Somewhere between 80 and 85 percent of Americans consume coffee regularly, according to the American Psychological Association. A portion of those coffee drinkers are the sometimes proud junkies who drag the nation's average up to 165 milligrams (about two cups) of caffeine per day. An FDA estimate puts the average closer to 300 milligrams. Either way, for the average to be there, there's a segment of the populations drinking much more.
For those jittery coffee hounds, a new study published in Food and Chemical Toxicology has good news. It suggests you can surpass the average and hit 400 milligrams of caffeine without worry.
The study, a review of more than 700 studies published between 2001 and 2015, looked at the potential toxic effects of consuming too much caffeine. The researchers specifically looked at "acute toxicity, cardiovascular toxicity, bone and calcium effects, behavior, and development and reproduction." They determined that 400 milligrams is fine for a healthy adult. (That number is 300 milligrams for pregnant women.)
"[T]he evidence generally supports that consumption of up to 400 mg caffeine/day in healthy adults is not associated with overt, adverse cardiovascular effects, behavioral effects, reproductive and developmental effects, acute effects, or bone status," the study states.
For reference, a tall (12 oz.) Pike Place roast coffee from Starbucks contains 235 milligrams of caffeine and a grande (16 oz.) iced coffee contains 190 milligrams. In homemade varieties, a 12 oz. cup of Folgers is between 60 and 80 milligrams and a single Green Mountain Keurig K-Cup contains 75 milligrams. A Diet Coke lands around 46 milligrams.
Should you start putting down five cups a day if you usually have two? Probably not. However, if you're drinking that much, and you're otherwise healthy, there probably isn't an urgent need to cut back. Some people are able to handle caffeine better than others due to their tolerance or size, among other factors. Due to the nature of the reviewed papers, the study isn't able to provide details on the health consequences of consuming in excess of 400 milligrams per day.
h/t The Science of Us