If you wonder why it feels like you need ten cups of coffee to make it through the day while your coworker gets along just fine with their one morning drink, researchers may have found the answer. A new study has linked coffee consumption to a particular gene, with genetic variations determining who will stick to one cup and who cannot seem to get enough of the caffeinated drink.
The study comes from Dr Nicola Pirastu and other researchers at the Universities of Edinburgh and Trieste, the Burlo Garofolo Pediatric Institute in Italy, and the Erasmus Medical Center, along with data analysis by Groningen in the Netherlands. The authors published their results in the journal Scientific Reports August 25th. Because coffee is such a popular drink with widely-studied health effects, the researchers wanted to see what drives some people to drink so much more coffee than others.
For their study, the researchers recruited 370 residents of a village in southern Italy and 843 residents from six villages in north-eastern Italy. The study participants completed a survey including information about how many cups of coffee they drink each day, and the researchers also analyzed their genetic information. The next step of the study involved getting the same information from 1,731 residents of the Netherlands.
When they crunched the numbers, the researchers discovered that people with the PDSS2 gene variant tended to drink fewer cups of coffee than their peers without that gene variant. Generally, people with the PDSS2 variant drank one fewer cup of coffee each day than their peers. This was especially true in Italy although the effect was a bit smaller in the Netherlands. The researchers attributed this to the larger cup sizes in the Netherlands, which leads the Dutch to drink three times as much caffeine per cup than the Italians.
The research seems to show people with the PDSS2 gene variant may feel less of a need to drink more coffee. The study authors suggest this may be because PDSS2 affects coffee metabolism in the body, since previous research had shown removing PDSS2 in the liver increased the expression of genes related to coffee metabolism. PDSS2 may reduce the ability of cells to break down caffeine, so the energy-boosting molecule remains in the body longer. If people are still feeling the effects of their last cup of coffee, they may be less inclined to pour themselves an additional cup. The authors say more research would need to clarify exactly how PDSS2 affects coffee metabolism.
Coffee is a popular drink around the world and especially in the United States, where more than half of adults enjoy their daily java. In fact, American coffee drinkers consume an average of three cups a day. The beverage remains controversial when it comes to health, with both benefits and risks associated with coffee consumption, thanks to its active compounds like caffeine, niacin, polyphenols, and the N-methylpyridinium ion.
Coffee can be a calorie-free drink option, but adding cream and sugar can mean more calories and more weight gain, especially when it comes to fancy coffee shop concoctions that may have 500 calories or more. Research has found a link between drinking unfiltered coffee and slightly higher cholesterol levels, and in combination with a particular genetic mutation, coffee can raise the risk of heart disease. Thanks to its high caffeine content, coffee can also affect sleep, reducing the quantity and quality of shut-eye. This suggests people should try to keep their coffee drinking to a minimum.
However, coffee may also offer health benefits with daily consumption. Research has suggested coffee can have protective health effects and be beneficial for heart disease, hypertension, Alzheimer’s disease, Parkinson’s disease, liver cancer, and type 2 diabetes. Some studies have even suggested that drinking coffee can help its drinkers live a longer life, and it may help improve cognitive function and reduce the risk of depression.
Studies continue to analyze the positives and negatives of being a coffee drinker. At least now when someone finds themselves craving that extra cup of coffee throughout the work day, they can understand that the reason may simply be genetic.