Demographic, clinical and lifestyle data were collected by the UK Biobank over the course of a year between 2009 and 2012. 171.616 adults without underlying heart disease or cancer at the start of the study did participate. Questions about the use of coffee were included. The data were analyzed and the patients were classified according to their usual coffee drinking habit. Participants (average age 55.6 years) were followed during up to 7 years. When compared to non-coffee drinkers, those who drank unsweetened coffee regularly in any amount were 16 to 21 % less likely to die. Adults who drank moderate amounts of coffee sweetened with sugar ( 1 teaspoon, 1,5 – 3,5 cups per day) were 29 to 31 % less likely to die. Results were inconclusive for those who added artificial sweeteners to their coffee.
This was an observational study and may have missed important factors. Confounding variables such as differences in socioeconomic status, diet, and other lifestyle factors may impact findings. Coffee drinking patterns were from over a decade before in a country where many drink tea. So a comparison with other countries might not be easy. The average amount of daily sugar per cup of coffee is much lower than specialty drinks at restaurants (4 vs. 15 g) and those who drink coffee may do so in place of other beverages with much sugar. Therefore comparisons to those who don’t drink coffee is more difficult.
The totality of the evidence does, however, not suggest a need for the most coffee drinkers –particularly those who drink it with no or modest amounts of sugar– to eliminate coffee.