Caffeine in coffee can be a beautiful morning wake up ritual!  Coffee has so many wonderful antioxidant benefits and most studies show drinking a small to moderate amount of coffee improves health. But what happens when we over do it? What exactly happens to the body when we take caffeine?  Could we be drinking too much?  How much is just enough and does not damage the body?  I hope to explain and shed some light on these and other questions that have come in recently.  

How does caffeine affect the body exactly?

The effects of caffeine on the body happen via many different pathways, both directly, and then as it is broken down, there are effects as well.  Caffeine acts on the brain cells and hits the A2A receptors in the central nervous system, which then blocks something called adenosine, which is a neuromodulator, this causes much of the stimulation effect and causes alertness (1).  Caffeine also binds reversibly to the monoamine oxidase enzymes. This blocks the detoxification of dopamine and increases the number of receptors in the brain hence increasing dopamine levels in the brain neurons. When dopamine is increased, we have more focus and more motivation (2).  Caffeine also blocks the breakdown of adrenaline, aka norepinephrine, which can cause a ‘Fight or flight’ response such as increased heart rate, breathing rate, and increased focus and attention. It also increases blood glucose levels. These two neurotransmitters can cause jitteriness, anxiety and panic in those who may have genetic variants of MAO, or COMT that slow down the detox of caffeine from the body.

Caffeine causes the release of ACTH, from the pituitary gland in the brain which sends a signal to the adrenal cortex to release cortisol (3). Cortisol is naturally secreted from the adrenal cortex in the morning 30 minutes after waking and diminishes throughout the day, this helps us have a diurnal rhythm, or sleep-wake cycle.  Caffeine taken in the morning increases the amount of cortisol released.  Some research says it is better to wait at least 30 minutes after waking so we allow our body to have its natural cortisol secretion time before stimulating more. Lastly, caffeine stimulates the release of glutamate, which is an excitatory neurotransmitter. It stimulates communication in the nerve cells and helps with learning and memory.

How do I build up tolerance to caffeine?

Tolerance means that your same cup of strong coffee does not do it for you any longer.  This happens in the area of the adenosine receptors. Due to the blockade created by the caffeine, the body creates more A2A receptors in response, and that means the adenosine neuromodulatory effect continues, which means you do not feel a stimulatory effect.  For the majority of people, it takes 6 hours until the caffeine is out of your system.  But if it is still within 6 hours of drinking the coffee, and you do not feel the stimulating effect, you have built up tolerance. Tolerance happens quickly at the higher levels of caffeine intake such as 500-600 mg and up.  For example, if you drink two or more cups within 6 hours, tolerance happens, which means the stimulating effect of the caffeine on the body only goes so far.  

Green tea contains 44 mg of caffeine and has literally hundreds of health benefits.  Green tea phyto-compounds contain antioxidants, are anticancer, anti-inflammatory phytochemicals.  Green tea is good for the immune system, is antiviral, antibacterial and combats hardening of the arteries.  I suggest switching to green tea for a couple days per week. It is amazing for your health and it will reset your caffeine tolerance when you do drink your coffee. 

Detoxification of caffeine and what I do to support this process

The body has to break down and get all chemicals out of the body one way or the other.  There are a set of enzymes involved called Phase 1 and Phase 2 detoxification.  Each chemical uses one or more of these enzymes to facilitate its detox process.  Caffeine uses primarily the Cytochrome P450 (CYP) 1A2 pathway. Secondarily NAT2 and CYP2A6 are involved.  Remember the effects of caffeine such as the increase of cortisol, dopamine, and norepinephrine, also are chemicals that the body has to now detoxify. There are two enzymes involved with dopamine and norepinephrine detox called MAO and COMT.  Cortisol detox is too complex for this blog discussion. 

As a caffeine consumer, it’s a good idea to support your detoxification pathways with the nutrients they need to do their work properly!  For starters, these include the B vitamins, magnesium, zinc and vitamin C.  The activated forms and methylated forms of the B vitamins are best. Specifically B12 and folate, you need to take methylcobalamin and 5-MTHF or methyltetrahydrofolate.  Feel free to contact me for more details.  Magnesium and potassium are depleted also as coffee and tea have a dehydrating effect.  So make sure you stay hydrated throughout the day.  A good rule of thumb is to drink half your body weight, in ounces daily and more if you are sweating during the day. 

Caffeine Withdrawal

At one cup per day with 200mg of caffeine or less, you may or may not experience any major withdrawal symptoms if you stop.  However, due to the uncomfortable symptoms possible, it’s best to wean down slowly over a week. You can also drink green tea to ease the process by giving you a little caffeine during your detox.

Caffeine Withdrawal symptoms: (4)

  • Irritability
  • Sleepiness
  • Headache
  • Nausea
  • Difficulty concentrating

There are plants and nutrients that can stimulate the detox of caffeine by inducing the CYP1A2 system

I recommend using some of these to support you and your adrenal glands as you wean down and off caffeine.  

Withdrawal support:

  • St. John’s Wort
  • Valerian root
  • Ginkgo biloba
  • Foods that help are bok choy, broccoli, brussel sprouts and other cruciferous veggies, or the supplement DIM, aka Diindolylmethane

If you wean off of caffeine and you are continually fatigued or lacking focus, I recommend you get tested for 

Adrenal fatigue and Neurotransmitter imbalance to find and treat what is going on in your system.  Fatigue can have many causes, but when the fatigue is hidden by caffeine use, it usually will fall in one of these two categories.  Finally, I invite you to take the Fatigue Ends Now quiz to see what may be causing the fatigue you are experiencing. 

Hope this helps! 


  4. US National Library of Medicine. Caffeine. MedlinePlus.