Dietary Pseudoconfusion
Saturated Fat Meets Pseudoconfusion
I know, you keep hearing conflicting reports about saturated fat and health outcomes. So do I. One recent study purportedly showed no association between saturated fat intake and heart disease in Dutch adults. Except, the study also reported that half of all the saturated fat in question was palmitic acid, a saturated fat abundant in palm oil, dairy and meat; and that variation in palmitic acid did predict variation in heart disease rates. Honestly, I had trouble making sense of this one, and that’s my job.
It’s also hard to reconcile with a recent, rather mammoth study out of Harvard, showing decisively that higher intake of saturated fat (think sausage, pepperoni, ice cream, etc.) leads to increased risk of early death, while increased intake of polyunsaturated and/or monounsaturated fat (think nuts, seeds, avocado, fish, seafood, and olive oil) reduces mortality.
What is being propagated by a never-ending sequence of competing headlines is dietary pseudoconfusion, and I’ve come up with five reasons for it.
1) Inattention to: instead of WHAT? Two widely cited meta-analyses about saturated fat and health outcomes, one from 2010, the other from 2014, share a very important blind spot. Both were inattentive to the foods being eaten more often when pepperoni pizza was being eaten less often, or vice versa.
Fortunately, a still more recent study did ask: when people eat less saturated fat, or more, what do they eat more (or less) of, instead- and how does that affect health outcomes? When saturated fat calories were replaced by trans fat calories, things went from bad to worse (i.e., heart disease and mortality rates went up). When they were replaced by sugar and refined starch, as has happened so often when people “cut fat” by eating Snackwells, rates of chronic disease and premature death remained comparably high both times. But when saturated fat calories were displaced by either whole grains, or unsaturated fat from the usual sources- rates of cardiovascular disease and mortality went down significantly.
2) Disregard for the Role of Ranges Major studies cited to show that saturated fat is “fine” now because its variation does not lead to variation in heart disease are often conducted within a given country or culture, be it the U.S. or the Netherlands or wherever else, where the prevailing range of variation in saturated fat intake is rather narrow.
Consider a study to determine if parachutes can save the lives of people who fall out of planes. The study compares parachutes that are 1sq inch in total surface area to parachutes that are 1.25sq inch in area. Would you expect to see any difference in survival rates? Of course not. But now imagine the headlines: “parachutes useless; size does not matter…”
3) Dietary Tunnel Vision Let’s imagine we hear that saturated fat from, say, butter, may help protect us against type 2 diabetes, at least a bit. But, unfortunately, we also hear it appears to increase the risk of both heart disease and mortality a bit as well. In fact, we recently heard exactly that.
What’s missing? ANY mention of all the foods long known to protect against diabetes AND against heart disease and premature mortality overall! What foods do that? All the good sources of soluble fiber, like beans, lentils, whole grains, berries, apples, and so on. All the good sources of monounsaturated fat, like nuts, seeds, olives, and avocado.
4) Conflating Lack of Harm for Good Let’s say the evidence of harms from saturated fat really is much less damning than we thought at the height of the “just cut fat” craze. It is. What, then, is the evidence that dietary patterns high in saturated fat from the prevailing sources- baked goods, processed dairy products, processed meats, and so on- produce the health outcome that matters most, longevity combined with vitality, anywhere in the world? There is none. The longest-lived, healthiest populations vary widely in their total fat intake, but they all consume diets of mostly wholesome plant foods, which tend to be low in saturated fat.
5) Neglecting the Link between Planet and Plate Finally, and emphatically, the day has come and gone when any of us can think about diet for health without factoring in the fate of the planet. There are no healthy people without a viable planet to live on, and prevailing dietary patterns emphasizing animal products are an even more obvious threat to the world around us than to the biological world within each of us.
We are not actually clueless about the basic care and feeding of Homo sapiens; we just seem to be. Unfortunately, that is quite bad enough, unless we fix it soon, to cook our goose.
-fin Dr. David L. Katz;www.davidkatzmd.com; author, Disease Proof; founder, True Health Initiative
