Health News Review

This was the best of three stories we reviewed about a study of omega-3 fatty acids and the aging brain. The difference: a clear and detailed description of the limitations of observational research.

Our Review Summary

This story made the key point that CNN and the Washington Post failed to communicate in their competing coverage: “This study … did not prove that omega-3 fatty acids prevent mental decline, merely that there may be an association between consumption of fatty acids and brain health.”


Why This Matters

Consumers have only so much capacity to implement behavior changes to improve their health. By critically evaluating the evidence, stories can help consumers focus on the changes that are most likely to be beneficial.

We know that people get easily overwhelmed by health claims and end up thinking that much of it is hype and doesn’t matter anyway.  If we are cautious about reporting on observational studies, it improves consumer understanding, critical analysis, and credibility of science and of journalism.


Criteria

Not Applicable

Does the story adequately discuss the costs of the intervention?

Not Applicable

The cost of fish is not in question, although a word about the cost of fish oil supplements would not have been inappropriate.

Not Satisfactory

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

Not Satisfactory

Although we think readers will come away with the correct bottom line message on this study, we’re going to rate this criterion unsatisfactory, for two reasons:

  • The active verb headline “Omega-3 Fatty Acids May Protect the Aging Brain” suggests a causative link that this study wasn’t designed to prove.
  • The story doesn’t tell us what the differences in the cognitive scores were and whether those differences would translate to a noticeable difference in one’s ability to function.
Not Applicable

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

Not Applicable

The harms of eating fish are not in question, although there is some concern that certain species high in mercury can be harmful for pregnant women and children.

Satisfactory

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

Satisfactory

This is where the HealthDay coverage shined. In addition to cautioning that the study couldn’t prove that omega-3 fatty acids prevent mental decline, the story had a nice discussion of the limitations that apply to this study and other observational studies:

  • “It remains possible that factors they did not control for, such as fruit and vegetable consumption, are really responsible for the brain benefits.”
  • “Another possibility is that the slight mental decline that the people in the older brain group were experiencing caused them to eat less healthy omega-3-rich foods, instead of vice versa.”

The story also mentioned that a clinical trial of high and low omega-3 intake would help prove whether there’s a beneficial effect.

Satisfactory

Does the story commit disease-mongering?

Satisfactory

There was no disease mongering.

Satisfactory

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

Satisfactory

The story quotes an independent expert, and there were no conflicts that should have been identified.

Not Satisfactory

Does the story compare the new approach with existing alternatives?

Not Satisfactory

There was no discussion of other habits or behaviors, such as exercise and mental stimulation, that are associated with maintenance of cognitive function with age. The story also did not mention other potential sources of omega-3 fatty acids, as CNN did.

Not Applicable

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

Not Applicable

The availability of fish isn’t in question.

Satisfactory

Does the story establish the true novelty of the approach?

Satisfactory

The story nods to previous research suggesting that fish consumption might have benefits for the aging brain.

Satisfactory

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

Satisfactory

The story was not based on a press release.

Total Score: 5 of 7 Satisfactory


Comments

Henry posted on March 5, 2012 at 11:03 am

There may be some harm in eating some fish from some markets these days. Mercury contamination, for one, comes to mind.

Reply

    Gary Schwitzer posted on March 5, 2012 at 11:22 am

    Henry,

    Thanks for your note.

    Our review included the following note: “there is some concern that certain species high in mercury can be harmful for pregnant women and children.”

    Reply

We Welcome Comments

But please note: We will delete comments that include personal attacks, unfounded allegations, unverified facts, product pitches, profanity or any from anyone who doesn't list what appears to be an actual email address. We will also end any thread of repetitive comments. We don't give medical advice so we won't respond to questions asking for it. Please see more on our comments policy.