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Berries, Tea May Cut Men’s Odds for Parkinson’s: Study


3 Star

Berries, Tea May Cut Men’s Odds for Parkinson’s: Study

Our Review Summary

Here’s what we thought could have been handled better:

  • The story used active verbs — “may cut odds,” “can lower risk” — to describe the potential benefits of foods and drinks that are rich in antioxidant compounds called flavonoids. This is inappropriate, since this observational study was not designed to show whether these foods were responsible for the reduction in risk.
  • Even if (especially if) a researcher uses active, causal verbs in the interview (“berries are protective in both men and women”), journalists have an obligation to counter that by explaining that such studies can’t prove a protective effect.
  • The story relied on relative risk comparisons when reporting that frequent consumption of these foods “lowered risk” of Parkinson’s disease by 40%. The story should have included absolute risk comparisons to give readers a more accurate picture of the potential benefits.

The story included some important caveats, and sought out an independent perspective to provide nuance to the reporting. But these strong points were overshadowed by the larger failure to grasp the quality of the evidence.


Why This Matters

Parkinson’s is a progressive disease which causes tremors and other movement symptoms that typically worsen over time. Patients often have considerable difficulty carrying out everyday tasks, and some become severely disabled. While there are effective treatments, we currently don’t know if there are modifiable factors that can prevent Parkinson’s disease from developing in the first place. These results are interesting because they suggest that certain dietary habits may be associated with lower risk. It will take much more careful research to prove whether these habits are, in fact, protective.



Does the story adequately discuss the costs of the intervention?

Not Applicable

The cost of berries and other foods rich in antioxidants is not in question.

Does the story adequately quantify the benefits of the treatment/test/product/procedure?

Not Satisfactory

It should be possible to calculate absolute risks from the data in this cohort study. However, this story reported only relative risks, which likely overstate the magnitude of the potential benefit.The absolute risk reduction for dietary changes and Parkinson’s risk is likely to be very small.

Does the story adequately explain/quantify the harms of the intervention?


The story spends most of its time discussing the potential health benefits of berries. We’re not aware of any harm attributable to berry consumption (provided they are the edible kind).

And the story included this quote from the author:

“There are no harmful effects from berry consumption, and they lower the risk of hypertension too,” Gao added.

Does the story seem to grasp the quality of the evidence?

Not Satisfactory

The story used cause-and-effect language to describe the findings of this observational study, which as we’ve noted repeatedly is inappropriate. We reiterate our call for journalists to read our primer on observational studies and stop using this kind of language.

We were pleased to see that the story mentioned some limitations of the study, and called for more research. But we think it missed one of the more important caveats: the fact that people who eat a lot of berries and drink green tea and red wine may differ in important ways from those who don’t eat and drink these things. It’s very difficult for a study such as this to account for all of those differences.

Does the story commit disease-mongering?


No disease-mongering.

Does the story use independent sources and identify conflicts of interest?


The story quoted an independent expert, who cautioned that people who already have Parkinson’s disease won’t benefit from eating berries or other flavonoid-rich foods.

Does the story compare the new approach with existing alternatives?

Not Applicable

There aren’t really any effective alternatives for preventing Parkinson’s disease, so we’ll rule this not applicable.

Does the story establish the availability of the treatment/test/product/procedure?

Not Applicable

The availability of these foods is not in question.

Does the story establish the true novelty of the approach?

Not Satisfactory

While this may be the first study to document a relationship specifically between berries and Parkinson’s, there have been studies documenting possible benefits from similar dietary approaches that involve antioxidant-rich foods, such as the Mediterranean diet. The story could have mentioned this research.

Does the story appear to rely solely or largely on a news release?


We don’t think this story was based on a press release.

Total Score: 4 of 7 Satisfactory


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