Although migraine headaches are believed to be caused by food allergie

If it is difficult to determine which foods cause migraines, then some foods that cause allergic reactions might not have been demonstrated to do so. Hence, if choice A is true, eliminating foods that have been demonstrated to cause migraines might not eliminate migraines, even if food allergies are the only cause of migraines. Choice A is the best answer.

Neither the fact that some food allergies do not result in migraines (choice B), nor the fact that few allergies result in symptoms more severe than migraines (choice E), explains why restricting one’s diet does not stop migraines. Choice C suggests that migraine sufferers do not naturally avoid the foods at issue. Choice D reiterates the information that eliminating certain foods does not usually solve the problem.

Pretty straight

For a low mid level student the question is a bit wordy: in particular D is being temptive

But for an advanced student is fairly easy. As it turns out, this question demonstrates how OG is NOT what is a real upper level question during the exam.

Regards

Although migraine headaches are believed to be caused by food allergies, putting patients on diets that eliminate those foods to which the patients have been demonstrated to have allergic migraine reactions frequently does not stop headaches. Obviously, some other cause of migraine headaches besides food allergies must exist.

Which of the following, if true, would most weaken the conclusion above?

A.Many common foods elicit an allergic response only after several days, making it very difficult to observe links between specific foods patients eat and headaches they develop.

B.Food allergies affect many people who never develop the symptom of migraine headaches

C.Many patients report that the foods that cause them migraine headaches are among the foods that they most enjoy eating.

D.Very few patients have allergic migraine reactions as children and then live migraine-free adult lives once they have eliminated from their diets foods to which they have been demonstrated to be allergic.

E.Very rarely do food allergies cause patients to suffer a symptom more severe than that of migraine headaches.

Can anyone explain me why 'C' is incorrect? I do find the same topic that had been discussed few years back, but couldn't explore why 'C' is incorrect as the contest was b/w A and D. I got to know why A is correct, but couldn't get the reasoning for why we should make it C as wrong.

As per the conclusion "some other cause of migraine headaches besides food allergies must exist." We can attack to the conclusion to prove that only the food allergy is the cause of the migraine headaches.

A. Many common foods elicit an allergic response only after several days, making it very difficult to observe links between specific foods patients eat and headaches they develop. [ Correct.] Food is the actual cause and no information which food is allergic

B. Food allergies affect many people who never develop the symptom of migraine headaches.[Not sure food is the cause] Incorrect.

C. Many patients report that the foods that cause them migraine headaches are among the foods that they most enjoy eating.[ Patients found the allergic foods, so they can eliminate from their diet] Incorrect.

D. Very few patients have allergic migraine reactions as children and then live migraine-free adult lives once they have eliminated from their diets foods to which they have been demonstrated to be allergic.[Same as C]

E. Very rarely do food allergies cause patients to suffer a symptom more severe than that of migraine headaches.[Some other cause] Supporting the conclusion.

I got the correct answer by eliminating all other answer choices. But couldn't understand how option A actually weakens the argument? As per my analysis
Conclusion : Obviously, some other cause of migraine headaches besides food allergies must exist.

Weaken the conclusion --->: Food allergies are the only cause for migraines or there is no other cause for migraines

Can someone help me understand how option A weakens the argument GMATNinja egmat

Quote:

Although migraine headaches are believed to be caused by food allergies, putting patients on diets that eliminate those foods to which the patients have been demonstrated to have allergic migraine reactions frequently does not stop headaches. Obviously, some other cause of migraine headaches besides food allergies must exist.

Which of the following, if true, would most weaken the conclusion above?

Our author states his conclusion that migraines are caused by more than food allergies. He defends this by stating that when eliminating allergic reaction foods from diets, the diet “frequently does not stop headaches.”

To weaken the argument, a possible answer might be that: perhaps it takes a long time for reactions to take effect. So even if the diet commenced last week, the symptoms wouldn’t show until days later and make it appear that the diet is not effective. The answer choice that matches this anticipation is (A).

(A) Many common foods elicit an allergic response only after several days, making it very difficult to observe links between specific foods patients eat and headaches they develop.
This is the correct answer, which matches our anticipated thought.

(B) Food allergies affect many people who never develop the symptom of migraine headaches.
We only care about the people who DO develop migraine headaches. This is an “opposing group” wrong answer and not relevant to our argument.

(C) Many patients report that the foods that cause them migraine headaches are among the foods that they most enjoy eating.
This would strengthen the argument because it states that the other cause is “the foods that [patients] most enjoy eating.”

(D) Very few patients have allergic migraine reactions as children and then live migraine-free adult lives once they have eliminated from their diets foods to which they have been demonstrated to be allergic.
This answer choice seems convoluted at first, but it simply tries to explain that it is rare for patients to live migraine free after eliminating foods they are allergic to. If anything, this strengthens the conclusion that migraines are caused by more than food allergies.

(E) Very rarely do food allergies cause patients to suffer a symptom more severe than that of migraine headaches.
Whether a patient suffers more than headaches is out of scope here.

The argument is that some other cause of migraines besides food allergies must exist.
This is supported by the fact that a recent test was conducted on those who suffer from migraine headaches in which sufferers were put on diets that eliminated suspected foods believed to have caused said migraines.

We are asked to weaken the argument.
A is correct because if it is true that many common allergic responses to food occur only after several days, then this casts significant doubt over the conclusion drawn from the experiment conducted. The argument does not say anywhere that the researchers controlled for this factor in some way, so if they did not control for it then it would likely lead the researchers to draw an erroneous conclusion.
B is incorrect - we are only concerned with those who develop migraines from food allergies
C is incorrect although it does try to lure people. C is incorrect because the fact that the patients enjoy eating foods that cause them headaches does not negate the fact that when such foods are taken out of the patients' diet it would cease to cause migraines.
D is completely irrelevant - who cares if people who experience migraines are the same ones who don't live migraine-free. That doesn't affect the deduction made from the experiment.
E is incorrect because it doesn't matter whether other symptoms are solicited. We only care about migraine symptoms.

Hi experts,

Can you please help me in understanding why option A, which says that a delay/difficulty in associating a headache with a food allergy, weakens the conclusion "Obviously, some other cause of migraine headaches besides food allergies must exist".

The premise states that "putting patients on diets that eliminate those foods to which the patients have been demonstrated to have allergic migraine reactions frequently does not stop headaches".

Referring to the bold part, if we are eliminating ONLY those foods that do cause an allergic reaction, why do we even care about the duration of allergic response or how difficult it is to "observe links between specific foods patients eat and headaches they develop" as per option A?

To illustrate my point, if we have demonstrated that food B led to migraine and then removed food B from the patient's diet, why do we care about how difficult it was to identify that food B led to migraine? Shouldn't the migraine just stop had food B (or any other food item, the link of which is demonstrated) been the sole cause of the migraine?

Thanks!

AndrewN

I know how A is correct. But somehow I am not able to eliminate option C.Why not C here??

People most enjoy eating the food that cause them migraines. They know that this food will cause them migraine but since they love it, they eat that particular food a lot.
If they eliminate that food, they will be free from migraines.

This weakens and says that food is the main culprit.

warrior1991 Take a look at this line from the question stem "putting patients on diets that eliminate those foods to which the patients have been demonstrated to have allergic migraine reactions frequently does not stop headaches".

It clearly states that even if you remove the food that causes migraine reactions (doesn't matter if the food happens to be a favourite), the headaches do not stop.

­Hi GMATNinja

I want to make sure I eliminated option C by the right reasoning. Could you help me with that?
My thinking is - we don't learn anything new from option C to understand how migraine headaches are caused by factors other than food allergies. If these people (mentioned in option C) stop having these foods and migraine headaches don't stop then we are back to the same question what is causing headaches besides food allergies? Hence, we can't proceed with this option and our confidence doesn't change.

Please let me know if my thinking is wrong somewhere.

You're certainly right that (C) doesn't give us anything about the link between food allergies and headaches. Why would it matter if the foods removed from somebody's diet are among their favorites?  If Tim cuts chocolate from his diet, the question of whether chocolate is his favorite food or his 17th-favorite food isn't going to have much bearing on whether his headaches go away, right?

So yeah, we can kick this one to the curb pretty quickly. Nicely done.

­I agree with the explanation above but wont D make a better weakener? 
As per my understanding, D is saying "If a child eats a food that makes him allergic, he will still have the migraine as an adult even without eating that food". So wont this make a better weakener? because it states that yes Food is the reason for migraine and this is the reason elimination of that food from that diet didnt work- because once u had it, u will get migraine even if u remove.

­The author argues that "some other cause of migraine headaches besides food allergies must exist."

Here's (D):

(D) actually supports the author's argument -- the children eliminated the problematic foods, and yet they still get migraines as adults. This heavily implies that the food is not the only cause of the migraines. Something else in their adult lives (environment? stress? the options are endless) must be causing the headaches.

Could it be that eating the foods as a child causes migraines for your whole life, as you've suggested? Perhaps, but that's a pretty big leap. It is at least equally likely that some other factor is causing these adults to get migraines.

Eliminate (D).

I hope that helps!­