Do High Levels of Caffeine Cause Liver Damage?

Maybe you love the energy rush that you get from coffee or an energy drink, but you're concerned about the effects caffeine could have on your body. You may even wonder if high levels of caffeine cause liver damage. The good news is that caffeine can help the liver — in the right dose.

​Read more:​ How Bad Is It Really to Drink More Than the Daily Recommended Amount of Coffee?

To better understand caffeine and its effects on the liver, it helps to know what the liver does. Weighing about 3 pounds, the liver is associated with more than 500 important functions in your body, according to Johns Hopkins Medicine. Those include filtering toxins, processing any medications you take and storing extra blood sugar.

Caffeine is a plant product that affects your central nervous system. You can find caffeine in many items, including coffee, tea, energy drinks, sodas, certain medications and even some caffeinated foods, though in very different amounts. You may feel the energy-boosting effects from caffeine for up to 6 hours, according to the University of Michigan (UM).

Most of the time, caffeine actually appears to be protective against liver damage, particularly the damage caused by alcohol or hepatitis C, says San Francisco-based James Wantuck, MD, an internal medicine physician and chief medical officer and cofounder of the telehealth platform PlushCare.

A February 2017 study in the ​European Journal of Gastroenterology & Hepatology​ linked drinking coffee regularly with a lower risk for non-alcoholic fatty liver disease (NAFLD), a condition affecting millions, and for liver scarring among those who had NAFLD. Other research found a lower risk of progression to liver cirrhosis, or severe scarring of the liver, among people with chronic liver disease who drank coffee daily, according to an April 2014 study in ​Liver International​.

For the average adult, up to 400 milligrams of caffeine appears to be safe, per UM. The average cup of brewed coffee has 96 milligrams of caffeine, according to the USDA. Bottom line, drinking up to four cups of coffee a day shouldn't cause issues. Because energy drinks can have many times the amount of caffeine as a cup of coffee, according to the Center for Science in the Public Interest, read labels carefully. One a day could be your limit.

On the other hand, getting more caffeine, such as 1,000 milligrams a day, could exacerbate sudden liver damage or inflammation, Dr. Wantuck says. This happens because the caffeine may block the body's attempts to stop inflammation. Ultimately, this could worsen inflammation in the liver, he says.

"I wouldn't say coffee or energy drinks are bad for the liver, but I also wouldn't recommend drinking them by the gallon," Dr. Wantuck says. Plus, you'll want to consider the other health effects of drinking too much caffeine such as jitteriness, anxiety and trouble sleeping, according to UM.

It's also possible for high levels of caffeine to raise liver enzymes, Dr. Wantuck says. Liver enzymes are measured as part of a blood test that includes alanine transaminase (ALT) and alkaline phosphatase (ALP) levels, according to the Cleveland Clinic. Higher liver enzymes can indicate if you have inflamed or injured liver cells.

If you're concerned about the amount of caffeine you take in or if you find that caffeine, even in small amounts, causes negative effects, talk to your doctor, Dr. Wantuck says. He adds that coffee may not be the only culprit; certain over-the-counter, prescription or illicit drugs and environmental toxins can all contribute to liver damage, so be aware of your exposures.

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