The Effects of Caffeine on the Blood Pressure of Human Beings - Lab Report Example

200mg of caffeine pill makes one cup of coffee. Therefore, the caffeine pills used in this experiment were 200mg (Warren, 2010). Since human beings’ absorption of caffeine is high in the morning hours, I carried out the experiment between 7 am and 9 am in the morning (Schmid-Holmes, 2001).

I carried out the experiment in our home where we have controlled temperatures maintained at 37 degrees Celsius. I used six out of the ten members of our family who are on one month's leave from work with an age bracket of between 30 and 50 years.

Hypothesis

 Caffeine affects blood pressure.

Materials and methods.

To begin this experiment I wrote a research proposal and had it approved by my instructor. I randomly selected six of the ten members of our family with ages between 30 and 50 who have never been diagnosed with blood pressure. I organized them into two groups of three and ensured that each group has at least one member of the opposite sex. Using an electronic scale, I measured each member of the experiment mass just to be sure that their mass falls around the 68 kg mark. I used a coffee pot to prepare coffee and three cups to serve the prepared coffee, every day for two weeks. I used the other three cups to serve regularly, every day for two weeks. Using a permanent marker pen, I  made an indelible mark on the small finger of the first three persons for easy identification of the persons who received coffee treatment in the first week. The unmarked persons received regular water in the first week. I gave each of the six persons 500 ml of regular water and allowed them to habituate to their new drink for 24 – hours. A calibrated 1000 ml cylinder came in handy in measuring the 500 ml of regular water.

Then, I prepared the amount of water with caffeine that I used for the experiment. On average, an adult weighs 68 kgs and the recommended caffeine dosage is 200 mg (Monroe, 1998). Since a cup of coffee contains approximately 200 mg of caffeine, I administered one cup of coffee every day for seven days for the first three marked persons(Nawrot, 2003). 1 hour after taking the coffee treatment, I used the sphygmomanometer to measure their blood pressure level and recorded it in the data collection sheet every day. I also measured and recorded the blood pressure of the other three persons who were on regular water.

In the second week, I took off the caffeine solution from the marked persons and put them in 100 ml of regular water from day 1 to day 7. I also removed the unmarked persons from regular water and put them on the caffeine treatment. Just like in the first week, I allowed the persons to be served with water with caffeine, a 24 – hour habituation period before starting the test. As I did in the first week, 1 hour after taking the coffee treatment, I used the sphygmomanometer to measure their blood pressure level and recorded it in the data collection sheet every day. I also measured and recorded the blood pressure of the other three persons who were on regular water.

Results

This experiment showed that the average blood pressure of human beings on the caffeine solutions was slightly higher than the blood pressure of human beings on the regular water (Figure 1).  

WEEK ONE MEASUREMENTS

WEEK TWO MEASUREMENTS

Trial in days

Mean Arterial Pressure

Trial in days

Mean Arterial Pressure

1

2

3

4

5

6

1

2

3

4

5

6

2

97

96

98

93

93

93

2

93

93

93

98

97

97

3

97

97

97

93

93

93

3

93

94

93

99

97

98

4

96

97

97

93

93

93

4

93

93

93

97

97

98

5

97

96

98

93

93

93

5

94

93

93

96

99

97

6

97

97

97

93

93

93

6

93

93

93

97

97

97

7

97

97

97

93

93

93

7

93

93

93

99

97

97

8

96

97

97

93

93

93

8

93

94

93

97

98

97

Mean

97

97

97

93

93

93

93

93

93

98

97

97

Although there was a difference, the P-value is less than  0.01 and therefore the observed difference is statistically significant.  Figure 2 below shows the average mean arterial pressure in a graphical format.

Discussion

Although my experiment supported my hypotheses that caffeine increases human blood pressure, there were some variations in blood pressure in some of the persons used in the experiment. This could have been caused by natural factors present in either sex. Another factor that might have led to the observed variations is the breakdown of the heater I used to maintain the room at body temperature. Ideal Mean Arterial Pressure is defined as 93 mm of mercury, which corresponds to 120/80( Edward, 2001). Many researchers have analyzed the effect of caffeine on human beings and the results are the same as my results(Bruke, 2008).

Conclusion

I have support for my hypothesis. The data show that it is not through chance that there was a significant difference in blood pressure between the groups of members under caffeine treatment and regular water.