Beer, bugs, DNA linked to stomach cancer
Genetic variant, low-grade infection and guzzling can add up to trouble
By Nathan Seppa
ORLANDO, Fla. — Swilling at least three beers a day over several years can increase a person’s risk of stomach cancer if combined with two other unseen risk factors, researchers have found. But oddly, wine and liquor didn’t show the same danger level for this malignancy, the team reported April 4 at a meeting of the American Association for Cancer Research.
The triple threat includes carrying two copies of rs1230025, a gene variant located amid a cluster of genes associated with degrading alcohol in the body. The third risk factor is an infection with Helicobacter pylori, a well-known bacterium that causes stomach cancer and ulcers. H. pylori infection is uncommon in the United States, but roughly half the world’s population carries the microbe.
Eric Duell, an epidemiologist at the Catalan Institute of Oncology in Barcelona, and his colleagues analyzed data on health status and alcohol intake among thousands of adults participating in a European study between 1992 and 1998. The researchers found a broad link between stomach cancer and drinking three or more beers daily, but no clear association for similar amounts of wine or liquor.
The researchers then focused on 364 people who had been diagnosed with stomach cancer and 1,272 others without cancer to test the combined effects of beer intake and having the variant gene. People who drank three beers or more daily showed a slight increase in stomach cancer risk if they carried one copy of the gene variant, compared with similar drinkers without the variant. Also, very modest drinkers who carried two copies of the variant had a slightly increased risk over similar drinkers without it.