Coffee is a massively popular drink, second only to water. In this article we take a deeper look at coffee, the many ways you can have it, the effects it has on your body and what it is doing to the planet.

Coffee is truly the drink of our times. As Australians steadily drink less alcohol (Roy Morgan reports that in 2006 73.5 per cent of Australians were regular drinkers, but that figure dropped to 66.3 per cent in 2020) we are embracing coffee in ever-increasing numbers. A few years ago, coffee overtook tea in Australia as the most consumed daily beverage after water. Amble through the doors of virtually any food outlet and you will be promised “barista-made” bounty, even if in some establishments the “barista” is just pushing a button. On the sidelines of sporting fields, at eisteddfods and just about any public event a takeaway coffee cup is an almost essential fashion item. Thankfully, “keep cups” are becoming more and more common as people try to combine their love of coffee with love of the planet.

There is no debate, coffee is popular. This beverage not only drives our food consumption habits; coffee forms a hub for our socialising, shapes our urban design and is a linchpin of global trade. In terms of value, coffee as a world commodity is second only to oil. However you look at it, coffee is certainly on trend, but is coffee’s popularity a good thing? To help make up your mind about it, let’s get Socratic about coffee. Socrates was the guy who supposedly said that the unexamined life is not worth living, so we will follow his lead and truly examine coffee, from tree to lips and beyond.

What are we talking about?

Coffee trees are commercially grown in Africa, Indonesia, Vietnam and South and Central America. Small plantations are also operating successfully in Australia. If you want to blow your mind, take a sip of the stats on coffee.

Across the world we drink around 2.25 billion cups of coffee every day. In 2020 that translated to 99,780,000,000 kilograms of coffee beans being consumed worldwide. In Australia alone in 2020 117,000,000 kilos of coffee beans were consumed and that was a slight COVID-19-induced drop from the 2019 figures. In 2019 total revenue from the Australian coffee market was US$5.97 billion.

With those mind-boggling statistics surrounding it, and the multilayered aura of socialising, contemplation and stimulation that it carries, coffee is certainly a romantic beverage. To strip away the veil, at its most unromantic level, coffee is made by infusing the dried and roasted beans of the Coffea arabica or the Coffea robusta trees. Yet in that word “infusing” there are a myriad of wrinkles and devotional experiences. How you prepare your coffee is central the coffee experience.

Espresso coffee

Espresso is made by forcing small amounts of hot water or steam through finely ground coffee beans. Although it contains more caffeine per volume than brewed coffee, it contains less per serve.
One shot of espresso (30–50ml) contains 30–60mg of caffeine. If you were to have a cup (240ml) of espresso you might have up to 300mg of caffeine but the reality is, we just don’t drink it that way.

Brewed coffee

This is made by pouring hot or boiling water over ground beans, maybe via a drip filter or a plunger. One cup (240ml) of brewed coffee contains 70–140mg of caffeine.

Instant coffee

Instant coffee is made by spraying liquid coffee concentrate as a fine mist into extremely hot, dry air. With the water removed the coffee is broken into small crystals that you spoon out of your jar and just add water. It is a far more complex process than it sounds, so do not try it at home. This is made by coffee that has been brewed then freeze dried or spray dried. One cup (240ml) of instant coffee contains 30-90mg of caffeine.

Coffee purists do look down on instant coffee, but a lot of coffee quality comes down to the beans that are used. Instant coffees have tended to use Coffea robusta beans which contain more caffeine, are more bitter and lack the fruity sweetness of Coffea arabica beans. Arabica beans are mostly grown in South America and tend to be more expensive than robusta.

Regardless of bean used, the consensus in coffee circles is that espresso is certainly the superior coffee form. It is described as “brighter” and “creamier” with “sugary sweet notes” when compared to the more intense, “clean” flavour of drip filter coffee. If you want more coffee descriptors to impress your friends, there is no shortage of terms out there; coffee snobbery is alive and well.

Coffee in your body

Coffee is such a lifestyle phenomenon that an enormous amount of research is going on into its effects on the human body. Some what we are finding out is good and some is not so good.

The good news

Many of the beneficial effects from coffee we are about to list arise at quite high consumption levels (like four or five cups a day), and at that level you also start to get some negative effects from high caffeine levels and so on. So don’t get too excited and think that more coffee is better. “Safe” levels of caffeine are hard to define, but for a healthy adult the Mayo Clinic, for example, indicates that up to 400mg daily is fine.

Coffee and dementia
A study from the journal Nature Neuroscience involved almost 6500 women aged 65 and older. Women who consumed the highest amount of caffeine (more than 261mg of caffeine daily, equalling three 250ml cups of coffee) were 36 per cent less likely to develop dementia or cognitive impairment compared to women who drank the least caffeine (less than 64mg daily).

The effect that exists here is probably related to a brain chemical known as adenosine. Caffeine blocks adenosine from attaching to receptors in the brain. Adenosine attaches to receptors and by influencing the release of neurotransmitters like dopamine and glutamate has a modulating effect on neuroplasticity in the parts of the brain involved in learning and memory. There is increasing thought that adenosine A2A receptors play a role in cognition and that they may be a way to treat cognitive conditions such as dementia.

Coffee and MS
Coffee may be performing a function in your nervous system that reduces your chances of developing multiple sclerosis (MS). This has been highlighted in research from the American Academy of Neurology.

The likely reason for the link is that caffeine suppresses the production of cytokines that promote inflammation and so diminish the mechanism by which MS occurs. The problem is that you need to be drinking four to six cups of coffee a day to get the effect. That is a lot of coffee, and it provides a lot of caffeine (depending on how you have your coffee) and may increase the risk of anxiety, depression, restlessness, increased heart rate and muscle tremors.

Coffee’s positive thinking effects
Many people have a cup of coffee in the morning to get their brain ticking over. Caffeine increases activity in the central nervous system (CNS), and that leads to improved performance on cognitive tasks. However, there is more to coffee than mere stimulation. A report published in PLOS One showed that people given caffeine equivalent to two to three cups of coffee showed greater recognition of words with positive emotional content but no change in recognition of words that were either neutral or negative. Caffeine’s effect on the neurotransmitter dopamine is thought to cause the positive thinking bias of coffee drinkers.

Coffee for longevity
Everyone wants to live a long life, provided they can be healthy. If coffee could contribute to that longevity then for many their cup would runneth over. Imagine the joy then at a study from the journal Circulation which found that people who drink moderate amounts of coffee, less than five cups a day, have lower risks of death from cardiovascular disease, neurological disease, type-2 diabetes and suicide. These findings held true for both caffeinated and decaffeinated coffee, so it must be other chemicals in the coffee besides caffeine that are having the beneficial effects.

It might also be something about the psychological experience of drinking coffee that is healthy as another study (from the journal Vascular Medicine) shows. For this study we need to go to the Greek island Ikaria. Researchers have been studying residents on Ikaria because while in the rest of Europe only 0.1 per cent of people living to be 90 years old, fully 1 per cent of Ikarians live to be over 90 — that is 10 times more than everywhere else. Is there a fountain of youth on Ikaria? According to the researchers it is their coffee.

When they looked at lifestyle choices of the Ikarian people they found that 87 per cent of them drank coffee. They found that blood vessel function was better in the coffee drinkers and that the boiled Greek coffee is the vascular basis for a long life. There is more to Greek coffee though than the beans

To make a Greek coffee as they drink it on Ikaria you need something equivalent to a briki which you can put on your stove to hold the coffee as it boils. You put coffee and water in your briki and place it on your stove on low heat. You slowly let the coffee heat up, until the surface starts to tremble and foam. You then remove it from the heat until the foam settles before returning it to the heat again to let it start foaming and puffing up, then you remove it. You then serve it, usually with a glass of cold water.

Coffee made this way is lower in caffeine than brewed or espresso coffee, but it retains antioxidants. However, it is the way that it is drunk that could be as important as what is in it. By tradition Greek coffee is consumed sitting down and is drunk in a leisurely manner. It is believed that to get the full flavour you need to sip the coffee slowly. Traditionally coffee has been consumed by Greeks two times a day, in the morning and in the afternoon after their nap.

Perhaps this deliberate, moderate, contemplative, ritualised nature of Greek coffee is the true magic of the brew.

The bad news

Coffee and blood pressure
We know that caffeine is a stimulant and that it increases blood pressure in the short term, but we also know that people who drink a lot of coffee develop a tolerance to it. What researchers who conducted a study published in the American Journal of Hypertension wanted to discover was whether coffee (or caffeine) consumption would affect your blood pressure in the short term if you had not had coffee for a while. The results showed that after abstaining from coffee for just two days the tolerance of the subjects to coffee did reduce and there was an immediate increase in blood pressure after drinking coffee. While you do build up a tolerance to it, caffeine certainly can raise your blood pressure.

Coffee and anxiety
The major problem with coffee is its caffeine content, although at times that caffeine can also be a good thing. The caffeine from coffee binds to receptors in your brain that are normally occupied by a brain chemical known as anandamide. This anandamide is a feel-good chemical, and when caffeine blocks it often enough problems can result. There is also evidence for instance that caffeinated coffee brings about different reactions in some people. For example, people living with panic or anxiety disorders are likely to become more anxious after consuming coffee. Research has also found that caffeine equivalent to five cups of coffee can cause hallucinations in people who are under high levels of stress. Still other research has reported that consuming coffee makes people with depression more anxious, indicating that certain people may be more sensitive to caffeine to begin with.

Insomnia
Due to its caffeine content, if you drink coffee late at night it can keep you awake. As obvious as this seems, it is something that people do overlook. It is a problem that can be avoided by drinking coffee early in the day and keeping your intake to a sensible level.

The dark power of coffee

The antioxidant effect of coffee is largely traced to a substance called chlorogenic acid, but research has shown that coffee beans lose 90 per cent of their chlorogenic acid during the roasting process. However, the darker the roast the more antioxidant activity present in the beans, so go for the darker roast if you want maximum antioxidant effect.

The organic advantage

In its natural state coffee grows on trees that are part of the diverse make-up of the rainforest. The coffee tree will usually be shaded by taller-growing trees and the canopy of the rainforest. Unfortunately, the very popularity of coffee is causing it some problems.

To keep up with global demand, coffee is frequently grown on cultivated land. This means clearing rainforest and planting coffee trees in rows where they get full sun. This intensive cultivation method has implications for both your taste buds and your conscience.

It is estimated that a coffee plantation will offer shelter to approximately 90 per cent less birdlife than trees grown under a canopy. Aside from what this means for the birdlife itself, since birds are natural insect scavengers, this means that an increased amount of pesticides must be used on the plants. It is believed that any pesticide residues are destroyed in the roasting of the beans. Even so, the knowledge that the farmers, who are often operating on a subsistence level, must be exposed to these pesticides will prick the conscience. As far as taste goes, coffee grown in the shade is thought to have a better taste since the beans take longer to ripen and develop full flavour when not in full sunlight.

Choosing organic Fairtrade coffee beans means you are protecting the rights of coffee growers, the bonus being that you are protecting your taste buds at the same time.

Coffee in your garden

There are several ways you can put used coffee grounds to work in your garden. You can put coffee grounds in your compost bin to provide a valuable source of nitrogen. You can also add them directly to the soil in your garden, either sprinkling them on the surface or scratching them into the top centimetre or two of soil. Not only do they fertilise but coffee grounds also repel garden pests like slugs and snails.