#17 - A 24-year study of 1,500 adults showed that those

[Administrator]

Complete Question Explanation

Resolve the ParadoxX. The correct answer choice is (D)

The stimulus describes two studies that produced discrepant findings about the health benefits of
consuming beta-carotene. In the 24-year study, the subjects with a high intake of beta-carotene-rich
foods were much less likely to die from cancer or heart disease than were those with a low intake of
such foods. On the other hand, a separate study observed no positive or negative effect on the health
of subjects taking beta-carotene supplements for 12 years.

Before attacking the answers, try to explain the discrepancy in your own words. One way to do it
would be to look for critical differences between the studies. After all, since the stimulus contains
a paradox where two items are different, an answer choice implying that they are similar will not
explain the paradox. The most obvious difference between the studies is that one of them observed
subjects over the course of 24 years, whereas the other was completed in only 12 years. This might
explain why the health benefits of beta-carotene were not apparent in the shorter study. Also, the 24-
year study followed subjects whose diet contained beta-carotene-rich foods, whereas the subjects in
the 12-year study only took supplements. If beta-carotene supplements are not as powerful or wellabsorbed
as foods rich in beta-carotene, this would explain why the subjects in the 12-year study
showed no health benefits.

The stimulus is followed by a ResolveX question, which means that among the five answer choices,
the four incorrect answer choices will provide a resolution to the paradox, and the one correct choice
will not provide a resolution.

Answer choice (A): If the human body processes the beta-carotene present in foods much more
efficiently than it does beta-carotene supplements, the subjects in the 24-year study who consumed
foods rich in beta-carotene would be more likely to benefit from it than the subjects who took
beta-carotene supplements in the other study. Because this answer choice resolves the apparent
discrepancy between the two studies, it is incorrect.

Answer choice (B): If beta-carotene must be taken for longer than 12 years to have any cancerpreventive
effects, this would explain why the subjects in the 12-year study showed no health
benefits. Had they been observed for a longer period of time, the cancer-preventative effects might
have been more easily apparent. Because this answer choice resolves the apparent discrepancy
between the two studies, it is incorrect.

Answer choice (C): If foods rich in beta-carotene also tend to contain other nutrients that assist in
the human body’s absorption of beta-carotene, this would explain why the group who consumed
such foods showed certain health benefits that the other group did not. Because this answer choice
resolves the apparent discrepancy between the two studies, it is incorrect.

Answer choice (D): This is the correct answer choice. If the 12-year study randomized the subjects
into two equal groups, one of which was given a placebo and the other—a beta-carotene supplement,
this would only explain why half of the subjects in that study would have had no positive or negative
effect on their health (they received the placebo). However, it is unclear why the other half showed
no benefit either. Because this answer choice does not explain the apparent discrepancy between the
two studies, it is the correct answer.

Answer choice (E): At first glance, this may seem like an attractive answer, since it is not
immediately apparent how it would resolve the paradox. To understand that, recall that any answer
describing a difference in the way in which the two studies are conducted could potentially explain
the discrepancy in their results. If, in the 24-year study, the percentage of subjects with a high intake
of beta-carotene-rich foods who smoked cigarettes was much smaller than the percentage of subjects
with a low intake of beta-carotene-rich foods who smoked, this means that the smokers were more
likely to consume foods that are low in beta-carotene. Since the higher risk of cancer among the
subjects with a low intake of beta-carotene-rich foods could easily be due to their smoking habits,
this would compromise the validity of the 24-year study and explain the discrepancy in the results
between the two studies.

Remember—for a study or a survey to provide a reliable basis for a given conclusion, it needs to
account for other possible causes that can explain the conclusion. This is usually done by control

[Basia W]

Good evening,

I had the answer choice down between D) and E). However the wording in E was rather confusing- is it relevant to resolving the paradox (and therefore incorrect) because of the fact that smoking can be related to both heart disease and cancer whereas the placebo's in D are not?

Thank you for your clarification,

Best,

Basia

[Nikki Siclunov]

Hi Basia,

The stimulus describes two studies that produced discrepant findings about the health benefits of consuming beta-carotene. In the 24-year study, the subjects with a high intake of beta-carotene-rich foods were much less likely to die from cancer or heart disease than were those with a low intake of such foods. On the other hand, a separate study observed no positive or negative effect on the health of subjects taking beta-carotene supplements for 12 years.

Four of the answer choices will resolve the paradox. One will not.

At first glance, answer choice (E) may seem attractive, since it is not immediately apparent how it would resolve the paradox. To understand that, you need to realize that any answer describing a difference in the way in which the two studies are conducted could potentially explain the discrepancy in their results. If, in the 24-year study, the percentage of subjects with a high intake of beta-carotene-rich foods who smoked cigarettes was much smaller than the percentage of subjects with a low intake of beta-carotene-rich foods who smoked, this means that the smokers were more likely to consume foods that are low in beta-carotene. Since the higher risk of cancer among the subjects with a low intake of beta-carotene-rich foods could easily be due to their smoking habits, this would compromise the validity of the 24-year study and explain the discrepancy in the results between the two studies.

Remember—for a study or a survey to provide a reliable basis for a given conclusion, it needs to account for other possible causes that can explain the conclusion. This is usually done by control groups or by careful screening of potential biases that can compromise the validity of the study.

Hope that clears things up!

[lanereuden]

I thought the LSAT didn’t require outside knowledge
I mean, how am I suppose to know that smoking, like in E, is linked to cancer or heart disease?

[Claire Horan]

Hi Lanereuden,

You don't have to know that smoking has an effect on general health, cancer, or heart disease. You don't need to ascribe any effect of smoking. As Nikki explains above,

you need to realize that any answer describing a difference in the way in which the two studies are conducted could potentially explain the discrepancy in their results. If, in the 24-year study, the percentage of subjects with a high intake of beta-carotene-rich foods who smoked cigarettes was much smaller than the percentage of subjects with a low intake of beta-carotene-rich foods who smoked, this means that the smokers were more likely to consume foods that are low in beta-carotene. Since the higher risk of cancer among the subjects with a low intake of beta-carotene-rich foods could easily be due to their smoking habits, this would compromise the validity of the 24-year study and explain the discrepancy in the results between the two studies.

The key is that differences in the two studies point to a possible reason that the studies had different results. ANY difference between the two studies will suffice, including differences that wouldn't seem to have a connection based on your background knowledge.

I hope this helps!
.

[hope]

I understand what you mean when you say that the conducting of a study is also to be considered, but the LR Bible 2016 states on page 390 that: 1. Explains only one side of the paradox. Then it goes on to say why this would be incorrect answer. Doesn't "D" explain only one side of the paradox? It only provides an explanation about the 12-year study. Please explain.

[Adam Tyson]

That's another good reason to select D, Hope! Remember, this is a Resolve-EXCEPT question, so we want the one answer that does NOT resolve the paradox. You're absolutely right that that answer only tells us about one of the two studies, and not a difference between the studies. It also told us nothing about a difference between the two groups within that one study, as answer E did. That's why answer E does help, even though it only deals with one of the two studies - it tells us about some important difference between the groups within the study other than the thing being tested. The study was flawed in that regard, and a flaw in one study could explain a difference between that study and another one.

Answer D is correct because it does NOT address both sides of the paradox, and we wanted the one answer that did NOT resolve it. Well done!

[ally.ni]

I thought the correct answer was D since if half were given supplements and half were given placebos that would make it seem as if there were no positive or negative effect overall on health. Is this line of thinking wrong because the study would account for the placebos instead of mixing that up with with supplements?

[Robert Carroll]

Ally,

Answer choice (D) could explain why there was no effect on health of the placebo group, but then half of the group would be unexplained. If the placebo group had no effect and the group taking the supplements showed some effect, the total effect might be apparently reduced because of the averaging, but there still would be some effect - or so we would think. So that can't explain why there was no effect for the entire group.

Robert Carroll

[desiboy96]

Hey Powerscore, I hope you are doing well.

I have a question about choice E. I managed to pick the correct answer (D) because I thought it doesn't really resolve the discrepancy since even if the second study had a control group, the underlying issue of why the studies are different still remains.

However, I eliminated choice E for a reason different from what has been discussed but still in accordance with the overarching theme of why E is incorrect (i.e. choice E presents a difference between the two studies). As such I want to see if my reasoning is correct or if I'm stretching it.

That said, I eliminated E because I thought even if the group who smokes but has a high consumption of beta carotene (lets call them group A) is smaller compared to the group of smokers with a low consumption of beta carotene (group B), then, as per the stimulus group A nevertheless has a smaller chance of dying from cancer or heart problems than group B. in other words its like a premise booster and shows a difference in the first study that the other study does not necessarily account for.

Am I way off in my reasoning?

Thanks for taking the time to read this and I'm sorry if I keep pestering you with my questions.