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Some cocoa may improve brain blood flow


4 Star

Some cocoa may improve brain blood flow

Our Review Summary

This story reports on a possible relationship between consumption of flavonoids, a compound found in cocoa and many other foods, and improved brain and cardiovascular health. Several lines of evidence are cited, but readers are given little information to determine whether this research is relevant to them. In addition, it is unclear if the cocoa products available to most Americans would improve their brain function at usual consumption patterns. The experts cited describe their own work accurately but do not help put this problem into perspective for the reader.  The article attempts only a glancing critique of the evidence. Many of the purported benefits of flavanol-rich cocoa appear to have been investigated in studies at the low end of the quality spectrum. Though the details are fuzzy, the report of the Cuna tribe seems to provide data from an observational study, a type of research that can hint at risk factors for disease or the benefits of certain lifestyle–but is incapable of determining cause and effect and usually crude in its ability to sort out important confounding variables that might also account for long lives or healthy brains. Observational trials have led doctors to support longstanding medical practices that later proved to be useless or even harmful when they were examined in more rigorous studies (e.g. routinely prescribing estrogen therapy to prevent heart disease in postmenopausal women). A second study of Dutch men appears to have similar limitations. Two additional studies mentioned in the news story did not directly test people with dementia or cardiovascular problems. One was conducted in apparently healthy mice. The study about blood flow in healthy women not only needs to be reproduced in people suffering from dementia (as the story notes), but to be relevant must also show that the increased blood flow can actually prevent, slow, or turn back dementia itself.   The story doesn’t mention other potential therapies for dementia or cardiovascular disease. 


Does the story adequately discuss the costs of the intervention?

Not Applicable

The article does not mention costs of flavanol-rich cocoa or chocolate, nor does it compare their costs to other lifestyle or medical strategies for improving brain function and cardiovascular health. However, most people must recognize the generally-low cost of these products.  

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

Not Satisfactory

The article is short on details about quantifying the potential benefits of flavanol-rich chocolate. Precisely how great are the observed changes in the various studies? How long-lasting is the effect?

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


The article does not report on any specific side effects observed during these or other studies. However, it quotes a researcher speculating about a likely potential harm of eating chocolate—fattening up people with extra calories. The story also does not attempt to compare this potential harm to the known harms of other medical and surgical interventions for dementia or cardiovascular disease.

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

Not Satisfactory

The article summarizes the apparently unpublished studies and musings of researchers attending a major medical conference. It notes some reservations (implied or explicit) about two of the studies (i.e. that the ability of flavanols to increase blood flow in healthy subjects must still be tested in individuals suffering with dementia; and that improved blood pressure and lower death rates of Dutch men could have been due to characteristics other than nibbling chocolate). Other important limitations of the research go unmentioned. (See "Summary" below.)

Does the story commit disease-mongering?


There are no obvious elements of disease-mongering.

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


The article cites numerous researchers and their affiliations, including a note that some of their research is supported by the candy-maker Mars, Inc.

Does the story compare the new approach with existing alternatives?

Not Satisfactory

There is no discussion of other treatment options for either dementia or cardiovascular disease.

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


The news story explains that cocoa or chocolate rich in flavanol (the ingredient purported to improve brain function and cardiovascular health) is not widely available in American stores.

Does the story establish the true novelty of the approach?


The article rightly notes that “cocoa long has been studied for potential medical benefits.”

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

Not Applicable

We can’t be sure whether the article relied solely or largely on a press release.

Total Score: 5 of 8 Satisfactory


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