The effects of coffee on human health are complex, but it is known that coffee has psychoactive properties.
According to Sandra Sanchez-Roige, Ph.D., an associate professor in the University of California San Diego School of Medicine Department of Psychiatry, coffee is a psychoactive substance. She and a group of researchers conducted a study comparing coffee-drinking habits in a 23andMe database with a larger set of records.The corresponding author of a study recently published in the journal Neuropsychopharmacology is a researcher from the United Kingdom. The lead author, Hayley H. A. Thorpe, Ph.D., is from the Department of Anatomy and Cell Biology at Western University in Ontario. The researchers collected genetic data and self-reported coffee-consumption numbers to conduct a genome-wide association study (GWAS). They aimed to find connections between genes associated with coffee consumption and various health-related traits or conditions.Thorpe explained that they used the data to locate specific regions on the genome that are linked to a person’s likelihood of consuming coffee. They also aimed to pinpoint the genes and biological factors that may be involved in the intake of coffee.
Dr. Abraham Palmer, a leading researcher on the paper and a professor at UC San Diego School of Medicine Department of Psychiatry, expressed surprise at the genetic influence on coffee consumption. He mentioned that earlier papers had already indicated the presence of genes that impact coffee intake, so the team’s findings were not entirely unexpected.The cohorts we studied showed statistical evidence that the amount of coffee you consume is a heritable trait. In simpler terms, the gene variants you inherit from your parents can influence your coffee consumption.”
Sanchez-Roige explained that understanding the genetic influence on coffee consumption was the first of two questions the researchers wanted to tackle.
“The second question is something that coffee enthusiasts are really interested in,” Sanchez-Roige added. “Is drinking coffee beneficial or harmful? Does it have any positive health effects?”
The answer isn’t clear-cut. The team’s genome-wide association study of 130,153 individuals based in the U.S. aims to address this.The study compared the genetic makeup of dMe research participants with the genetic data of 334,649 Britons from the UK Biobank database. The results showed consistent positive genetic connections between coffee consumption and negative health effects such as obesity and substance use. A positive genetic association occurs when a specific gene variant is linked to a particular condition, while a negative genetic association indicates a protective quality that prevents the development of a condition. However, the findings become more complex when it comes to psychiatric conditions. For example, the genetic factors related to anxiety and other psychiatric disorders.Bipolar disorder and depression: In the 23andMe data set, there is a positive genetic correlation with coffee intake genetics,” Thorpe stated. “However, in the UK Biobank, there is a negative genetic correlation. This was unexpected.”
There were other cases where the 23andMe set did not match with the UK Biobank, but the biggest difference was seen in psychiatric conditions.
“It is common to combine similar datasets in this field to increase study power. However, the data suggests that combining these two datasets was not a wise decision. And we did not expect this outcome.”Thorpe mentioned that combining the databases could potentially obscure the effects, leading to incorrect conclusions or canceling each other out. Sanchez-Roige suggested that the differences in results may have been due to the different survey questions used in the studies, such as the 23andMe survey asking about the number of cup-sized servings of caffeinated coffee consumed each day, while the UK Biobank survey asked about the number of cups of coffee consumed, including decaffeinated coffee. Additionally, differences in serving size and caffeinated versus decaf coffee may have contributed to the varying results.The surveys did not take into account the various ways that coffee is typically served. According to Thorpe, in the U.K., instant coffee is generally preferred, while in the U.S., ground coffee is the more popular choice. Sanchez-Roige mentioned the American trend of consuming sugary frappuccinos, which was not considered in the surveys. Palmer also noted that other caffeinated drinks, such as tea, were not included in the GWAS, which focused solely on coffee. Additionally, Palmer highlighted that the GWAS shows that the connection between genotype and phenotype is more complex than previously thought.relationship between genetics and coffee consumption is all about,” Sanchez-Roige explained. “Your genetic makeup can influence how you respond to coffee and how much you enjoy it, but cultural and environmental factors also play a significant role in shaping your coffee habits.” He also noted that while some people may be genetically predisposed to enjoy coffee, others may prefer tea or other beverages. The interplay between genetics, culture, and personal choices ultimately determines how much coffee a person drinks and how they experience its effects.The speaker pointed out that behavior and choices made in the environment have a significant impact on the interaction between genotype and environmental factors, unlike height. The collaborators emphasized the importance of further research to understand the connections between genetics and the environment, including substance use issues beyond coffee and caffeine intake. In addition to the researchers mentioned, co-authors from UC San Diego include Benjamin K. Pham, John J. Meredith, and Mariela V. Jennin.Mariela V. Jennings, Sevim B. Bianchi, and Sandra Sanchez-Roige, from the Department of Psychiatry, are supported by funds from the California Tobacco-Related Disease Research Program (TRDR). The other co-authors include Pierre Fontanillas from 23andMe, Inc., Laura Vilar-Ribó from the Universitat Autònoma de Barcelona in Spain, Julian Mutz from King’s College London in the U.K., Sarah L. Elson and Jibran Y. Khokhar from the University of Guelph in Canada, Abdel Abdellaoui from the University of Amsterdam in The Netherlands, and Lea K. Davis from Vanderbilt University Medical Center. The 23andMe Research Team also contributed to the study.P; Grant Number T29KT0526 and T32IR5226). Sevim B. Bianchi and Abraham Palmer were also funded by P50DA037844. BKP, Julian Mutz, and Sandra Sanchez-Roige are recipients of support from NIH/NIDA DP1DA054394. Hayley H. A .Thorpe is funded through a Natural Science and Engineering Research Council PGS-D scholarship and Canadian Institutes of Health Research (CIHR) Fellowship. Jibran Y. Khokhar is supported by a CIHR Canada Research Chair in Translational Neuropsychopharmacology. Lea K. Davis is supported by R01 MH113362. Natasia S. Courchesne-Krak is funded through an Interdisciplinary Research Fellowship in NeuroAIDs (Grant Number R25MH081482). Julian Mutz receives funding from the National Institute for Health and Care Research (NIHR) Maudsley Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London.
