Drinking two to three cups of coffee a day is associated with a longer lifespan and a lower risk of cardiovascular disease compared to avoiding the brew, a study has found.

A team at the Baker Heart and Diabetes Research Institute, Australia, examined the link between types of coffee and incident arrhythmias or irregular heart beat, cardiovascular disease and death using data from the UK Biobank about adults between 40 and 69 years of age.

"The results suggest that a mild to moderate intake of ground, instant and decaffeinated coffee should be considered part of a healthy lifestyle," said study author Professor Peter Kistler.

In the study, cardiovascular disease included conditions such as coronary heart disease, congestive heart failure and ischaemic stroke.

The study, published in the European Journal of Preventive Cardiology, included 449,563 participants free of arrhythmias or other cardiovascular disease. The median age was 58 years and 55.3 per cent were women.

Outcome information was obtained from medical records and death records. The median follow up was 12.5 years. All types of coffee were linked with a reduction in death risk from any cause, the researchers said.

The greatest risk reduction was seen with two to three cups per day, which compared to no coffee drinking was associated with a 14 per cent, 27 per cent and 11 per cent lower likelihood of death for decaffeinated, ground, and instant preparations, respectively.

A total of 27,809 (6.2 per cent) participants died during follow up.

"In this large, observational study, ground, instant and decaffeinated coffee were associated with equivalent reductions in the incidence of cardiovascular disease and death from cardiovascular disease or any cause," said Kistler.

Cardiovascular disease was diagnosed in 43,173 (9.6 per cent) participants during follow up. All coffee subtypes were associated with a reduction in cardiovascular disease incidence.

Again, the lowest risk was observed with two to three cups a day, which compared to abstinence from coffee was associated with a 6 per cent, 20 per cent, and 9 per cent reduced likelihood of cardiovascular disease for decaffeinated, ground, instant coffee, respectively.

An arrhythmia was diagnosed in 30,100 (6.7 per cent ) participants during follow up.

Ground and instant coffee, but not decaffeinated, was associated with a reduction in arrhythmias including atrial fibrillation, an irregular and often very rapid heart rhythm that can lead to blood clots in the heart.

Compared with non-drinkers, the lowest risks were observed with four to five cups a day for ground coffee and two to three cups a day for instant coffee, with 17 per cent and 12 per cent reduced risks, respectively.

"While caffeine is the most well-known constituent in coffee, the beverage contains more than hundred biologically active components.

"It is likely that the non-caffeinated compounds were responsible for the positive relationships observed between coffee drinking, cardiovascular disease and survival," said Kistler.

Participants were asked to complete a questionnaire asking how many cups of coffee they drank each day and whether they usually drank instant, ground (such as cappuccino or filtered coffee), or decaffeinated coffee.

They were then grouped into six daily intake categories, consisting of none, less than one, one, two to three, four to five, and more than five cups per day.

The usual coffee type was instant in 198,062 (44.1 per cent) participants, ground in 82,575 (18.4 per cent), and decaffeinated in 68,416 (15.2 per cent).

There were 100,510 (22.4 per cent) non-coffee drinkers who served as the comparator group.

"Our findings indicate that drinking modest amounts of coffee of all types should not be discouraged but can be enjoyed as a heart healthy behaviour," Kistler added.