Even today, as new studies emerge showing saturated fat does not cause heart disease, you’ll occasionally find a misguided journalist incorrectly lump it with trans fat or use “artery clogging” to describe saturated fat.
The tiding is slowly changing. One recent meta-analysis in the Annals of Internal Medicine concluded “current evidence does not clearly support cardiovascular guidelines that encourage high consumption of polyunsaturated fatty acids and low consumption of total saturated fats.”
Other researchers ask we reconsider stigmatizing saturated fat.
“The adverse health effects that have been associated with saturated fats in the past are most likely due to factors other than SFAs [saturated fatty acids],” writes Glen D. Lawrence in a 2013 Advances in Nutrition review, who then asks “for a rational reevaluation of existing dietary recommendations that focus on minimizing dietary SFAs, for which mechanisms for adverse health effects are lacking.”
The question becomes, why did saturated fat ever develop a bad reputation that it needs to be vindicated today? We have a very influential researcher named Ancel Keys to thank for that.
In 1955 at the World Health Organization in Geneva, Keys offered what became known as his lipid hypothesis, which claimed dietary fat raised cholesterol, subsequently increasing heart disease.
Initially, Keys targeted dietary fat as the culprit, but over time, he modified his argument to point the finger solely at saturated fat. Whereas unsaturated fat in vegetable oils could benefit health, he claimed, saturated fats create adverse affects.
The American Heart Association quickly embraced Keys’s hypothesis, warning that butter, eggs, meat, and other saturated fat-rich foods contributed to heart disease and emphasizing a low-fat diet to prevent heart disease.
Eventually, Keys presented his Seven Countries Study, which argued countries where people ate more fat—particularly saturated fat—had more cases of heart disease.
Why Saturated Fat Is Not the Enemy
“Saturated fat has been demonized ever since Ancel Keys’s landmark ‘seven countries’ study in 1970,” writes Aseem Malhotra in a British Medical Journal review appropriately called “Saturated fat is not the major issue.”
As Malhotra and numerous other researchers point out, correlation is not causation, and Keys neglected to account for many factors that could also contribute to heart disease. Keys cherry-picked his data, conveniently excluding whatever didn’t fit his hypothesis. In fact, the countries he studied that had the highest rates of heart disease also were the countries with the highest intakes of sugar and refined carbohydrates. Was it the fat or the sugar? Turns out it was the sugar!
Even though critics pointed out these and other fallacies in Keys’s work, the public bought into the saturated-fat-is-harmful myth, avoiding it like the plague for decades and choosing instead inflammatory vegetable oils and trans fats in fake foods like margarine.
The truth becomes much more complicated. Some fats do raise cholesterol, whereas others lower cholesterol. Even when saturated fat does, the type of cholesterol becomes more important than cholesterol itself. Saturated fat does raise the LDL or bad cholesterol, but it also raises the good or HDL cholesterol. But sugar lowers HDL cholesterol. And it is the ratio of total to LDL cholesterol that is a far more important predictor of heart attacks than LDL cholesterol itself.
Quality becomes paramount here. The saturated fat in a fast-food bacon cheeseburger will have an entirely different effect than saturated fat in coconut oil.
Let’s use grass-fed beef as an example. Although lower in saturated fat than grain-fed beef, roughly 40 to 50 percent of the fat in grass-fed beef is saturated.
Compared with grain-fed beef, grass-fed beef contains more stearic acid, a saturated fat that doesn’t increase cholesterol. In fact, one study in the journal Lipid found stearic acid lowered LDL cholesterol.
Grass-fed beef contains lower amounts of palmitic acid and myristic acid, two saturated fats that can potentially raise cholesterol.
Even then, the type of cholesterol becomes more relevant than raising cholesterol itself. Researchers now understand high density lipoprotein (HDL) and low-density lipoprotein (LDL), the molecules that carry cholesterol, come in several types. Larger, fluffy “good” molecules are harmless, whereas small, pellet-like “bad” molecules can actually create or exacerbate problems.
Interestingly, researchers find when folks consume more saturated fat—especially from healthy sources like coconut oil—their “good” LDL cholesterol increases and their “bad” LDL decreases. Saturated fat in foods like extra virgin coconut butter fuels your mitochondria, provides anti-inflammatory benefits, and could even improve your cholesterol numbers.
In her recent book, The Big Fat Surprise, Nina Teicholz, takes a deep dive into the world of fat, saturated fat, cholesterol and heart disease and comes up with a big fat nothing. The data linking dietary fat (other than trans fats) and heart disease is weak at best, and corrupt at worst. She not only looks at the research, but the politics, money and personalities that demonized fat and why there is very little real evidence that fat is a problem, even saturated fat. For anyone who wants to deep, honest look into this topic, I encourage you to read her book.
Why Sugar Is the Enemy
We must also consider other factors, other than saturated fat and cholesterol, that could contribute to heart disease. The purple elephant in the room—the one that researchers neglected to focus on for decades—is sugar, especially high-fructose corn syrup and other man-made sugars.
A century ago, we ate far more saturated fat but had less heart disease. Butter and lard were staples and heart attacks were rare and almost unknown. We also ate a lot less sugar, and zero of our sugar came from high-fructose corn syrup (HFCS). Today, the average kid consumes 34 teaspoons of sugar every day, largely as HFCS in sodas and processed foods. We went from eating about 10 pounds of sugar a year in the 1800s to 150 pounds today. That’s average; some people eat much more than that.
In the past 30 years since HFCS was introduced into our diet, we’ve gone from zero calories to 66 pounds of this Frankenfood annually. It’s no coincidence that, within that time period, we’ve seen obesity and chronic illness rates (including heart disease) skyrocket.
One recent study published in JAMA Internal Medicine found, even accounting for other risk factors, that those with the highest sugar intake had a four-fold increase in their risk of heart attacks compared to those with the lowest intakes.
Ironically, U.S. Dietary Guidelines today restrict saturated fat to no more than 10 percent of a person’s caloric intake; yet, they set no limit to added sugar. Can you see why we’ve gone after the wrong enemy for so long?
Among its many problems, sugar contributes to inflammation (the root of heart disease) as well as high triglycerides, lower HDL (good) cholesterol, and dangerous, small LDL (bad) cholesterol.
Many of the low-fat and fat-free Frankenfoods we’ve consumed over the past few decades have been higher in sugar, particularly HFCS.
“We’ve all been sold a bill of goods about so-called healthy low-fat foods like cookies and muffins,” writes Christiane Northrup, MD. “When you begin to read labels, you’ll quickly see how much sugar is added to just about everything, especially to low-fat foods.”
Lumping all saturated fats into one category over-simplifies things much like claiming all carbohydrates are bad. Broccoli and a hot fudge sundae are both carbohydrates, yet you know one benefits you and the other doesn’t.
Don’t be afraid of saturated fat. Instead, maximize healthy sources like coconut and grass-fed beef and you’ll automatically edge out unhealthy sources. Combine that with a diet free of added sugars and you have an effective strategy to normalize cholesterol, as well as reduce your risk for heart disease, obesity, type 2 diabetes, and numerous other chronic conditions.
Over the past decade, we’ve seen a paradigm shift from dietary fat to sugar becoming the enemy.
How has this awareness shaped your eating habits? Share your thoughts below or on my Facebook fan page.
Wishing you health and happiness,
Mark Hyman, MD