Drinking Coffee: More good than harm?

How regularly do you check your blood pressure? Well, next time you need to have your blood pressure checked, experts say you’d better abstain from drinking coffee for about two days to ensure its reading is accurate.

Research published in the August 2016 edition of the American Journal of Hypertension has found that drinking coffee before a blood pressure test can affect the results. Also, it indicated that patients who drink the occasional cup could be reducing the effect of medication for lowering blood pressure.


Best coffee for consumption

Studies indicate that caffeinated coffee can acutely increase blood pressure, but decaffeinated coffee does not. They suggested that caffeine could impact blood pressure, and, as such, could be a trigger for cardiovascular events. But people that consume coffee and caffeine regularly are not thought to face such a risk, because they develop a tolerance. This suggests that the intervals at which people drink coffee are of some significance. However, for occasional rather than regular consumers, it might be a different story.


How coffee affect a blood pressure test

A team of experts from Western University and Lawson Health Research Institute in Ontario, Canada, came up with some shocking results when they measured the effect of occasional coffee consumption on blood pressure, and especially how coffee consumption affects the action of calcium channel blockers. Calcium channel blockers are a type of medication for lowering blood-pressure. They are commonly prescribed for patients with hypertension. Calcium channel blockers help to relax and widen the blood vessels, making it easier for blood to flow. In this way, they reduce blood pressure.

In the study, the team wanted to find out what would happen to the blood pressure if a person abstained from caffeine long enough to eliminate the caffeine from the blood.


Coffee’s effect on medication for lowering blood-pressure

They expected to see a higher blood pressure the next time a person drank coffee, because eliminating caffeine and then consuming it again could cancel out the pressure-lowering effects of medication for lowering blood-pressure such as Calcium channel blockers.

To test their theory, 13 people with an average age of 52 with normal blood pressure were recruited to participate in an experiment. They carried out three tests on the subjects, separated in time by one week. Before each test, the people consumed no coffee, caffeine-containing products, or other items such as alcohol, grapefruit, marmalade, tobacco, and medications for 48 hours.

Results indicated that, after the participants avoided coffee for only two days, enough caffeine was eliminated from the body so that the next time they drank coffee, their blood pressure rose.

After just one cup of coffee, the participants in the coffee-only group experienced the greatest increase in blood pressure. The blood pressure rose within an hour after drinking the coffee, and it lasted for several hours.

Combining coffee with felodipine, blood-pressure lowering medication, led to higher levels of blood pressure than taking only felodipine. The researchers, therefore, reasoned that the caffeine blocks the positive effect of the drug on the blood vessels.

They also suggested based on the findings that a morning cup of coffee could affect the diagnosis and treatment of hypertension, or high blood pressure.


Moderation of coffee consumption is key

However, Professor Sola Ogunniyi, a consultant neurologist at the University of Ibadan, said there were no direct proofs that coffee increased blood pressure. But he adds that doctors always advise moderation in the intake of coffee.

While saying that coffee is a stimulant, Dr Rufus Akinyemi, a neurologist at the Institute for Medical Research and Training, University of Ibadan, adds that there is no strong evidence to suggest that coffee really impacts hypertension in an adverse manner, particularly in Africa.

Dr Akinyemi, however, declared that it was also difficult to determine the amount of coffee that could be termed moderate because what might cause severe reaction in one individual might not be so in another.

But, he stated, “e always advise that each individual should just understand his physique, what is good for their system. We all know the moment we are going beyond our boundaries.”


Caution on coffee for hypertensives

Chairman, Pharmaceutical Society of Nigeria (PSN), Oyo State branch, Mr Adeyinka Ishola, described caffeine in coffee as a central nervous system stimulant, which had potential to disrupt the sleep cycle, thus potentially increasing blood pressure in those that were vulnerable.

“This is why people who are suffering from hypertension should take coffee with caution,” he stated.

Rather, he suggested that people who were suffering from hypertension should drink decaffeinated coffee, if they were in love with the smell of coffee.