Call (479) 752-8555

Caffeine, Blood Flow, and the Brain

Before we have ingested caffeine, have we considered its effect upon our brains?

ABC News correspondent, Lisa Stark, drank 4 cups of coffee containing 400mg of caffeine at once. This is the amount that doctors say is a safe level to consume in a day. She took an MRI and experienced a 40% loss of blood flow to her brain. Below is the ABC News clip:

What is adenosine? How does adenosine affect blood flow to the brain? Why do nerve cells in our brains accept caffeine instead of adenosine?

How Stuff Works says, “As adenosine is created in the brain, it binds to adenosine receptors. This binding causes drowsiness by slowing down nerve cell activity. In the brain, this also causes blood vessels to dilate [become larger], most likely to let more oxygen into that organ during sleep.

To a nerve cell, caffeine looks like adenosine: Caffeine binds to the adenosine receptor. However, caffeine doesn’t slow down the cell’s activity like adenosine would. As a result, the cell can no longer identify adenosine because caffeine is taking up all the receptors that adenosine would normally bind to.”

This video from How Stuff Works shows how caffeine tricks nerve cells into believing it is adenosine:

What happens to the blood flow to the brain when caffeine is ingested?

Discovery Fit & Health says, “…Caffeine also causes the brain’s blood vessels to constrict, because it blocks adenosine’s ability to open them up.”
What does the brain do to counteract the effect of caffeine?

The says, “…Brain cells grow more adenosine receptors, which is the brain’s attempt to maintain equilibrium in the face of a constant onslaught of caffeine, with its adenosine receptors so regularly plugged…This explains why regular coffee drinkers build up a tolerance over time—because you have more adenosine receptors, it takes more caffeine to block a significant proportion of them and achieve the desired effect.”

What is a reason why people get headaches from caffeine withdrawal?

Discovery Fit & Health reports, “If you have been taking caffeine every day and you stop, you can get an incredible headache because of the increased blood flow in your brain.” The adenosine receptors are able to function properly again.

The Smithsonian writes, “…Your brain is used to operating in one set of conditions (with an artificially-inflated number of adenosine receptors, and a decreased number of norepinephrine receptors) that depend upon regular ingestion of caffeine. Suddenly, without the drug, the altered brain chemistry causes all sorts of problems, including the dreaded caffeine withdrawal headache.”


How long does it take for a caffeine withdrawal to cease?

According to the Smithsonian, “you only need to get through about 7-12 days of symptoms without drinking any caffeine. During that period, your brain will naturally decrease the number of adenosine receptors on each cell, responding to the sudden lack of caffeine ingestion. If you can make it that long without a cup of joe or a spot of tea, the levels of adenosine receptors in your brain reset to their baseline levels, and your addiction will be broken.”


Do you want diminished blood flow to the brain as a result of consuming caffeine?

Please consider this statement from Science Daily about the importance of the frontal lobes of our brain. “The frontal cortex of brain has been long known to affect the internal control of behavior. It controls the capacity to plan, reason, conduct higher-level thinking and connect what we know about the world to how we behave.”

Blood gives this essential region of the brain oxygen, nutrition, and it takes away waste from the cells located there. Can we afford to decrease the blood flow to the area of our brains which helps us “plan, reason, and conduct higher level-thinking”?

Do you want to quit your caffeine addiction and once again have more blood flow to your brain?

Learn about Wellness Secrets’ affordable 5 day health retreat, which has very friendly service and is very educational.

Posted in

Reader Interactions