Coffee or Tea?: Trust Your Drinking Preference With DNA

As you take the journey of getting to know who you are, there are a lot of moments when you might find yourself indecisive even with the littlest things. This includes your preferences. Sometimes, one couldn’t decide an answer to a question as simple as, “Do you like coffee or tea?”. While there are various methods that could help you solve this concern, experts say there lies a scientific answer to this - which is DNA. Come to think of it. You could’ve been going over one drink to another and choosing them without giving much thought on how are you able to know what you want, is that right? Find out on the discussions below what DNA has got to do with all this seemingly intuitive behavior of having preferences.

The science of taste preferences

Why do we prefer some things but not others? Why do we have a favorite food and those that we dislike? Why do we like coffee more than tea, or tea more than coffee? We usually don’t think about these things that much, as the body does it very naturally and unnoticeably.

There are two processes that make each individual’s preferences different from another. 

Affective Process

In this process, the taste is integrated with post-ingestive feedback. The type of change of preference depends on what the feedback is all about. This negative or positive feedback urges from gut feelings and the sensations brought by hunger, state, and a feeling of nausea. 

Cognitive Process 

Meanwhile, in the cognitive process, it’s more about the integration of the senses - particularly visuals and an odor along with its taste. Like animals, sometimes we tend to base our choices and preferences with the look and smell of a food or drink.

These processes are interceded by two types of spinal nerves - the dorsal and ventral vagus nerves. They come from the gut that converges with nerves for taste in the brain stem. There is an enormous amount of brain information sent by the gut about the well-being of the body to the brain, including sensations that arise from digestive functions as well as illness. It is said that your preference isn’t as simple as a quick thought, but also noncognitive-emotive-synthetic feedback arising from the body. 

Letting your DNA choose between coffee or tea

So, back to a simple question that some of us can’t instantly decide on: Are you a coffee or a tea person? More importantly, what’s most responsible for the process of making a choice on this?

A study from the Scientific Reports journal titled Understanding the role of bitter taste perception in coffee, tea, and alcohol consumption through Mendelian randomization talked about the perception of bitterness in one substance or another helps us in the selection on the variety of the substances consumed. According to Dr. Marilyn Cornelis, co-author of the research from Northwestern University in Illinois: “The study adds to our understanding of factors determining beverage preferences – taste, in particular – and why, holding all other factors constant, we still see marked between-person differences in beverage preference as well as the amount we consume.” There are two sets involved in this study.

For the first set, data were analyzed from a large Australian study of 1,757 twins and their siblings, aged 12-25, 54 percent of whom were females and all were of European ancestry. In this experiment, it was observed that genetics play an important role in the strength of perception of different tastes, and in this case, various forms of bitterness: one specific variant was associated with caffeine, another to greater for quinine and a third to a drug known as propylthiouracil (PROP).

The second set is from a research firm on health-related information called UK Biobank. They recruited more than 400,000 participants aged 37 to 73 between 2006-2010, involving the collection of genetic data as well as health information, and filling out touch-screen questionnaires on how much coffee, tea, and alcohol they consume. According to the results, here are a couple of things found, as shared by Jue Sheng Ong, a doctoral student at QIMR Berghofer who co-led the study:

• Light coffee drinkers drank fewer than two cups per day and heavy coffee drinkers drank more than four cups
• Heavy tea drinkers drank more than five cups per day while heavy alcohol consumption was defined as drinking more than three to four times per week
• Those who tasted the bitterness in caffeine were more likely to be the coffee lovers, and the opposite group who were less able to taste the bitterness wasn’t as keen on coffee
• Increased perception of the bitterness of quinine and prop resulted in a small reduction in coffee drinking
• People were more likely to prefer tea if they were genetically inclined to taste the bitterness in brussels sprouts or broccoli

While the studies still have its limitations, it surely helped us indicate the difference is based on the sensitivity and perception of the genes for caffeine or other bitter tastes. According to Stuart MacGregor, an associate professor and the head of QIMR Berghofer’s Statistical Genetics research group, who co-authored the study, “It improves our understanding of people who are big drinkers of alcohol or coffee and opens the door to new research into treatments.” He also added that this study highlights the vitality of taste genes on drinking habits - which is a good way to specify as there are lots of factors affecting the reasons behind what people drink. The research team has planned on continuously trying to expand the results that shed light on the science behind preferences.

And while you’re at your cup of preferred drink, why not expand your knowledge on the vital role of DNA and dive into epigenetics - for a more specific take?

Epigenetics is the study of molecular information that controls how our DNA code is read (gene expression) without changing the DNA sequence. The ability to understand what causes the changes in your health through genetics enables you to find treatments and helps in the prevention of further health decline linked to aging.

Our Healthspan not only tells you what and how much to consume in your drinking culture but also expands to various health indicators that make sure you’re up for a healthy living journey. It gives you accurate tracking of your current and envisions a future health status by telling you how well you are aging. It also uses next-generation sequencing  (NGS) which holds data beyond biological systems in a greater capacity than ever before, and of which makes it the most advanced epigenetics testing in the world. Take the test now!