Why drinking six cups of coffee daily cuts risk of gallstones by 25%

Drinking six or more cups of coffee a day drastically reduces the risk of developing gallstones, according to a study.

The high intake slashed the chances of getting the painful ailment by 23 per cent, compared to those who did not drink any coffee at all.

Researchers analysed official health and lifestyle data among 104,500 adults, who were tracked for up to 13 years. They compared how much coffee participants drank with whether or not they had ever suffered from symptomatic gallstone disease (GSD).

A team from the Copenhagen University Hospital in Denmark conducted the study. Drinking just one cup a day lowered the risk of GSD by three per cent but the biggest effect was from drinking several cups each day.

The study was published in the American Journal of Medicine. European guidelines recommend no more than 400mg of caffeine per day – a cup of coffee contains anywhere from 70 to 140mg.

Gallstones are lumps of solid material that form in the gallbladder. In the United Kingdom (UK), up to one in 10 adults have the condition. Gallstones, which can resemble grains of sand or large pebbles, are formed from chemicals in bile and can consist of just cholesterol, a mixture of calcium and pigment from red blood cells, or a combination of the two.

They have been linked to high-cholesterol diets. Most people are unaware they have them. The most common symptom is abdominal pain, which can last up to eight hours and be severe.

The researchers said caffeine is released via bile and contains chemical compounds called methylxanthines that stimulate the production of acid. They said this might prevent the cholesterol from forming gallstones. The research team, led by Ask Tybjaerg Nordestgaard of the university’s department of clinical biochemistry, said: “A coffee-induced increase in bile acid production could reduce the risk of cholesterol gallstones.

“Moreover, coffee has been shown to induce UGT1A1, the enzyme responsible for the conjugation of bilirubin. Elevated levels of unconjugated bilirubin in bile are a causal risk factor for gallstone formation.”

The findings come after a Harvard University study linked coffee to migraines.

Researchers found that drinking three or more cups a day substantially increased the risk of an attack.

The study tracked 98 sufferers of ‘episodic’ migraines – defined as having the debilitating headaches on up to 14 days a month.

They found that drinking up to two cups of coffee or other caffeinated drinks made no difference to their chance of a migraine.

But when they drank three cups, the risk of having an attack the same day went up by 40 per cent. If they had five cups, it rose by 161 per cent.

The researchers, whose findings are published in the American Journal of Medicine, said the impact of caffeine on migraines is complex because it depends on dose and frequency. And while it may trigger an attack, it can also have a painkilling effect.

And pregnant women have been warned against drinking more than two cups of coffee a day as it can damage the baby’s liver.