Drinking coffee may raise risk of oesophageal cancer… but only if it’s piping hot, study claims

Drinking coffee may raise your risk of cancer… but only if it’s piping hot, research suggests.

Scientists think it’s because hot liquids damage tissues in the oesophagus — also known as the food pipe.

It means, in theory, tea lovers could also be at risk.

Therefore, people should wait for their cups of coffee or tea to cool down before drinking them, experts advise.

Coffee is one of the most widely consumed drinks worldwide, but there has been mixed evidence on its health effects. 

Some studies have suggested the beverage cuts the odds of getting cancer, while others — including the World Health Organization’s cancer research panel — have found the opposite. 

The truth is murky, however, because of how older experiments have been carried out, scientists say. 

Previous research often compared drinking habits against the onset of conditions such as oesophageal cancer.

But this has been unable to prove whether drinking coffee itself is responsible or if other lifestyle factors common among fans of the beverage are at play.

People who are genetically more likely to drink coffee may have an increased risk of developing oesophageal cancer but not other cancer types, a study claims [stock image]

Cambridge University experts have now attempted to overcome the hurdles seen previously by using a different statistical approach. Their findings are published in the journal Clinical Nutrition.

They compared the genes of over 360,000 people in the UK and Finland, and linked it to the risk of developing 22 types of cancer for 11 years.

They did this to account for the same factors that may have skewed previous research.

For example, self-confessed coffee drinkers also tend to drink more alcohol, which may explain their heightened risk of cancer. 

But the genes that are associated with liking coffee are not necessarily linked to lifestyle factors like smoking or drinking.

Dr Steve Burgess and the team say, therefore, that looking at the DNA of volunteers makes it easier to determine whether it is coffee specifically that is causing cancer.

Data revealed that people deemed genetically more likely to drink coffee were nearly three times more likely to develop oesophogeal cancer. 

No such link was found for any other cancer type.

‘The good news is that coffee drinking doesn’t increase your chance of getting most cancer types,’ said Dr Burgess.

Coffee-drinking genes increased the risk in actual coffee fans, as well as people who favoured other hot beverages. 

This suggested the effects may be due to the tissue damage caused by hot liquids, rather than the coffee itself. 

‘The most likely reason for the association between coffee drinking and oesophageal cancer is that pouring scolding hot liquid down your throat is doing some damage,’ said Dr Burgess.

This idea is supported by a previous study carried out in 2019 which found drinking tea at over 60C increased the risk of oesophageal cancer.

Scientists think when cells in the food pipe are burned by hot drinks, this generates inflammation that damages genes, causing cancer. 

Further evidence is needed to confirm the findings.

Although, the WHO five years ago concluded is safe if consumed at ‘normal serving temperatures’ — i.e. 65C or under.

‘It’s important to consider that our study does not prove a causal link between coffee-drinking and oesophageal cancer risk, it just provides strong evidence to suggest there is one,’ added Dr Burgess.

Around 9,300 people are diagnosed with oesophageal cancer each year in the UK, meaning it accounts for 2 per cent of new cancer cases.