Signs that your coffee habit is doing more harm than good.
Ninety percent of American adults ingest caffeine every day, and the average intake is about 300 milligrams, or roughly a medium-size coffee. The humble 16-ounce Starbucks drip coffee contains 310 milligrams. A 20-ounce light roast has 475 milligrams. So if you’re downing multiple cups a day, you could be ingesting north of 1,000 milligrams.
Anything over 400 milligrams a day can bring about side effects like headaches, insomnia, an upset stomach, and anxiety, according to theMayo Clinic, and 14 percent of Americans drink that or more regularly. However, there isn’t a hard number that is unhealthy for everyone, says Maggie Sweeney, a researcher at the Johns Hopkins Medical Institute. Your response is likely influenced by your lifestyle and your genes. In rare cases, large amounts of caffeine can even increase the likelihood of having ministrokes (also called transient ischemic attacks), during which blood flow to your brain is briefly cut off, says Chris Winter, a neurologist and author of The Sleep Solution. “It’s really weird to see a 21-year-old who’s had lots of subtle vascular strokes over the years, and these tend to be people who were really pounding energy drinks,” says Winter. “There is certainly such a thing as too much caffeine.”