High Fat, Low Fat, Saturated Fat, What the Fat?

I rarely write letters to publications, because, frankly, what’s the point? Very few people seem to read these letters and comments. In the end, it’s unlikely that sharing an opinion about how the publication got this or that detail wrong will reach anyone. Recently, however, I felt compelled to respond to an article. I believe it missed the mark so badly, and presented such an incomplete view of a complex nutrition topic; I just had to respond.Wired Magazine published “Why Are We So Fat? The Multimillion-Dollar Scientific Quest to Find Out,” a story about Gary Taubes’ efforts to further the research into what type of diet truly is best for health. I applaud Taubes’ efforts, and especially appreciate that his approach attempts to maximize the objectivity of the studies he’s seeking to fund. The article, on the other hand, left much to be desired. If you’re interested in what I found problematic in this story, read on.

Letter to the Editor:

Re: Gary Taubes “aha” moment about nutrition research:

The scientists and health professionals railing against salt didn’t seem to notice or care that the diets of those populations might differ in a dozen ways from the diets of populations with more hypertension. Taubes began to wonder if his critique applied beyond salt, to the rest of nutrition science.”

This is an incredibly obvious statement, and reveals a simplistic and shallow understanding of health research, on the part of both Wired and Taubes. This is something every public health student is taught on day one, of Epidemiology 101. It’s really not an amazing, revelatory event.

These things are called confounders, and go far beyond differences in diet that may affect the variable being studied… body weight, exercise, smoking habits, reproductive choices, environmental exposures, genetic differences, differences in rates of other diseases, the list is endless.

Further, Taubes himself demonstrates an inability to look at the full picture – something he accuses his detractors of doing. The population of the United States never has followed the advice that arose from the early 20th century ecological studies on diet and disease. In truth, nobody ever said, “add loads of simple carbs and keep your intake of saturated fat and total fat the same,” but that is exactly what happened in the US.

Sure, percent of calories from fat in a typical American diet appeared to decrease, but only because simple carb intake increased so dramatically. Nobody really followed a low-fat diet in the way in which it was intended. Total fat intake did not decrease.

The American public (and Taubes, apparently) completely missed the mark on this one, and the processed food industry was off and running, stuffing simple sugar into every food product imaginable. The advent of high fructose corn syrup (HFCS) further exacerbated the problem, not because HFCS is so much worse than sugar (they are both problematic), but because it is so cheap that it allows simple sugar to permeate the food supply at unprecedented levels.

The low-fat message was warped and misinterpreted, and Americans took this as an excuse to eat large quantities of completely nutrient-devoid, calorie-laden foods.

But don’t mistake me for a low-fat advocate; I’m not. I believe a diet that derives as much as 40 or 50% of calories from fat is fine, so long as the majority of it is not (most types of) saturated fat, and is not artificially created trans fats.

In essence, the true message was that the optimal diet is PLANT-BASED (not carbohydrate-based), derived from vegetables, legumes, nuts, seeds, fruit, and whole grains (ideally, in that order of importance).

All of these folks who embrace meat, butter, and saturated fat as the “healthiest” option misinterpret existing data. If you replace saturated fat with simple carbs, YES, I agree, that likely worsens health, and certainly contributes to insulin resistance, obesity, and cardiovascular disease. THAT is what the “low-fat experiment” taught us.

However, if you replace saturated fat with polyunsaturated and monounsaturated fats – the PUFAs and MUFAs from plants – WITHOUT increasing intake of simple carbohydrates, you will see better health outcomes. Unfortunately, nobody has really studied this, and very few Americans actually eat this way.

As for inflammation, cholesterol, other lipids, and similar biomarkers, if you replace the average, crappy, high simple carb, low-fiber, processed food, American diet with ANYTHING else, you will see improvements in these markers. You can replace the current American diet with a paleo diet, a vegan diet, a vegetarian diet, a plant-based low-fat diet, a plant-based high fat diet, the Mediterranean diet, the Okinawan diet, the Inuit diet, or just about anything else that eliminates processed foods; you will see improvements in health.

Again, no big revelation, because the standard American diet is so poor.

However, which one improves health the most? My money is on plant-based diets, low or high fat.

Over two decades ago, Dean Ornish proved that a low-fat vegan diet can REVERSE, yes, actually shrink, established plaques (fatty build ups) in arteries. Dr. Ornish more recently demonstrated that this type of diet can reduce markers associated with prostate cancer progression in men living with the disease, including a demonstrated lengthening of cellular telomeres. Telomeres are the small “caps” on the end of strands of genetic material, and the longer, the better. Longer indicates a younger “cellular age.”

Dr. David Jenkins’ Portfolio diet has been shown to lower so-called “bad” cholesterol levels (LDL-cholesterol) by 29.6% vs. a lowering of 33.3% for first line statin drugs. Can the high saturated fat diet advocated by Taubes, et al. match that? I’m eagerly awaiting results.

What does the Portfolio diet look like? Plants, plants, and more plants, including specifically selected foods known to have significant cholesterol-lowering effects: soy, almonds, oats, barley, psyllium, okra, eggplant, and almonds. A far cry from a meat-based diet being promoted as the “healthiest” option.

Further, the longest-lived people on the planet do not follow a meat-heavy diet. They eat plants. Period. Think Okinawan and Mediterranian dietary patterns. Not a paleolithic, caveman diet.

Until someone proves that a saturated fat, meat-heavy diet can reverse coronary artery disease, slow and possibly reverse cellular aging, improve markers in people living with cancer, and improve cardiovascular biomarkers nearly as well as a statin drug, I’ll stick to plants.

There is one thing we all can agree on: ANYTHING is better than the typical American diet.

Suzanne Dixon, MPH, MS, RD
Epidemiologist/Registered Dietitian

​Portland, Oregon​
@NoNutritionFear​
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