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Reasoning in a Scientific Context Caffeine May 2006. 3(a) For each of the following decide whether it can reliably be concluded from the evidence in the above passage. Someone who drinks four 150 ml cups of filter coffee exceeds the average UK daily consumption of caffeine.(1 ½ )
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3(a) For each of the following decide whether it can reliably be concluded from the evidence in the above passage. • Someone who drinks four 150 ml cups of filter coffee exceeds the average UK daily consumption of caffeine.(1½) No, it cannot be reliably concluded because we cannot be sure of the caffeine content of the individual's coffee. The UK figure of 280 mg is an average; the Canadian study shows that there is a wide range from 30 to 170 mg per 150ml cup (although not all in filter coffee)
(ii) It would be extremely difficult to consume a fatal dose of caffeine as part of a normal diet.(1½) Yes, assuming that there are no other caffeine rich sources of food in a normal diet that are not on the table. A fatal dose is 10 g. That would be the equivalent of 71.5, 200 ml cups of coffee to be drunk in a very short space of time, or around eight and a half kilos of dark chocolate.
(iii) In the Canadian study, no actual serving contained less than 30 mg of caffeine. (1½) No, it cannot be reliably concluded. 30 mg was the minimum caffeine content in a range for a 150 ml cup. Actual servings included much smaller cups i.e.. less than 150 ml cups , which may have contained less than 30 mg of caffeine.
(iv) The average daily caffeine consumption per person is greater in Canada than in the UK.(1½) No, we cannot reliably conclude this. We have no information on how much caffeine Canadians consume.
(b) How well does the evidence support the statement that, ‘caffeine’s critics are wrong?’ (3) Not very well. • No evidence is presented to support this conclusion directly by showing that people’s supposed health worries are unfounded. The evidence the author has given only supports the claim that caffeine has many health benefits. • However there is a confusion in the evidence between caffeine and coffee. It is assumed that the beneficial ingredient in coffee is caffeine. The last paragraph suggests this may not be the case. It may be one of the 2000 other chemicals found in coffee such as polyphenols that may be the beneficial ingredient.
Example of an acceptable answer from a student The evidence supports the statement in so far as caffeine has a multitude of health benefits.(1) However it does not support the statement very well because the evidence does not dismiss the fact that caffeine is addictive, can cause strokes, heart palpitations etc.(1) Also the evidence talks of how it is coffee that reduces the risk of colorectal cancer, liver cancer , Parkinson's disease etc. and not caffeine per se. It could be the other chemicals in coffee e.g. polyphenols as suggested by the passage, that bring the beneficial effects.
(c) How would you respond to the author’ suggestion that we should drink the amount of coffee we feel happy with? (2) Examples of relevant responses: • The author’s suggestion is very sensible because coffee has benefits and disadvantages. We need to consider the best option for us (2) • The author's suggestion is worrying because many of us feel happy with things that are bad for us and we end up making bad choices (2) • The author assumes we will make good choices (1) We need rules toguide us (1)
An example of an acceptable answer from a student I disagree with the author’s suggestion that we should drink the amount of coffee we are happy with. The emotion ‘happy’ is highly relative/subjective and there is the possibility coffee addicts will drink excessive amounts of coffee that they are ‘happy with’ but which will not be good for them. This would then lead to them experiencing the negative effects of excessive caffeine intake. The author should instead suggest a more definitive serving within the tolerable amount of coffee an individual should consume.
(d) ‘Nobody steals or commits murder for caffeine as they do for hard drugs.’ How far does this comment answer concerns raised in the above argument about the addictiveness of caffeine? (4) • The comment suggests that caffeine is not worryingly addictive like heroin or cocaine . Besides, addiction to caffeine does not result in social problems nor does it lead to criminal behaviour. To this extent the comment answers concerns. • However, it does not answer concerns about withdrawal symptoms and the effects it might have on the well-being of the individual user. • The fact that caffeine products are relatively cheap and readily available on the market makes it a cause of concern
Example of an acceptable answer from a student This comment does answer concerns raised in the argument that caffeine addiction is not as serious as addiction to hard drugs like cocaine or heroin and is therefore not so worrying. Caffeine addiction is not likely to become a serious social problem and it may not lead to criminal behaviour. However it does not answer concerns raised about withdrawal symptoms and the effects it might have on the well-being of the individual. The fact that caffeine products are relatively cheap and readily available on the market makes it a further cause for concern as coffee addicts will have within their reach an unlimited supply that might work against their health and general well being.
