Critical Reasoning

Citing the frequency with which gum disease and heart disease occur in the same patients, many dentists believe that periodontal disease is a cause of a variety of cardiovascular problems, including Coronary Artery Disease

Which of the following, if true, would most weaken the claim that periodontal disease is a cause of Coronary Artery disease?

A. Bacteria present in infected gums can become mobile and enter the bloodstream, causing arterial plaque to accumulate.
B. People who brush and floss their teeth regularly are also more likely to exercise and eat a healthy diet.
C. Infected gums are more prone to bleeding, which allows bacteria to escape the mouth and irritate arteries.
D. People who experience loss of teeth due to periodontal disease usually cut back on many foods that are harder to chew, such as lean meats and vegetables, and increase their consumption of processed foods like pudding and ice cream.
E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.

Please support answers with explanations. OA later.

What's the question here? Weaken or strengthen or something else?

DanaJ wrote:What's the question here? Weaken or strengthen or something else?

So sorry! Thanks for informing, DanaJ

IMO E
its atypical cause and effect type Cr
to weaken such a cr , one way is to show that the relationship is reverse
E does the same thing claiming that heart disease causes periodonatl

Citing the frequency with which gum disease and heart disease occur in the same patients, many dentists believe that periodontal disease is a cause of a variety of cardiovascular problems, including Coronary Artery Disease

Which of the following, if true, would most weaken the claim that periodontal disease is a cause of Coronary Artery disease?

Premise : Frequency of congruent occurance of Gum and Heart in a same patient...
Conclusion of this Arguement : Peridontal Disease --> variety of CV probs( CAD)

So we have to weaken this..
We attack the conclusion...show that the cause and effect does not occur...or show that the relation is opposite ( i.e. CV probs cause gum disease.


A. Bacteria present in infected gums can become mobile and enter the bloodstream, causing arterial plaque to accumulate.
Strengthens

B. People who brush and floss their teeth regularly are also more likely to exercise and eat a healthy diet.
Great..but i am searching for an answer, not for people who floss...( may be a little strengthen..

C. Infected gums are more prone to bleeding, which allows bacteria to escape the mouth and irritate arteries.
Strengthens

D. People who experience loss of teeth due to periodontal disease usually cut back on many foods that are harder to chew,
such as lean meats and vegetables, and increase their consumption of processed foods like pudding and ice cream.
Processed food a'int that bad...Processed also means that the food is clean..so it may actually help the heart...well that's arguable...

E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.
Reverses the cause and effect....IMO the best answer Whats the OA....

What is the meaning of C???

Any more takes on this one? I got this wrong as well, and for reasnoning similar to the one already sighted in some replies.

My answer would be D.
As for E - Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.

I would have chosen this is instead of Cardiac Transplant, there was a clear mention of CAD. E only states heart diseased in general and refers to cardiac transplant, which is not in context of the Conclusion

As a result, D suits to weaken the argument the most given the scope of what we have to work with.

So, whats the OA???

KP

B looks good. This indicates that there is no relation between coronary artery disease and gum disease. It's a person's habit that leads to the occurrence of both the diseases.

OA is B, for the reasoning cited by apex231.

However, my doubt is, aren't we making assumptions in B that brushing teeth regularly reduces the probability of having gum diseases and exercising and eating a healthy diet reduces the probability of having heart diseases?

Experts, please help..

I am also not comfortable with B. IMO it should be E

prepgmat09 wrote:OA is B, for the reasoning cited by apex231.

However, my doubt is, aren't we making assumptions in B that brushing teeth regularly reduces the probability of having gum diseases and exercising and eating a healthy diet reduces the probability of having heart diseases?

Experts, please help..

Experts, please help...

prepgmat09 wrote:

prepgmat09 wrote:OA is B, for the reasoning cited by apex231.

However, my doubt is, aren't we making assumptions in B that brushing teeth regularly reduces the probability of having gum diseases and exercising and eating a healthy diet reduces the probability of having heart diseases?

Experts, please help..

Experts, please help...

A. Bacteria present in infected gums can become mobile and enter the bloodstream, causing arterial plaque to accumulate.

This would actually strengthen the argument, not weaken it

B. People who brush and floss their teeth regularly are also more likely to exercise and eat a healthy diet.

This is the correct answer. It does require you to conclude that brushing and flossing reduces gum disease, and exercising and eating a heart-healthy diet reduces heart disease. For that to be spelled out here would make the answer too easy to identify. I understand your point, but I think you'll find that many correct answers actually require some kind of common knowledge that is assumed to be held by the reader.

C. Infected gums are more prone to bleeding, which allows bacteria to escape the mouth and irritate arteries.

Again, this strengthens the argument.

D. People who experience loss of teeth due to periodontal disease usually cut back on many foods that are harder to chew, such as lean meats and vegetables, and increase their consumption of processed foods like pudding and ice cream.

This strengthens the argument, since it would explain one way that periodontal disease indirectly causes consumption of unhealthy foods, which would increase the occurrence of negative health effects.

E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.

This answer choice doesn't really accomplish anything. It basically just restates the evidence from the prompt: periodontal disease and cardiovascular problems often occur in the same patients. There's no indication here which would be cause and which would be effect. Further, "cardiac transplant" is too narrow; it doesn't address any cardiovascular problems that might not result in a cardiac transplant.

I hope this helps to clear up some of the confusion!

grockit_andrea wrote:
E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.

This answer choice doesn't really accomplish anything. It basically just restates the evidence from the prompt: periodontal disease and cardiovascular problems often occur in the same patients. There's no indication here which would be cause and which would be effect. Further, "cardiac transplant" is too narrow; it doesn't address any cardiovascular problems that might not result in a cardiac transplant.

I hope this helps to clear up some of the confusion!

Andea, Thanks so much for the explanation.

In choice E, when the statement reads "Patients with no history of heart disease are much less likely to have periodontal disease", does this no imply that the Cause -> Effect relationship is "No history of heart disease" -> "Less likelihood of periodontal disease" ?

prepgmat09 wrote:

grockit_andrea wrote:
E. Patients with no history of heart disease are much less likely to have periodontal disease than patients who have had a cardiac transplant.

This answer choice doesn't really accomplish anything. It basically just restates the evidence from the prompt: periodontal disease and cardiovascular problems often occur in the same patients. There's no indication here which would be cause and which would be effect. Further, "cardiac transplant" is too narrow; it doesn't address any cardiovascular problems that might not result in a cardiac transplant.

I hope this helps to clear up some of the confusion!

Andea, Thanks so much for the explanation.

In choice E, when the statement reads "Patients with no history of heart disease are much less likely to have periodontal disease", does this no imply that the Cause -> Effect relationship is "No history of heart disease" -> "Less likelihood of periodontal disease" ?

No, it doesn't. All it establishes is correlation. Assuming that causation is implied is a classic argument mistake, and one that the answer choice is designed to produce (which is what makes this question challenging). If it had said "patients with no history of heart disease are much less likely to DEVELOP periodontal disease" or something along those lines, the causation would be somewhat better supported, but even then, an outside factor could be responsible for both (as in Choice B, where the overall health-conscious behavior of that group of people causes the correlation).