I. Title: Determining the effects of caffeine on blood pressure and heart rate
II. Purpose: to determine the short term effects of caffeine on blood pressure and heart rate using two different types of tea.
III. Hypothesis: I predict that the ingestion of caffeine will increase the heart rate and blood pressure of the subjects; however, I believe that the black tea will increase blood pressure and heart rate more than green tea. The expected results from this lab are an overall increase in blood pressure and heart rate.
IV. Materials: 1 Orange Pekoe Tea Bag (Tetley), 1 Tropical Green Tea Bag(Revolution Tea), Tea Kettle, 250ml glass measure, 2 mugs 300ml, blood pressure/ Heart Rate machine, Pen, Paper and a cell phone (stopwatch)
V. Procedure:
Step 1: BEFORE YOU START THIS EXPERIEMENT, DO NOT CONSUME ANY CAFIENE! Boil water in kettle, pour into glass measure and measure 250ml of hot water, then pour into one mug, measure out 250ml of water again, and put it into the second mug
Step 2: Place green tea bag into one mug, place orange pekoe in the other mug, set timer for 5 minutes for the teas to brew in the mug
Step 3: while the teas are brewing, take your blood pressure/heart rate and your team members. Write down your blood pressure and heart rate BEFORE YOU DRINK TEA.
Step 4: Now you have your blood pressure/heart rate this becomes your control, now that the tea has been brewed for 5 minutes it is time to begin the experiment!
Step 5: remove the tea bags, drink the teas. Immediately after drinking the teas, take blood pressures and record it. The set timer for 5 minutes, take your BP at 5-minute intervals until 15 minutes has passed. Do this for all types of teas and record your results. MAKE SURE YOU ONLY DRINK ONE TYPE OF TEA OTHER WISE YOUR DATA WILL BE INCORRECT! DO THIS IN A GROUP.
VI.Data Collected:
Person
Tea
Time in minutes
Systolic
Diastolic
Heart Rate
Justine
Green Tea
Control
106
79
64


1
93
61
78


5
106
73
70


10
93
54
75

After Justine did this experiment, she disclosed that she regularly drinks green tea therefore, I believe that green tea may not have a huge affect on her body system, so I re did the experiment with my mother.
Person
Tea
Time in minutes

Diastolic
Heart Rate
Neena (mom)
Green Tea
Control
135
90
75


1
120
80
64


5
125
83
70


10
130
80
70
After my mother did this experiment I have change my belief. I do not think green tea increases your blood pressure, instead I think it relaxes the body more than it stimulates. To compare this with another tea, I did an experiment with myself using normal orange pekoe.

Person
Tea
Time in minutes
Systolic
Diastolic
Heart Rate
Aneesha
Orange Pekoe
Control
106
83
79


1
121
80
100


5
121
70
97


10
93
71
90
graph_(1).jpg

I rarely drink tea therefore Justine and I concluded that the increase in heart rate was going to be large.
I. VII.Assigned Questions : None
VI I. Conclusion:
From the results of this lab, one may conclude that green tea has a low amount of caffeine because, when compare to the normal resting heart rate and blood pressure, a reduction was showed. Therefore, one can conclude that green tea has a relaxing effect on the body and it does not stimulate the nervous system the same way black tea does. The data shows us that after drinking green tea our body relaxes and slows down and that is shown through the decrease in heart rate and blood pressure. However, when the subject drank black tea a huge increase in heart rate and blood pressure occurred. Some sources of error would be the choice of subjects; a random sample would have been better with varied ages to get a more diverse view on how green tea affects our body differently than black tea. Another source of error would that the subject(Justine) already drinks green tea on a daily basis which may mean that her nervous system has been accustomed to the caffeine in the tea and therefore have no effect. the are several ways to improve this experiment, using more accurate blood pressure and heart monitors would be highly beneficial in further experiments like this one. Another improvement would be to familiarize yourself with the blood pressure/heart monitor so that you are able to get accurate results. Therefore, to further this experiment, doing this daily over a longer period would allow results that are more accurate. To further research on this topic one could test which part of the nervous system the caffeine effect and how the neuron transmission is done, either antagonist or agonist. With that research, we will be able to figure out how the caffeine reacts and then with that information will could find out how green tea and maybe other herbal teas affect the nervous system.