from Harvard School of Public Health (HSPH) March 2012
When you read about or listen to media information regarding nutrition and health, be skeptical. Use Harvard’s questions as guidelines:
1) Is the story reporting the results of a single study? Rarely would the results of a single study be influential enough (or valid enough) for people to change their behaviors. If the given information doesn’t explain how the study fits in with other studies on the topic, do some digging on your own.
2) How large is the study? Size matters. Large studies over long periods of time with a large number of participants give more reliable results than do small studies.
3) Was the study done in animals or humans? To determine how food or other factors affect human health, the factor almost always must be studied in humans.
4) Did the study consider real disease end points, such as the presence of heart disease or osteoporosis, rather than just markers for the disease? Chronic diseases, such as heart disease and osteoporosis, take decades to develop. To get around long waits, researchers sometimes look at markers for these diseases, like narrowing of the arteries or bone density. These markers don’t always develop into the disease.
5) How were the results of the study assessed? Some methods of assessment are better than others. Good studies, and good reports of studies, will give evidence that the methods have validity.
My Take on evaluating health-related information: In addition to the above, I check out the qualifications of the authors of the study and confirm that they are working with an accredited institution of higher learning if it’s a university study.
I verify that the study has been peer-reviewed in a professional journal.
If a study deviates from any of the above, I’ll either not publish its results or will advise the readers where the study hasn’t met established criteria.
Above all, I urge you to remember that nutrition is a very new science. Please don’t be discouraged when a study contradicts the result of an earlier study. The contradiction represents progress and a refinement of previous conclusions, not stupidity or confusion.