But perhaps the magnitude of coffee’s benefits all boils down to what many coffee lovers and researchers believe:
Coffee drinkers live longer.
But is there scientific evidence behind this claim? This article will find out!
What the studies say
Apparently, several studies have been conducted on the subject. To find out whether coffee drinkers live longer, let’s list down the various studies done in recent years and find out what they have to say:
A 2018 study among 500,000 British adults – a mix of coffee and non-coffee drinkers – show “slightly lower risk” of death over a 10-year period.
The study, published in the Journal of the American Medical Association, specifically in the JAMA Internal Medicine, covered research done at the National Cancer Institute. Information from 500,000 participants in the genetic study, U.K. Biobank, were analyzed. Details about their medical history, coffee consumption, smoking and drinking habits were reviewed. The study found that 14,200 participants died over the 10-year period. It also showed that coffee drinkers were 10 to 15 percent less likely to die over the same period, with minimal variations in the amount of coffee and genetic makeup. It has to be noted that coffee drinkers consumed instant, ground and decaf alike. 
The JAMA article states:
A new study of nearly half a million people (ages 38 to 73) in the United Kingdom suggests a lower risk of death was associated with drinking more coffee, including among coffee drinkers who have eight or more cups per day, in both slow and fast metabolizers of caffeine, and in drinkers of ground, instant and decaffeinated coffee. 
A 2017 study concluded that three to four cups of coffee a day are linked to a whole range of health benefits
Coffee consumption is “more often associated with benefit than harm,” according to a review of over 200 studies about coffee consumption’s effect on health. 
Three to four cups of coffee are found to be the optimal amount to consume in a day, although coffee lovers who drink up to seven cups still enjoy several health benefits. They enjoy a lower risk of cardiovascular diseases, diabetes, liver disease, dementia and some forms of cancer.
A 2017 study was conducted to find the link between coffee consumption and mortality in 10 European countries
This study aimed to examine a potential interrelation between coffee-drinking and mortality in “diverse European populations.”
After examining the results from 521,330 persons enrolled in EPIC (European Prospective Investigation into Cancer and Nutrition), the study concludes that “coffee drinking was associated with reduced risk for death from various causes” and that “this relationship did not vary by country.” 
Specifically, coffee drinkers are found to have lower death risk from digestive, circulatory, liver disease and other illnesses. 
A 2017 study found that people who drink one cup of joe a day enjoy a 12 percent reduced risk of death from chronic diseases, and an even lower risk for drinking more cups.
Led by Veronica W. Setiawan of the University of Southern California and funded by the National Cancer Institute, a 2017 study examined coffee-drinking habits among more than 180,000 participants from diverse backgrounds over a 16-year period. They included whites, African-Americans, Latinos, Japanese-Americans, and native Hawaiians.
The study showed that there’s a 12 percent lower risk of death from heart disease, cancer, stroke, diabetes, respiratory and kidney disease, and a total risk reduction of 18 percent among those drinking 3 cups daily. 
A 2012 study shows that older coffee-drinking adults have a lower risk of death over those who don’t drink coffee.
According to a 2012 study conducted at the National Cancer Institute (NCI), which is part of the National Institutes of Health and AARP, “older adults who drank coffee — caffeinated or decaffeinated — had a lower risk of death overall than others who did not drink coffee.” [6, 7]
The study looked into 229,119 men and 173,141 women aged 50-71 years old.
It concluded that those who drink coffee are less likely to die from chronic diseases like heart disease, respiratory disease, stroke, as well as injuries and accidents, diabetes, and infections.
Researchers found that “coffee consumption was inversely associated with total and cause-specific mortality. Whether this was a causal or associational finding cannot be determined from our data.”
Note that caffeine content varies in different products so don’t forget to check the label!
And if you’re wondering how much the “killer” amount is (literally), then USA Today reports it would “likely take anywhere from 50-100 cups of coffee,” or a teaspoon of pure powdered caffeine ingested at once. 
Erectile dysfunction. In combination, those are two of the ugliest words known to man. But can caffeine help you get it up?
Science hasn't found the definitive answer to this question, but one study concluded that fewer men who consume caffeine have problems performing. The study said:
Caffeine intake reduced the odds of prevalent ED, especially an intake equivalent to approximately 2-3 daily cups of coffee (170-375 mg/day). This reduction was also observed among overweight/obese and hypertensive, but not among diabetic men. Yet, these associations are warranted to be investigated in prospective studies