Several cups of coffee a day, with or without sugar, reduces the risk of death, scientists have found in a new study published in the Annals of Internal Medicine.

Researchers found that people who drank a moderate amount of coffee, regular or sweetened with about a teaspoon of sugar, were about 30% less likely to die from any cause over a seven-year period compared to those who didn't drink coffee daily, according to a U.K. Biobank, an ongoing study of health information in the UK population.

The study involved 171,616 people from the UK Biobank, whose average age was 55.6 years. At the same time, the participants did not have cardiovascular diseases or cancer at the time of the study.

Participants were asked to complete a 24-hour dietary questionnaire five times over the course of one year from April 2009 to June 2012, which included questions about the frequency of coffee consumption and the number of teaspoons of sugar, if any. Mortality data was obtained from death certificates up to 25 February 2018.

About 76% of study participants consumed coffee. Most people (55.4%) drank unsweetened coffee; 14.3% added sugar to their coffee (about a teaspoon per cup on average), and 6.1% used artificial sweeteners.

During the follow-up period of seven years, 3177 deaths occurred, including 1725 deaths from cancer and 628 deaths from cardiovascular disease.

Overall, people who drank any amount of unsweetened coffee were less likely to die from any cause during the follow-up period than people who didn't drink coffee, the researchers found. People who drank 1 1/2 to 3 1/2 cups of coffee a day, unsweetened or sweetened with sugar, were 29% to 31% less likely to die than those who didn't drink coffee.