Study finds genes affect coffee consumption

Coffee, that magical elixir some of us swear by during midterms and finals, has been found to genetically affect our bodies. Scientists at the Harvard School of Public Health and Brigham and Women’s Hospital recently released the results of a study that suggests that people naturally adjust their coffee intake to experience the optimal effects produced by caffeine.

The study also found that the most powerful genetic factors associated with increasing coffee consumption may act directly on the body by increasing caffeine metabolism. Their findings may allow them to identify portions of the population most likely to benefit from decreasing or increasing coffee consumption for better health.

Caffeine affects the human body by reducing physical fatigue and restoring alertness when drowsiness occurs. A growing body of research shows that coffee drinkers, compared to non-drinkers, are less likely to have type 2 diabetes, Parkinson’s disease, dementia, certain cancers, heart rhythm problems and strokes. However, excessive consumption can lead to a state of intoxication known as caffeinism, which is characterized by restlessness, agitation, excitement, rambling thoughts or speech and insomnia.

Due to the fact that it is inexpensive and readily available in many different forms, approximately 90 percent of Americans consume caffeine in one form or another. According to a Hopkins study that reviewed over 170 years of caffeine withdrawal research, as little as one standard cup of coffee a day can produce caffeine addiction. People who don’t get their usual “dose” can suffer a range of withdrawal symptoms including headache, fatigue and difficulty concentrating. They may even experience flu-like symptoms including nausea and muscle pain.

While trying to explain why caffeine affects some of us differently, researchers suspected that variations in our genetic makeup might be the answer. However, specific explanations have eluded them.

The scientists running this study evaluated more than 120,000 European and African American subjects who drink coffee regularly. They identified two new genetic variants involved in caffeine metabolism and two other variants that potentially influence the rewarding effects of caffeine. The researchers’ findings propose that coffee drinkers adjust their consumption innately to experience the best effects produced by caffeine and that genetic factors may increase caffeine metabolism and subsequently increase coffee drinking.

The researchers concluded by saying that their research, similar to that of previous genetic analyses of smoking and alcohol consumption, serves as an example of how genetics can influence some types of habitual behavior.