This month’s column features a guest-post by Mary K. Assad, Ph.D.: she critiques recent health debates on nutrition and encourages us to question the science behind medical claims being made about heart disease.  Assad is a Lecturer in the English Department at Case Western Reserve University who studies medical rhetoric, with a focus on health communication aimed at the general public.


In The Big Fat Surprise (2014), investigative journalist Nina Teicholz “lays out the scientific case for why our bodies are healthiest on a diet with ample amounts of fat and why this regime necessarily includes meat, eggs, butter, and other animal foods high in saturated fat.” She argues that current medical guidelines are based on unproven hypotheses about dangers of saturated fat.

Teicholz’s book echoes arguments of writers including Gary Taubes, who in a 2002 New York Times essay and subsequent books urges that medical recommendations for a low-fat diet have caused America’s obesity epidemic. Multiple sources have condemned low-fat approaches and urged Americans to consume more fat and fewer carbohydrates: e.g.,  Dr. Peter Attia’s Eating Academy, Mercola Products and PCC Natural Markets.

As a medical rhetorician and writing instructor, I care about how health messages aimed at the general public transform medical information into public knowledge. We learn about our bodies and health through such discourse. However, distinguishing fact from fiction within these conversations is often more challenging than deciphering the original research studies because writers with competing arguments all cite “science” as their evidence.

While researching women’s heart health for my dissertation, my professional and personal worlds collided: I learned I had high cholesterol at age 29 despite a low BMI and regular exercise. Based on my doctor’s advice (which resembled the American Heart Association’s guidelines), I drastically revised my diet and realized that “burning off” calories is not the same as preventing arterial blockages. Yet, what if my doctor’s advice was misguided? What if reducing cholesterol and saturated fat would hurt rather than help me? The Big Fat Surprise and similar texts call into question decades of medical guidelines. They aim to do more than stir controversy: they seek to persuade us to change our approaches to healthy eating and to distrust medical advice that, presumably, was based on faulty science.

However, close inspection of these texts reveals that they often misrepresent medical research when translating it for the general public. For instance, Attia asserts: “Eating cholesterol has very little impact on the cholesterol levels in your body. This is a fact, not my opinion. Anyone who tells you different is, at best, ignorant of this topic. At worst, they are a deliberate charlatan…To see an important reference on this topic, please look here .” The linked abstract states, “the relation between dietary cholesterol and the risk of CHD [coronary heart disease] is not clearly understood.” Nowhere does the source state that ingesting cholesterol has “very little impact.”  Further, this article raises the possibility that 15-25% of the general population are “hyperresponders,” meaning that dietary cholesterol affects their measured LDL cholesterol more than usual. The researchers urge the importance of examining the relationship between dietary cholesterol and CHD among this group. Attia acknowledges none of this information.

By providing a link to a medical journal, Attia points to medical authority to support his argument without acknowledging how this source complicates or contradicts his claims. This tendency to draw on medical evidence by gesturing toward research, rather than actively conversing with it, is problematic: readers may be drawn in by liberating claims (eat as much red meat as you want!) because they believe them to be scientifically supported.

Indeed, the summary for Teicholz’s book proclaims, “science shows that we have needlessly been avoiding meat, cheese, whole milk, and eggs for decades and that we can now, guilt-free, welcome these delicious foods back into our lives.” In a culture where we are conditioned to feel guilty for eating indulgent foods, promises of dietary freedom may be persuasive because they tap into social — and particularly female — anxieties about weight, food, choices, and guilt.

As a woman, I am conscious both of the social pressures to “watch what I eat” and the medical guidelines that advise the same. However, navigating competing claims to scientific truth requires interrogation of not only the claims but also the ‘means of persuasion’.  A rhetorical approach creates a critical distance between health messages and our decision-making processes.  When reading an article, book, or website, we must ask several key questions: What is this text trying to persuade me to believe or do?  How does it go about accomplishing this task? What evidence is offered, and how is it presented?

Over the past year, I’ve read about cholesterol from many sources but have been most persuaded by a friend who told me how a vegan diet reduced his cholesterol. In closing, then, I ask: who or what has persuaded you to make a health-related decision in your life, and what made the claim convincing?  Conversations about health need to include attention to language and persuasion. Only then can we begin to make sense of what we’re being told and determine how to respond.