Dispelling nutrition myths, ranting, and occasionally, raving


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What came first: the fried chicken or the heart disease?

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Last month a study was published about fried food consumption and the risk of coronary artery disease. The study was conducted with US military veterans and concluded that: “In a large national cohort of U.S. Veterans, fried food consumption has a positive, dose-dependent association with CAD.” Meaning that the more fried food a veteran consumed, the more likely they were to have heart disease. But what does this mean for the average person?

It’s important to note that the vast majority of study participants were men (90%) and the average age was 64. It’s well known that heart disease in women is poorly researched and important to acknowledge that the results of this study don’t necessarily apply to women. There are also many factors that contribute to the risk of developing heart disease and the researchers took the following into account: race (insofar as to categorize participants as black, white, or other), BMI, alcohol use, education status, exercise, smoking status, pre-existing type 2 diabetes, consumption of fish, fruit, and vegetables. After controlling for these factors, the researchers still found a relationship between fried food consumption and CAD.

However, the authors neglected to control for one important factor: poverty. Poverty is a significant risk factor for many so-called “lifestyle-related diseases”, including CAD. Other lifestyle factors are often also enmeshed with poverty making it nearly impossible to determine true contributing factors. People who live in poverty often have poorer diet quality than those with higher incomes and may rely on fast food, including fried foods. If poverty is indeed a greater risk factor than fried food consumption, or if fried food consumption is a result of poverty, this means that simply telling people to consume less fried food may not be the most helpful advice. It takes a certain level of privilege to be able to “choose” to consume the recommended diet. It means having the financial means, time, access, and facilities necessary to prepare nutritious meals.

While the findings of this study support the common belief that fried food is not a healthy choice they also serve to entrench the belief that diet is all about choice when for many people it is not. We need to look further than fried food to determine the root causes of illnesses such as coronary artery disease if we truly want to work to reduce incidence of these diseases.


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Revisiting Dr Esselstyn

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A reader recently commented on a blog post from over a year ago: <a Something's Greasy About Dr Esselstyn's Diet. He suggested that I take a look at some recently published research supporting the diet (and, I think, revise my previously stated opinion).

One of the links was to a series of case studies presented by Dr Esselstyn. As we know, case studies can be interesting, especially in cases of rare conditions, but are not readily generalized. As coronary artery disease (CAD) is a fairly common condition, I feel that it’s more prudent to focus on larger research studies when developing recommendations for the public.

The other link was to a study conducted by, you guessed it, Dr Esselstyn. The study followed 198 CAD patients who were counselled in plant-based nutrition for approximately 44 months. Upon follow-up it was found that 21 were non-compliant (what ever that means… more on this to follow). The remaining participants all showed significant improvement, and only one experienced a related medical incident (i.e. stroke) during those 44 months.

The biggest issue with this study is that there was no control group. There is nothing to compare the participants with. It’s entirely possible that a group, provided with all the same medical treatments and advice, minus the nutritional counselling would have fared just as well. It does seem unlikely, but without the inclusion of such a group, there is no way to be certain that the nutrition counselling (and subsequent adherence) was the reason the participants fared so well. In addition, there was no control for any potential confounding factors. The authors didn’t control for anything. That means that the success could have been due to physical activity/exercise, sleep, stress reduction, socioeconomic status, etc.

There are a few other issues I have with this research. The article states that:

Initially the intervention avoided all added oils and processed
foods that contain oils, fish, meat, fowl, dairy
products, avocado, nuts, and excess salt. Patients were also asked to avoid sugary foods
(sucrose, fructose, and drinks containing
them, refined carbohydrates, fruit juices, syrups, and molasses). Subsequently, we also
excluded caffeine and fructose

However, “We considered participants adherent if they eliminated dairy, fish,
and meat, and added oil.”

My issue with the diet prescribed by Dr Esselstyn was the lack of healthy fats. I have no issue with a vegetarian diet (yes, I’m still not convinced that oil, fish, and dairy products are unhealthy, especially for those who do not suffer from CAD) which is what the adherent participants followed. This means that they could have added nuts, seeds, nut butters, sugar, coffee, avocado, and so on, to their diets and still been adherent. A far cry from the original Esselstyn diet. In turn, I also wonder what the non-adherent participants consumed. Did they eat some fish or meat? Drink some milk? Or were they chowing down on fast food and Hungry Man dinners on the regular? Without knowing these things we shouldn’t be too quick to jump to the conclusion that the Esselstyn diet is superior to all other diets when it comes to treating CAD.

Naturally, there’s also the issue that (despite stating that the authors had no known conflicts of interest) Dr Esselstyn is the author of a number of heart health and lifestyle books that would surely take a hit in sales were research contrary to his hypothesis to be published.

Sure, this study warrants further research into the benefits of plant-based diets (and Dr Esselstyn’s very low-fat plant-based diet) for CAD patients. I’d like to see some larger studies with control groups conducted. Until then, I’ll still be cooking with oils and enjoying my guacamole.