"Epistemic Certainty Surrounding Dietary Recommendations for Meat"
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Ellen M. StreetEllen Street is a Ph.D. student in Nutrition at Oregon State University. Her graduate research is
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MethodsResearch materials were comprised of government health recommendations, specifically the 2015-2020 Dietary Guidelines for Americans and the earlier 2010 edition of the DGA for comparison, public health organization recommendations, and peer-reviewed research articles evaluating the relationship between red meat intake and mortality. I chose to analyze the conclusion and discussion/results sections of the research articles where claims are made and significance is indicated. In the public health and government recommendations and guidelines, I focus on the primary sections outlining red and processed meat consumption. In my discussion, I evaluate similarities and differences between current research and current red and processed meat recommendations put forth by public health and governmental organizations given the current scientific evidence. To determine levels of certainty expressed in these documents, I hand-coded and used keyword searches to identify the use and frequency of certainty and uncertainty markers: boosters and hedges, respectively. I also included markers of the indicative present, medium modality verbs, and directives in the appendices’ tables, due to their ability to communicate confidence or lack thereof. For markers of hedging, I referenced two lists found in Hilary Glasman-Deal’s Science Research Writing for Non-Native Speakers of English (p.107-108, 148). The lists focus on description of results. The first list includes markers communicating reluctance to commit to an interpretation and the second delineates markers for possible indications. From these reference lists, I identified common markers of hedging in the results and conclusions of my chosen sources. After identifying hedges, boosters, directives, medium modality verbs, and use of the indicative present, I grouped the sentences containing markers into tables (see appendix). The first two tables list the hedges and boosters found in all documents. The remaining six tables categorize the sentences containing hedges, boosters, and additional markers from each source. Markers of interest are indicated with the use of italics. Document Selection I began my document selection with the most recent publication of the Dietary Guidelines for Americans (2015). Due to the breadth of the DGA's impact, and its status as a referential guide, I chose to focus primarily on this document, using outside sources to compare with its recommendations. For my supporting documents, I chose scholarly, peer-reviewed, online-accessible articles. I focused on well-established public health organizations outside government involvement or influence. The American Heart Association and the American College of Cardiology also publish health guidelines, as well as the American Institute for Cancer Research (AICR), now known as the World Cancer Research Fund (WCRF). These organizations are largely non-profit, funded through research grants and public support. I chose to analyze the AHA recommendations for adherence to the 2013 AHA/ACC Guidelines on Lifestyle Management to Reduce Cardiovascular Risk, and the 2007 second expert report, Food, Nutrition, Physical Activity, and the Prevention of Cancer: A Global Perspective, published by the AICR/WCRF. The two chosen reports are relevant to the topic of red and processed meat consumption as cardiovascular disease and cancer risk are both known to be closely linked to consumption of saturated and trans-saturated fats. I analyzed a variety of research article genres, focusing on high-profile journals implementing scholarly peer-review processes. I chose to analyze a prospective study published in the Archives of Internal Medicine, a meta-analysis published in the American Journal of Epidemiology and an International Agency for Cancer Research (IARC) monograph published in The Lancet Oncology[1]. All three publications consistently receive high rankings and impact factors in their respective fields. Document Analysis I completed this analysis to evaluate the presence or absence of epistemic certainty regarding red and processed meat recommendations by identifying epistemic modality markers, boosters, and hedges. I searched for markers of epistemic certainty, by reading the results and/or discussion and concluding sections of each research article and relevant sections of the 2015-2020 DGA and public health organization publications. I used the word search function on Mendeley to find mention of red and processed meat, and from there, I identified hedges, communicating reluctance to commit to a recommendation or suggestion, and boosters, establishing certainty and confidence. Unless otherwise indicated, the italics I use in this article indicate markers of epistemic certainty, boosters, and hedges. Similarly, I used boldface to indicate modal verbs. ____________________________________________________________________ [1] The selected monograph in The Lancet Oncology is subjected to an eight-day formal peer-review and consensus process prior to publication by the IARC Working Group (IARC, 2006). The Working Group consists of independent, international experts and invited specialists. |