Decoded: Why people love to have coffee or beer

Whether you choose a dark roast coffee or hoppy beer in the summer, it may actually depend on how the drink makes you feel rather than how it tastes, reveals a genome-based study.

The researchers 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.

They found that taste preferences for bitter or sweet beverages are not based on variations in our taste genes but rather genes related to the psychoactive properties of these beverages.

"People like the way coffee and alcohol make them feel. That's why they drink it. It's not the taste," said Marilyn Cornelis, Assistant Professor at Northwestern University Feinberg's School of Medicine.

For the study published in the journal Human Molecular Genetics, beverages were categorised into a bitter-tasting group and a sweet-tasting group.

Bitter included coffee, tea, grapefruit juice, beer, red wine and liquor.

The researchers provided questionnaires to about 336,000 individuals asking them to report what they ate and drank over the past 24 hours.

The scientists also did a genome-wide association study of bitter beverage consumption and of sweet beverage consumption.

"To our knowledge, this is the first genome-wide association study of beverage consumption based on taste perspective.

"It's also the most comprehensive genome-wide association study of beverage consumption to date," said Victor Zhong, the study's lead author.

According to the researcher Marilyn Cornelis, 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.