Many of you have probably already heard of this trial that just got published, an energy-unrestricted Mediterranean diet supplemented with either extra-virgin olive oil or nuts that resulted in an absolute risk reduction of approximately 3 major cardiovascular events per 1000 person-years, for a relative risk reduction of approximately 30%, among high risk persons who were initially free of cardiovascular disease, as compared to a control group consuming a typical low fat diet.

But you may not have heard Dr. Esselstyn's response. Dr Esselstyn is a successful surgeon (featured in video above) and author of “Prevent and Reverse Heart Disease: The Revolutionary, Scientifically Proven, Nutrition-Based Cure,” who promotes a low fat vegan diet that does not allow olive oil, dismissed the new study. Those in the Mediterranean diet study, he expained, still had heart attacks and strokes! So all the study showed was that “the Mediterranean diet and the horrible control diet were able to create disease in people who otherwise did not have it.”

This logic is absolutely absurd and needs to be addressed. The study population consisted of men and women with an average age of 67 (ranging from 55-80) with no cardiovascular disease at enrollment, who had "either type 2 diabetes mellitus or at least three of the following major risk factors: smoking, hypertension, elevated low-density lipoprotein cholesterol levels, low high-density lipoprotein cholesterol levels, overweight or obesity, or a family history of premature coronary heart disease." 

In other words they were elderly patients followed for a median of 4.8 years, who were by definition at high risk to have a heart attack.  So according to Dr. Esselstyn's logic, the patients would have been heart disease free during these 5 years had they not been enrolled in to this study and succumbed to the toxic effects of the mediterranean and "horrible control" diets that were able to actually "create disease" in the study subjects.

If this were true, then every randomized clinical trial in the history of medicine would be invalid, and ongoing trials must be stopped immediately due to ethical reasons and impending harm. A certain percentage of patients assigned to take a placebo in a drug trial will almost certainly develop the disease in question, as will many in the experimental group of even the most successful drug trials in history. Does this mean that the drug or placebo caused the diseases observed? Of course not. A successful drug would have prevented more disease or death than the placebo, but the disease still occurs in both groups.

And what was this "horrible control diet" he speaks of? Subjects in the control group were encouraged to eat low-fat dairy products, bread, potatoes, pasta, rice, fresh fruits, vegetables, lean fish and seafood, while avoiding foods such as vegetable oils, fried snacks, red meat, fatty fish, and visible fats in soups. Also known as the government recommended, low fat high carbohydrate diet.

As Gina Kolata reports in the New York Times, "The magnitude of the diet’s benefits startled experts. The study ended early, after almost five years, because the results were so clear it was considered unethical to continue."
Mrs. Kolata also says that  these published findings were based on the first major clinical trial to measure the Mediterranean diet’s effect on heart risks. However, this is untrue. This result and early termination is almost identical to the last time the Mediterranean diet was tested to prevent heart disease, published in 1994 out of France.

The Lyon Diet Heart Study, which tested the benefits of a Mediterranean-type diet on the recurrence of heart attacks in 605 subjects, was originally planned for five years but was ended prematurely due to the intervention diet’s dramatic cardio-protective effects.  After 27 months, the risk of cardiac death or non-fatal MI was 73% lower in the experimental group compared to the controls (RR= 0.27, 95% CI: 0.12-0.59, p=0.0001) and overall mortality was 70% lower (RR=0.30, 95% CI: 0.11-0.82, p=0.02).

The benefits of the Mediterranean diet occurred despite no differences in serum LDL or total cholesterol levels between exposure groups, suggesting that diet’s influence on CVD risk extends further than the current, overly simplistic explanation that ties the mechanism to serum cholesterol elevations caused by excessive Saturated fat  intake.  At the four-year follow up, a 47% lower risk of CHD was experienced by the experimental group compared to the control group (RR=0.53, 95%CI: 0.38-0.74). There was a 72% decreased risk (RR=0.28, 95% CI: 0.15-0.53) of cardiac death and nonfatal MIs (14 events in the experimental group vs. 44 in the control, p=0.0001), and a 67% reduced risk (RR=0.33, 95% CI: 0.21-0.52) of secondary endpoints - unstable angina, stroke, heart failure, and pulmonary or peripheral embolism (27 events vs. 90, p=0.0001) - associated with the Mediterranean diet compared to the control diet.

Published in the Lancet in 1994, the Lyon study was originally rejected by the New England Journal of Medicine specifically because the intervention diet induced no changes in serum lipids, demonstrating how firmly held the diet-heart hypothesis was at the time, that somehow it was impossible to reduce heart disease without reducing total or LDL cholesterol. 

When someone is confronted with inconvenient, overwhelming evidence contrary to their livelihood, it is understandably very difficult to concede. However, when the two most dramatic reductions in cardiovascular disease ever seen in clinical trial history are breathing down your neck, denial is the only possible escape.

Inconspicuously Absent Evidence

And what about these 14 clinical trials? How can the calorie unlimited, high fat diets keep producing more weight loss as compared to a low fat, calorie-restricted diet (at least in the short term), if they are characterized by high amounts of dietary fat, the vilified cause of obesity according to Dr. Ornish?

Even more striking is the fact that to our knowledge, a low-fat diet has NEVER in dietary clinical trial history produced more weight loss than a calorie unlimited, high fat diet. Many studies have shown no difference, but if it is true that a fat makes you fat, where are the clinical trials supporting this? 

If you can find a randomized control trial in which a calorie restricted low fat diet produces more weight loss than a calorie unlimited high fat diet, please e-mail it to us and we will post it: [email protected].


Saturated Fat is Bad for you

Dr. Ornish says that "It’s not low carb or low fat," and then a few words later explains that an optimal diet is  "low in fat (especially saturated fats and trans fats) as well as in red meat and processed foods."

While we can definitely agree that trans fats and highly processed foods should be limited, the saturated fat argument is an archaic one that is not supported in the literature and has become an academic argument perpetuated by selective citation of supportive trials and variations in inclusion criteria. 

If we were to focus on the largest (i.e. > 100 subjects), randomized, most famous trials ever done lasting longer than 1 year, we are left with very few to assess that meet the following 2 criteria:

1) The only significant intervention involved a reduction in fat and saturated fat and an increase in polyunsaturated fats
2) They ask the question: does this diet reduce heart disease? (defined as heart attacks or death from heart disease)

Listed in reverse chronological order:
Women’s Health initiative (2006) – 48,835 women, 8 years, no significant difference between intervention and control.

Diet and Reinfarction trial (1989) – 2,033 men, 2 years, no significant difference between the groups given and not given fat and fiber advice. No significant differences in ischaemic heart disease between intervention and control (intervention was only advice in this trial)

Minnesota Coronary Survey* (1989) – 4,393 men and 4,664 women, double-blind, 4 years, no significant reduction in cardiovascular events or total deaths from the treatment diet

Finnish Mental Hospital (1972) – 12 years, physicians not blinded, significant decrease in coronary heart disease (CHD) death in men ( 5.7 deaths /1000 person-years vs 13 deaths /1000 person-years in the control. Non-significant decrease in CHD in women. (Not randomized, although included here because this is main experiment cited in support of diet-heart hypothesis)

Los Angeles Veteran’s Trial* (1969) –  846 subjects, up to 8 years, non significant difference in primary endpoints –  sudden cardiac death or myocardial infarction. More non-cardiac deaths in experimental group, resulting in near identical rates of total mortality

Oslo Heart Study (1968) – 412 men, 5 year, slight decrease in CHD with intervention. Many dietary interventions accompanied the low saturated fat diet. When stratified by age, the results were significant only in subjects younger than 60.

* Double blind

A full list of all the trials done supporting and refuting the saturated fat-heart-disease relationship, and a more in depth description of each, can be found here. 

Meta-analyses
If we instead focus on the recent meta-analyses of clinical trials testing this relationship, the majority have failed to elucidate a benefit associated with a low saturated fat diet:

• In 2010, Ramsden et al. published a meta-analysis of randomized clinical trials, including trials where polyunsaturated fats (PUFAs) were increased in place of saturated fats (SFAs) and/or trans fatty acids (TFA), and non-fatal heart attacks, coronary heart disease related deaths, and/or total deaths were reported.  In the nine studies included, there was a non-significant increased pooled risk of 13% for n-6 PUFA intake (RR=1.13, CI: 0.84, 1.53) and a decreased risk of 22% (RR=0.78, CI: 0.65, 0.93) for mixed n-3/n-6 PUFA diets. In other words, increasing polyunsaturated fats in the diet provides no benefit, and may be harmful according to this study.        

• Also in 2010, Mozaffarian et al published a systematic review and meta-analysis of randomized clinical trials investigating the effects of increasing PUFAs in place of other nutrients.  Among the seven studies included, an overall pooled risk reduction of 19% (RR= 0.81, CI=0.83-0.97) was observed for each 5% of energy of increased PUFA in the diet.      

• In 2009, Mente et al. published a systematic review of the randomized clinical trial (RCT) evidence that supports a causal link between various dietary factors and coronary heart disease.  The pooled analysis from 43 RCTs showed that increased consumption of marine omega-3 fatty acids (RR=0.77; 95% CI: 0.62-0.91) and a Mediterranean diet pattern (RR=0.32, 95% CI: 0.15-0.48) were each associated with a significantly lower risk of CHD. Higher intake of polyunsaturated fatty acids or total fats were not significantly associated with CHD, and the link between saturated fats and CHD received a Bradford Hill score of only 2 (out of a maximum score of 4), signifying weak evidence of a causal relationship.

• Also in 2009, the Cochrane Collaboration, an international not-for-profit organization, published a meta-analysis of clinical trials that either reduced or modified dietary fat for preventing cardiovascular disease. Twenty-seven studies met the inclusion criteria, and no significant effect on total mortality (RR = 0.98, 95% CI: 0.86-1.12) or cardiovascular mortality (RR = 0.91, 95% CI: 0.77-1.07) was found between the intervention and control groups 

The only study above showing a benefit to replacing saturated fats with polyunsaturated fats was the Mozaffarian meta-analysis. The authors of the study claim to have only included randomized clinical trials in their meta-analysis. Surprisingly, the Finnish Mental Hospital Study was included twice – split into separate analytical pools of male and female subjects. It is unclear why this study was even included to begin with, since it was not randomized and contained a disproportionate number of control subjects who were taking cardio-toxic medications and consuming higher levels of trans fats than the experimental group. 

Inclusion of male and female Finnish data separately further raises concern since it clearly exaggerates the apparent cardio-protective effect of PUFAs demonstrated in this meta-analysis. Excluding the Finnish data from their pooled analysis would diminish the observed results and elicit a null finding, since all other included studies apart from the Oslo heart study (RR=0.75, CI 0.57-0.99) were null:    

Closing Thoughts

In medical school we are taught how to take an HPI (History of present illness) whenever we see a new patient. The importance of this history is stressed in every class, because of how important the patient's story is, and how helpful it can be in coming up with the diagnosis. 

Yet when it comes to figuring out why people are gaining weight, we don't listen. We are absolutely sure that the patient is at fault and we are correct: Just Eat less. 

We don't listen to the fact that people are universally hungry on a calorie-restricted diet. Eat 500 less calories a day than you normally would, then run for an hour each day, then ignore your most basic physiological drive to eat when you get hungry. And repeat this for the rest of your life and our obesity problems will be solved.

What if instead there was a way of eating in which people ate when they were hungry, and stopped when they were satisfied. A way of eating which didn't force you to count calories. A way of eating that, based on our most rigourous scientific data available, produces the most weight loss, reduces triglycerides and increases HDL. 

This way of eating exists, vilified by the medical community as "The Atkins diet", and relegated to a fringe movement and diet fad by the media as the "Caveman diet."

Yet when it comes down to which diet we should eat, the media, physicians and dietitians can make their case, but the final vote should be given to the patient. To the person actually eating the diet. If these patients from all over the world say they are no longer hungry, then maybe we should listen. 


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