The skeptical cardiologist has heard a few cardiologist colleagues rave about the movie “Forks Over Knives” and promote the so-called “whole-foods, plant based diet.”
One of the two major physician figures in the movie is Dr. Caldwell Esselstyn, a former surgeon and now a vegan evangelist.
Esselstyn, along with T. Colin Campbell (of the completely discredited “China Study” (see here for a summary of critical analyses of that data), Dean Ornish, and Nathan Pritikin, are the leading lights of a dying effort to indict any and all fat as promoting heart disease and all the chronic diseases of western civilization.
Esselstyn, in his book, “Preventing and Reversing Heart Disease” lists the following rules:
- you may not eat anything with a mother or a face (no meat, poultry, or fish)
- you cannot eat dairy products
- you must not consume oil of any kind
- generally you cannot eat nuts or avocados
What? No Fish or Olive Oil? You Cannot Be Serious!
The best randomized controlled trials we have for diet to prevent coronary artery disease (CAD, the cause of heart attacks) have shown that supplementing diet with olive oil and nuts substantially lowers CAD.
Every observational study in nutrition has demonstrated that fish consumption is associated with lower cardiovascular disease.
Esselsstyn’s Really Bad Science
While working at the Cleveland Clinic, Esselstyn developed an interest in using a plant-based diet to treat patients with advanced CAD. He says he had an epiphany one rainy, depressing day when he was served a slab of bloody roast beef.
In his own words:
“my original intent was to have one group of patients eating a very-low fat diet and another receiving standard cardiac care and then compare how the two groups had fared after three years.”
If he had followed his original intent, and randomized patients entering the study, he could claim that he had performed a legitimate, important scientific study. Twelve of the 24 would be allocated by lottery to the Esselstyn diet and 12 to whatever was the standard recommended CAD diet at the time. Unfortunately this approach, due to a “lack of funding, was not practical.”
So instead, 24 patients were sent to him, “all suffering from advanced CAD” and began the horrifically strict dietary program he had developed based on his “logic and intuition.”
Interestingly, patients not only were put on Esselstyn’s incredibly low fat diet, but they were also given cholesterol lowering medications and were “switched to statin as soon as these became available in 1987.”
In addition, 9 of the 18 patients who stuck with the program had previously undergone coronary bypass surgery and two had undergone angioplasty of a coronary artery.
6 of the 24 original patients “could not comply with the program” and were sent back to their regular cardiologists. This gives you an idea of how difficult it was to follow this diet.
Esselsstyn’s “data” then consists of following 18 patients, 9 of whom had already undergone coronary bypass surgery, all of whom were taking statin drugs with his diet without any comparison group.
This group of 18 did well from a heart standpoint, of course. It is impossible to know if the diet had anything to with their outcome. Most of them had already undergone the “knife” or had had angioplasties that took care of their most worrisome coronary blockages. They were all taking statin drugs . They were all nonsmokers and they were all highly motivated to take good care of themselves in all lifestyle choices.
Any patients who were not intensely motivated to radically change their diet would have avoided this crazy “study” like the plague.
This “study” is merely a collection of 18 anecdotes, none of which would be worthy of publication in any current legitimate medical journal.
Three of the 18 patients have died, one from pulmonary fibrosis, one presumably from a GI bleed, and one from depression. Could these deaths be related to the diet in some way? We can’t know because there is no comparison group.
Should Anyone Eat Ultra-low Fat Diets?
It is possible that the type of vegan/ultra-low fat diets espoused by Esselstyn and his ilk have some beneficial effects on preventing CAD, but there is nothing in the scientific literature which proves it.
Scientific reviews of the effect of diet on CAD in the last 5 years have concluded that the evidence is best for the Mediterranean diet, which emphasizes fish consumption, olive oil and nuts. These reviews dismiss ultra-low fat diets because of a lack of evidence supporting them, and an inability to get people to follow them.
If you have ethical or philosophic reasons for only eating things with no mother or face, then by all means follow your conscience.
Too often, however, I find that those who choose veganism for philosophic reasons want to find health reasons to support their diet and mix the bad science and philosophy into a bland evangelical stew they recommend for all.
I remain, therefore, in favor of cioppino, paella, butter and all the glories of the omnivore that make life so rich.
For an amazingly complete (and surprisingly entertaining) dissection of the scientific inaccuracies of “Forks Over Knives” with humorous overtones, I recommend Denise Minger’s post “Forks Over Knives: Is the Science Legit? (A Review and Critique). Be prepared for lots of graphs!