I just attended an online webinar sponsored by the Preventive Cardiovascular Nurses Association (PCNA) on Translating Epidemiology into Sound Public Health Advice, and I wanted to share the great information presented by Dr. Douglas Weed, former chief, Office of Preventive Oncology at the National Cancer Institute.
There are many times we hear about a new study that has people running to buy blueberries, trash all their diet soda, burn their stashes of artificial sweetener, or start hoarding dark chocolate. Many times, the results of the study were published in a newspaper or became viral through email and it seems everyone has heard the new "evidence" and are all running to make a change. This seminar warned about being too quick to make a change, based on any singular study.
Dr. Weed spoke very knowledgeably and intelligently throughout the seminar, and especially during the question-and-answer session at the end. He gave an example of a study that linked drinking alcoholic beverages to being diagnosed with various types of cancer in women and led us through the hour showing the evidence published, and then the quotes published in newspapers and magazines. It was amazing: even the head scientist conducting the study started to make statements, quoting results that were not in line with the study's outcome!
Conclusions were made like "drinking any amount of alcohol has shown an increase in the incidence of cancer in women", when the study actually showed some cancer incidences decreased; furthermore it was explainedthat the reason "all cancer risk" appeared elevated was because the risk of some specific cancers were elevated. The Washington Post took some of the study results and wrote an article that started: For years, many women have been buoyed by the news about one of life's guilty pleasures: That nightly glass of wine may not only take the edge off a day but also improve their health. Now it turns out that sipping pinot noir might not be such a good idea after all. And they go on to include quotes from the author of the study such as "no level of alcohol intake can be considered safe" (neglecting the health benefits of alcohol that have been shown in numerous studies), and that "if you are regularly drinking even one drink per day you are increasing your risk of cancer" (neglecting to mention several types of cancer that were shown to be reduced in this study in groups of women who consumed alcohol).
Dr. Weed cautioned health professionals that "just because a study is published [even in a reputable journal such as The New England Journal of Medicine] does not give a reason to encourage people to change their behavior [based on that article alone]".
We need to read a study and ask ourselves these questions: "Does the study give us new information?"; "Is there evidence of a new causal relationship?"; "Does this give us cause to change public policy or make new recommendations to the public or even warn the public about something?"
No causation claims should be made based on one study, but instead the study should be examined for causation: Is there a strong and consistent association between the food or drink and the outcome? Is there biological plausibility? What do other studies on the same topic have to say?
Before health professionals start making recommendations we need to wait for the consensus from the scientific community and not start running wild with the information from a newspaper or magazine headline...Newspaper quotes are often worded to mean something far different that what the study actually showed.
Dr. Weed recommended some good resources for what we can rely on to make suggestions to our clients: Look to review papers and current textbook chapters for peer-reviewed conclusions. There, the research has already been gathered and assessed. A new journal article alone does not give sufficient evidence to start encouraging changes in our clients' lifestyle habits.
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