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.

To prepare for each set of readings, I sat down for 5 minutes before taking the first reading.

The coffee used in this experiment was strong filtered coffee. After taking a few baseline readings, I drank the coffee in one go. The amount was equivalent to 4 small expresso coffees. I then continued to take my blood pressure every few minutes. I then sat as still as possible, taking my blood pressure every three minutes.

Here are my results:

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

You’ll see that there is an almost immediate increase in systolic pressure, followed by a drop. This then increases again about 10 minutes after drinking the coffee to a maximum measured blood pressure of 138/89 about 23 minutes after the coffee was drunk. The blood pressure then starts dropping again, until normal blood pressure is restored at around 30 minutes after drinking the coffee.

What we see happening is a temporary increase in blood pressure in response to the coffee, which the body then corrects. How caffeine raises blood pressure seems to be unclear, but what is certain in my case is that it did raise my blood pressure, but only for a short period of time.

For those with high blood pressure, it would appear that coffee could be a problem due to the high spike after drinking the coffee. However, since my blood pressure is normal, I wont be switching to decaf.

My next experiment is to see what effect drinking filtered decaffeinated coffee has. Is it the caffeine in the coffee that raised my blood pressure, or something else?  You can see the results of my experiment on the does decaffeinated coffee affect blood pressure page.  The results may surprise you!

It is vitally important that you keep checks on your blood pressure, and if high, seek medical help. While blood pressure medications can help reduce a dangerously high blood pressure, they often do have side-effects. In my own case, I wanted to find ways to help control my blood pressure naturally, and within a couple of months, my blood pressure was largely under control. The following tips are for information only. Please consult your doctor if you have high blood pressure.

Tips for controlling blood pressure

• Reduce alcohol intake if you drink more than three alcoholic beverages a day. Small amounts of alcohol don’t seem to affect blood pressure in the same way, but heavy drinkers will benefit from reducing alcohol intake.
• Drink plenty of fresh water – your body is made up of a high percentage of water. If you don’t drink enough, your body tries to hold onto it, causing bloating. By drinking water regularly throughout the day, your body can detoxify your body. Your urine can be a good gauge to whether you are drinking enough water. The darker it is, the more dehydrated you are.
• Increase levels of activity – this will exercise your heart. Studies regularly show that increased exercise will help lower blood pressure.
• Lose weight if you need to – if you are over-weight, your heart has to work harder to pump blood around your body. Losing weight can reduce blood pressure, and you’ll feel a lot better as well.
• Reduce salt intake – your body does require salt, but in most cases, it can be supplied in sufficient doses by eating a balanced diet. Foods contain salt, so you don’t need to add extra. Since sodium (a component of salt) is involved in regulating body fluids, it can play a role in high blood pressure. If you eat canned products, read the labels. Look for food sources low in sodium.
• Avoid food high in fat or cholesterol.
• Stop smoking – nicotine has been shown to constrict blood vessels (making them narrower), raising the pressure in the vessels.
• Reduce Caffeine intake – My morning coffees are an important part of my daily routine, but I found that by having one caffeine coffee, and then switching to decaffeine coffee for the rest of the morning, I could have the best of both worlds, while helping to reduce my blood pressure.

Prior to following these tips, my blood pressure regularly reached 140/90 and even 140/100. After two months of following these tips, my blood pressure was normal, and often as far down as 115/68. These tips were responsible for controlling my high blood pressure, and meant that I could avoid going onto drugs. If you decide to try the natural route, please do consult your doctor first. The above information does not constitute medical advise.