Scientists find how much coffee cuts liver cancer risk by almost half

Your daily coffee habit may sharply lower the risk of liver cancer and cirrhosis, new findings suggest

A major new body of research following 355,000 UK adults over 23 years has found the heaviest coffee drinkers - those having five or more cups a day - have a significantly lower risk of liver cancer.

Blood tests on the participants also showed elevated markers of good liver function.

The research, led by Hyunseok Kim of Cedars-Sinai Health Sciences University, points to coffee as a possible shield against fatty liver disease.

This condition affects an estimated one in three UK adults and is linked to a sharp rise in liver cancer deaths across Europe in recent decades.

Fatty liver disease develops when the organ treats accumulating fat as a threat, triggering inflammation that can progress to scarring and eventually cancer.

But coffee appears to interrupt the chain of events in several ways.

Caffeine is believed to be a major driver, as research suggests it can block the formation of tissue in at-risk livers - a theory bolstered by the fact that tea, which contains far less caffeine, doesn’t offer the same protective effect.

Coffee also contains more than 100 plant compounds which appear to boost the liver’s natural antioxidant defences, and even decaffeinated drinkers in Kim’s study showed some benefit.

There’s a gut connection too, as the plant compounds have been shown to encourage beneficial gut bacteria and calm inflammation that would otherwise spread to the liver via the bloodstream.

So how much should you drink?

Evidence from some of the largest observational cohort studies to date indicates that drinking two to four cups of coffee daily correlates with a lower risk of premature mortality, heart disease and type 2 diabetes.

An American Heart Association Statement on Caffeine and Cardiovascular Disease supports this, noting that anything exceeding this amount increases the likelihood of side effects such as palpitations.

Brewing methods all matter, with cafetieres, filter and instant varieties carrying the strongest evidence, while express and Americano-style drinks have shown weaker links to liver protection, likely due to lower caffeine content of each serving.

Milk appears to have little impact, but sweeteners, including both sugar and artificial sweeteners, were associated with more liver inflammation, though both experts agree the occasional spoonful won’t undo the benefits.