Coffee and Green Coffee Bean Extract

Also known as: Coffea arabica

Safety Rating: 

Dose Safety

While caffeine is generally safe in moderate doses, the meaning of “moderate” depends on the person, their medications, and their current health conditions.  According to the Mayo Clinic, up to 400 mg a day seems to be safe for most healthy adults. The American Academy of Pediatrics cautions that children under age 12 should avoid caffeine, and older children should limit their daily intake to 100 mg.

The recommended maximum daily intake of caffeine (and the equivalent amount of regular black coffee) for otherwise healthy people are listed below:

Potential Side effects

Agitation/Irritability

Anxiety/Nervousness

Diarrhea

Headaches

Heartburn/GERD

Increased eye pressure

Increased urination

Insomnia

Nausea

Spikes in blood pressure

Stomach upset/stomach pain

Tremors

Overview

What is it? 

• Coffee is fruit from the Coffea plant, which comes in many different varieties. The beans contain caffeine, which is a stimulant. Green coffee beans are “raw”, while the more common dark brown coffee beans are roasted.
• Green coffee beans contain a much higher amount of chlorogenic acid than roasted coffee beans.

Why is it used? Stimulants like caffeine are popular ingredients in supplements that claim to “promote weight loss”, “increase energy”, or “increase focus”. Green coffee beans can also be found in supplements that claim the high chlorogenic acid  content may lower blood pressure.

What’s the harm? Besides the side effects listed above, caffeine can interact with many medications and conditions, sometimes in very serious ways (see Interactions below).

Interactions with health conditions

ADHD: May cause or increase side effects from ADHD medications

Aneurism/Bleed risk: Caffeine can increase bleeds in patients with higher bleed risks.

Anxiety: May cause or worsen anxiety

Bone density/Osteoporosis: coffee can reduce the effectiveness of some medications meant to treat or prevent osteoporosis.

Glaucoma: Increased intraocular pressure due to tightened blood vessels

Heart problems: Temporarily increased blood pressure and/or heart rate is usually seen 30 minutes after ingesting caffeine, and can last up to 4 hours after drinking.

Insomnia: Could worsen insomnia symptoms

Drug Interactions

ADHD medications: Combining Caffeine with ADHD medications may:

• increase blood pressure
• worsen other medication side effects such as insomnia and loss of appetite

Anxiety medications: Caffeine may increase anxiety, requiring higher or more frequent doses of anti-anxiety medications

Blood Thinners: Caffeine may increase risk of bleeding when taken with blood thinners.

Blood Pressure medications: Caffeine may raise blood pressure for up to 4 hours, working against the effects of blood pressure medications.

Bone density/Osteoporosis: Taking Alendronate (Fosamax) with coffee has been shown to decrease the amount of Alendronate available to the body by 60%. This may be avoided by taking them 2 hours apart.

CYP1A2 inhibitors: Combining caffeine with CYP1A2 inhibitors may increase the amount of caffeine in the body, resulting in increased caffeine side effects. 

Examples: Cimetidine, Ciprofloxacin, Ethinyl Estradiol, Fluvoxamine

Heart Rate Control medications: Caffeine may increase heart rate for up to 4 hours, countering the action of medications meant to lower heart rate. These medications include Beta Blockers, some CCBs like Diltiazem and Verapamil, and Digoxin.

Pain medications: Interactions with some pain medications could lead to serious reactions like Serotonin Syndrome and Call-Fleming Syndrome.

Sleep medications: Could worsen insomnia, requiring higher doses of sleep medications

Stimulants: Combining caffeine with other stimulants can increase side effects and risk of heart attack, stroke, or seizure. Stimulant drugs are often used for ADHD and weight loss. For stimulant herbs, see "Interactions with herbs/supplements" below. 

Interactions with herbs/supplements

Blood clot prevention: There may be an increased risk of bleeding when combined with caffeine

Calcium and Magnesium: High caffeine intake can increase the amount of Calcium and Magnesium removed from the body in urine.

CYP1A2 inhibitors: Taking with CYP1A2 inhibitor ingredients may raise the amount of caffeine in the body, resulting in increased caffeine side effects. Examples include:

• Danshen
• Echinacea
• Kudzu
• Red clover
• St John’s Wort

Stimulants: Combining a stimulant like caffeine with other herbal stimulants could worsen the side effects from both ingredients. Examples include:

• Green tea extract
• Guarana
• Octodrine

• PEA

Interactions with foods

Alcohol:Combining caffeine and alcohol can raise caffeine levels, resulting in increased caffeine side effects.

Interactions with lab tests

Caffeine may impact several lab and test results. The results of these test can help decide if medication might be needed to treat a condition, and even point towards which medication and what kind of dose! Because of that, accuracy in these tests is extremely important.  Make sure to speak to your health care team about your caffeine intake (how much, how often, and when you last had some) before getting these labs/tests done:

Cancer screening: One important tool used to help detect certain types of cancer is testing the urine for specific chemicals. Caffeine may temporarily increase the levels of some of these chemicals in the urine, making the tests innacurate.

Heart function: Caffeine may temporarily increase blood pressure and heart rate, which could change the results of tests measuring heart function.

Kidney function: Creatinine urine tests can show how well (or poorly) your kidneys are working. They can also help identify harmful muscle breakdown. Caffeine can increase the amount of creatine in urine.

Lung function/breathing: Caffeine may change the results of tests measuring lung function, such as in patients with asthma. 

References

1. *Natural Medicines. (2019, March 21). Coffee[Monograph]. Natural Standard Professional Monograph. Retrieved from: https://naturalmedicines.therapeuticresearch.com/databases/food,-herbs-supplements/professional.aspx?productid=980 
   
2. *Natural Medicines. (2019, February 21). Green Coffee [Monograph]. Natural Standard Professional Monograph. Retrieved from: https://naturalmedicines.therapeuticresearch.com/databases/food,-herbs-supplements/professional.aspx?productid=1264 
3. American Academy of Pediatrics. (2011 Retrieved 03/2019: https://www.aap.org/en-us/about-the-aap/aap-press-room/pages/Kids-Should-Not-Consume-Energy-Drinks,-and-Rarely-Need-Sports-Drinks,-Says-AAP.aspx  
4. Mayo Clinic. (2017). "Caffeine: How much is too much?". Retrieved 03/2019: https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/caffeine/art-20045678  
5. Mayo Clinic. (2017). "Serotonin Syndrome". Retrieved 03/2019: https://www.mayoclinic.org/diseases-conditions/serotonin-syndrome/symptoms-causes/syc-20354758 
   
   

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