Coffee Health Benefits
The History of Coffee
Coffee is thought to have originated in Ethiopia.
The first evidence of coffee drinking is from the 15th century in Yemen.
Coffee had reached the rest of the Middle East, South India, Persia, Turkey, and Northern Africa by the 16th century.
It then spread to the Balkans, Italy, and the rest of Europe, to Indonesia, and then to America.
Coffee Species
Over 130 species of the genus Coffea have been identified. However, there are only 2 species that dominate the worldwide market.
Arabica
The Arabica coffee plant Coffea arabica accounts for almost two-thirds of the world’s coffee production.
Robusta
Also known as Coffee canephora a species that was cultivated due to an outbreak of leaf rust that virtually wiped out production of coffee in Asia.
Robusta is a poorer quality coffee in comparison to Arabica. It is commonly described as having a burnt rubber taste. It is most often used as a blend, or in instant soluble coffee products. Robusta contains twice the caffeine as Arabica.
Coffee consumption
Coffee is the most widely consumed beverage in the world behind water.
It is estimated that 2.25 billion cups of coffee are consumed each day worldwide.
Depending on where you live in the world will determine how coffee is served.
How is coffee prepared around the world?
America - Filter coffee, Starbucks. You know the coffee is terrible in America when the best option is Starbucks. I spent way more time than I would like to admit trying to find a drinkable coffee in the States. From memory, the best coffee we could find on the west coast was in either Portland, Oregon, or Boise, Idaho.
Australia - Flat white, long black, cappuccino, ristretto, latte. I may be biased but I do believe from my ventures around the world that hands down Australia makes the best coffee!
Austria - Kapuziner (espresso and whipped cream)
China - Yuangyang (coffee, black tea, sweetened condensed milk)
France - Cafe, cafe creme, cafe au lait, French press
Greece - Frappe, frappuccino, freddo espresso
Indonesia - Kopi terbalik, kopi joss (coffee with burning charcoal), kopui luwak (coffee bean that has been collected from the poo of the civet. kopi turbruk (coffee grounds, water)
Ireland - Irish coffee (Irish whiskey, coffee, sugar, cream)
Italy - Espresso, espressino (espresso, steamed milk, cocoa), caffee latte (espresso, steamed milk, milk foam), cappuccino, ristretto, caffe americano, macchiato, barbajada (espresso, sweetened milk, cocoa)
Malaysia - Ipoh white coffee (coffee beans, margarine, condensed milk)
Mexico - Cafe de Olla (ground coffee, cinnamon-infused sweetened water, cocoa beans, anise, clove or orange zest)
Portugal - Cafe com cheirinho
Saudi Arabia - Arabic coffee
Senegal - Cafe touba (coffee, guinea pepper, cloves)
South Korea - Dalgona (instant coffee, sugar, water, whipped)
Spain - Cortano, cafe bombon (coffee and condensed milk), cafe del tiempo (coffee, ice, lemon). cafe con miel (espresso, steamed milk, honey, cinnamon)
Turkey - Turk Kahvesi (coffee, water, sugar) brought to a boil in a cezve.
Vietnam - Vietnamese Yoghurt coffee, ca phe trung (Vietnamese coffee, egg yolks, condensed milk)
Coffee Absorption
Caffeine is quickly absorbed primarily in the small intestine with some absorption occurring in the stomach. The majority (99%) of caffeine is absorbed within ~45 mins.
The peak level of caffeine in the body occurs 1-2 hours after coffee consumption.
The half-life of caffeine is 2.5-5 hours depending on a few factors. Smoking, genetics, health status, oral contraceptives, and pregnancy are some of the factors that can influence caffeine’s half-life.
The half-life of something refers to the amount of time that it takes for the concentration of a substance to decrease to half the starting dose in the body.
Coffee can also impact the absorption and excretion of some vitamins and minerals as well as the metabolism of some medications.
Bioactive Compounds in Coffee
Coffee contains more than 1,000 different bioactive compounds.
Caffeine
The most abundant and well-known chemical in coffee is caffeine, which is responsible for coffee’s strong aroma and it’s bitterness. As well as the component that is responsible for keeping you awake. Caffeine also has anti-oxidant, pro-inflammatory and anti-diabetic properties.
Chlorogenic Acids
Are also responsible for coffee’s bitterness and have anti-oxidant benefits.
Caffeic Acid
Has potential anti-oxidant, anti-inflammatory, and anti-cancer benefits.
Trigonelline
Has anti-inflammatory, anti-cancer, and neuroprotective benefits.
Kahweol and Cafestol
Tryptophan has various biological effects on the body including altering mood, cognition, sleep, aggressiveness, vomiting, and other physiological processes. Consuming coffee has been shown to increase the availability of the neurotransmitter 5-hydroxytryptamine (5-HTP) a precursor to serotonin production.
Melanoidins
Have anti-oxidant, anti-inflammatory, and anti-hypertensive benefits.
Diterpenes
Have anti-oxidant, anti-inflammatory, and anti-cancer benefits and is also pro-cholesterol.
Niacin aka Vitamin B3
Helps in the metabolism of carbohydrates, fats, and protein. It improves cholesterol levels, blood circulation, enhances the immune system, and helps to maintain the nervous system, and improves psychological wellbeing.
Coffee and the Gastrointestinal System
This won’t be a surprise for those of you who use coffee as part of your morning routine to help you poo.
Coffee stimulates the movement of the large intestine as quickly as 4 mins after drinking coffee which is comparable to eating cereals. Decaffeinated coffee has a similar effect with the effect seen 4 - 30 mins post-consumption.
One study compared coffee intake to water intake and the time until the first poo after a caesarean section. The coffee group did their first poo in a shorter amount of time compared to the water group.
Another study compared coffee, warm water, and nicotine use on rectal tone and visceral sensitivity. Rectal tone was increased by 45% 30 mins after coffee intake and by 30% 30 mins after water intake. Rectal tone change was not significant in the nicotine or placebo groups.
Another study compared coffee and water in patients who were experiencing postoperative ileus after abdominal surgery. A postoperative ileus generally occurs after an abdominal surgery where the intestines have been moved around. An ileus just means that the normal intestinal muscle function that contracts and pushes food through the digestive system has temporarily stopped. When the normal pushing of food through the digestive system stops food isn’t going anywhere and this causes bloating, vomiting, constipation, cramping, and loss of appetite. This often means that people need to be fed with liquid food through a nasogastric tube that goes through the nose and into the stomach. In this study, the coffee group had their nasogastric tube removed quicker than the water group and also had a reduced length of stay at the hospital.
The evidence for coffee causing or increasing symptoms of reflux is inconclusive. Some studies say coffee consumption is associated with reflux symptoms, others say that it is not, and another says that decaffeinated verse caffeinated reduced symptoms.
Coffee, awakeness, and sleepiness
Have you ever wondered why caffeine makes you feel more awake and can keep you from sleeping?
A molecule called adenosine plays a role in sleep-wake regulation. Adenosine levels continually rise while we are awake and are thought to promote sleep by reducing the areas of the brain that keep us awake. The longer you stay awake the higher the concentration of adenosine, and the more you want to sleep. Adenosine levels then decrease while we are asleep.
Caffeine blocks adenosine receptors which keeps adenosine levels low, this promotes wakefulness.
For chronic caffeine users, a caffeine metabolite paraxanthine is thought to change the adenosine system which may affect sleep. In rat and mouse model studies chronic caffeine consumption increases the number of adenosine receptors.
Coffee & Anxiety
Research shows that disturbed sleep and anxiety are seen in people chronically consuming 5 cups (>500mg caffeine) of coffee per day.
In people who have anxiety disorders consuming 10mg/kg of caffeine can cause symptoms of anxiety and panic attacks due to plasma caffeine levels.
Healthy people, with variations in the ADORA2A gene, have an increased risk of anxiety symptoms when consuming normal amounts of caffeine.
What are the health benefits of coffee?
Type 2 Diabetes
2-3 cups per day of caffeinated and noncaffeinated coffee lowers the risk of type 2 diabetes. Coffee is thought to decrease the absorption of glucose.
Cardiovascular Disease Risk
3 cups per day lower the risk of high blood pressure, cardiovascular disease, stroke, heart failure, death after a heart attack, and death by any cause.
Bone Health
Men - 3 cups per day lowers your risk of osteoporotic fractures.
Ladies - will pull the short straw yet again, one cup a day increases the risk of osteoporotic fractures.
Depression
Lowered risk of depression by 24% with 3-4 cups verse none.
Kidney health
Dose-dependent lowered risk of chronic kidney disease, kidney stones, and gout.
Alzheimer’s disease
Conflicting results may be a lower risk of Alzheimer’s disease with the highest intake versus no intake.
Liver Disease
Dose-dependent lowered risk of chronic liver disease-related conditions (fibrosis, cirrhosis, NAFLD), liver cancer, pancreatitis, and gallstone disease.
Gut Health
Increases Bifidobacterium, prebiotic effect in animal studies, increases gut motility (movement of food through the digestive system).
In people with irritable bowel syndrome, symptoms worsened with coffee intake.
All-cause mortality
Lowered risk of death by any cause.
How much coffee should I be drinking?
3-4 cups per day for optimal health benefits.
1 cup is equal to ~100mg of caffeine.
Who should be watching how much coffee they drink?
Pregnancy
No more than 200mg of caffeine per day.
Caffeine and its metabolites pass freely across the placenta to the fetus.
High caffeine intake (>300mg/day) during pregnancy increases the risk of pregnancy loss, low birth weight, and first and second-trimester preterm birth.
Ladies with or at risk of osteoporosis
Consumption of large amounts of coffee has been shown to increase urinary excretion of calcium. In postmenopausal women, calcium is an important nutrient due to the loss of oestrogen and the role it plays in bone formation and prevention of bone breakdown.
Conditions or diseases of the digestive system
Coffee has been shown to increase symptoms of irritable bowel syndrome.
The evidence for inflammatory bowel disease is not solid. In one study, coffee intake decreased the risk of ulcerative colitis but not the risk of Crohn’s disease. A meta-analysis showed that coffee intake may be protective for both individuals with UC and CD, although not significant. A reported two-thirds of people with IBD avoided coffee due to gastrointestinal symptoms.
High blood cholesterol
Coffee has a short-term effect of increasing blood fats including total cholesterol, LDL (bad) cholesterol, and triglycerides.
References
Sloots, C. E. J., Felt-Bersma, R. J. F., West, R. L., & Kuipers, E. J. (2005). Stimulation of defecation: Effects of coffee use and nicotine on rectal tone and visceral sensitivity. Scandinavian Journal of Gastroenterology, 40(7), 808–813. https://doi.org/10.1080/00365520510015872