Origin of coffee, unroasted and roasted coffee beans, caffeine and chlorogenic acids, caffeine as stimulant, side effects and documented deaths from overdose.

1. BREWED COFFEE :
CAFFEINE
FROM
ANCIENT DRINK
TO
MODERN SCIENCEBy
Kevin KF Ng, MD, PhD.
Former Associate Professor of Medicine
Division of Clinical Pharmacology
University of Miami, Miami, FL., USA
Email: kevinng68@gmail.com
A Slide Presentation for HealthCare Provider Seminar July 2020

2. Lecture Outline
▪ What is coffee ?
▪ History
▪ Cultivation
▪ Ingredients
▪ Scientific studies
▪ Benefits
▪ Side effects
▪ Summary

3. Potential Coffee Crisis?
▪ The world currently enjoys a two-billion-cup-a-day
habit.
▪ The demand for coffee can only be met if we
encroach on 2.2 million hectares of valuable
rainforest.
▪ The livelihood of 25 million people may depend on
scientists finding a way to protect vulnerable coffee
plants and their ripening berries.
https://www.bbc.com/future/article/20150728-coffee-the-bitter-end-of-our-favourite-drink?ocid=fbfut

4. Roasting green coffee bean removes chlorogenic acid,
enhance flavor
without affecting caffeine content
Lecture on chlorogenic acid will be presented in near future.

5. What is Coffee?
▪ Coffee is a brewed drink prepared from roasted coffee
beans, the seeds of berries from certain Coffea species.
▪ Roasted beans are ground and then brewed with near-
boiling water to produce the beverage known as coffee.
▪ Coffee is darkly colored, bitter, slightly acidic and has a
stimulating effect in humans, primarily due to its
caffeine content

6. Cultivation of coffee from Ethiopia to other parts of the world

7. Milestones in the history of coffee, caffeine and
chlorogenic acid

8. The Coffee Belt, A World Map of the Major Coffee Producers (2018)
https://seasia.co/2018/01/27/the-coffee-belt-a-world-map-of-the-major-coffee-producers

9. Top 10 coffee consuming countries in the world
https://coffeforus.com/coffee-consumption-by-country-top/

10. Number of publications on Coffee” and “Caffeine” in PubMed
up to 2019
Coffee Caffeine
https://pubmed.ncbi.nlm.nih.gov/?term=coffee

11. The Most Amazing Coffee Statistics
▪ Americans consume 75% of all their caffeine in the form of coffee.
▪ 66% of women drink coffee every day, compared to 62% of men.
▪ 79% of Americans prepare coffee at home.
▪ 48% of millennials consume gourmet coffee.
▪ About 29% of US coffee consumers drink coffee to relax.
▪ Robusta beans have a higher caffeine content than Arabica beans.
▪ A coffee plant can live up to 100 years.
▪ Brazil exports 5.7 billion pounds of coffee every year.
https://disturbmenot.co/coffee-statistics/

12. Scientific classification of coffee plant

13. 2 main varieties of cultivated coffee beans
There are over 100 species
▪ Robusta: This type of coffee, which contains 2.5% more
caffeine than other types, has a pretty strong taste.
▪ Arabica: This coffee bean with low caffeine and a
smoother taste is aromatic and delicious. 80% of the
coffee in the world is produced from these types of
beans.
▪ Liberica: Liberica is a low yield type of coffee compared
to Arabica and Robusta.
https://www.eliteworldhotels.com.tr/blog-en/for-coffee-lovers-7-different-types-of-
coffee-beans-from-different-countries-and-their-characteristics.3373.aspx

14. Difference between Arabica and Robusta coffee

15. Coffee berry at different stages of ripening
https://www.nature.com/articles/s41598-018-29842-4

16. Structure of the coffee bean
https://www.feedipedia.org/node/549

17. Types of coffee roasts
https://www.homegrounds.co/how-to-roast-coffee-beans/
Roasting machine

18. 7 types of coffee beans from different countries
Coffee is grown in about 70 countries
1. Vietnam – Robusta
2. Indonesia - Robusta & Arabica
3. Brazil - Arabica
4. India - Arabica & Robusta
5. Colombia - Arabica
6. Ethiopia - Arabica
7. Uganda – Arabica & Robusta
https://www.eliteworldhotels.com.tr/blog-en/for-coffee-lovers-7-different-types-
of-coffee-beans-from-different-countries-and-their-characteristics.3373.aspx

19. Nutrient composition of coffee beans
▪ There are many nutritive substances in coffee brews which vary with the
types of techniques employed in brewing processes.
▪ Coffee contains small amounts of mineral such as Ca, K, Fe, P, Ni, Mg,
and Cr .
▪ The major bioactive compounds are:
▪ Alkaloid: caffeine
▪ Polyphenol: chlorogenic acid
▪ Melanoidins: herterogeneous polymers
▪ Carbohydrates: polysaccharides
▪ Roasting the coffee beans removes >90% of chlorogenic acids leaving
the caffeiene content unchanged

20. Coffee manufacturing process
https://www.iloencyclopaedia.org/part-x-96841/beverage-industry/item/955-coffee-industry
green coffee

21. Beans and ground coffee
(unroasted or with different levels of roasting). 2018
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6274859/
Beans
Ground coffee

22. Chemical Changes in the Components of Coffee Beans
during Roasting (2015)
https://www.sciencedirect.com/science/article/pii/B9780124095175000103
Chlorogenic acids
Caffeine
unroasted
roasted

23. Chemical composition of unroasted and roasted C. Arabica
coffee bean (2012)
https://www.researchgate.net/figure/Chemical-composition-of-unroasted-and-roasted-C-Arabica-Farah-2012_tbl7_305510847

24. Caffeic and chlorogenic acids contents in the soluble extracts of
green, light roasted, medium roasted and dark roasted Robusta coffee,
submitted to freeze-drying and spray-drying (2018)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6274859/

25. Nutrient facts of 1 cup (8 fl oz) of Yeman coffee
Percent Daily Values are based on a 2,000 calorie diet
https://fdc.nal.usda.gov/fdc-app.html#/?query=ndbNumber:14209

26. What is Caffeine?
▪ Drug class: central nervous system stimulant
▪ Onset of action: ~1 hour
▪ Duration of action: 3–4 hours
▪ Metabolism: Primary: CYP1A2; Minor: CYP2E1, CYP3A4, CYP2C8, CYP2C9
▪ Elimination half-life: Adults: 3–7 hours; Infants: 65–130 hours
▪ Other names: Guaranine; Methyltheobromine; 1,3,7-Trimethylxanthine; Theine
https://en.wikipedia.org/wiki/Caffeine

27. Caffeine content in different preparations of coffee
https://headaches.org/2019/02/24/does-caffeine-trigger-or-treat-headaches/

28. Acute effects of caffeine on the systems of the body
https://www.researchgate.net/figure/Caffeine-ingestion-has-acute-effects-on-
numerous-body-systems-including-the-following_fig1_249646232

29. Mechanism of stimulant action of caffeine on brain:
adenosine receptor blockade by caffeine
A=adenosine C=caffeine

30. Mechanism of action of phosphodiesterase 4 inhibitors (PDEIs):
enzyme inhibition by caffeine
https://www.researchgate.net/figure/Mechanism-of-action-of-phosphodiesterase-4-inhibitors-PDEIs-PDE4Is-inhibit-the_fig1_282345439
caffeine

31. Effects of caffeine on neurotransmitters
As a consequence of its blockade of adenosine receptors, caffeine also has profound
effects on other major neurotransmitters, including dopamine, acetylcholine,
serotonin, and, in high doses, on norepinephrine.
http://worldofcaffeine.com/caffeine-and-neurotransmitters/neurotransmitters-venn-diagram-2/

32. Bioavailability of caffeine (1983)
Half-life 2.7 to 9.9 h
Adapted from https://pubmed.ncbi.nlm.nih.gov/6832208/

33. The half-life of caffeine is about 4 hours
https://www.sketchplanations.com/post/153511487793/the-half-life-of-caffeine-is-about-4-hours-the

34. Breakdown of caffeine in the liver
by enzyme CYP1A2
Liver CYP1A2

35. Caffeine Dependence, Withdrawal, and Tolerance
▪ Dependence:
▪ a pattern of behavior focused on the repetitive and compulsive seeking and taking
of a psychoactive drug.
▪ Withdrawal symptoms in humans
▪ Headaches
▪ Fatigue
▪ Weakness
▪ Drowsiness
▪ Impaired concentration
▪ Work difficulty
▪ Depression
▪ Anxiety
▪ Irritability
▪ Increased muscle tension
▪ Tremor, nausea, and vomiting (occasionally)
▪ Withdrawal symptoms generally begin 12-24 hours after sudden
cessation of caffeine consumption and reach a peak after 20-48
hours.
▪ Tolerance: tendency to increase consumption of caffeine
https://emedicine.medscape.com/article/1182710-overview?src=ppc_google_rlsa-traf_mscp_emed-mid-cohort_md_us#a6
1

36. Main symptoms of Caffeine Overdose
https://www.researchgate.net/figure/Caffeine-ingestion-has-acute-effects-on-numerous-body-systems-including-the-following_fig1_249646232

37. 25 Common Caffeine and Drug Interactions classified as
severe to moderately severe
https://www.caffeineinformer.com/caffeine-drug-interactions

38. Safety of caffeine
▪ Caffeine is classified by the US Food and Drug Administration as
generally recognized as safe (GRAS).
▪ Toxic dose is over 10 grams per day for an adult
▪ A cup of coffee contains 80–175 mg of caffeine, depending on what
"bean" (seed) is used and how it is prepared (e.g., drip, percolation, or
espresso).
▪ Thus it requires roughly 50–100 ordinary cups of coffee to reach the
toxic dose.
https://en.wikipedia.org/wiki/Caffein
e

39. Toxic and lethal plasma concentration of caffeine (2018)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5986491/

40. Documented Deaths By Caffeine
▪ Death By Caffeine Pills: (4)
▪ Death by caffeine powder: (1)
▪ Death by Energy Drinks : (4)
▪ Death by Monster: (3)
▪ Death By Red Bull : (3)
https://www.caffeineinformer.com/a-real-life-death-by-caffeine

41. Use of Roasted coffee
▪ Roasting coffee transforms the chemical and physical properties
of green coffee beans into roasted coffee products.
▪ The roasting process is what produces the characteristic flavor of
coffee by causing the green coffee beans to change in taste.
▪ The stimulant property of caffeine has been exploited for
enhancement of physical performance.
▪ Recent studies have been made on the effects of caffeine on
obesity , metabolic syndrome and cancer.

42. The effect of caffeine on exercise performance when ingesting caffeine
before exercise (above horizontal hashed line) or
before and during exercise (below horizontal hashed line)
https://www.researchgate.net/figure/The-effect-of-caffeine-CAF-on-exercise-performance-when-ingesting-CAF-before-exercise_fig2_23658597

43. Effect of caffeine ingestion as compared to a placebo on
single and repeated jump performance in team sport athletes (2018)
https://www.tandfonline.com/doi/full/10.1080/15438627.2018.1552146
Favors caffeine

44. Clinical studies on the effects of coffee on
selected medical conditions

45. Meta-analysis of caffeine induced diuresis. (2015)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4725310/

46. Harmful and beneficial effects of Coffee consumption:
meta-analyses of multiple health outcomes (2017)
https://www.bmj.com/content/359/bmj.j5024
Harmful
Beneficial

47. The effect of coffee consumption on serum lipids:
a meta-analysis of randomized controlled trials (2012)
https://www.nature.com/articles/ejcn201268/figures/2

48. Coffee Intake and Obesity: A Meta-Analysis (2019)
https://www.mdpi.com/2072-6643/11/6/1274/htm
Our meta-analysis suggests that higher coffee intake might be modestly associated with reduced adiposity, particularly in men.

49. Relative Risk (RR) of coffee and cancer incidence (2016)
▪ Inverse associations were observed on:
▪ Oral cancer: RR 0.69 (95% CI = 0.48-0.99, I2 = 73.4%, P = 0.044)
▪ Pharyngeal cancer: RR 0.87 (95% CI = 0.78-0.96, I2 = 28.4%, P = 0.007),
▪ Colon cancer: RR 0.46 (95% CI = 0.37-0.57, I2 = 0%, P = 0),
▪ Liver cancer: RR 0.89 (95% CI = 0.84-0.93, I2 = 30.3%, P = 0.003),
▪ Prostate cancer: RR 0.73 (95% CI = 0.67-0.80, I2 = 0%, P = 0)’
▪ Endometrial cancer: RR 0.89 (95% CI = 0.80-0.99, I2 = 0%, P = 0.031)
▪ Lung cancer: RR 2.18 (95% CI = 1.26-3.75, I2 = 63.3%, P = 0.005)
▪ Breast cancer: No association was found between overall coffee drinking
and breast cancer
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5036059/https://www.nature.com/articles/s41598-019-49205-x

50. Is caffeine consumption safe during pregnancy?
▪ Moderate caffeine consumption (less than 200 mg per
day) does not appear to be a major contributing factor in
miscarriage or preterm birth.
▪ The relationship of caffeine to growth restriction remains
undetermined.
▪ A final conclusion cannot be made at this time as to
whether there is a correlation between high caffeine
intake and miscarriage.
https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2010/08/moderate-caffeine-consumption-during-pregnancy

51. Summary
▪ Originating in Ethiopia almost two thousand years ago, coffee plant is
now cultivated in many tropical countries.
▪ Only 2 species of coffea are grown for human consumption: Arabica
and Robusta.
▪ 70% of the world drinks Arabica and 30% drinks Robusta coffee.
▪ The major bioactive compounds in coffee are caffeine and chlorogenic
acids.
▪ Roasting degrades almost all the chlorogenic acids leaving the caffeine
unchanged.
▪ Caffeine is mainly used as a stimulant; chlorogenic acids are now been
studied for their anti-obesity, anti-hypertension, anti-hyperlipidemia,
anti-diabetes and anticancer properties

52. ANY QUESTION?
Please contact
Kevin KF Ng, MD, PhD
Email: kevinng68@gmail.com