Re: How does Coffee affect Blood Pressure?

I found some really great explainations for your questions:

How much does coffee raise blood pressure?

By: Thomas Pickering, MD, DPhil, FRCP, Director of Integrative and 
Behavioral Cardiology Program
of the Cardiovascular Institute at Mount Sinai School of Medicine, New 
York. 
 
Caffeine is a powerful stimulant of the cardiovascular system, and the 
immediate effects of drinking a cup of coffee are an increase of blood 
pressure and heart rate, which may last for 15 minutes or so. It has also 
been suggested that regular consumption of coffee may produce a more 
sustained elevation of blood pressure, which might be of concern to people 
who have hypertension. A recent review of the evidence on this point 
examined all the studies in which blood pressure was measured in coffee 
drinkers during periods of two weeks or longer when they were either 
drinking coffee (on average five cups per day) or abstaining. All the 
subjects in these studies had normal blood pressures. The effect of 
drinking this amount of coffee was to raise blood pressure by 2-3 mmHg of 
systolic pressure, and 1 mmHg of diastolic. It was also concluded that 
coffee had a bigger effect on blood pressure in younger than in older 
people. 

Doctor’s comments 

If you have high blood pressure and drink a lot of coffee, the results of 
this analysis suggest that if you stop drinking coffee (or possibly switch 
to decaffeinated) you may experience a slight fall of your blood pressure, 
but don’t expect a dramatic change. It is worth noting that people who 
drink a lot of coffee do not appear to be at increased risk of stroke or a 
heart attack. 

This information was found at the following link:  http://www.lifeclinic.com/focus/blood/articleView.asp?MessageID=224 and 
published by S H Jee, et. al., The effect of chronic coffee drinking on 
blood pressure. meta-analysis of controlled clinical trials. Hypertension 
199;33:647. 




A previous Mad scientist has provide a very detailed answer regarding 
the effects of decaffeinated coffee on blod pressure. I have pasted it 
below. The link is:  http://www.madsci.org/posts/archives/jan99/915293960.Me.r.html

I have included a brief description of the process by which decaffeinated 
coffee is made. When purchasing decaffeinated coffees, it is helpful to 
understand the processes used. Opinions differ as to which process 
is "better". Both remove at least 97% of the naturally-occurring caffeine 
from the beans.

EUROPEAN PROCESS

The green coffee beans are steeped in hot water, which gradually removes 
the caffeine. The water is separated from the beans and treated with 
methylene chloride. In this process, the solvent never touches the actual 
bean. The solvent absorbs the caffeine, which is removed with heat by a 
process of evaporation. The vital coffee oils in the remaining water are 
then added back to the beans. Many customers prefer this method because 
the flavor of the coffee is least affected by this process.

SWISS WATER PROCESS

Here the beans are immersed in water, without chemical additives, for 
several hours until the caffeine is removed. The resulting solution, which 
contains caffeine as well as the other essential coffee elements, is 
passed through activated charcoal or carbon filters to remove the 
caffeine. Then the coffee elements are added back to the beans.

Amount of caffeine per serving in milligrams

Drip 115-175

Espresso 100mg of caffeine

Brewed 80-135mg

Instant 65-100mg

Decaf, brewed 3-4mg

Decaf, instant 2-3mg

Tea, iced (12 ozs.) 70mg


Thus from the above please note that even decaffeinated coffee does 
contain caffeine, albeit, in much smaller amounts than non-decaf. As far 
as raising blood pressure I cite from a paper by Green and Shuls (1),who 
measured heart rate and blood pressure in coffee drinkers drinking decaf 
with either added caffeine or cornstarch. In this group of people systolic 
and diastolic pressures were elevated on the day caffeine was consumed, 
not when cornstarch was added. 

References:

1. Green, Suls The effects of caffeine on ambulatory Blood Pressure, heart 
rate and mood in coffee drinkers. Journal of Behavioral Medicine.1996 
April 19 (2) 111-28.

hope this helps,

gabriel