New research in The Lancet Oncology estimates that a total of 741,300 newly diagnosed cancer cases were associated with alcohol consumption in 2020. This figure represents 4.1 percent of all cancer diagnoses worldwide, leading to calls for more education around the carcinogenic effects of drinking alcohol.
Regular drinking is thought to contribute to the development of certain cancer types, with liver, breast, colon, and mouth cancers all having well-established causal links to alcohol consumption. This is largely due to the actions of acetaldehyde, a carcinogenic metabolite of ethanol that can damage DNA and other cellular components. Drinking can also upset the regulation of hormones like estrogens and androgens, while ethanol has the potential to act as a solvent for other carcinogenic chemicals, such as those found in cigarettes.
To calculate the impact of alcohol use on cancer development, the study authors obtained data relating to alcohol production, sale, and consumption in every country around the world in 2010. According to the researchers, “a ten-year latency period between alcohol consumption and cancer diagnosis” should be expected, meaning cancers diagnosed in 2020 are likely to be linked to drinking statistics from a decade before.
Using this data, the researchers established an estimate for alcohol intake per person in each country, which they then cross-referenced with global cancer cases in 2020. In doing so, they were able to conclude that heavy drinking – which involves the consumption of more than six alcoholic beverages a day – was linked to 346,400 cancer diagnoses in 2020. This figure accounts for 47 percent of all alcohol-associated cancer cases last year.
Risky drinking, which involves consuming between two and six drinks a day, contributed a further 39 percent of all such cases, while moderate drinking – defined as any amount up to two drinks a day – accounted for 14 percent of alcohol-associated cancer diagnoses.
“We urgently need to raise awareness about the link between alcohol consumption and cancer risk among policy makers and the general public,” explained study author Harriet Rumgay in a statement. “Public health strategies, such as reduced alcohol availability, labelling alcohol products with a health warning, and marketing bans could reduce rates of alcohol-driven cancer.”
Breaking down the data, the researchers noted that alcohol use contributed to 189,700 esophagus cancers in 2020, as well as 154,700 liver cancers and 98,300 breast cancers. The country with the highest proportion of alcohol-associated diagnoses was Mongolia, where ten percent of all new cases in 2020 can be linked to drinking. At the other end of the scale, virtually no alcohol-associated cancer cases were found in Kuwait, where drinking is uncommon.
The study authors calculate that around three percent of new cancer cases in the US last year were linked to alcohol consumption, while in the UK this figure was closer to four percent.
According to the researchers, these statistics should be considered “conservative estimates”, and the actual burden of cancer attributable to alcohol consumption may be even higher. However, because they did not take smoking into account when compiling their data, they concede that some of these cases could have been caused by tobacco rather than alcohol.