Would you prefer to down a bitter black coffee or swig on a sickly sweet latte? Researchers investigating differences in our tastebuds have been surprised to discover our taste preference is related not to our taste genes but to genes related to the psychoactive properties of certain beverages.
Scientist Marilyn Cornelis wanted to better understand the way our taste buds worked with the idea it could assist in intervening in people's diets. But the results she found were not what she expected.
Black coffee because it feels good
"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 surprising results have been published in Human Molecular Genetics.
The paper shows how behavior-reward components are linked to beverage choice; these findings will help understand the links genetics and beverage consumption. Drinks with high sugar content are linked to many diseases and health conditions including obesity and type 2 diabetes.
Gene variant surprises researchers
Alcohol is also a huge contributing factor to many diseases worldwide and accounts for up to 6% of global deaths. Another surprising find was the variant in a gene called FTO. Cornelis discovered that people who possess a variant in the FTO gene preferred sugar-sweetened beverages - despite the same variant being previously related to lower risk of obesity.
"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."
Research thanks to bio-bank
The study was conducted using the UK Biobank - a cohort study of deep genetic, physical and health data collected on ~500,000 individuals across the United Kingdom.
Initially, beverages were categorized into either bitter-tasting or sweet-tasting — the bitter group coffee, tea, grapefruit juice, beer, red wine, and liquor and the Sweet group included sugar-sweetened beverages, artificially sweetened beverages, and non-grapefruit juices.
This taste classification has been validated by previous studies. The intake of beverages in a 24-hour period was collected by dietary recalls or questionnaires. The number of bitter and sweet beverages consumed by about 336,000 individuals were collected from UK Biobank cache.
The researcher then did a genome-wide association study of bitter beverage consumption and of sweet beverage consumption. The results were then validated from data from three US cohorts.