Drinking coffee can lower blood pressure and smoking will counteract this effect.

Regular coffee drinking may have a positive effect on blood pressure, but smoking can counteract this effect, according to a Swiss study.

Researchers at the University of Lausanne in Switzerland reported in the new British academic journal Human Molecular Genetics that they examined 16000 people's blood pressure, coffee drinking habits and an enzyme in their bodies and found a link between them.

Studies have shown that the enzyme that encodes CYP1A2 plays a decisive role in the process of breaking down caffeine in the liver. People who are more active in this enzyme often drink coffee, and their blood pressure is generally lower than those who are less active.

Previous studies have suggested that excessive caffeine intake can lead to higher blood pressure and insomnia, but Idriss Geisu, lead author of the new report, said that although drinking coffee increases blood pressure in a short period of time, long-term persistence can have the opposite effect. This is similar to jogging's effect on blood pressure-blood pressure rises during jogging, but persisting in jogging can prevent cardiovascular disease.

The study also found that the blood pressure-lowering effect of coffee applies only to non-smokers because smoking affects the activity of CYP1A2 enzymes, thus counteracting this beneficial effect of coffee.