Scientists have been trying to figure out whether coffee is good or bad for our health for ages, and a new study has shown that the impact of drinking coffee depends on one's genes.
The study also showed that a person's coffee-drinking habits depend on their genetic makeup as well, Knewz.com has learned.
The study was conducted by an international group of researchers using large databases of genetic information from both the United Kingdom and the United States: the 23andMe database of over 130,000 Americans, and the UK Biobank with over 334,000 British participants.
"We had good reason to suspect from earlier papers that there were genes that influence how much coffee someone consumes," Dr. Abraham A. Palmer, a professor of psychiatry at the UC San Diego School of Medicine and one of the authors of the research, said in a media release via StudyFinds.
"And so, we weren’t surprised to find that in both of the cohorts we examined there was statistical evidence that this is a heritable trait. In other words, the particular gene variants that you inherit from your parents influence how much coffee you’re likely to consume," Dr. Palmer added.
Using genetic data from the two massive databases, the team of researchers conducted a genome-wide association study (GWAS) of coffee intake.
"We used this data to identify regions on the genome associated with whether somebody is more or less likely to consume coffee... And then identify the genes and biology that could underlie coffee intake," Dr. Hayley Thorpe from Western University in Ontario, lead author of the study, explained (via StudyFinds).
The team analyzed each database and tried to find correlations between "genetic variants" and the coffee-drinking habits reported by the studied subjects in a survey.
StudyFinds noted that the 23andMe survey participants were asked specifically about caffeinated coffee drinking habits, whereas the UK Biobank survey included the habit of drinking decaf in their questions.
"We examined genetic correlations and performed a phenome-wide association study across hundreds of biomarkers, health, and lifestyle traits, then compared our results to the largest available GWAS of coffee intake from the UK Biobank," the research, that was published in the journal Neuropsychopharmacology, noted.
"Our study shows that the genetics of coffee intake associate with substance use and obesity across cohorts, but also that GWAS performed in different populations could capture cultural differences in the relationship between behavior and genetics."
Simply put, the study confirmed that the habit of drinking coffee is related to a person's genes, with both databases showing that certain genetic profiles are associated with higher or lower coffee consumption.
However, the study also found that "other genetic correlations were discrepant, including positive genetic correlations between coffee intake and psychiatric illnesses, pain, and gastrointestinal traits in 23andMe that were absent or negative in the [UK Biobank], and genetic correlations with cognition that were negative in 23andMe but positive in the [UK Biobank]."
"In other words, the same genetic variants associated with more coffee drinking were tied to higher risks of mental health issues in one population but appeared to be protective in the other," StudyFinds explained.
Therefore, the research found that while coffee-drinking habits are related to one's genes, whether it is harmful varies from person to person based on an array of external factors. As a result, experts cited by StudyFinds recommend taking "plain, modest servings of high-quality coffee without a lot of added sugars and fats."