February 22/Baltimore/Counsel & Heal -- Scientists have discovered that drinking coffee can add years to a person's life. The study, which involved nearly half a million older Americans, revealed that the risk of death decreased the more cups of coffee participants consumed.

While health experts have long warned that too much caffeine is unhealthy, the new study, published in the New England Journal of Medicine, found that the more coffee a person drinks, the less likely he or she will die from heart and respiratory disease, stroke, injuries, accidents and infections.

Researcher Dr. Neal Freedman of the National Cancer Institute said in an interview, published recently in the Journal of Caffeine Research, that the latest study is among the most comprehensive to date of the health benefits of coffee.

Freedman and his team studied 500,000 U.S. men and women between the ages of 50 and 71 for about 12 years. Not only did the study show a clear correlation between coffee and longevity, it also revealed that people who drank the most coffee tended to have the greatest health benefits. Researchers found that participants who drank two or three cups of coffee were 10-15% less likely to die an early death.

"What we found was that over the course of follow-up, there was an inverse association between coffee drinking and the risk of death overall and with a number of different causes as well," said Freedman, according to Newsmax Health.

"The association was similar for men and women, and tended to get stronger as participants drank more coffee, though the result was very similar for those who drank two or three cups per day and those who drank more than that," he added. "The top category we had was six or more cups per day. And by cup, I mean a U.S. 8oz. cup. This is what we found."

However, researchers added that drinking more than two to three cups of coffee a day did not produce more benefits because participants who drank up to six cups of coffee a day did not reap anymore benefits than those who had two to three cups a day.

Researchers also added that the main obstacle to coffee drinkers who wanted to increase their lifespan was smoking, after they found that participants who drank coffee were also significantly more likely to smoke cigarettes, which is a very strong predictor for early death. Coffee consumption was also linked to many poor health behaviors like excessive alcohol intake and red meat consumption and sedentary lifestyle.

"All of those risk factors are usually associated with increased risk of death, which they were in our study too," Freedman said, according to the Daily Mail.

Researchers were unable to pinpoint exactly how coffee reduced mortality, and they hope that future studies could identify the chemical compounds in coffee that may be responsible for the beverage's health benefits.

"We do not really know the mechanism of coffee's action," Freedman explained, according to Newsmax Health. "It is possible that coffee affects blood pressure, but then also many other mechanisms ... might affect cardiovascular disease. We do not really have mechanistic data about the different compounds in coffee and what they do ...It is possible that different compounds in the coffee are important."

Researchers were also unable to determine whether normal coffee was better than decaffeinated coffee or vice versa.