Earlier this week, the American Heart Association updated its dietary guidelines with a number of notable improvements, but one glaring flaw - a recommendation to reduce intake of saturated fat to less than 7% of calories. A number of researchers and scientistist are wondering "where is the evidence?" to support such a recommendation on a population-wide basis.
Today, Dr. Gil Wilshire, shares his thoughts with us in this space in a guest editorial.
ENOUGH IS ENOUGH
Gil Wilshire, MD, FACOG
As I get older and a bit wiser, I have learned to let emotions simmer down a bit before putting thoughts to paper. Restraint of tongue and pen is a true virtue. Suffice it to say that the recent AHA recommendation to further reduce dietary saturated fat consumption has left me angry, dumbfounded, and very frustrated. Now that I have had a chance to absorb this news, I believe I can now calmly formulate an intelligent response.
My thoughts gelled last night as I read the Skeptic column in this month's Scientific American magazine. The author of this monthly piece, Michael Shermer, quotes Francis Bacon thusly:
The human understanding when it has once adopted an opinion (either as being the received opinion or as being agreeable to itself) draws all things else to support and agree with it. And though there be a greater number and weight of instances to be found on the other side, yet these it either neglects and despises, or else by some distinction sets aside and rejects, in order that by this great and pernicious predetermination the authority of its former conclusions may remain inviolate. (Novum Organum, 1620)
Clearly, what was true in 1620 remains true today. Once people's minds are made up, they see what they want to see, and they gather information in a selective way.
Low-fat dietary recommendations were born in the late 1950's out of the work of Ancel Keys. Although we can now see that these studies were fatally flawed by selection bias and confounding variables, the "conclusions," which were actually inferences, were widely accepted. In the past, this phenomenon of acceptance of an authority opinion was common at this time. Healthcare workers and policy makers were generally unaware of the concept of evidence-based medicine, let alone the rigor of Level 1 evidence; that is prospective, randomized human studies.
Now it is 2006, and the low-fat and cholesterol dietary recommendations of Keys remain essentially unchanged, except for the fact that the extremists are now becoming ever more so. We are now experiencing the full onslaught of what Bacon so aptly described as "pernicious predetermination."
What I find so alarming and disturbing is the fact that in the past half century NOT ONE SMIDGEN OF LEVEL 1 EVIDENCE HAS BEEN GENERATED TO SUPPORT THESE RECOMMENDATIONS. I don't know how to say it any louder or clearer.
Virtually everything I do in my medical practice must have rigorous scientific validation before I use it on a patient. Why should public dietary advice be an exception?
My levels of alarm and frustration are very high. If people can convince themselves to drink cyanide-laced Kool-aid, I consider that to be their choice and their problem; but in this analogy, the powers that be want all the rest of us to drink it too! The low-fat proponents consider their position to be so obvious that it does not need any scientific validation. I'm sure they believe their position much the same way when people believed the sun revolves around the earth. It's just obvious, no?
I now live and work in my newly adopted state of Missouri. They have a great motto around these parts: "Show Me." Please somebody, anybody, show me a body of Level 1 (or well-done Level 2) evidence that supports low fat and low cholesterol dietary recommendations for the population at large! Show me some high-quality data. Show me that someone has bothered to properly test the 50 year-old hypothesis.
In the absence of this information, I would like to make the following recommendation:
AN IMMEDIATE MORATORIUM ON ALL POPULATION-WIDE DIETARY RECOMMENDATIONS THAT LACK SUPPORT FROM WELL-PERFORMED, PROSPECTIVE, EVIDENCE-BASED HUMAN STUDIES.
Sanity in this field will only come out of a complete overhaul. We need to tear down the current edifice of confusion to its most basic foundations, and rebuild it from the bedrock up.
As a side note, I am not blind to the ramifications of my statements. The thought of six billion or so apex predators (which we are) returning to a diet we evolved to eat is a very scary proposition. The current ravages of the bush meat trade in Africa would be trivial in comparison to the carnage wrought by billions of hunters on a global landscape. It is likely that Homo erectus has caused numerous mass extinctions of prey species in the past from uncontrolled hunting. Numerous animals and large fish are currently undergoing decimation.
I also wish nothing ill upon our grain farmers. I now live in the Heartland, and one would be hard-pressed to find a more honorable and hard-working bunch of people anywhere in the world. I understand the economic implications of a shift back to meat-based protein food sources would be profound.
Nevertheless, if a grain-heavy food pyramid is being promoted because it is in our country's best economic interests, then just tell me and also communicate this to the American public. I'm actually OK with that. I am willing to put environmental stewardship ahead of my personal interests, just don't call it good nutrition, evidence-based, a balanced diet or healthful eating and expect me to buy it or promote it to patients with chronic disease.
We are in a health crisis in the United States. Surely, with all of our accumulated knowledge and wisdom, we can find a workable solution that is supported by evidence, is economically feasible and returns our population to good health.