Question

Osteoporosis is a disease that reduces bone mass, leading to fragile bones that break easily. Current treatments for osteoporosis such as estrogen or calcitonin help prevent further loss of bone but do not increase bone mass. Since fluoride is known to increase bone mass, administering fluoride to osteoporosis patients would therefore help make their bones less susceptible to breaking.
Which of the following, if true, most seriously weakens the argument above?

• A. Most people who suffer from osteoporosis are not aware that administration of fluoride can increase bone mass.
• B. Fluoride is added to drinking water in many locations in order to strengthen the teeth of people who drink the water.
• C. The risk of contracting osteoporosis and other degenerative bone diseases is lessened by exercise and an adequate intake of calcium.
• D. Unlike administration of fluoride, administration of estrogen or calcitonin is known to cause undesirable side effects for many people.
• E. The new bone mass that is added by the administration of fluoride is more brittle and less elastic than normal bone tissue.

Hint:

In arguments that propose a solution to a problem, look for unstated assumptions about the quality or effectiveness of the solution. A classic way to weaken such an argument is to show that the proposed solution has a negative side effect that negates its intended benefit.

Answer 1

Answer: (E)

Step 1: Understanding the Concept:
This is a weaken question. The argument concludes that since fluoride increases bone mass, it will help make bones less susceptible to breaking in osteoporosis patients. We need to find a statement that undermines this conclusion.
Step 2: Detailed Explanation:
Let's break down the argument:

Problem: Osteoporosis causes low bone mass, leading to fragile bones.
Premise 1: Current treatments prevent loss but don't increase mass.
Premise 2: Fluoride is known to increase bone mass.
Conclusion: Therefore, giving patients fluoride will make their bones less susceptible to breaking.
The argument makes a key assumption: that the \textit{new bone mass} created by fluoride is strong, healthy bone that will effectively prevent fractures. To weaken the argument, we should attack this assumption. Let's evaluate the options:

(A) Patients' awareness is irrelevant to the medical effectiveness of the treatment.
(B) The use of fluoride for strengthening teeth is a different application and doesn't tell us about its effect on skeletal bones in osteoporosis patients.
(C) Information about preventing osteoporosis through other means does not weaken the argument about how to treat it once it has occurred.
(D) This statement actually strengthens the case for using fluoride by pointing out that other treatments have undesirable side effects, while fluoride (in this context) does not.
(E) This directly attacks the unstated assumption. If the new bone mass is "more brittle and less elastic," it is not strong, healthy bone. Brittle bone is exactly the kind of bone that is \textit{more}, not less, susceptible to breaking. This statement shows that while fluoride might increase bone mass (quantity), it does not improve bone strength (quality), thereby completely undermining the argument's conclusion.
Step 3: Final Answer:
The argument is weakened by the fact that the new bone generated by fluoride is of poor quality and would not make bones less susceptible to breaking.