Feel a pang of concern when you reach for that second, or even third, cup of coffee in the morning? Go ahead and indulge. A November 2017 review published in Food and Chemical Toxicology concluded that a safe amount of caffeine per day for a healthy adult is up to 400 milligrams. (For the record, that's about four 8-ounce cups of coffee or six shots of espresso.)
Like us, you're probably wondering what the researchers actually mean when they say it's "safe" to consume that much coffee. After reviewing 15 years of conflicting data, they found that consuming four cups of coffee doesn't have a negative effect on bone health, calcium intake, heart health or behavioral health, nor does it have a negative effect on reproduction and development.
But bear in mind that coffee is not a one-dose-fits-all kind of thing — and just because something won't kill you doesn't mean you'll enjoy it. Like with booze, your ability to consume caffeine and tolerate side effects like jitters and anxiety depends on your sensitivity, height and weight.
How Many Cups of Coffee Is Too Much?
If you drink too much caffeine, you can experience some really unpleasant side effects, such as migraines, insomnia and irritability, according to the Mayo Clinic. Drinking more than four cups of coffee per day has even been linked with an increased risk of cardiovascular disease.
According to a March 2019 study in the American Journal of Clinical Nutrition, individuals who drank more than six cups of coffee per day experienced a 22 percent higher risk of cardiovascular disease when compared to those who only drank one to two cups.
That four-cup limit still gives you plenty of room to enjoy coffee and its many health benefits — which even include potentially reversing liver damage from alcohol. Participants in a 2016 study in Alimentary Pharmacology and Therapeutics who added two extra cups of coffee to their daily routines lowered their chances of developing cirrhosis of the liver by as much as 44 percent.
All this is fantastic news if you love a good latte. However, if you're pregnant (or planning to be), you should slow your roll to maybe three cups a day. And if you're trying to get pregnant, you should consider easing up on your coffee consumption even more. A 2016 National Institutes of Health study linked pre-pregnancy caffeine consumption to an increased risk of miscarriage.
- Systematic review of the potential adverse effects of caffeine consumption in healthy adults, pregnant women, adolescents, and children
- Caffeine: How much is too much?
- Drinking coffee may reduce the risk of liver cirrhosis
- Harvard School of Public Health: "Drinking coffee may decrease depression risk in women"
- Prospective study of coffee consumption and risk of Parkinson's disease.
- Journal of Natural Products: "Cafestol, a Bioactive Substance in Coffee, Stimulates Insulin Secretion and Increases Glucose Uptake in Muscle Cells: Studies in Vitro"