That rate dropped to 6% for those who drink less than one cup of coffee daily. Those who drank around 6 to 7 cups of coffee per day had around a 16 percent lower risk of death, the study found. As Howard Bauchner, editor in chief of the medical journal JAMA and The JAMA Network, almost all studies about coffee are association studies. Volunteers for the study ranged from 38 to 73 years old, with a mean age of 57. For the current study, the researchers analyzed information provided by about 500,000 people, who answered questions about their coffee consumption, smoking and drinking habits, health history and more. Using non-coffee drinkers as the reference group, the scientists were able to surmise that drinking instant, ground, and decaffeinated coffee was "inversely associated with mortality".
The study was led by National Cancer Institute researcher Erikka Loftfield and was published in the Journal of the American Medical Association Internal Medicine. He drinks about three cups a day.
However, people are normally advised to drink no more than four cups of coffee a day - about 400mg.
For the study, researchers invited nine million British adults to take part - 498,134 women and men aged 40 to 69 agreed.
In other words while coffee drinking has some benefits especially in dealing with non-communicable diseases, your genes decide how well you metabolise caffeine.
Drinking coffee could be beneficial, regardless of whether a person metabolizes the drink quickly or slowly.
"To better understand the potential biological mechanisms underlying the observed associations of coffee with various health outcomes, additional studies are needed". So, the benefit of drinking more than 8 cups of coffee over around 4 may be small.
The results support the recommendations of the U.S. Dietary Guidelines Advisory Committee, which states consuming three to five cups of coffee per day, or 400 milligrams per day, of caffeine is not detrimental to healthy individuals.
It might reduce inflammation in the body, improve how insulin gets used, it might help liver function and it might benefit the linings of the blood vessels. However, earlier studies focused primarily on health risks after the presence of such diseases were found.
In the end, there were 14,225 deaths due to cancer (58 percent); cardiovascular disease (20 percent) and respiratory disease (4 percent).
The research did not include whether participants drank coffee black or with cream and sugar.