Question 22.16

Q: What is the claim? A 2011 research study—described by media around the world, including Time, MSNBC, and CBS—touted the first experimental support for the adage “an apple a day keeps the doctor away.”

Question 22.17

Q: What is the purported apple advantage? The media stories reported that participants in the study experienced:

1. A 23% decrease in LDL (low-density lipoprotein, which is associated with a higher risk of cardiovascular disease).

2. A 4% increase in HDL (high-density lipoprotein, which is associated with a reduced risk of cardiovascular disease).

3. A 32% decrease in C-reactive protein (a protein that is associated with inflammation and is a marker for cardiovascular disease).

4. A 33% decrease in lipid hydroperoxide (a chemical associated with plaque formation in arteries).

5. A loss of 3.3 pounds of body weight by each subject, on average.

Question 22.18

Q: How did the researchers evaluate the benefits of apples? The study lasted for one year and included 160 post-menopausal women, aged 45–65, who were randomly assigned to one of two groups. In the “treatment” group, participants were assigned to eat 75 grams (2.7 ounces) of dried apples each day. In the “control” group, participants were assigned to eat 100 grams of prunes each day.

Question 22.19

Q: What do the results mean for you? The headlines suggested that “an apple a day” confers a general and dramatic benefit—and they are correct in that regard. Unfortunately, this story illustrates a common difficulty in translating technical research reports into popular news stories. The research publication—from the Journal of the Academy of Nutrition and Dietetics—is a rigorous study, notable for randomizing subjects to the experimental groups and for including subjects—post-menopausal women—frequently overlooked in research. But how might this reduce the generalizability of the results? Why?

Additionally, of the five important results listed above, the researchers found statistically significant differences for only two findings—the LDL decrease and the lipid hydroperoxide decrease. Do you think the media should make claims about the 3.3-pound weight loss and the 4% increase in HDL levels when those results were not sufficiently different between treatment and control groups? Is there another way the media could present those results for people without statistical training?

Question 22.20

Q: What can you conclude? Be cautious when reading sensational claims. When a study is presented in the form of a media-friendly sound bite, much can be lost in translation. Because there are limits to what researchers can definitively conclude from any study, read with caution. In this case, there are indeed two promising results. In post-menopausal women, daily apple consumption improved two measures of heart health: (1) LDL level, an important measure of the risk of cardiovascular disease, was reduced, and (2) lipid hydroperoxide, an indicator of plaque formation in arteries, was reduced. Though encouraging, these results fall short of the claims made by news reports that apples are a “miracle fruit” and that “everyone can benefit from consuming apples.”