Passage II

Bone mineral density (BMD) is an indicator of overall bone health. Low BMD increases the risk for bone fracture. Scientists have determined that BMD is linked to dietary intake. Two studies, one with humans and one with rats, examined the effect of caffeinated cola consumption on BMD.

Study 1

A food-and-drink questionnaire was given to 1,413 adult women who had an average age of 58.2 yr. Each woman was assigned to 1 of 5 groups according to her caffeinated cola consumption. The average BMD for each group is shown in Figure 1.

Figure 1 adapted from Katherine L. Tucker et al., "Colas, but Not Other Carbonated Beverages, Are Associated with Low Bone Mineral Density in Older Women: The Framingham Osteoporosis Study." @2006 by American Society for Nutrition.

Study 2

Thirty 10-week-old rats were divided into 4 groups: Groups 1 and 2 consisted of 10 male and 10 female rats, respectively; Groups 3 and 4 consisted of 5 male and 5 female rats, respectively. Each rat in Groups 1 and 2 was provided with unlimited supplies of a solid rat food, drinking water, and caffeinated cola for 30 days. Each rat in Groups 3 and 4 was provided with unlimited supplies of the rat food and drinking water, but no cola, for 30 days. Figure 2 shows, for each group, the average daily caffeinated cola consumption per rat, the average daily drinking water consumption per rat, and the average daily total fluid consumption per rat.

Figure 3 shows, for each group, the average BMD on Day 30.

Figures 2 and 3 adapted from Recai Ogur et al., "Evaluation of the Effect of Cola Drinks on Bone Mineral Density and Associated Factors." @2007 by Nordic Pharmacological Society.

11. Consider the statement “It is possible that average BMD differed among the groups in the study partly because the subjects in the study ate different types of solid food.” This statement applies to which of the studies, if either?

Answer and Explanation

Your Answer is

Correct Answer is A

Explanation

The fifth and eighth lines of the text part of Study 2 say that the mice use a/the solid rat food, so the solid food of the mice is also the same. From study 2, it is impossible to see how different solid food will affect the results;

However, study 1 did not mention what the diet of these adult women was, so the dietary reasons may have affected the experimental results . Therefore, although it is not 100% certain, it can be seen from Study 1 that diet may be a factor that affects BMD. "