Even one drink a day raises mouth cancer risk by 50%, study warns

Even low alcohol consumption when combined with a combination of factors like chewing tobacco, is linked to a 50 per cent increase in mouth cancer risk, scientists warn in a new study.

Oral cancer is the eleventh most common cancer globally, with a very high prevalence in South Asia, particularly India.

However, exactly how a combination of major risk factors amplifies the chances of a person developing the cancer remains unclear.

Now, researchers have found that consuming alcohol, even as much as a glass a day, alongside chewing tobacco, a common practice in South Asia, had an especially severe combined effect.

This pairing could be responsible for nearly two-thirds of all mouth cancer cases in India, scientists found in the study published in the journal BMJ Global Health.

The strongest link, according to researchers, was among those who consumed local alcoholic beverages, such as apong, bangla, chulli, and mahua.

In the study, scientists compared data from 1,803 people, aged between 35 and 54 years, diagnosed with buccal mucosa cancer with those from 1,903 randomly selected individuals without the disease.

Participants provided information about how long they had been drinking alcohol, how often they drank, and the types of alcohol they consumed.

These included 11 international drinks like beer, whisky, vodka, rum and breezers, along with 30 locally brewed options.

The participants were also quizzed about their tobacco use, including duration and type.

Of those diagnosed with cancer, 781 reported drinking alcohol, while 1,019 said they did not.

In comparison, among those in the control group, 481 drank alcohol, and 1,420 did not.

Researchers found that frequent alcohol consumption was strongly linked to increased cancer risk, with locally brewed drinks showing the greatest effect.

Even drinking very small amounts of alcohol, as little as 2 grams of beer per day, was still linked to an increased risk of buccal mucosa cancer, scientists found.

Consuming one standard drink a day, roughly about 9 grams of alcohol daily, was associated with about 50 per cent higher mouth cancer risk, according to the study.

The combined exposure of alcohol and tobacco was linked to more than a fourfold increase in risk, researchers warned.

They suspect alcohol may change the fat content of the mouth's inner lining, making it more permeable and susceptible to cancer-causing chemicals in chewing tobacco products.

Locally brewed alcohol may have even more risk, partly due to their alcohol content as well as contamination with toxic substances such as methanol and acetaldehyde, scientists say.

“Locally-brewed liquor market is unregulated, with some forms used by participants containing up to 90 per cent alcohol content," researchers wrote.

"In summary, our study demonstrates that there is no safe limit of alcohol consumption for [buccal mucosa cancer] risk,” they concluded.