Effects of decaffeinated coffee on my blood pressure

In these experiments, I used an upper arm cuff home blood pressure monitor to measure my blood pressure on an empty stomach, after drinking a large cup of decaffeine coffee.

I used a filter coffee machine to prepare a large cup of coffee, made with decaffeinated ground coffee. The process was exactly the same as my experiment to see if caffeine coffee affected bloood pressure, except for the type of coffee, which in that case was obviously a standard caffeine coffee. In the current experiment, the coffee was decaf.

Here are my results:

Here is the data as a graph showing the effect of de-caffeine coffee on blood pressure:

Before drinking the coffee, my blood pressure was fairly stable at around 125/82. However, at 10:31, around 5 minutes after drinking the decaf coffee, my blood pressure fell to 116/78, and fell even further at 10:36 to 112/75.

For 10:31 to 10:50, my blood pressure was below the starting blood pressure of around 125/82. From 10:58 until the end of my experiment, blood pressure had returned to near the starting level.

It appears from these results that drinking the decaffeinated coffee reduced my blood pressure for a period of around 25 minutes before blood pressure returned to normal.

Now, whether this is due to the decaf coffee itself, or some other factor involved remains to be seen. For example, it may well be that the decaf coffee itself has no effect on blood pressure, and something like the heat in the drink was responsible.

As a follow up experiment, I need to drink an equivalent volume of hot water.

That will be my next experiment.

Effects of smoking on blood pressure

In this blood pressure experiments, I used a home blood pressure monitor (upper arm cuff), to measure my blood pressure before, during and after smoking a large cigar. I took readings every 5 minutes or so, to see if smoking would cause changes to my blood pressure.

Incidentally, I am not a doctor. These experiments are for my own curiosity, and I do not recommend you do the same.

Here are my results:

Here is the chart of this data:

While the graph may not look too impressive, you can see a large jump in blood pressure almost immediately. Before starting to smoke the cigar, the average blood pressure for the three preceding readings was 133/83. The first reading after starting to smoke was 149/92. That’s quite a jump.

The initial increase in blood pressure is spectacularly quick. Not surprising really, as smoke enters our bodies through the thin membranes of the lungs, as well as through the membranes in our mouth. This is why smokers can get a neat instant “hit” when they light up.

Blood pressure is raised for about 20 minutes before it returns back down to a more normal reading (that’s normal for me). When there is a stimulus to increase blood pressure, our bodies are going to try to combat that increase and lower the blood pressure. In this case it took about 20 minutes for my body to do so. Blood pressure then remained fairly constant for the remainder of the experiment.

It would be interesting to see how blood pressure would be affected if I continued to smoke all day (as in a chain smoker), and whether my body could compensate over a long period of time. I wont, however, be doing that experiment ;o)

Look out for new experiments soon. You’ll find them in the left hand menu.