. This chapter focuses on the protective effects of coffee and its main active compounds against neurodegeneration and brain injury.”
It should be noted much of the data, but not all per abstract above, that supports the benefits of coffee are correlational (Epidemiological), and correlation does not always equal causation, but as mentioned previously, that effect has been consistent and robust. One study – Acute impact of drinking coffee on the cerebral and systemic vasculature – did directly test the effects of coffee ingestion with volunteers on pulsatility index (PI), middle cerebral artery blood velocity (MCAv) and brachial-ankle pulse wave velocity (baPWV) as “indices of cerebral pulsatile stress and arterial stiffness, respectively” and found no statistically significant differences between coffee and placebo and concluded “These findings suggest that drinking coffee does not increase cerebral pulsatile stress acutely despite an elevation in arterial stiffness in the systemic circulation.”
Another study was more complex in its findings, which was that “…coffee drinking augments dynamic CBF regulation with cerebral vasoconstriction. This phenomenon may be associated with a reduction in the risk of cerebral vascular disease.”
Take home there is, as with anything brain/neuro science related, it’s complicated, but does not indicate a negative impact on the brain, especially when taken in context with the existing data to date suggesting coffee is neuro-protective.
While I don’t think the effects of caffeine on CBF should be ignored, and more data is needed as to the impact of caffeine on CBF, the “real world” results of a brain being starved of a blood supply, and by extension, oxygen, does not result in improvements in mood, memory, performance, endurance, coordination and increases arousal, vigilance, while reducing fatigue, as found in studies with caffeine. I don’t think one needs a PhD in neuro-science to make that leap, so clearly something is missing from the full picture as to the impact and physiological relevance of caffeine and its impact on CBF. No doubt, dose is an essential factor there… Having said that, I have never been a big fan of caffeine, and recommend people use it sparingly, recommending limited use of energy drinks, caffeine pills, and pre-workout products often containing high doses of synthetic caffeine. Personally, I never liked how caffeine felt, and tried ephedrine once back in the day and hated it, but that’s another story.
As for coffee, that’s clearly a different animal, and again, for the love of God, I wish people, including people with the educational background to know better, would stop using caffeine and coffee as interchangeable terms. Does that mean I dismiss any possibility of a negative effect of coffee on CBF? No, but the bulk of data, which is extensive, strongly suggests coffee ingestion is a net benefit to health, disease prevention, and sanity! What does need to happen is, all studies that used caffeine for studying CBF should be ignored as they apply to coffee, and more studies done using coffee with regards to CBF need to be performed.
Bottom line here is, there’s a risk/benefit to everything and anything we do or ingest, and to date, the evidence overwhelmingly supports regular coffee ingestion as a net benefit. But, with over 800 compounds discovered that exist in coffee and counting, there’s a lot of research left to do!
Take home: I’m not giving up my coffee any time soon, nor should you if you enjoy coffee.
Everyone who knows me knows I love coffee, so much so that I developed a formula that takes coffee, and it’s benefits, to the next level. If that’s of interest to readers, see The Science Of Alpha Joe.
Will Brink is the owner of the Brinkzone Blog. Will has over 30 years experience as a respected author, columnist and consultant, to the supplement, fitness, bodybuilding, and weight loss industry and has been extensively published. Will graduated from Harvard University with a concentration in the natural sciences, and is a consultant to major supplement, dairy, and pharmaceutical companies.
His often ground breaking articles can be found in publications such as Lets Live, Muscle Media 2000, MuscleMag International, The Life Extension Magazine, Muscle n Fitness, Inside Karate, Exercise For Men Only, Body International, Power, Oxygen, Penthouse, Women’s World and The Townsend Letter For Doctors.
He’s also been published in peer reviewed journals.
You can also buy Will’s other books on Amazon, Apple iBook, and Barnes and Noble.