A recent meta-analysis by an accomplished international team of researchers, published in a prestigious medical journal, shows that high intake of saturated fat is exactly as bad for health as a high intake of sugar and refined starch. The study also suggests there is something far worse.
The study, which pooled data from prior research and in the process aggregated findings for over 500,000 people, compared the rates of coronary artery disease -- the particular bad health outcome on which the researchers chose to focus for fairly obvious, epidemiologic reasons -- between those with the highest intake of saturated fat as a percent of calories, and the correspondingly lowest intake of refined starch and added sugar; to those with the highest intake of sugar and refined carbohydrate, and correspondingly lowest intake of saturated fat. The rate of cardiovascular disease was virtually identical in both groups.
This indicates that a high intake of saturated fat is as bad as a high intake of sugar, as well as vice versa.
OK, now that I presumably have your attention, I'll tell you my real agenda, which has nothing to do with saturated fat, or sugar, and everything to do with stupidity. Because, folks, when it comes to food, and food for thought alike, it is mostly stupidity that is killing us. Stupidity is worse for us than either sugar or saturated fat.
The "recent meta-analysis" to which I am referring is the very one you already know (although I very much doubt many of you actually read it). The meta-analysis in question is the very one published in the Annals of Internal Medicine in March. The paper itself is entitled: Association of Dietary, Circulating, and Supplement Fatty Acids With Coronary Risk: A Systematic Review and Meta-analysis. The corresponding pop culture headlines were along the lines of, "Don't Fear the Fat" and "Butter is Back."
I did, of course, read the study in detail, reviewing all of the data before opining, which I did back in March. I won't reiterate that analysis now -- it remains available to you. For today, there is just one point to make: What we are looking for seems to matter much more than what we find.
The study was designed to look at variation in fatty acid intake, admittedly. But the metric applied was: AS A PERCENT OF CALORIES. Obviously, the calories we take in are always 100 percent of the calories we take in, so if our percent intake from one thing goes down, our percent intake from another must go up correspondingly. This, I trust, does not invite argument.
The study itself pretty much ignored this consideration -- a fundamental limitation. But we certainly know from population trends what we ate more as we ate saturated fat less: sugar and refined starch. We certainly didn't eat more vegetables -- our intake of those has in fact trended down.
Because this paper came out at a time when we are disgusted that decades of (allegedly) cutting fat have left us all fatter and sicker, we were looking for something else to throw under the bus. After all, we have decided to end the war on fat. One of our favorite scapegoats these days, although by no means the only one, is sugar. So this study was interpreted not based on what was found, but based on what we were seeking. The thus entirely predictable, pop culture response was advice to bring back the butter.
But let's try a thought experiment. Imagine if we had been cutting sugar for decades, and eating more butter, cheese, and deli meats instead -- and were just as fat and sick and coronary disease-prone as ever. Then, we would be disgusted with the "just cut sugar" hypothesis and would be looking for something else to blame for our woes. This study would have provided it just as readily. Because, as noted, it showed that the highest intake of saturated fat produced THE EXACT SAME BAD OUTCOMES as the alternative, which we may confidently infer to be a high intake of sugar and refined carbs.
We should all be pretty worried if we can use the exact same study to reach such opposing conclusions. We should all be pretty worried if our convictions about diet and health derive more from what we are seeking, based on the frustrations and disgust du jour, than on what we are finding based on an unbiased assessment of the epidemiologic evidence. And folks, they clearly are. And so pretty worried, I am.
The study in question said nothing good about butter, meat, or cheese. It simply showed that the typical American diet has been identically bad for decades in more ways than one, with typically high rates of heart disease to show for it every step of the way. We had a whole lot of preventable heart disease both before and after we swapped out saturated fat for sugar. Conversely, we had a whole lot of preventable heart disease both after and before we swapped in sugar for saturated fat.
I invite those of you inclined to roll your eyes at me to read the meta-analysis in its hoary detail, scrutinize the data tables, and come back with a data-driven rebuttal. I promise to listen -- then. Until and unless you can do that -- and I am confident you can't -- we are done here.
And folks, we are done for if we let this brand of stupidity persist. Stupidity is what's killing us, far more surely than sugar or saturated fat. It really has to stop -- because literal lives are at stake.
We do, in fact, know what dietary patterns are associated with optimal health outcomes. We know it based on vast, diverse, robust, and astonishingly consistent evidence. As evidence of the consistency of the evidence, I reached a particular set of conclusions based on my commissioned review of the literature with one set of analytical objectives. Dr. Frank Hu at Harvard and his colleagues reached a virtually identical set of conclusions based on an entirely independent review of the literature born of a different set of analytical objectives.
We are not clueless about the basic care and feeding of Homo sapiens. We really are not.
But eating well cannot be achieved by shifting from one scapegoat to the next; that merely invites new ways to eat badly. It can't be done one nutrient at a time. If ever there was a case of fixating on a tree while the forest burns down, modern trends in nutrition exemplify it.
When we approach the interface of science and pop culture representations of it with an agenda, we are going to find what we are seeking. That won't make it true. But since we were seeking it, we will be prone to embrace it as truth. Worse, we are increasingly prone to do so with religious zeal. I am routinely a victim of that failure to separate church and plate myself, being called names that make my wife and mother wince. All this, despite having no dietary pattern to sell anyone, and simply trying to advance this platform: wholesome foods in sensible combinations.
Yes, I argue that should be "mostly plants," because the evidence argues that way -- not because I own stock in Brussels sprouts. A Paleo style diet that derives 50 percent of its calories from game is still "mostly plants" by volume, and a legitimate variation on the theme for those inclined to go that way. But the popular mantra of more "meat, butter, and cheese" is off the theme altogether. I don't say that because I win a prize every time someone declines pastrami. I say that because it's what the weight of evidence indicates.
Honestly, I am a bit tempted to surrender, because the name-calling does get tedious. But this is my job -- it's what I do. My training in preventive medicine and my role in lifestyle medicine define and obligate me. I simply have to keep trying to add years to life and life to years, because it is what I do, and who I am. The success of that mission is highly dependent on the quality of our food.
And that, in turn, is highly dependent on the quality of our food for thought. And that has been an appalling load of mostly junk for far too long already.
No, saturated fat is NOT our nutritional nemesis, and never was. But neither is sugar, nor wheat, nor all grains. No one thing is THE thing wrong with our diets, and no one food, nutrient, or ingredient will be our salvation either. Wholesome foods, mostly plants, in sensible combinations could be -- assuming an 80 percent reduction in all chronic disease qualifies as salvation. It's about as close as we can come in the context of epidemiology, and pretty darn good.
What stands in the way is not our admittedly imperfect knowledge of nutrition, because frankly, we know enough. What stands in the way is hyperbolic headlines, fixed agendas, reactionism, religious zeal, profiteering, finding only what we're seeking, and failure to learn from the follies of history.
In other words, what is far more perilous to our health than saturated fat or sugar is the prevailing standard of stupidity in the food for thought we swallow routinely. If there is a war to be waged against anything ingestible, I humbly suggest it be that.
-fin
Dr. David L. Katz is the founding director of Yale University's Prevention Research Center at Griffin Hospital in Derby, CT. He has authored three editions of a nutrition textbook for health care professionals; his latest health book for the general public is Disease Proof. He has also recently published his first novel, which has allowed for time spent on worlds that are home to intelligent life. His wife and mother love him. So do his three dogs, and everyone knows you can trust dogs!