- Drinking 3 coffees a day could help extend your life, British research has found
- Research also shows the benefits of a cup of coffee one hour before a work-out
- Drinking 4 cups of coffee a day almost halves the risk of deadly mouth cancer
- And coffee contains several substances that can affect metabolism, experts say
For years, we were told that caffeine was bad for us - and in the battle of the hot drinks, coffee always came off worse.
But today, barely a week goes by without the health benefits of the beverage being extolled.
Indeed just last week, Portuguese researchers declared that three cups of coffee a day may help people with chronic kidney disease live longer.
The research adds to the growing body of evidence that the drink has a host of health benefits – and that commonly held beliefs that coffee dehydrates you are just a myth.
So, what is the truth about coffee?
IT COULD HELP YOU LIVE LONGER
Simply drinking three coffees a day could help extend your life, British research has found.
Two major studies independently found consuming up to three cups a day reduces the risk of an early death.
The papers, published in the Annals of Internal Medicine, found links between coffee and reduced risks of liver disease, circulatory problems and diseases linked to the digestive tract.
The drink also seems to reduce inflammation and boost the immune system, researchers discovered.
Rather than caffeine, it's thought the antioxidant plant compounds in coffee are responsible for the longevity benefit.
As a result, people who drink decaffeinated coffee are also protected, the researchers found.
IT MAKES WORK-OUTS LESS PAINFUL
Research has shown that people who had a cup of coffee one hour before a work-out could exercise for longer.
'It's thought that caffeine may block chemicals that cause the muscles of become tired and uncomfortable during exercise,' explains Fiona Hunter, a nutritionist for Healthspan.
Caffeine works on a system in the brain and spinal cord (the adenosine neuromodulatory system) that's involved in pain processing.
And because caffeine blocks adenosine, a biochemical that plays an important role in energy transfer and therefore exercise, lead researcher Professor Robert Motl, from the University of Illinois, wanted to see if it could also reduce the pain that comes when we work out.
He found it did – regardless of whether people consumed caffeine regularly or not.
There were two groups: people who consumed very little, if any caffeine, and those who had around 400 milligrams a day, the equivalent of three to four cups of coffee.
Both groups saw the same reduction in pain during exercise after caffeine consumption.
Professor Motl believes the finding could help us battle through the workout for longer.
'If we could give people a little caffeine and reduce the amount of pain they're experiencing, maybe that would help them stick with that exercise,' he said.
SLASHES MOUTH CANCER RISK
Drinking four cups of coffee a day almost halves the risk of deadly mouth cancer – regardless of whether a person drinks or smokes.
Researchers at the American Cancer Society found that sipping the beverage every day has a powerful protective effect against tumours that form in the mouth and throat.
Scientists found decaffeinated coffee also reduced the risk, although to a lesser extent, while drinking tea did nothing to prevent the disease.
BUSTING COMMON COFFEE MYTHS
IT DOESN'T DEHYDRATE YOU
The idea that drinking coffee dehydrates us is a myth.
In fact, a few cups of coffee a day is as hydrating as water, Birmingham University researchers claimed in a 2014 study.
Their industry-funded study argues the idea that coffee dehydrates us is based on research done on samples of caffeine more 80 years ago – and this research is not relevant to modern life.
To find out, the researchers asked 50 healthy men to drink either four mugs of water or coffee a day for three days and then switch.
The men ate the same food during the two parts of the study and were banned from vigorous exercise and alcohol.
Tests of blood and urine samples showed the men were just as well hydrated when they drank coffee and when they had water.
They also passed the same amount of urine, the journal PLOS ONE reports.
IT 'DOESN'T CAUSE PALPITATIONS/IRREGULAR HEARTBEATS'
A wealth of evidence has found no link between the two.
Indeed, the British Heart Foundation states: 'studies which have investigated the link between caffeine and abnormal heart rhythms, or cardiac arrhythmias, have found that moderate amounts of caffeine do not necessarily lead to life threatening arrhythmias.
'This implies that drinking a modest amount of coffee should not increase your risk.
IT DOESN'T TRIGGER HIGH BLOOD PRESSURE
Research published in the European Journal of Public Health states high blood pressure is mainly caused by factors such as obesity, lack of physical activity and a high salt intake – with the impact of coffee being quite small by comparison.
In fact, it states the slight increase in blood pressure level caused by coffee is the same that experienced while holding a conversation.