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:

Time
Upper (systolic)
Lower (diastolic)
10:10
124
83
10:12
118
82
10:15
125
85
10:19
126
81
10:22
126
80
10:25
125
81
I DRANK THE COFFEE AT THIS POINT
10:27
122
79
10:29
126
79
10:31
116
78
10:33
119
76
10:36
112
75
10:38
119
78
10:41
117
78
10:45
117
78
10:50
118
78
10:58
123
79
11:05
126
82
11:12
122
84
11:17
122
90
11:23
125
79

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

decaffeinecoffee

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.

About Andy

Andy writes for a number of health related sites but has always been fascinated by alternative medicine and home remedies. His deep interests in nature and the body's innate ability to heal itself (given the right condition) have lead him to a pivotal time in his life - and so, Holistic Home Fitness was born. While it's relatively new at the moment, Andy wants to build this site into a huge reference site for a more holistic approach to health and fitness.

Comments

  1. John Strain says:

    FINALLY! Somebody who doesn’t just take others words but actually does some actual testing and uses scientific results to draw conclusions!
    Thanks very VERY much for this informative information.

  2. it is my opinion that the change in bp was due to the heat of the beverage. i see that change whenever i drink something hot and then take my bp which drops considerably for a short time.

    • Lynda
      You may be right. I haven’t done any new experiments recently, but I had planned a control experiment of drinking a hot cup of water. I’ll have to find time to do that.

  3. The experimenter didn’t tell us whether he or she was on any anti-hypertensive medication while the experiment lasted!