Genetics Explains Why You Drink So Much Coffee

By Carl Engelking | October 7, 2014 1:19 pm


If your favorite order at Starbucks is the “red-eye,” you can thank genetics for your ability to slog down all that caffeine without the shakes.

In a new study, scientists identified eight genetic variants that could partly explain why some people drink coffee by the pot, while others avoid the stimulating beverage altogether. By outlining the genetic foundation for coffee consumption, scientists believe they can find firmer evidence to support the positive — and negative — health effects of the popular beverage.

Java Genes

Researchers from the Harvard School of Public Health and Brigham and Women’s Hospital investigated the genomes of 120,000 European and African American coffee drinkers along with data on how many cups a day they consumed, using findings from dozens of previous studies. Their statistical analysis revealed six new gene variants that governed coffee consumption, and reaffirmed the presence of two others previously discovered by the same group of researchers.

The team identified variants in or near genes that play roles in learning, caffeine metabolism, blood pressure regulation and addiction. Two newly discovered variants, near the genes BDNF and SLC6A4, reinforce the positive effects of coffee’s molecular properties. For example, BDNF is involved in the release of pleasure-inducing neurotransmitters like serotonin and dopamine.

Researchers published their findings Tuesday in the journal Molecular Psychiatry.

Heavy Drinkers

Participants in the study that inherited five or six of the gene variations were more likely to be heavy coffee drinkers — four or more cups a day — than those who inherited just one or two, the Boston Globe reports. People with more coffee gene variants may drink more because they metabolize it quickly; thus, they enjoy coffee’s stimulating effects for a shorter period of time.

Some of the same gene variations seen in heavy coffee drinkers are risk factors for smoking initiation and obesity. Both obesity and smoking may be fueled by addiction, which could explain why some people can’t stop at just one cup. Researchers plan to dig deeper into the genetics of coffee drinking to see how variants may be positively and negatively affecting coffee fanatics’ health.

In the debate about whether coffee is good or bad for your health, genetics could cut through the noise and someday offer more definitive answers.


Photo credit: /Shutterstock

CATEGORIZED UNDER: Living World, top posts
MORE ABOUT: genes & health
  • constitutionalive

    Interesting correlation betw coffee/caffeine & smoking, addictions, weight, though don’t agree w/conclusion;prefer some caffeine-ated beverages to others,seek more cold-high-caffeine-content in summer than winter,never smoked anything/aversion,chocolate/caffeine approach “addiction” description but never experience w/drawal symptoms over months/year+,weight depends on mental state~kinds activity more than intake. In conclusion, think there needs to be lot more research done before ANY scientific conclusions can be drawn, and, correlation is never scientific basis for scientific conclusion/theory formation, B&W’s …

    • Metalhead Nick

      No,don’t say that, I need an excuse for my viceful ways.

    • Rob Neff

      I think we can all be addicted to something – food, exercise, alcohol, etc. (popping bubble-wrap?) If you’re lucky it’s something without an additional physical addiction. Addictions may come in clusters – smoking and drugs perhaps, but I agree, a lot more research need to be done before we can start casting any judgements.

  • JainePaine

    I have interviewed Peter Frazen from the UPMC Sleep Center. He says, any caffeine effects everyone’s sleep. The quality of sleep is dramatically effected. So while one might be able to drink a lot coffee, all people benefit from not drinking it seven hours before they go to sleep.

    • Ivar Ivarson

      Good advice for the vast majority.

    • Herne Webber

      Since my early twenties, I have lived on diet cola, without which I get crushing headaches. I drink a bit before falling asleep, so it takes effect after I have fallen asleep, not awakening me, but simply preventing me from developing a headache in my sleep. Also, since puberty I have not had a normal circadian rhythm, but seem to fall into a natural 4-8-4-8 sleep-wake cycle when I have no outside obligations. I know from genetic testing that on the first gene discovered, I am a fast metabolizer. My paternal grandmother lived on coffee and BEER and cigarettes, plus grossly prepared (as opposed to properly prepared) Southern food.

      • JainePaine

        My sleep is all screwed up from working the grave yard shift. A person who I used to work with, who is now a good friend, has these weird sleep patterns, too. I essentially live by myself and so what I get up at 3 am. I do not do anything too strenuous so sleep will come back.

      • JainePaine

        Herne, you would a interesting person to study. I’ve never heard of anyone getting headaches from not drinking diet soft drinks. I quit smoking about 7 months ago. Cutting out the bad good stuff out of our lives is hard to do (Neil Sedaka Breaking up is Hard to Do) is cursuring my mind. I might add golden oldies.

    • TLongmire

      I consume on average a gram of caffeine a day and sleep fine 4 hours after 200 mgs if I feel agitated I drink water which works. Once I consumed 200mgs (the equivalent of a cup of coffee) and fell asleep 15 minutes later presumably because my body sought equilibrium and flooded my system with some natural tranquilizer.

  • Rob Neff

    What about those of us who don’t drink any coffee or tea, apparently because it doesn’t really do anything for us? I can drink a Mountain Dew and go to sleep a few hours later. I don’t drink coffee or tea because without the benefits of coffee there was never any reason to become accustomed to the bitterness of the drink. I’ve had actual coffee maybe 4 or 5 times in my life and the only thing I noticed was a bad aftertaste.

    • 1kenthomas

      4 or 5 times? That’s like having beer four or five times. For all you know, you had cruddy coffee.

  • Clio Halpin

    Conclusions are best experienced by the individual. Personally, due to my view that my mind and body does not negotiate where the consciousness resides, I have concluded I am a whole being. With this said, and having experienced all sorts of caffeine and nicotine, for me, it’s about what neurotransmitters the body needs in order to get the task done for the day. Basically, our bodies can detect even the slightest potential for certain substances to enhance certain organ or organ systems which may be lagging or lacking due to many unknown factors. Without going into much detail, one seeks and becomes dependent when one is in need. When the organ or certain pathway becomes dependent on the substance and begins to take control of other systems, then perhaps a physical addiction. This is how my body works and this is my conclusion.

  • Jolly Roger

    Good, I never liked coffee anyway.

    • DED

      Me either. Made me nauseous. The smell of it alone used to make me gag. I followed the advice that was given to me to make it more palatable, but it never worked. So it’s been Mtn Dew (now diet) and Vivarin ever since for caffeine intake (until energy drinks came along).

      I couldn’t drink tea either until a couple of years ago. I finally figured out to tweak it so that I can drink it.

  • denise

    I drink an average of 6-8 pots a day! I use an ground espresso beans in my coffee pot and mix 2 shots of brewed espresso in my coffee instead of sugar or cream! I like coffee! If I have a hard time sleeping, my husband will make me 8 shots of espresso in a coffee cup! It relaxes me and I can fall asleep. If I don’t get enough caffeine, I end up with a migraine headache!

  • Dayna Tolley

    I had a genetic profile done at the behest of my doctor. It came back that I was a fast metaboliser of caffeine. I LOVE coffee, but it doesn’t affect me in the least. I can drink it just before bed. Apparently that is because it races through my body before it has any time to take effect. Conversely, slow metabolizers of coffee feel all the effects. Unfortunately, I have the same type of genes for narcotics, which means for most of my life I have been unable to feel pain medications, and have had monumental pain due to a number of horrific events. Other genes showed up which told whether or not I metabolize all types of other medicines. This test has proven to be extremely valuable. It would be worth it to have most individuals have these genetic tests BEFORE they start taking medications.



Briefing you on the must-know news and trending topics in science and technology today.

See More


Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

Collapse bottom bar