Caffeine causes 40% drop in blood flow to brain
Dr Paul Laurienti, Wake Forest Baptist Medical Center
https://153news.net/watch_video.php?v=W361OK6411HA
The real, unbiased science on caffeine and cerebral blood flow is clear in several peer-reviewed studies:
Caffeine Decreases Blood Flow in the Brain
Caffeine is a vasoconstrictor — it narrows blood vessels, including those in the brain.
Multiple studies using PET and MRI imaging confirm that caffeine reduces cerebral blood flow (CBF) by 20–30%, even though mental alertness may subjectively feel increased.
Key Evidence:
1. Cameron et al. (1990, Nature) Found significant reductions in CBF after caffeine ingestion, especially in areas involved in attention and arousal.
2. Field et al. (2003, NeuroImage) Showed a 25–30% decrease in global CBF after typical caffeine doses (200–400 mg).
3. Addicott et al. (2009, Human Brain Mapping) Confirmed that even habitual caffeine consumers show acute vasoconstriction and CBF reduction after intake.
But It’s More Complex Than Just “Less Blood Flow”
Despite less blood flow, cognitive performance may improve due to increased neuronal efficiency and adenosine receptor blockade (which increases alertness). The brain adapts to regular caffeine use, and tolerance develops — habitual users may have less pronounced blood flow reduction.
What Happens When You Quit Caffeine
Rebound vasodilation occurs — your brain increases blood flow, which is one reason for caffeine withdrawal headaches.
Summary
Yes, caffeine does reduce blood flow in the brain, objectively measured. This is due to vasoconstriction. But, this does not necessarily impair brain function — and can even enhance certain aspects short-term (like alertness and reaction time). Overuse, dependency, and withdrawal can lead to opposite effects, including headaches, fatigue, and brain fog.
The article titled “Caffeine causes 40% drop in blood flow to brain” from wp.4wellness.org presents a claim that caffeine significantly reduces cerebral blood flow (CBF) by up to 40%. This assertion is grounded in the well-documented vasoconstrictive properties of caffeine, which primarily operates through antagonism of adenosine receptors.
Mechanism: How Caffeine Reduces Cerebral Blood Flow
Caffeine acts as a non-selective antagonist of adenosine receptors, particularly the A1 and A2A subtypes. Adenosine typically promotes vasodilation, leading to increased blood flow. By blocking these receptors, caffeine induces vasoconstriction, resulting in reduced cerebral blood flow. This effect has been substantiated by various imaging studies, including positron emission tomography (PET) and magnetic resonance imaging (MRI), which have observed reductions in CBF ranging from 20% to 30% following caffeine consumption. (PubMed)
Acute vs. Chronic Effects
The impact of caffeine on cerebral blood flow varies between acute and chronic consumption:
- Acute Consumption: In individuals who do not regularly consume caffeine, a single dose can lead to significant vasoconstriction and a corresponding decrease in CBF.
- Chronic Consumption: Regular caffeine consumers may develop a tolerance to its vasoconstrictive effects. Studies have shown that habitual users exhibit a diminished reduction in CBF in response to caffeine compared to non-users. (PubMed)
Cognitive Implications
Despite the reduction in cerebral blood flow, caffeine is known to enhance certain cognitive functions, such as alertness and reaction time. This paradox is attributed to caffeine’s ability to increase neuronal firing rates and neurotransmitter release, thereby enhancing cognitive performance even in the context of reduced blood flow.
Withdrawal and Rebound Effects
Abrupt cessation of caffeine intake after prolonged use can lead to withdrawal symptoms, including headaches. This is believed to result from rebound vasodilation, where blood vessels dilate beyond their normal state, increasing cerebral blood flow and potentially causing discomfort. (verywellhealth.com)
Conclusion
The claim that caffeine can cause a significant reduction in cerebral blood flow is supported by scientific evidence, primarily through its action as an adenosine receptor antagonist leading to vasoconstriction. However, the extent of this effect is influenced by factors such as dosage and individual tolerance levels. Moreover, the cognitive benefits of caffeine, despite reduced blood flow, highlight the complexity of its effects on the brain.
This is absolutely true. When I did my research a few years ago after trying to come down off of coffee and ended up with a sledgehammer headache for over a week, I decided it was time to figure out why exactly this was harder than most drugs I have detoxed from. In my research it was very evident that coffee does cut off the blood flow to your brain. Videos like this weren’t out and I was the only one that was yelling how dangerous coffee was. People have come from all over and told me how great it is and how healthy it is and when you end up with the shakes, a migraine beyond anything that you can take, then its not healthy. Its a drug just like anything else and those that drink coffee are addicts just like those smoking crack. If you don’t believe me, stop your coffee cold turkey and let me know how you do. The more you drink the more of an addiction it is and it will stay in your body for weeks. Those who defend the entire coffee not being dangerous are the drinkers of the coffee. I had this battle over on youtube when I put these videos out and I standby the research that I have done and the scientific papers that expose this. Its not easy info to find as everyone is a drug coffee pusher and its a huge business but if we are in for the truth and for saving lives, well being addicted to anything is going to hurt you eventually. And one of the greatest things for coffee is a pesticide. When you use the grounds in the garden you will have far less bugs that take them. Bottom line is this isn’t MSM and I was very impressed people actually did an MRI to prove exactly what I have been saying for years. Coffee is simply low grade meth until you get accustomed to it and then you need it to even “wake up” and get going.