Coffee: types, benefits, side effects

Hands up – how many of us go for a tasty cup of coffee in the morning to get us going? Coffee is great, whether you’re drinking to start your day or getting a pick-me-up in the afternoon. But how much do you actually know about our go-to energy cup?

Coffee is a source of caffeine, a natural stimulant that occurs in coffees, teas, and cacao. There are many different types of coffee from different sources around the world. Coffee and caffeine have several associated health benefits, although they’re not without their side effects either.

If you want to learn all about coffee, you’ve come to the right place. We’ll give you a rundown of coffee and its history, types, benefits and side effects, and how much of it you can actually drink.

A history of coffee

Coffee as we know it traces its roots all the way back to ancient Ethiopia and Yemen. Its cultural significance goes back fourteen centuries (yep, centuries!) when it was discovered – although whether it was in Ethiopia or Yemen is up for debate. There are several stories, but two remain very popular.

Ethiopian coffee history

There’s a very common legend in Ethiopia about a goat herder named Kaldi. One day he noticed his goats were very energetic, which was strange. He found the source – a small shrub with bright red berries. Amazed, Kaldi filled his pockets and rushed to show his wife, who told Kaldi he should share the berries with the monks.

The monks at first rejected the berries, and tossed them into the fire. But that roasted the beans, causing a tempting aroma. The monks quickly removed the beans from the fire and attempted to preserve them in a jar of hot water. This “brewed” the coffee, which the monks tried and found to be uplifting. They then decided to produce it as a drink.

Many written and oral accounts date this discovery to around 850AD, which matches the commonly-held belief that Ethiopians began cultivating coffee in the 9th century. However, it’s likely believed that people originally chewed coffee berries as a stimulant rather than brewing it.

It’s unclear what started the cultural shift from consuming coffee to drinking it. But in the 13th century, coffee spread to the Islamic world, where they began brewing stronger decoctions – bringing about the coffee we know today. [1]

The monks at first rejected the berries, and tossed them into the fire. But that roasted the beans, causing a tempting aroma.

Yemeni coffee history

There are several stories regarding the origin of coffee in Yemen, but one of the most basic involves a Sufi mystic called Ghothul Akbar Nooruddin Abu al-Hasan al-Shadhili. Ghothul was travelling through Ethiopia on spiritual matters when he saw some very energetic birds. It turned out they were eating the fruit of a bunn plant.

Tired from his travels, Ghothul decided to try these berries for himself. When they energized him as well, he decided to bring the berries with him.

The earliest credible record of humans interacting with the coffee plant is in the mid-15th century. Monks in Sufi monasteries in Yemen would drink coffee to stay alert during their long hours of nighttime prayer.

However, the belief is that coffee was an export from Ethiopia to Yemen, where Yemeni traders began cultivating coffee for themselves.

Yemen is also the origin of “mocha,” which today we associate with chocolate-flavored coffee drinks. But its origins are in the city of Mocha along the Red Sea coast of Yemen. This was a trading center for the Mocha coffee bean, which many prized for its distinct flavour. [2]

Coffee’s journey from Arabia to America

By the 16th century, coffee had spread to Persia, Egypt, Syria and even Turkey. People enjoyed it in homes and public coffee houses (in West Asia, these were termed “qahveh khaneh”). Here, patrons would drink coffee while watching music or performers, and exchanging news. Coffee houses became vital sources of information.

European travellers then began bringing back stories of this “dark beverage” from West Asia. Come the 17th century, coffee began making its way to Europe, where it began growing in popularity. However, local clergies and some people condemned the beverage as “a bitter invention of Satan.” But when Pope Clement VIII intervened and tasted the drink himself, he enjoyed it so much that he gave it papal approval.

Much like in West Asia, coffee houses began becoming popular all across Europe. It also became a common breakfast drink, which allowed people to start their days feeling energized and alert. They found their quality of work improved as well.

In the mid-1600s, the British brought coffee to New Amsterdam (later New York). While its popularity would grow, the New World people continued to prefer tea until the 1773 revolt against tea taxes.

This newfound popularity all across the world began a competition for coffee production. The Dutch would bring it to their colonies in Java (Indonesia) and Sumatra, while Americans grew it in the Caribbean Isles. Eventually, it spread to Central and South America.

These days, coffee is one of the world’s most profitable exports and one of the most sought-after commodities around the globe. [3]

Nowadays, plenty of countries cultivate their own coffee beans, each with distinctive flavors. Over 50 countries in the world produce coffee, with some more popular than others.

All information about coffee sources comes from the National Coffee Association USA (NCAUSA). [4]

Nowadays, plenty of countries cultivate their own coffee beans, each with distinctive flavors.
  • Hawai’i

The largest island of Hawai’i produces some of the best-known coffee beans – Kona coffee. It is grown along the slopes of the Mauna Loa volcano, in volcanic soil. The area often experiences cloudy skies in afternoons, which forms natural shade to protect the plants from the intense sun.

  • Costa Rica

This is the only country that produces wet-pressed Arabica beans. Costa Rica coffee has a medium body with sharp acidity, so it’s often praised for its “perfect balance.” Coffee growers work on small farms called fincas, and they pay careful attention to growing and processing methods.

  • Colombia

Colombia is second only to Brazil in terms of worldwide annual coffee production. The country maintains a high standard for coffee quality, and coffee growing is a source of pride among many small family farms. The Colombian environment provides the perfect conditions for growing coffee – especially Colombian Supremo, the highest grade.

  • Kenya

Kenyan coffee beans have a sharp, fruity acidity and a full body. Small farmers grow coffee along the foothills of Mount Kenya, with an emphasis on quality during processing and drying.

  • Vietnam

French missionaries brought coffee to Vietnam in the mid-19th century. It languished as a product for a while, but more recently, the Vietnamese coffee industry has boomed. Vietnam is now one of the world’s largest producers and exporters of coffee, growing mostly Robusta coffee with a mild body.

Steps to processing coffee

From these sources, your coffee takes a long journey to your kitchen and coffee cup. From seed to bean to brew, here are the steps coffee takes throughout the production process.

Steps based on information from the NCAUSA. [5]

#1 – Planting seeds

Coffee is actually a seed – it’s just a matter of whether it’s roasted or planted. For unprocessed seeds, these go back into the soil to grow into a coffee tree. They’re often grown in shaded nurseries and small family farms.

#2 – Harvesting berries

Coffee trees take 3–4 years to bear fruit, which is called the coffee cherry. These are bright red and shiny when ready for harvest, which takes place about once a year. They are either strip picked (all cherries stripped from a branch) or selectively picked (hand-picking only ripe cherries).

#3 – Processing

Coffee cherries need to be processed immediately; otherwise, the fruits could spoil. There are two ways to process: dry and wet methods.

Dry processing involves spreading the cherries on a surface and leaving them to dry in the sun. During the day, they are raked and turned to prevent spoilage. Then at night or during rain, they are covered so they don’t get wet. This process may take several weeks, until the moisture content falls to 11%.

Wet processing means removing the pulp from the cherry, leaving only the parchment skin on the bean. Beans are then separated by weight and size, after which they are transferred into water-filled fermentation tanks, The mucilage layer will dissolve over 1–2 days, after which the beans are ready for drying.

Coffee cherries need to be processed immediately; otherwise, the fruits could spoil. There are two ways to process: dry and wet methods.

#4 – Drying

Coffee beans are dried either by laying in the sun or by turning through tumblers. Dried beans are referred to as “parchment coffee.” They sit in jute or sisal bags until they are ready for export, at which point they will be milled.

#5 – Milling and exporting

First, processed and dried beans will be hulled – removing the parchment layer for wet-processed coffee, or the dried husk for dry-processed coffee. Then the beans are graded and sorted by size and weight. At this point, they’re also checked for imperfections such as colour spots. Defective beans are removed.

Following these quality checks, the beans are prepped for export.

#6 – Testing

Quality testing coffee is called “cupping,” which involves evaluating taste and visual quality. Beans are assessed visually, then roasted in a laboratory roaster. Following that, they are ground and infused in temperature-controlled water. The tester will evaluate aroma, taste, and characteristics.

#7 – Roasting

Approved batches of coffee are sent to be roasted, which transforms green coffee beans into the gorgeous brown ones we’re all familiar with. Machines roast the beans at a consistent temperature of about 550ºF, during which the beans constantly tumble and move to prevent burning.

This roasting process unlocks the caffeol – a fragrant oil in the beans. This is the source of the flavor and aroma of coffee.

Right after roasting, the beans will be cooled by air or water. After this, they are sent in batches to wholesalers or coffee houses for drink production.

#8 – Grinding and brewing

At this point, the coffee reaches its final stages. Whether a wholesaler, coffee house, or individual, a good brew starts by grinding coffee beans into “grounds.” You can grind coffee coarse or fine depending on the kind of brew you want. After that, it’s just a matter of brewing it using your preferred method, and presto – a cup of coffee!

At this point, the coffee reaches its final stages. Whether a wholesaler, coffee house, or individual, a good brew starts by grinding coffee beans into “grounds.

Health benefits of coffee

With a cup of coffee in hand, you may wonder – is it healthy for you? As it turns out, coffee and caffeine have plenty of health benefits. Here are just some of the good effects of drinking 95–400mg of caffeine (or 1–5 8oz cups of coffee) every day.

#1 – Source of vitamins and minerals

One 8oz cup of brewed coffee contains about 95–100mg of caffeine, which improves your blood flow and boosts energy. [6] Coffee is also a good source of vitamin B2 or riboflavin [7] and magnesium [8], both of which are essential for your body’s health.

#2 – Lower risk of Type 2 Diabetes

Coffee has lower calories and carbohydrates than most sugary drinks, so it’s an excellent substitute. Coffee and tea may also hold diabetes-preventing ingredients. [9]

#3 – Lower chances of heart attacks and strokes

Drinking coffee can lower your risk of heart failure – dropping around 5–12% per cup, versus people who drink no coffee. This is, of course, only for unsweetened or low-sugar and low-fat drinks. [10]

Meanwhile, research has shown that coffee can reduce your risk of suffering a stroke. [11]

#4 – Reduced risk of depression

You’re less likely to develop depression and associated mental divergences if you drink coffee. Caffeine has antioxidant effects that can lower oxidative stress in your blood levels. It also lowers inflammation-related proteins, which are more present in people with depression. [12]

#5 – Decreased risk of Alzheimer’s

Some research has shown that elderly women (65 years and older) who drank 2–3 cups of coffee were less likely to develop dementia versus those who drank no coffee. Over 60% of Americans who have Alzheimer’s are women. [13]

Side effects of coffee

On the flip side, coffee and caffeine aren’t wholly beneficial. There are associated adverse effects, especially if you drink too much or drink sweetened, high-fat beverages. [14]

#1 – Increases anxiety

Drinking excess amounts of coffee can cause you to feel anxious and jittery. This is because caffeine blocks adenosine receptors, which increases dopamine and noradrenaline. It also increases your heart rate.

If you already have a pre-existing anxiety condition, excess caffeine may worsen your symptoms. [15]

#2 – Disrupts sleep patterns

Since caffeine is a stimulant, it keeps you awake – and may subsequently affect the quality and amount of rest you get at night. It interferes with your circadian rhythm, which signals to your body when it’s time to sleep. This is especially detrimental if you consume coffee in the late afternoon to evening. [16]

#3 – Increases blood sugar

Drinking plain black coffee may actually reduce your risk of Type 2 Diabetes, but if you favor sugary and high-fat drinks such as lattes and macchiatos, you’ll instead be increasing your blood sugar. [17]

#4 – Worsens heartburn or acid reflux

Coffee and caffeine can make heartburn or acid reflux worse. It’s not responsible for your gastro-oesophageal reflux (usually), but its acidity and caffeine content can heighten symptoms. [18]

Decaffeinated coffee

You can mitigate some of these negative effects – or get your coffee fix without the caffeine – by drinking decaffeinated coffee. Just like regular coffee, decaf starts as unroasted green beans. However, instead of going straight to roasting, the beans are first soaked in liquid (either water, or water mixed with chemicals) to remove the caffeine.

The decaffeination process removes about 97% of the caffeine from the coffee beans, leaving about 2mg of caffeine per cup. [19]

Decaffeinated coffee

How much coffee can I drink?

Coffee isn’t for everyone, of course. Children, for example, should not be consuming coffee (although mildly caffeinated beverages such as cola are permitted). Other people who should not be drinking coffee include:

  • Persons on anti-anxiety medications and similar prescriptions
  • Pregnant or breastfeeding women
  • People suffering from heart disease or high blood pressure

Healthy adults can consume a maximum of 400mg of caffeine in a day. That’s about four to five 8oz cups of brewed coffee. Meanwhile, teenagers should consume 100mg of caffeine or less per day. [20]

It’s essential that you’re mindful of all potential sources of coffee. Caffeine isn’t just in coffee or tea – it can be found in other foods and beverages, such as chocolate and cola. Being conscious of the amount of caffeine you take in every day can prevent the effects of excessive caffeine intake.

Side effects of too much coffee

If you consume over 400mg of caffeine in a day, you’re likely to suffer adverse effects such as:

  • Restlessness
  • Jitteryness or shakiness
  • Headaches
  • Elevated heart rate
  • Dehydration
  • Anxiety symptoms
  • Insomnia

You may also develop a dependency on caffeine. [21]

So that’s that – the science shows that coffee in moderation is actually good for you, and can actually benefit your longevity. It won’t make you live longer, necessarily, but it reduces mortality risks and promotes bodily health. This means coffee isn’t just great for starting your day or giving you more energy in the afternoon – it’s good for your overall well-being.

REFERENCES

[1] https://www.ncausa.org/about-coffee/history-of-coffee
[2] https://www.thespruceeats.com/the-origin-of-coffee-765180
[3] https://www.ncausa.org/About-Coffee/History-of-Coffee
[4] https://www.ncausa.org/About-Coffee/Coffee-Around-the-World
[5] https://www.ncausa.org/About-Coffee/10-Steps-from-Seed-to-Cup
[6] https://www.hsph.harvard.edu/nutritionsource/caffeine/
[7] https://www.hsph.harvard.edu/nutritionsource/riboflavin-vitamin-b2/
[8] https://www.hsph.harvard.edu/nutritionsource/magnesium/
[9] https://www.hsph.harvard.edu/nutritionsource/disease-prevention/diabetes-prevention/preventing-diabetes-full-story/
[10] https://www.heart.org/en/news/2021/02/09/coffee-may-help-reduce-risk-for-heart-failure#:~:text=Across%20all%20three%20studies%2C%20people,people%20who%20drank%20no%20coffee.
[11] https://pubmed.ncbi.nlm.nih.gov/28693038/
[12] https://www.ncausa.org/Portals/56/PDFs/Communication/20200504_Leviton_white_paper_final.pdf
[13] https://www.hopkinsmedicine.org/health/wellness-and-prevention/9-reasons-why-the-right-amount-of-coffee-is-good-for-you
[14] https://www.aarp.org/health/healthy-living/info-10-2013/coffee-for-health.html
[15] https://www.medicalnewstoday.com/articles/anxiety-and-caffeine#symptoms-of-caffeine-induced-anxiety
[16] https://www.sleepfoundation.org/nutrition/caffeine-and-sleep
[17] https://www.aarp.org/health/healthy-living/info-10-2013/coffee-for-health.html
[18] https://pubmed.ncbi.nlm.nih.gov/7918922/
[19] https://www.ncausa.org/Decaffeinated-Coffee
[20] https://health.clevelandclinic.org/how-much-caffeine-is-too-much/#:~:text=Here%20are%20the%20boundaries.,about%20two%20cans%20of%20cola).
[21] https://medlineplus.gov/caffeine.html

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