NEW DELHI: More than six out of 10 people in India are suffering from mouth (buccal mucosa) cancer due to frequent consumption of alcohol, with locally brewed drinks associated with the greatest risk, along with chewing of smokeless tobacco products such as gutkha, khaini, paan, according to a large study published on Wednesday.

The study, authored by a team of researchers from the Center for Cancer Epidemiology, and Homi Bhabha National Institute, in Maharashtra, showed that as little as under 2 g a day of beer was associated with a heightened risk of buccal mucosa cancer, while 9 g a day of alcohol -- equivalent to around one standard drink -- was associated with an approximately 50 per cent increased risk of mouth cancer.

When combined with chewing tobacco, it likely accounted for 62 per cent of all such cases in the country.

The findings, detailed in the open-access journal BMJ Global Health, suggest that more than one in 10 cases (nearly 11.5 per cent) of all buccal mucosa cancers in India are attributable to alcohol, rising to 14 per cent in some of the states with a high prevalence of the disease, such as Meghalaya, Assam, and Madhya Pradesh.

“Alcohol was a contributory factor to the heightened risk of mouth cancer, irrespective of how long tobacco had been used. Ethanol might alter the fat content of the inner lining of the mouth, increasing its permeability and therefore its susceptibility to other potential carcinogens in chewing tobacco products,” explained the research team led by Grace Sarah George.

“Possible contamination with toxins, such as methanol and acetaldehyde, in locally brewed alcohol, might help explain the higher risk associated with these drinks, the manufacture of which is largely unregulated,” they said.

Mouth cancer is the second most common malignancy in India, with an estimated 143,759 new cases and 79,979 deaths every year. Rates of the disease have risen steadily, and now stand at just under 15 for every 100,000 Indian men, noted the researchers.

The primary form of mouth cancer in India is that of the soft pink lining of the cheeks and lips (buccal mucosa). Less than half (43 per cent) of those affected survive five or more years.

In the study, the researchers compared 1,803 people with confirmed buccal mucosa cancer and 1,903 randomly selected people free of the disease (controls) from five different study centres between 2010 and 2021. Most of the participants were aged between 35 and 54; nearly half (around 46 per cent) of cases were among 25-to 45-year-olds.

Compared with those who didn't drink alcohol, the risk was 68 per cent higher for those who did, rising to 72 per cent for those favouring internationally recognised alcohol types such as beer, whiskey, vodka, rum, and breezers (flavoured alcoholic drinks), and to 87 per cent for those opting for locally brewed drinks like apong, bangla, chulli, desi daru, and mahua.

"Our study demonstrates that there is no safe limit of alcohol consumption for [buccal mucosa cancer] risks. Our findings suggest that public health action towards prevention of alcohol and tobacco use could largely eliminate [buccal mucosa cancer] from India," the team said.