Question+1

=Question 1=

1. If you have a double espresso and a Red Bull half an hour before bed will you be able to sleep?
The way an individual is affected by caffeine depends on a variety of factors including age, weight, and how much tolerance the individual has for caffeine. People who are frequent consumers of caffeine may develop a tolerance for the drug (Smith et al. 2006, 44). People with insomnia or anxiety disorders may also be affected differently by caffeine. For any calculations and conclusions drawn, average values will be used, even though realistically the effects can vary by quite a lot. We will consider an average person to be a healthy adult who consumes coffee 3 or 4 times a week. There is no set threshold of caffeine levels in the body below which an individual will be able to sleep. Caffeine functions by inhibiting adenosine (Wills 2005), which is a chemical suspected to encourage sleep, so caffeine levels must decrease enough to allow adenosine to take its effect (Ruiz et al. 2007). The amount by which they decrease is not an exact value by any means. The ability of an individual to fall asleep also depends on whether they are sleep deprived or well rested, and what time of the day it is. Aside from the caffeine content, espressos and Red Bulls can contain quite a bit of sugar, which may also act to keep a person awake by giving them energy. To obtain an average for the maximum amount of caffeine present in the body at which one could fall asleep, a few simple examples were considered. The rate of decay of caffeine levels in the body can be modelled by the equation                      (1) Where //A//(//t//) is the amount at time //t//, //A//(0) is initial amount, //t// is time, and //k// is the decay constant which is equal to     (2) Where //t//1/2 is half-life, which is equal to 5 hours. This value can vary greatly, but 5 hours is an average so it will be used for these calculations (Wills 2005). So equation (1) becomes    (3) In the first example, 400mg, the recommended daily maximum amount of caffeine ( Health Canada 2007), was used for //A//(0). Using this equation, the graph below was created to show the decay of caffeine levels in the body over 14 hours. If we take 14 to be the number of hours a person is awake during the day, and assume that the 400 mg of caffeine were all consumed at t = 0, the time they wake up, then the amount of caffeine present when they go to bed is approximately 61.6 mg. The next example considered uses a more realistic model: one coffee consumed at t=0, and a second coffee consumed at t=3. The amount of caffeine in a coffee is taken to be 260 mg, which is the amount present in a 12 fl. oz. Coffee from Starbucks (Starbucks Corporation 2009). To take the second coffee into consideration, at t=3, another 260 mg are added, and their decay from t=3 is modelled as well. The graph below shows the decay of caffeine levels in the body over 14 hours. The amount of caffeine left at 14 hours, when the individual goes to sleep, is 93.9 mg. From this example and the previous one, we can get an average of caffeine levels at normal bedtime for the average, daily coffee drinker: 77.8 mg. The next step is to consider the amount of caffeine in the situation described in the question. A double espresso from Starbucks contains 150 mg ( Starbucks Corporation 2009), and a can of red bull contains 76 mg ( Mayo Clinic Staff 2009)  , giving a total of 226 mg of caffeine. Using 226 as //A//(0), the graph below was produced. After 30 minutes, which is the absorption time for caffeine, there are 226 mg of caffeine present. Seeing as this is more than double the normal amount a person would have at bedtime, the chances of sleep are extremely low. Even after another 30 minutes, there is way too much: 211 mg. If we consider the caffeine levels at bedtime from the examples above to be maximum levels for sleep, then the subject would need to wait somewhere from 6 to 10 hours before being able to fall asleep. While it can be said with a high degree of certainty that sleep would be impossible 30 minutes after drinking a double espresso and a red bull, there is definitely a possibility for exceptions. The effect of caffeine varies greatly from person to person depending on age, weight, caffeine tolerance and a number of other factors. The half-life of caffeine can vary from 2 to 12 hours (Wills 2005) among adults, so the uncertainty associated with the calculations is significant. (how do I conclude this?)

Health Canada. It's your health - caffeine. in Minister of Health of Canada [database online]. 2007 [cited November/26 2009]. Available from    @http://www.hc-sc.gc.ca/hl-vs/iyh-vsv/food-aliment/caffeine-eng.php     (accessed 26 November 2009). Mayo Clinic Staff. Caffeine content for coffee, tea, soda and more. in Mayo Foundation for Medical Education and Research [database online]. 2009 [cited November/26 2009]. Available from @http://www.mayoclinic.com/health/caffeine/AN01211    (accessed 26 November 2009). Ruiz, Pedro, Eric C. Strain, and John G. Langrod. 2007. Caffeine. In //The substance abuse handbook.//, eds. Pedro Ruiz, Eric C. Strain and John G. Langrod. 1st ed. Vol. 1. Philadelphia, PA: Lippincott Williams & Wilkins, [] (accessed 22 November 2009). <span style="font-family: "Verdana","sans-serif"; font-size: 9.0pt; line-height: 115%;">Starbucks Corporation. Starbucks beverage details: Espresso. in Starbucks Corporation [database online]. 2009 [cited November/26 2009]. Available from @http://www.starbucks.com/retail/nutrition_beverage_detail.asp  <span style="font-family: "Verdana","sans-serif"; font-size: 9.0pt; line-height: 115%;">  <span style="font-family: "Verdana","sans-serif"; font-size: 9.0pt; line-height: 115%;">(accessed 26 November 2009). Wills, Simon. 2005. Caffeine. In //Drugs of abuse.//, ed. Pharmaceutical Press. 2nd ed. London, England: Pharmaceutical Press, @http://www.r2library.com.libaccess.lib.mcmaster.ca/marc_frame.aspx?ResourceID=707 (accessed 19 November 2009).
 * Literature Cited**