Diet sodas can lead to strokes! Zinc helps common colds! Pomegranate juice is an antioxidant powerhouse!
In a recent article in the San Francisco Chronicle, Marion Nestle explains why headlines like these can be misleading and how to question the studies that lead to them.
Nestle says that any study that makes a sweeping claim about a single food or ingredient sets off warning bells for her. She then mentions three major factors we should always consider when judging these health studies: plausibility, controls, and sponsorship.
Plausibility simply means asking yourself if the study makes sense. She points to the study linking diet sodas and increase heart disease, questioning their methods and saying, "Mostly, I can't think of a biological reason why diet sodas might lead to cardiovascular disease." If the study doesn't explain the link sufficiently, there's good reason to be skeptical.
By controls, Nestle means taking a look at how the study was carried out and whether the control groups were sufficiently, well, controlled. She mentions the studies done on zinc and Vitamin C supplements as an aid for the common cold with this one.
And finally, sponsorship of health studies is something for which we should always be alert. As Nestle says, "Vested interests influence the design and interpretation of studies." This is the case with the claim that pomegranate juice is high in antioxidants. Nestle explains that it's not so much that this claim is wrong, but that the study doesn't give enough context.
We really appreciate hearing how a nutrition and food policy expert like Marion Nestle approaches the headlines we read every day!
• Read the Article: Be Skeptical of Food Studies by Marion Nestle in the San Francisco Chronicle
Related: 2010 Dietary Guidelines: A Change for the Better
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