This Many Cups of Coffee Protects the Liver

And oh boy does it get damaged. We modern day humans, in general, overwork and abuse the hell out of our livers. We're constantly ingesting all manner of drugs and compounds with little regard to how it affects it. Most of the time the cells regenerate, but punch your liver in the gut often enough and you can develop cirrhosis (a scarring of the liver which mucks up the way it functions).

In turn, cirrhosis can lead to liver cancer, or cirrhosis can just plain kill you on its own. Here's just a small sampling of the substances that can cause liver damage:

• Acetaminophen (about 60,000 people in the U.S. overdose on acetaminophen every year and have to be rushed to the hospital in an attempt to save their liver and their life)
• Alcohol
• Anticonvulsants
• Antibiotics
• Methyldopa
• Statins
• Vitamin A (in large doses)
• Niacin (in large doses)
• Sugar (too much too often leads to a fatty liver, which can develop into cirrhosis)
• Kava
• Ephedra
• Comfrey
• Black Cohosh
• Smoking
• Anabolic Steroids
• Obesity (which is associated with a fatty liver)

The list is probably considerably longer but we just don't know. Americans are introduced to a plethora of new drugs, supplements, and herbs every year. Some of them, or some of them in specific combinations, might well damage the liver.

And I haven't even mentioned hepatitis or autoimmune diseases that target this underappreciated organ. It's a wonder all Americans aren't on a waiting list for a new liver.

Luckily, a new study says that drinking a few cups of coffee a day – with 4 cups exhibiting the maximum protective effect – can protect us from liver disease. What's more, it doesn't matter much if it's regular or decaf.

Researchers from the University of Southampton looked at data that tracked the dietary habits of 495,585 Brits over 10.7 years to determine whether any external factors played a role in whether they developed liver disease or not.

One thing stood out: Seventy-eight percent of the Brits drank some form of coffee (regular ground coffee, decaffeinated coffee, or instant), while the rest didn't drink any coffee at all.

All this coffee drinking correlated with the following hepatic developments during the course of the analysis:

• 3,600 cases of chronic liver disease, of which 301 individuals died
• 5,439 cases of chronic liver disease or steatosis (fatty liver disease)
• 184 cases of hepatocellular carcinoma, a type of liver cancer.

Here's the exciting part, though: Compared to non-coffee drinkers, the coffee drinkers had a 21% reduced chance of developing chronic liver disease; a 20% reduced risk of chronic or fatty liver disease; and a 49% reduced chance of death from chronic liver disease.

The type of coffee that conveyed the highest level of protection was ground coffee. Instant coffee was also associated with a lower risk of chronic liver disease, but it didn't work quite as well as regular ground coffee. The optimal protective effect was seen in those that drank 3-4 cups of coffee a day.

Coffee is chock-full of various plant chemicals, almost any of which, or any combination of which, might be responsible for playing bodyguard to the liver. Chief suspects among the heroes, though, are chlorogenic acid, kahweol, and cafestol.

The first is a polyphenol well known for having hepato-protective properties, in addition to also being antibacterial, cardioprotective, antiviral, and anti-hypertensive.

The second and third suspects, kahweol and cafestol, are what's known as "diterpines," which are a class of chemical compounds that are generally known to be antimicrobial and anti-inflammatory.

While the study is compelling, they didn't bother to discuss whether certain varieties of coffee or certain blends of coffee might be more hepatoprotective than others. That's too bad, because certain types of coffee do indeed contain more chlorogenic acid (CGA), and probably more kahweol and cafestol, too:

• The coffee beans with the highest CGA are grown at high altitudes and near the equator. Opt for Kenyan, Ethiopian, or Columbian.
• The commercial coffees with the highest CGA content that you can buy are Dunkin' Donuts Original Blend and McCafe Premium Roast Decaf, medium roast.
• Artisanal coffees, though, generally have 50% more CGA than those you can find at the grocery store.
• Caffeinated versions generally have about 25% more CGA than decaffeinated versions.
• Flavored blends don't usually have a high CGA content because they typically use low-quality, low CGA beans (the artificial flavor negates the need for good-tasting, high-CGA beans).
• Light and medium roast coffees preserve CGA, while dark roasts destroy them (along with generating undesirable byproducts like acrylamide, the carcinogen found in French fries and potato chips).
• Use fresh ground coffee beans when possible. Pre-ground versions usually lack flavor and are short on CGA.
• Very fine grinds are the most healthful, but also the most bitter. Medium grinds have an acceptable amount of CGA.

Ah, maybe I'm over-thinking it. Maybe it's enough to just drink the stuff, regardless of whether it's fresh-ground, light roast, very fine Kenyan, or the instant crap that comes out of a jar.

1. Kennedy OJ et al. All coffee types decrease the risk of adverse clinical outcomes in chronic liver disease: A UK Biobank study. BMC Public Health. 2021 Jun 22;21(1):970. PubMed.
2. Arnot B. Coffee: The Ultimate Health Drink. BottomLine Health. 2017 Oct;31(10):1-3.