Researchers at Western University and Lawson Health Research Institute are out with a warning for coffee drinkers.
A phase-one study looked into how occasional coffee consumption impacted the action of a common type of blood-pressure lowering medication, calcium channel blockers.
“Coffee causes the blood vessels in your body to narrow and this raises the blood pressure whereas the calcium channel blockers cause the blood vessels to expand in order to lower the blood pressure,” Dr. David Bailey, Lawson Scientist and researcher at Western’s Schulich School of Medicine & Dentistry.
“What you have is essentially a competition between the two.”
Dr. David Bailey tells AM980 this could have huge implications for accurate diagnosis and management.
“If you were to, for example, have coffee on the morning of a visit to see your local doctor for a checkup, they may find your blood pressure a bit high. When in actual fact, it’s not due to the fact that you have a problem, an abnormality in how your blood pressure is regulated – it’s just that you had coffee earlier in the day.”
According to a recent survey, roughly 17% of coffee drinkers are “occasional coffee drinkers”, meaning they have a cup twice a week or less. Dr. Bailey says this research impacts a lot of people, and yet so few studies have been done.
“It’s even more emphasized by the fact that guidelines from societies that deal with high blood pressure in North America, in Europe, in Canada have no comments about coffee consumption or the potential interaction with drugs that lower blood pressure.”
The study was funded by the Heart and Stroke Foundation of Canada and Dr. Bailey hopes it will encourage further studies on issues associated with occasional coffee consumption.