Why you love coffee and beer
Northwestern University
Scientist Marilyn Cornelis searched for variations in our taste
genes that could explain our beverage preferences, because understanding those
preferences could indicate ways to intervene in people's diets.
To Cornelis' surprise, her new Northwestern Medicine study
showed taste preferences for bitter or sweet beverages aren't based on
variations in our taste genes, but rather genes related to the psychoactive properties
of these beverages.
"The genetics underlying our preferences are related to the
psychoactive components of these drinks," said Cornelis, assistant
professor of preventive medicine at Northwestern University Feinberg School of
Medicine. "People like the way coffee and alcohol make them feel. That's
why they drink it. It's not the taste."
The paper was published May 2 in Human Molecular
Genetics.
The study highlights important behavior-reward components to beverage choice and adds to our understanding of the link between genetics and beverage consumption -- and the potential barriers to intervening in people's diets, Cornelis said.
Sugary beverages are linked to many disease and health
conditions. Alcohol intake is related to more than 200 diseases and accounts
for about 6 percent of deaths globally.
Cornelis did find one variant in a gene, called FTO, linked to
sugar-sweetened drinks. People who had a variant in the FTO gene -- the same
variant previously related to lower risk of obesity -- surprisingly preferred
sugar-sweetened beverages.
"It's counterintuitive," Cornelis said. "FTO has
been something of a mystery gene, and we don't know exactly how it's linked to
obesity. It likely plays a role in behavior, which would be linked to weight
management."
"To our knowledge, this is the first genome-wide
association study of beverage consumption based on taste perspective,"
said Victor Zhong, the study's first author and postdoctoral fellow in
preventive medicine at Northwestern. "It's also the most comprehensive
genome-wide association study of beverage consumption to date."
How the study worked
Beverages were categorized into a bitter-tasting group and a
sweet-tasting group. Bitter included coffee, tea, grapefruit juice, beer, red
wine and liquor. Sweet included sugar-sweetened beverages, artificially
sweetened beverages and non-grapefruit juices. This taste classification has
been previously validated.
Beverage intake was collected using 24-hour dietary recalls or
questionnaires. Scientists counted the number of servings of these bitter and
sweet beverages consumed by about 336,000 individuals in the UK Biobank.
Then they did a genome-wide association study of bitter beverage consumption and of sweet beverage consumption. Lastly, they looked to replicate their key findings in three U.S. cohorts.
Then they did a genome-wide association study of bitter beverage consumption and of sweet beverage consumption. Lastly, they looked to replicate their key findings in three U.S. cohorts.
