A new large-scale study found that high consumption of coffee – up to five cups per day – is associated with lower risk of dying from heart disease, neurological disease, Type 2 diabetes and suicide.

Harvard researchers studied the association of coffee intake and risk of death based on self-reported coffee habits of more than 200,000 doctors and nurses over the course of 30 years, reported NBC News. Every four years, participants filled out questionnaires on various lifestyle factors, including how frequently they consumed coffee. During the follow-up period, more than 31,000 participants died of various causes.

Researchers found that non-smokers who drank between less than a cup of coffee and three cups a day had a 6 percent to 8 percent lower risk of dying than non-coffee drinkers. People who drank three to five cups per day had a 15 percent lower risk of premature mortality compared to people who didn't drink coffee.

Moderate coffee drinkers had a lower chance of dying from cardiovascular disease, neurological diseases, Type 2 diabetes and suicide, and researchers also noted that coffee consumption was not associated with deaths from cancer.

"The chlorogenic acid, lignans, quinides, trigonelline, and magnesium in coffee reduce insulin resistance and systematic inflammation," which could be responsible for the inverse association between coffee and mortality, the researchers wrote.

Researchers did not test whether increasing coffee consumption improved health outlooks, so they could not conclude that upping coffee consumption actually causes a decreased risk of death.

Andrew Maynard, who studies risk assessment at Arizona State University, said the results do, however, point to an association between drinking coffee and living longer, but said there remain a lot of "unknowns as to what [may explain] the increase in life expectancy," according to NPR.

Either way, researchers said regular coffee consumption can be safely incorporated into a healthy diet.

"The main takeaway is that regular consumption of coffee can be incorporated into a healthy diet," senior author Frank Hu of the Harvard School of Public Health in Boston told Reuters. "There is no evidence of harm of regular consumption in terms of chronic disease risk or mortality, and consistent evidence that consumption of coffee reduces the risk of diabetes and cardiovascular disease."

He added: "People who are already drinking it should continue to enjoy it, but for people who don't drink it or don't like it, there's no particular reason to start for the sole reason of health."

The study was published Monday in the American Heart Association journal Circulation.