There is a funny thing going on in nutritional sciences that I find difficult to explain, but not completely unheard of. As opticians we are subscribers to the Wave Theory of light as developed by Christian Huygens. This wasn’t always the case. Early in optics history, Newton’s Corpuscular Theory of light was favored even though it wasn’t quite correct. It couldn’t fully explain certain experimental phenomena like diffraction and interference. The current theory of light is encompassed in Quantum Mechanics. Einstein, in describing the photoelectric effect, essentially combined both Newton’s (particle) and Huygen’s (wave) paradigms. As opticians, we stick to Huygens. As I mentioned, that wasn’t always the case. Newton was and still is considered one of the greatest scientific minds in human history. Unfortunately for Huygens, he had to compete with a first rate scientist even though his theory of light was correct (or more complete if you will). This is known as arguments from authority and are considered logical fallacies. Conventional Wisdom can and has been wrong many times, which is why science is trial and error until the theory matches the data points. Sometimes we have to face quackery that is in our field, for example the See Clearly Method, which undergoes a respawn every ten years or so. It unfortunately bastardizes vision therapy and/or overstates possible outcomes. Another example of quackery are Blu-blockers and the outrageous claims proponents sometimes make. As an eye care professional, we inform our patients about what we know as honestly and accurately as possible.
So, what’s my gripe? Right now there are theories on saturated fat and cholesterol that are nonsensical, over-simplified, flat out wrong or combinations thereof. It actually makes me a little mad that I had to spend lots of time trying to figure out how some of the metabolic processes and biochemistry of the body work because of the crap advice I’ve been given. If one does their job right generally the recipient doesn’t go researching to verify your work (or if they do, it is out of personal curiosity). After all, the evidence is laid plain for all to see. There are organizations that are supposed to give us unbiased and truthful information but, in my honest opinion, have the appearance of being corrupted by money. One example is the Academy of Nutrition and Dietetics which was formerly known as the ADA or American Dietetics Association. I guess I can understand the name change since the American Dental Association have the same initials. For those people (RDs or Registered Dietitians) who are truly inspired to give unbiased information, hats off to you. You do a great service to your fellow man.
If the underlying theory doesn’t work, one would expect a high failure rate. Comparing fields; If opticians success in dispensing glasses which patients can see clearly versus dietitians success in dispensing dietary advice resulting in weight loss, opticians would have remakes upwards of 90%. To top it off the patient would really have to get used to it. There isn’t another recourse. No Rx check. The patient is blamed for either sloth or gluttony and to come back when the advice is followed properly.
Let’s take saturated fat or as Tom Naughton humorously calls it “arterycloggingsaturatedfat,” because it’s all one word really. I highly recommend the movie Fat Head which is Tom Naughton’s movie in which he tackles current orthodoxy on saturated fat and cholesterol in a humorous way. There are so many downright funny and erroneous information on saturated fat and cholesterol that I don’t know where to begin, but I’ll try anyway.
In the UK they have a PSA-like (public service announcement) video on saturated fat that is downright hilarious. The video shows a refrigerated liquid fat being poured down the drain and then solid in a sink pipe at room temperature. I don’t know what the chemical could be, but it isn’t a saturated fat. Saturated fat usually is solid at room temperature or below. A polyunsaturated fat would have been liquid in a fridge. As to the metaphor it is trying to imply, fat doesn’t enter directly into the blood stream from your mouth, either. There is a whole metabolic process that isn’t as intuitive as the commercial implies.
The second and not so obvious finding is the fat mostly found in atheromas are unsaturated and polyunsaturated fat. In other words, those heart healthy oils you’re recommended to consume on a regular basis. Interestingly, a major component of atheromatous plaques are dead macrophages, and cholesterol in particular Lp(a); lipoprotein (little a) which is a subset of what we have come to know as LDL which I will refuse to call cholesterol because it isn’t cholesterol. VLDL (very low density lipoprotein), LDL (low density lipoprotein), HDL, (high density lipoprotein), IDL (intermediate density lipoprotein) and chylomicrons are not cholesterol. You may not have heard of IDL or chylomicrons, but they exist in our blood and if the past is any indication of the way scientists have been trending, these will shortly be blamed for something. They are all proteins that carry cholesterol and triglycerides to and fro. Some categories, if not all, have subdivisions that differentiate them by size.
Anyway, the current dietary guidelines recommend reductions of overall fat intake and specifically a reduction of saturated fats in favor of polyunsaturated fats. Dr. Oz recommends staying away from saturated fat that are solid at room temperature. Why? What difference should it make? Does the evidence truly indict saturated fat. I don’t question Dr. Oz’ ability as a surgeon but I do take issue with his food recommendations. He went on a Raspberry Ketone kick which I think is plain silly. Bear in mind that glucose is converted into the saturated fatty acid, palmitic acid. It is difficult to assert that the body converts excess energy only to kill us later on of heart disease. The body doesn’t differentiate between your adipose fat tissue and and fat in our diet in terms of using this store of energy. In study after study, the confounding variable sugar is de-emphasized and saturated fat is blamed as the primary culprit in heart disease.
Saturated fat and cholesterol have been, and wrongly I would add, linked together. There is no known way to make cholesterol out of saturated fat and vice versa. Research is showing that cholesterol has many genetic components that are as yet, not understood. Diet may not affect our level of cholesterol for any great length of time. Oddly, eating a high fat diet can raise your LDL, but also your HDL count. What is most shocking is that, to date, no clinical trial has shown that either saturated fat or cholesterol have a causal relationship in the development of CHD.
On to cholesterol. Cholesterol is one of the most important chemicals the body can produce. It is a precursor to a host of hormones like androgens and estrogens as well as vitamin D. With the exception of Familial Hypercholesterolemia, there is no causal link to heart disease. In various observational studies, it has been associated with it, but nothing more. Association does not equal causation. Heart disease can be easily associated with graying hair because heart disease is primarily a disease that effects older people rather than younger. Older people have a likelier chance of having grayer hair (baldness, incontinence could also be used to draw associations etc..). It would be silly to conclude that gray hair causes heart disease no matter how much fancy math or teleoanalysis one applies to it (which I would wag my finger to any scientist who considers teleoanalysis as an acceptable form of analysis), you would really have to show causation (ie clinical trial) to confirm theories.
Scientists can perform a study to look for associations and find that people who eat eggs do and do not associate with heart disease if an observational study is performed. Irresponsibly the media tends to hype said studies conclusions without looking at the quality of the study performed or look for flaws and confounding variables in the study. There isn’t a whole lot of good science writers or journalists. Unfortunately, too many media outlets are actually causing more harm than good.
Coming around full circle I urge dietitians to demand more from the scientists than what they have received. A little more criticism would go a long way between applied scientists (that means you, RDs) and researchers who sometimes use the same word but whose context is completely different (ie significant: for researchers it means the statistical threshold has been reached, for everyone else it means impressive. One can have a very insignificant result from a study that shows a “significant” association) Another step in the right direction would be to remove Pepsi, Coca Cola and others as corporate sponsors. I would also suggest avoiding going after people who think a little differently than what your field allows: Supermodel Miranda Kerr’s suggestion to eat coconut oil for instance (by the way I use a leave in conditioner that has stearic, arachidic, and palmitic acids aka saturated fats found in coconut, and peanut oils) or the unwarranted attack against a former diabetic. Even if you’re right, it just makes one look petty. If this field demands to be taken seriously, it would only help having a skeptical mindset and having a theory that has been shown to work for the majority of the people.