A warm cup of coffee is a necessary part of the morning routine for millions of people around the world but for some sleep-deprived individuals, a cup of coffee is never the answer to get them to perk up in the morning, no matter what. For some individuals, even just the smallest amount of caffeine may give them some pretty negative side effects. So, why is it that caffeine affects people in such dramatically different ways? The answer, according to a new study lies in your genes.
People who react positively to caffeine do so usually pretty easily. For these individuals, even just the smell of caffeine alone can issue an almost Pavlovian response which helps them feel more alert and energetic. Additionally, these regular coffee drinkers make up more than half of America’s population, with one survey finding that 64 percent of Americans aged 18 or over said they had at least one cup of coffee in the previous day. Although, according to National Geographic, our DNA may tell us more about how we process caffeine and subsequently, how coffee affects us as a whole.
“What we’re finding is that we have built-in genetic factors that help us with self-regulating our caffeine intake,” Marilyn Cornelis, a caffeine researcher at Northwestern University, told National Geographic. “It’s interesting how strong of an impact our genetics have on that.”
“For someone who has a genetic variant that leads to decreased caffeine metabolism, they’re more likely to consume less coffee compared to someone who has a genetic variant that leads to increased caffeine metabolism,” Cornelis added.
When caffeine enters the human system, two genes are linked to much of the processing: CYP1A2 (which generates an enzyme in the liver that breaks down around 95 percent of consumed caffeine) and AHR (which regulates CYP1A2). How much caffeine flows in your bloodstream, and how long it circulates for, is determined by these two genes.
Additionally, in another research conducted by 23andMe, the company giant analysed data from roughly 1.8 million users to investigate just how genetics might affect caffeine consumption, in which they focused primarily on genetic variants near CYP1A2 and AHR to estimate how an individual’s body might handle caffeine.
Based on their findings, 23andMe has stated that as part of its efforts to source data for analysis on traits like caffeine consumption, people from places within the united states, like North Dakota, Washington, Oregon, Utah, and Colorado were most likely to consume more caffeine than average based on their genes, based on their data.
Interestingly enough, following the results, New Yorkers’, despite being known for being fans of consuming a high intake of coffee were found to be compared alongside other East Coast states New Jersey, Connecticut, and Rhode Island which were considered the five states likely to consume less caffeine than average based on genetic predisposition.
23andMe’s data also indicated that individuals in their 20s were less likely to consume more caffeine than other age groups based on their genes. Although in saying that,women were found to be more likely to consume more caffeine than men regardless of age. Baby boomers – or those aged 55 to 70 were most likely to be genetically predisposed to more caffeine consumption than the average.
“Whether individuals with impaired ABCG2 function have higher or longer central nervous system exposure to caffeine and thus a lower caffeine dose requirement for neural effects merits further study,” Cornelis indicated.
Although the body of research investigating the links between DNA and coffee tolerance is growing each day, more research is needed to better understand the true length behind the results. For now though, it’s safe to say your coffee drinking habits are linked to something beyond your control such as your genetics.