Coffee is often associated with staying awake, but caffeinated consumers may have a reason to sleep easy after a new study found it is not as bad for our arteries as previously thought.
Research from Queen Mary University of London has shown that drinking coffee, even up to 25 cups a day, is not associated with hardened arteries.
The study contradicts earlier opinion that claims drinking coffee increases arterial stiffness, which QMU researchers say is inconsistent and could be limited by lower numbers of participants.
The new study, conducted on almost 8,500 people in the UK, was part-funded by the British Heart Foundation and is due to be presented at the British Cardiovascular Society Conference in Manchester this week.
Arteries carry blood containing oxygen and nutrients from the heart to the body.
If they become stiff, it can increase workload on the heart and chances of a heart attack or stroke.
In the British survey, coffee consumption was categorised into three groups: those who drink less than one cup a day; those who drink between one and three cups a day; and those who drink more than three.
People who drank more than 25 cups a day were excluded. But the arteries of those drinking that impressive amount were no more stiff than those who drank less than a cup a day.
The researchers say the associations between drinking coffee and artery stiffness were corrected for contributing factors such as age, gender, ethnicity, smoking, height, weight, alcohol consumption, diet and high blood pressure.
As coffee drinkers in much of the Arab world will attest to, it is part of life - and a ritual many are looking forward to as Ramadan draws to a close.
Ahmad Zoul, 38, drinks a minimum of eight cups of coffee a day and comes from a family of self-confessed addicts.
“I have been drinking coffee since I was one-year-old - they used to put some for me in the milk bottle so I would agree to drink it," said the construction supervisor, who is from Palestine and lives in Dubai.
“I used to ask for it ‘aweh aweh’ before I could even pronounce it properly.” Qahwa is the Arabic word for coffee.
“Myself, my father and my grandfather are all heavy coffee-drinkers and none of us have ever had any heart problems or thrombosis. My grandfather died at age 85."
Even among Arab family and friends, his intake, of strong drip-filtered Arabic coffee, is high.
“Now I have a scientific research to back up my argument when people criticise me for my heavy drinking," he said.
“Now that we are fasting I drink an entire pot for suhoor [the last meal before dawn] to get the dose that I need; it includes around six cups.”
Muna Tamim, 34, a Canadian-Palestinian HR manager, described her family are "top addicts".
“We are famous for the Turkish coffee we make at home, people just come over to have coffee with us," she said.
“I started with my mother, she is an addict and drinks coffee like water, she even breaks her fast [in Ramadan] over coffee.
“Our hearts are perfectly fine, and for me coffee has many benefits, I never perceived it as harmful.”
“It helps me concentrate and make decisions.
Dr Marwan Al Assila, a consultant from Emirates Hospital, said it is common to see patients who take in too much caffeine and have interrupted sleep.
“It causes lack of sleep for some people, and more importantly it could cause heart rate acceleration, and it has its effects on the nervous system,” he said.
Of the 8,412 participants who underwent MRI heart scans and infrared pulse wave tests, the research showed moderate and heavy coffee drinkers were most likely to be men who smoked and regularly drank alcohol.
“Despite the huge popularity of coffee worldwide, different reports could put people off from enjoying it," said Dr Kenneth Fung, who led the data analysis for the research.
"While we can’t prove a causal link in this study, our research indicates coffee isn’t as bad for the arteries as previous studies would suggest.
“Although our study included individuals who drink up to 25 cups a day, the average intake among the highest coffee consumption group was five cups a day.
"We would like to study these people more closely in our future work so that we can help to advise safe limits.”
Prof Metin Avkiran, associate medical director at the British Heart Foundation, said: “There are several conflicting studies saying different things about coffee, and it can be difficult to filter what we should believe and what we shouldn’t.
"This research will hopefully put some of the media reports in perspective, as it rules out one of the potential detrimental effects of coffee on our arteries.”