How healthy is your coffee?
Greek coffee could be good for the heart, one recent research study suggests. Could all coffee be as healthy?
Macchiato, cappuccino, flat white, long black, latte, espresso - for coffee drinkers, there is a myriad of choices out there.
Everyday billions of us choose to overlook or embrace its addictive properties and down our caffeine hit, or hits, as the case may be.
But chances are, we are not choosing to drink it due for its health benefits. Or are we?
"I've never believed there is anything bad in drinking five cups a day," says Will Corby, a coffee "hunter" or specialty coffee merchant with Mercanta - The Coffee Hunters, and trainer at the London School of Coffee.
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Caffeine is such a powerful stimulant, people are known to have overdosed on espressos, and drinking too much has been associated with negative health effects, such as insomnia, jitteriness, diuresis and headaches.
Will Corby says quality is key. He can drink 20 cups of excellent coffee while judging, with no side effects. But what happens when he has three badly-brewed ones?
"I drink a lot of coffee, and I drink a well-brewed cup. I have no problems sleeping. But if you drink a badly-brewed cup, it has a bad effect on you," the coffee expert says.
In fact health research over the years has found good things in a cup of coffee - most recently in Greek-style coffee.
The coffee consumption of elderly people on the Greek island of Ikaria was linked to a reduction in one risk factor for heart disease according to a study in the Vascular Medicine journal.
Is Greek coffee special?
It is brewed in a stove-top pot known as a briki, and is very strong, with a heavy foam, and can be brewed with sugar to increase sweetness. It is also served with a glass of water.
Brewed coffee is the richest in caffeine content (135mg per 8oz (227g) of coffee), the study reports, more than filter coffee (112mg) or percolated (74mg).
Greek coffee also contains a greater amount of anti-inflammatory organic compounds.
There have been plenty of studies over the years which show positive and negative health effects after drinking coffee.
That is explained in part by the lack of consistency in what we drink say experts.Milk and sugar
Different roasts, species and varieties of coffee beans can have different caffeine contents and compositions too.
There is also added sugar, sugar syrups, milk and cup sizes so there are differing levels of caffeine but also of other ingredients, like proteins, fats and sugars.
On the plus side, coffee is known to be packed full of antioxidants, which stop other molecules oxidising and producing free radicals.
Women who drink two or more cups of coffee a day are less likely to get depressed, other research suggests.
There are plenty of reasons to love it, but perhaps the simplest are the taste, and the "lift" it gives to drinkers.
Brew it the best way:
"Coffee hunter" Will Corby's top tips for a good brew:
- Grind your coffee fresh
- Use the right dose of coffee for water - weigh it and stick to 72g of coffee for 1L water
- Use water at the correct temperature - 96C
- Make sure the grind size is correct - it should take 3 - 3 1/2 minutes for water to pass through the coffee
- Buy a hand grinder with ceramic burrs to ensure even coffee particles and an even extraction of caffeine
For as Will Corby says: "Coffee is one of the most complex flavour profiles on the planet, it has about double the flavour range in it of wines.
"The chemical structure gives you more flavour and it is full of caffeine, it wakes you up and gives you a buzz."
However previous studies have linked high caffeine intake to raised cholesterol and short-term high blood pressure.
In recent times however there has been a sea change in the debate over whether coffee is good for you or bad for you.
A recent study by the Harvard School of Public Health suggests there is no link between coffee and mortality.
Even drinking up to six cups a day "is not associated with increased risk of death from any cause, or death from cancer or cardiovascular disease", says Rob van Dam, assistant professor in the Department of Nutrition at the Harvard School of Public Health.
"This finding fits into the research picture that has been emerging over the past few years: For the general population, the evidence suggests that coffee drinking doesn't have any serious detrimental health effects," he says.Regular or large?
Yet the experts still warn against drinking too much. As in most research, the Harvard study assumed six 8-ounce (225ml) cups, each containing 100mg of caffeine, "not the 16 ounces (450ml) you would get in a grande coffee at a Starbucks, which has about 330mg of caffeine," says Rob van Dam.
But his findings are backed up by a study in the Maturitas journal, conducted by the University of Valencia in Spain.
It concludes that "information gathered in recent years has generated a new concept of coffee, one which does not match the common belief that coffee is mostly harmful".
How much is too much?
It's difficult to suggest a safe limit for coffee intake because of the huge variation in caffeine content across different brands and an individual's sensitivity to caffeine.
People with high blood pressure and pregnant women are advised to limit their consumption.
- A mug of instant coffee contains 100mg caffeine
- A mug of filter coffee contains 140mg caffeine
It says: "Contrary to previous beliefs, the various forms of arterial cardiovascular disease, arrhythmia or heart insufficiency seem unaffected by coffee intake. Coffee is associated with a reduction in the incidence of diabetes and liver disease.
"Protection seems to exist also for Parkinson's disease among the neurological disorders, while its potential as an osteoporosis risk factor is under debate."
Psychologically and socially, coffee also has another benefit arguably on our mental health.
"If you look at European culture people go out and switch on when drinking coffee, while alcohol makes people lethargic," says Will Corby.
"Coffee is a means to communicate. It's why people love coffee, it aids social interaction," he explains.
The Specialty Coffee Association of America (SCAA) has 5,000 members and recently held its Symposium, an international meeting of experts.
The SCAA's director Peter Giuliano suggested caffeine is useful in connecting people, as well as different areas of our brain, as shown in a University of California San Diego Department of Psychiatry study.
Despite the good news, many of those conducting the research say it "must be stressed that much still needs to be known".
Most clinical studies, particularly those with high numbers of participants, are only observational.
Time for a caffeine fix then.