11 Apr 2013

Unhealthy Saturated Fat - What is the reality?

I dedicate this post to a friend who looks at me like I'm a two-headed alien when he hears me saying that saturated fats are perfectly healthy. And who can blame him! I completely understand why he, or any normal person, would think this way.  To believe that saturated fats are healthy goes completely against all conventional wisdom. 

Up until about five years ago I also believed saturated fats were very unhealthy and strongly linked to heart disease and other illnesses.  These beliefs were based upon the information I had grown up with, as well as some of my University education in the 90's which scratched the surface of the pathophysiology of heart disease.

Even today in 2013 one of the most common misconceptions regarding nutrition is the fear of cholesterol and saturated fats.  This stems from their long-standing mislead association with ischemic heart disease.  Where does this misconception originate?

The common fear follows this pattern of logic: When you eat foods high in saturated fats, the fat and cholesterol in these foods enter your blood, become all gloopy and stick to the inside of your arteries.  

At a very simplistic level, the assumption is made that because these saturated fats are solid outside the body, they will solidify inside your bloodstream too; and even though the internal average temperature of a human being is significantly higher than room temperature, the arteries much like simple non-biological plumbing waste pipes get caked up with hardened fat, blood flow is restricted, and wham - heart attack!!!

The above sounds so over-simplified that you'd immediately think "Who'd be gullible enough to believe that?!".  Most Brits might because its what they've been told by the British Food Standards Agency.  In 2009 the following TV advert was broadcast in the UK by the FSA.  They used that very same metaphorical description to perpetuate the fear of saturated fat. Why? Because they're as confused as everyone else, and it's easier to sell a simple lie, than to fathom or explain a more complicated truth.

None of the prominent scientists who originally promoted the idea that cholesterol might be a factor in the development of heart disease ever believed anything remotely resembling the above nonsense. 

A deeper understanding of the pathophysiology of coronary heart disease reveals that whilst cholesterol is indeed found in the plaque which builds up in the arteries which supply the heart muscles with blood, it's a gross over-simplification to conclude from this that cholesterol itself must therefore be the cause.

In research dating back to the turn of the last century, scientists recognized the complex nature of how atherosclerotic plaque accumulates not on but behind the layer of the artery in contact with the blood, called the endothelium, and that the cholesterol and fat within it is engulfed in white blood cells as part of an inflammatory process.

The truth is that there is no real correlation between cholesterol levels and cardiovascular disease, not by age groups, not by gender, and not by population.  But don't take my word for it, start by watching the following very short video by Dr Malcolm Kendrick:

The nutritional advice that our government, National Health Service, and most mainstream nutritionists has been providing us regarding saturated fats and cholesterol is unfortunately based upon fundamentally flawed principles.  The mainstream dogma is so seriously off target, that excellent, free-thinking, and well-read Doctors are starting to stand up and demonstrate their dissatisfaction.

The cholesterol precept is so entrenched in mainstream medicine that an organisation called The International Network of Cholesterol Skeptics (THINCS), made up of many leading doctors in the field from around the world, is trying to change the views of the medical community in this area.  As a result more and more Doctors are becoming aware of the weaknesses in the research which formed the foundation of what they were taught at med-school.

The misunderstandings regarding saturated fats and cholesterol have many origins, but can primarily be traced back to over-simplified misrepresentations of research drawn from the cholesterol-fed rabbit and the pathology of the genetic disorder - familial hypercholesterolemia.  

Nikolai Anichkov's 1913 cholesterol-fed rabbit model, which is where much of the confusion started, was predominantly viewed as a model of hypercholesterolemia, but it revealed much more than this.  It also identified the crucial role of lipoproteins, their oxidation, and the importance of healthy clearance of unstable lipoprotein lipids from the bloodstream. 

Nikolai Anichkov's 1913 cholesterol-fed rabbit model, simplified pictorially above, was a model not merely of hypercholesterolemia but of hyper-oxidized-lipoproteinemia.

The saturated fat  and cholesterol misconceptions were perpetuated further in the 1950s by the selective research findings of an American biochemist named Dr.Ancel Keys.  Among his most famous research is the "Seven Countries Study" - probably the most notorious example of falsified research in the field of nutrition. 

The American government bought into Keys' hypothesis and the rest of the west followed.  As a result many western government health departments, the media and the medical-pharmaceutical complex have demonized saturated fats and cholesterol for decades.

The adverse effects of Ancel Keys' research upon health, quality of life and medical research are inestimable.  His scientific shenanigans were borne out of a need to be right, at the expense of honesty.  He had a pet hypothesis and was clearly blinded by his own bias and need to validate, not investigate. He cherry picked his data to support his pre-existing idea of the connection between saturated fat, cholesterol and heart disease. 

In a 1957 paper, Dr. Jacob Yerushalmy, founder of the biostatistics graduate program at the University of California at Berkeley, pointed out that while data from the six countries Keys examined seemed to support the diet-heart hypothesis, as mentioned in the above clip,  statistics were actually available for twenty-two countries, but fifteen of these did not support Keys' pet hypothesis so he discarded them! (He also counted the UK as two countries, separating the data from England and Wales) 

When all 22 were analysed, the apparent link between fat consumption and heart disease disappeared. Further flaws in Keys' reports were identified by Dr. Raymond Reiser's research in 1973.

The other prominent criticism of Keys’s study was that he had observed only a correlation between two phenomena, not a clear causative link. This left open the possibility that something else was leading to heart disease, which is only now starting to become more apparent.

If saturophobes want more proof, search through the medical publications for research similar to  this meta-analysis which shows that over a 5-23 year follow-up of 347,747 subjects, there is no association between the intake of saturated fat and heart disease or stroke.  

A concise account of research supporting the health benefits of eating saturated fats and cholesterol is presented in David Evan's book "Cholesterol and Saturated Fat Prevent Heart Disease", which provides evidence from 101 scientific papers.

Much of the controversy and debate about cholesterol focuses on correlations with cholesterol.  What is their magnitude? How consistent are they? Why do they exist in the young but not in the old, and in men more than women?

The cholesterol debate really misses the point.  Since the early 1980s the molecular evidence has made it very obvious that it is oxidised Low-Density-Lipoprotein (oxLDL) that contributes to atherosclerosis, a situation which is highly exasperated by polyunsaturated oils and minimised by saturated fats - as recently identified by this 2013 study.

Branding saturated fat as unhealthy is problematic because we need fat in our diets, and its displacement is resulting in its substitution with more harmful unsaturated fats and oils.  Any well intended advice recommending the avoidance of saturated fat is having the opposite effect and causing long-term harm.

The magnitude of the scientific debacle surrounding saturated fats is summed up nicely by nutritional biochemist Dr. G. Mann - "The Diet-Heart Hypothesis is the greatest deception of our times" (From -Coronary Heart Disease - "Doing the Wrong Things" )

Other saturated fat related research and articles:-

10 Apr 2013

Increasing PUFAs while reducing SFAs increases mortality rates

Increasing dietary polyunsaturated fats and decreasing saturated fats is associated with an increase in both overall death rates and heart disease death rates
Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis.
Laboratory of Membrane Biophysics and Biochemistry, National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA. Chris.Ramsden@nih.gov
Erratum in
·         BMJ. 2013;346:f903.
To evaluate the effectiveness of replacing dietary saturated fat with omega 6 linoleic acid, for the secondary prevention of coronary heart disease and death.
Evaluation of recovered data from the Sydney Diet Heart Study, a single blinded, parallel group, randomized controlled trial conducted in 1966-73; and an updated meta-analysis including these previously missing data.
Ambulatory, coronary care clinic in Sydney, Australia.
458 men aged 30-59 years with a recent coronary event.
Replacement of dietary saturated fats (from animal fats, common margarines, and shortenings) with omega 6 linoleic acid (from safflower oil and safflower oil polyunsaturated margarine). Controls received no specific dietary instruction or study foods. All non-dietary aspects were designed to be equivalent in both groups.
All cause mortality (primary outcome), cardiovascular mortality, and mortality from coronary heart disease (secondary outcomes). We used an intention to treat, survival analysis approach to compare mortality outcomes by group.
The intervention group (n=221) had higher rates of death than controls (n=237) (all cause 17.6% v 11.8%, hazard ratio 1.62 (95% confidence interval 1.00 to 2.64), P=0.05; cardiovascular disease 17.2% v 11.0%, 1.70 (1.03 to 2.80), P=0.04; coronary heart disease 16.3% v 10.1%, 1.74 (1.04 to 2.92), P=0.04). Inclusion of these recovered data in an updated meta-analysis of linoleic acid intervention trials showed non-significant trends toward increased risks of death from coronary heart disease (hazard ratio 1.33 (0.99 to 1.79); P=0.06) and cardiovascular disease (1.27 (0.98 to 1.65); P=0.07).
Advice to substitute polyunsaturated fats for saturated fats is a key component of worldwide dietary guidelines for coronary heart disease risk reduction. However, clinical benefits of the most abundant polyunsaturated fatty acid, omega 6 linoleic acid, have not been established. In this cohort, substituting dietary linoleic acid in place of saturated fats increased the rates of death from all causes, coronary heart disease, and cardiovascular disease. An updated meta-analysis of linoleic acid intervention trials showed no evidence of cardiovascular benefit. These findings could have important implications for worldwide dietary advice to substitute omega 6 linoleic acid, or polyunsaturated fats in general, for saturated fats.
Clinical trials NCT01621087.