Although high cholesterol levels have been associated with the develop

Question

Although high cholesterol levels have been associated with the development of heart disease, many people with high cholesterol never develop heart disease, while many without high cholesterol do. Recently, above average concentrations of the blood particle lipoprotein (a) were found in the blood of many people whose heart disease was not attributable to other causes. Dietary changes that affect cholesterol levels have no effect on lipoprotein (a) levels. Hence, there is no reason for anyone to make dietary changes for the sake of preventing heart disease.

Which one of the following most accurately describes a flaw in the argument?

Which one of the following most accurately describes a flaw in the argument?

(A) It fails to consider the possibility that lipoprotein (a) raises cholesterol levels.
(B) It provides no evidence for a link between lipoprotein (a) and heart disease.
(C) It presents but ignores evidence that, for some people, high cholesterol contributes to heart disease.
(D) It fails to consider the possibility that poor diets cause some people to develop health problems other than heart disease.
(E) It offers no explanation for why some people with high cholesterol levels never develop heart disease.

Bunuel · Accepted Answer

EXPLANATION FROM Fox LSAT

Whoaaaaaaa, what?! The conclusion here is, “There is  no reason  for  anyone  to make dietary changes for the sake of preventing heart disease.” That is some crazy nonsense right there. Look how big and bold and absolute it is! There’s no way this can possibly be justified by the premises. Let’s see if we can figure out what happened here.

The first sentence is just silly. It’s like saying, “Many people survive gunshot wounds, and many people without gunshot wounds die.” If you go on to conclude, from that evidence, that gunshot wounds don’t cause death, you are an idiot. This flaw appears time and time again on the LSAT. Remember: correlations can still be causal even when the correlation is not a perfect one-to-one relationship.

Is that what the argument did? Well, maybe. The argument does eventually conclude with “don’t change your diet to prevent heart disease.” Part (but not all) of the support for this argument is the fact that high cholesterol and heart disease do not have a perfect one-to-one correlation. So let’s keep an eye on that.

The next sentence brings up a previously unmentioned factor, the “blood particle lipoprotein (a).” The argument says lipoprotein (a) is correlated with heart disease. Okay, fine. The next sentence says dietary changes that affect cholesterol do not affect lipoprotein (a). So what?

The logic now looks parallel to something like this: “Gunshot wounds are correlated with death, but it’s not a perfect one-to-one correlation. Cancer is also correlated with death. Taking steps to avoid gunshot wounds does nothing to reduce your risk of cancer. Therefore there’s no point in taking steps to avoid gunshot wounds.” This, my friends, is stupid.

There was a lot going on here, so I’m not sure we can articulate the flaw exactly before looking at the answer choices. Still, we can try. It might be something like, “The argument assumes that if there are multiple health risks, there is no benefit to avoiding one particular health risk.” The answer could either be that, or something close to it. Let’s see.

A) Hmm. This isn’t what we were looking for, so we have to move on. This just seems like grabbing a couple terms from the argument and crossing them up into something that might sound attractive but doesn’t actually make sense.

B) Again, this isn’t what we were looking for. Furthermore, the argument does cite a correlation between lipoprotein (a) and heart disease, which sure seems like “evidence for a link.” If the argument doesn’t even  do  this, then this cannot be the flaw the argument makes.

C) This sounds pretty good. The argument does, in the first sentence, say that “high cholesterol levels have been associated with the development of heart disease.” And then the argument ends up concluding that dietary changes to reduce cholesterol to prevent heart disease are useless. I’m worried about the word “ignored” in Answer C, because that’s a pretty specific accusation. Still, C is the best answer so far. At this point I’m comfortable enough with C that I’m hoping D and E are both terrible.

D) This one is clearly a trap, because “other health problems” are not what the argument was talking about. The conclusion was specifically about heart disease, so this can’t be our answer.

E) This is just a red herring. Arguments do not have to always fully explain every single one of their premises. (If they did, then every argument would end up being encyclopedic in length and scope.)

It looks like C comes closest to describing a flaw that is actually in the argument. We could be comfortable making C’s accusation against the speaker: “Hey dumbass, you just said that high cholesterol causes heart disease, and now you’re telling me that eating less lard will not reduce my risk of heart disease? You have presented, but ignored, evidence that high cholesterol contributes to heart disease.”

It’s not exactly what we predicted, but C is our answer.

Nidzo · Answer

A) Incorrect. If lipoprotein (a) did raise cholesterol, then a change in diet would still help be beneficial.

B) Incorrect. Irrelevant in deducing whether diet will help reduce the chances of heart disease.

C) Correct. The author talks about the link between cholesterol and heart disease in the beginning, only to completely ignore it in the conclusion. While some cases may be caused lipoprotein (a), and in this case a dietary change may not help, those with high cholesterol will benefit from changing their diet. Therefore for some a change in diet will be beneficial in preventing heart disease.

D) incorrect. Irrelevant to the argument.

E) Incorrect. Irrelevant to the argument.

Answer C

100mitra · Answer

Wrong  (A): This consideration is irrelevant.

Wrong  (B): This is an irrelevant consideration.

Correct  (C): The author presents evidence in the first sentence of a link between high cholesterol and heart disease, and then later concludes that cholesterol decreasing dietary changes are of no use.

Wrong  (D): this is an irrelevant consideration.

Wrong  (E): It is presented as a simple premise.

Posted from my mobile device

Crytiocanalyst · Answer

(A) It fails to consider the possibility that lipoprotein (a) raises cholesterol levels.
It's addressed perfectly in the passage therefore out

(B) It provides no evidence for a link between lipoprotein (a) and heart disease.
THis is not required a coonection or a direct relation or indirect link isn't the main concern therefore out

(C) It presents but ignores evidence that, for some people, high cholesterol contributes to heart disease.
This is exactly the gap we are looking to fill therefore let us hang on to it

(D) It fails to consider the possibility that poor diets cause some people to develop health problems other than heart disease.
The main objective is the development of heart disease and it's causes others are out of context therefore out

(E) It offers no explanation for why some people with high cholesterol levels never develop heart disease.
This however doesn't help us understand the relationship between dietary routine and heart diseases therefore out

Therefore IMO C

ashutosh_73 · Answer

KarishmaB   GMATNinja   DmitryFarber   AjiteshArun 
I couldn't choose between (B) and (C). Below is how i thought about both of the options, and i would like some help to get a better understanding of the option (B). Please help!!
 Premise 1:  high cholesterol levels have been associated with the development of heart disease
 Premise 2:  Recently, above average concentrations of the blood particle lipoprotein (a) were found in the blood of many people whose  Premise 3:  heart disease was not attributable to other causes
 Premise 4:  Dietary changes that affect cholesterol levels have  no effect on lipoprotein (a) levels .
 Conclusion:  Hence, there is  no reason for anyone  to make dietary changes for the sake of  preventing heart disease .
 
Argument says: ''no effect on lipoprotein (a) levels ---> no reason to make dietary changes for the sake of preventing heart disease''
So argument seems to assume that  changing lipoprotein levels can have some effect on heart disease , right?
This option describes Correlation to Causation flaw, and because stimulus gives no hint of such causation link, (B) should be the answer.
 
This too should be the answer as  Premise-1  and  Conclusion  contradict each other. (C) describes internal contradiction.

DmitryFarberMPrep · Answer

Careful,  ashutosh_73 . Answer B makes no mention of causation. A "link" is just a correlation, and we already have that, so B is false.

Also, the argument does *not* rely on the assumption that we can change lipo(a) levels. In fact, it doesn't say anything to suggest that we have any ability to change our risk of heart disease. It simply says that a particular approach (changing diet) will NOT help. That doesn't mean that another approach WILL help. So the main flaw is just that the author leaps from "this one potential cause may not be affected by diet" to "diet is never a cause." It's possible that the cause varies from one person to the next, or that there can be multiple factors at play, so we have no basis to conclude that changing diet is NEVER helpful.

VerbalBot · Answer

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