Most experts agree that caffeine of coffee can cause a temporary increase in blood pressure (BP). Though the effect is temporary, but it may be dangerous for those with hypertension. How about with decaf coffee (decaffeinated coffee)? Does it also have the same effect?
Decaf coffee – What actually is it?
In an effort to avoid and limit caffeine due to certain health conditions such as hypertension, heart arrhythmia (irregular heartbeats problem), or if you are taking medicines that are advised to limit /avoid caffeine – you may turn to decaf coffee. As the label ‘decaf’ implies, it refers to decaffeinated which means the coffee has been processed to contain less caffeine.
The good news, the process to make decaffeinated coffee is now safe. Several years ago, some people doubted about the safety issue of making decaf coffee that might cause negative health impact! Today, a few different techniques in production are available.
In the past, the use of solvents was needed to make decaffeination. Nowadays, a new modified machine is designed to use carbon dioxide (CO2) as a solvent for a direct decaffeination.
How much caffeine in a cup of coffee and a cup of decaf coffee?
A cup of coffee (237 gram or 8 fl oz) may contain about 95 mg of caffeine. How about with decaffeinated coffee?
The answer may vary because each brand of decaffeinated beverages can have its own guideline in making the product. But in general, the label of decaf coffee must be qualified to get at least 97 % or more of its caffeine removed! The following is the table for the amounts of caffeine in some popular types of coffee.
How does caffeine affect both systolic and diastolic pressure?
When you measure your blood pressure (BP) with a device called sphygmomanometer, you will find two different numbers given in mm Hg; top number (systolic pressure) and bottom number (diastolic pressure). The pressure inside your blood vessels when your heart at rest is called diastolic pressure, and when your heart beats (contracting) is called systolic pressure.
While many studies have confirmed that caffeine can cause a temporary increase in both systolic and diastolic pressures, but there is still no a satisfied answer to explain this.
Caffeine may stimulate the adrenal glands to make and release more adrenaline /aldosterone hormone, making the kidneys retain more water and salt – as a result, systolic and diastolic pressures increase.
It’s also thought that caffeine may block an essential hormone that keeps blood vessels (especially arteries) widened!
So, will decaf coffee cause high blood pressure?
Again, in fact this kind of coffee is actually not 100 % free of caffeine. If you drink it too much, this may be powerful enough to affect your blood pressure.
The dose of caffeine in 5-10 cups of decaffeinated coffee may be equal to about one or two cups of caffeinated coffee – according to a small research conducted by the University of Florida in 2006 [reference].
Therefore, if your concern is to limit caffeine intake as less as possible, drink decaf coffee appropriately! Regardless to the issue of caffeine in decaffeinated coffee, the role of caffeine in affecting blood pressure is also still debatable.
Experts only know that caffeine can temporarily increase blood pressure – as noted before. But there is still no scientific evidence that drinking caffeine in long term would increase the risk of hypertension.
Moreover, the effect of caffeine can vary from person to person. The way of your body to react is probably dependent on the amounts of caffeine you are used to drinking.
If you get used to regularly drinking coffee for 2-3 cups a day, your body may be less sensitive to the negative reaction of caffeine. On the other hand, if you don’t get used to coffee, your body is more likely to become more sensitive to caffeine.
It seems the body may develop a tolerance to the hypertensive effects of coffee after a while. Other factors that may affect your body to react to caffeine include: