Argument142【0706G－CRUSADE小组】第5次作业

rose_07UID：2276843

TOPIC: ARGUMENT142 - The article entitled 'Eating Iron' in last month's issue of Eating for Health reported that a recent study found a correlation between high levels of iron in the diet and an increased risk of heart disease. Further, it is well established that there is a link between large amounts of red meat in the diet and heart disease, and red meat is high in iron. On the basis of the study and the well-established link between red meat and heart disease, we can conclude that the correlation between high iron levels and heart disease, then, is most probably a function of the correlation between red meat and heart disease.
WORDS: 400+          TIME: 0:30:00          DATE: 2007-2-25

1.there is no limitation how much iron is good for our health. There is no data whether the content of iron in red meat is within the limitation or not.
2. the absorption of iron still begs the question, which might be influenced by the cooking process.
3.there is no evidence that the correlation between large amounts of red meat and heart disease is due to the high iron in red meat.


The argument suffers from several critical flaws. Thus the conclusion that equates the high iron levels with the large amounts of red meat in diet is unconvincing.

To begin with, the arguer fails to provide the limitation of how much iron is harmful for our health. Without the key data, it is impossible to distinguish whether the content iron in red meat exceeds the limitation or not, which makes the fact that red meat is high in iron amounts to nothing. Considering the common sense that appropriate iron taken in is helpful and necessary for a balanced diet, unless the arguer shows us that the iron in red meat is beyond the acceptable level for our health, we can not simply accept the claim that large amount of red meat in diet harms our health.

Even if the amount of iron in red meat is proved to exceed what we need in daily diet, the absorption of the iron is still begging the questions. Just as different cooking methods of vegetables will cause loss of vitamins, the way how we cook the red meat might also influence the iron which we can absorb easily. Perhaps, stewing red meat will contain more iron left compared with frying them. Meanwhile, there is no evidence that the form of iron in red meat is suitable for human absorption, providing that iron cations have two different forms. If the absorption becomes an obstacle, it is meaningless to discuss how the amount of iron has impact on human health. Therefore, without considering these and other possible factors influencing the process of absorption, the assumption that the higher level of iron in red meat, the more we take in is dubious.  

Furthermore, the arguer fails to attribute the well-established link between red meat and heart disease to the high amount of iron in red meat. Considering that the proteins and fat in red meat is much more than the iron, it is unfairly to assume that iron leads to heart disease without any evidence. It is entirely possible that fat in red meat causes heart disease while on the contrary, the suitable amount iron in red meat is necessary for curing the disease. Since the evidence that the iron in red meat directly results in heart disease is unavailable, the well-established link lends no strong support to the argument.

Based on the analysis above, the conclusion that the correlation between high level of iron and heart disease is most probably the function of the correlation between red meat and heart disease is dubious. Unless the arguer further provides evidence that the high level of iron in red meat is the main reason for the occurrence of heart disease, and that the amount of iron we can take from red meat is far beyond how much we need, we will not accept the conclusion.

[ 本帖最后由 rose_07 于 2007-2-28 19:42 编辑 ]