25 Cups of Coffee a Day Is (Kind of) OK

... For your arteries, that is. We dig into new research to see what it means for the rest of your body.

by Lara DeSanto Health Writer

Sounds crazy, but it’s true: Drinking up to 25 cups of coffee throughout the day—a serious caffeine commitment—isn’t as bad for you as previously thought, at least when it comes to your arteries. But that doesn’t mean you should go nuts with the java.

Contrary to past studies’ claims that drinking cups upon cups o’ Joe could seriously stiffen your arteries, thereby upping your risk of heart disease, a new study of 8,000 people at Queen Mary University of London found no such association. In fact, even those who drank 25 cups a day (the study cut-off) had no more arterial stiffening than those who drank less than 1 cup a day. But while this is good news for your arteries, keep in mind that there are other not-so-great things coffee can do to your body if you drink it in excess.

“Understanding the impact that coffee has on our heart and circulatory system is something that researchers and the media have had brewing for some time,” said Metin Avkiran, Ph.D., professor of molecular cardiology and associate medical director of the British Heart Foundation, which co-funded the study. “There are several conflicting studies saying different things about coffee, and it can be difficult to filter what we should believe and what we shouldn’t. This research will hopefully put some of the media reports in perspective, as it rules out one of the potential detrimental effects of coffee on our arteries.” Key words: One of.

Yep, There’s Such a Thing as Too Much Caffeine

We all could use a jolt of energy once in a while, and coffee can often do the trick. But how much is too much? According to the Mayo Clinic, up to 400 mg of caffeine a day is a safe amount for healthy adults—in coffee language, that’s about four brewed cups.

Drinking more than that can make you feel super jittery or anxious, along with other unpleasant side effects. It might be a sign to cut back if you drink more than four cups a day and experience any of the following, per the Mayo Clinic:

  • Insomnia

  • Nervousness

  • Irritability

  • Upset stomach

  • Migraine headache

  • Restlessness

  • Frequent need to pee

  • Fast heartbeat

  • Muscle tremors

And keep in mind—some people are more sensitive to caffeine than others, so listen to your body if less than four cups gives you unwanted jitters, sleep problems, or other issues.

And a final word of caution: It’s also important to check with your doctor if you’re on any medications to make sure caffeine won’t mess with them. For example, mixing caffeine with ephredrine, a drug found in decongestants, can increase your risk of serious health issues like heart attack and seizure.

Lara DeSanto
Meet Our Writer
Lara DeSanto

Lara is a former digital editor for HealthCentral, covering Sexual Health, Digestive Health, Head and Neck Cancer, and Gynecologic Cancers. She continues to contribute to HealthCentral while she works towards her masters in marriage and family therapy and art therapy. In a past life, she worked as the patient education editor at the American College of OB-GYNs and as a news writer/editor at WTOP.com.