T.S. Eliot famously asked, in The Love Song of J. Alfred Prufrock, "do I dare to eat a peach?" Peaches are not saliently controversial these days, although fixation on fructose has perhaps at times made that calculus just a bit fuzzy. But most of us seem to agree: peaches are good.
Skim milk is quite another matter.
Skim milk has its fans to be sure. It figures prominently in the DASH diet, which has won the U.S. News & World Report best diet rankings for several years in a row (for better or worse). But to the growing clan convinced that advice to cut fat was not merely incomplete but actually the nefarious cause of virtually all that ails us, including unrest in the Middle East, climate change and nuclear proliferation -- skim milk epitomizes dietary guidance run egregiously amok. And then, of course, there is opposition to dairy consumption altogether from both the ardent vegans, and the apostles of Paleo, who don't agree about anything else and tend not to like one another very much. Not to mention the fact that two-thirds of the global human population, in common with the adult mammals of every other species, are lactose intolerant.
And so it is that the general topic of dairy intake, let alone the specific question of skim milk, is in rather a constant state of froth. Anyone hoping to reach a reasonably evidence-based conclusion on the matter has some challenging miles to slog through a river of curds and woods of whey.
I have gone those miles, because that's my job. And I think my view of "the truth" as best we know it is reasonably good from my tuffet at grandmother's house. I'll tell you what I think about skim milk before we're done. But first, I want to tell you what I think about people telling me what they think about what I think about skim milk.
It can be irksome. Wow, I'm glad I got that off my chest.
The easiest way to know something for sure is to know as little as possible about it. If you know what you think you know, and make no particular effort to get to know what you don't know, then what you think you know winds up looking very good. I have made the point before that often in this modern world, people make grandiose claims about having done their "homework," when all they really mean is: I have read three blogs by people who think just like I do.
The differences between experts and non-experts tend to distill down to two main considerations: (1) the experts actually do know more, and (2) consequently, the experts tend to be a whole lot less certain about anything.
Bertrand Russell said it best, if a bit harshly: "The whole problem with the world is that fools and fanaticsare always so certain of themselves, and wiser people so full of doubts." I can't help but wonder if Mr. Russell was, in fact, certain that was the whole problem with the world. Well, let's move on.
I hear from people, all the time, who are certain they know what the whole problem with our diet is. Some seemingly do think it's peaches -- or at least fruit in general -- and their answer to J. Alfred's question would be: Heavens no! They are wrong. Even Dr. Robert Lustig, who put fructose on "America's most wanted" (or perhaps "unwanted") list in the first place has said they are wrong.
Others, as noted, blame it all on skim milk. I got this message most recently in a review of my book, Disease Proof, on Amazon. Personally, I think the book is quite good -- and apparently, so do most others. But there have, of course, been criticisms -- and they have come in two basic flavors.
The first is that the book, which is overwhelmingly about the skill set for losing weight and finding health, offers nothing truly "new." For those who already have the skill set for healthy living, that is, as it should be, absolutely true. The question of course is: why would someone who already knows "how" read a "how-to" book on any topic? For all those who clearly don't have the requisite skill set, then what's in the book is new to them -- and that's whom it's for. Given the prevalence of obesity and chronic disease in our culture, that's a very ample audience. If you are lean and healthy and know how to stay that way and share those blessings with those you love, you don't need my book.
The other criticism is the one that really bothers me. It's the cursory review of material spanning nearly 400 pages in an effort to find one point of disagreement. In that recent review, the point of disagreement was skim milk. Because I recommended fat-free milk for those who drink milk, the reviewer concluded I was deluded, ignorant, and probably too lazy to have done my homework, and my book must be rubbish.
But here's the thing: I recommend fat-free milk for those who choose to drink milk because I've done MORE homework, not less. And honestly, I am not entirely certain. But I am fairly confident. Perhaps more importantly, the book places no particular emphasis on dairy in the first place, noting -- as I have before -- that while the basic theme of optimal eating is well established, the clear superiority of a given variant on that theme to another is not. A diet can be optimal with or without dairy, let alone dairy fat. Denigrating Disease Proof for its nominal suggestions about dairy is only slightly less ridiculous than tossing The Lord of the Rings on the bonfire of vain presumptions because the elves eat lembas bread -- and all right-thinking people now know that grains are the true root of all evil.
As for that skim milk, here's what we actually know. In the U.S., more dairy in the diet -- of whatever variety -- is generally associated with better health and weight outcomes. But that is likely because in the context of our culture, more dairy means less soda. In global context, some of the world's healthiest diets and most convincing intervention trials have de-emphasized, or even excluded dairy. Vegan diets exclude dairy, and show impressive health benefits. Dairy figures in Mediterranean diets, but its role is modest.
As for dairy fat, the groundswell of enthusiasm for it is misguided. True, not all saturated fat is created equal, and true, saturated fat is not the nemesis we once believed. But the research that many are mistaking for reasons to canonize saturated fat really just shows that there is more than one way to eat badly. When saturated fat is cut and replaced with sugar and starch, things can go from bad to worse. But that doesn't prove any benefits of eating more saturated fat.
In the aggregate, the relevant literature does NOT indicate health benefits from increasing saturated fat intake. It merely demonstrates lack of health benefits from cutting saturated fat and finding other kinds of junk. In contrast, the literature shows quite decisively that a liberal intake of monounsaturated fats from nuts, seeds, olives and avocados; and a balance of polyunsaturated fats with an emphasis on omega-3s from nuts, seeds, fish and seafood -- does indeed confer actual benefit. That said, the evidence that a plant-based, low-fat diet can confer at least comparable benefit remains fully convincing, despite the popularity of refuting it.
It is true that full-fat milk offers more satiety -- a lasting feeling of fullness -- than fat-free milk. But a hot dog offers more satiety than a glass of water, too. That doesn't mean we should all eat more hot dogs and drink less water. Rather, satiety matters at the level of the whole diet. If we eat a variety of wholesome, nutrient-dense, satisfying foods -- we will tend to fill up on fewer calories. That certainly matters.
And so finally, back to the passing reference to fat-free dairy in Disease Proof: yes, I think it is the way to go. Get your fats preferentially from those nuts, seeds, olives, avocados, fish, seafood and so on. In the context of an optimal diet of wholesome foods with plenty of the most healthful fats, there is no evidence that adding saturated fat confers benefit, and some to suggest it does the opposite. I will keep watching the literature, and if the weight of evidence tips another way, so will my position -- but not until then.
My career is devoted to helping people add years to life, and life to years. I care passionately about it, because I care about people. The privileged intimacies of patient care are a routine reminder of my indelible connections to the human family at large. I know everyone wants a good life, and to the best of my knowledge, most people deserve just that, for themselves and those they love. If I can help them lose weight, find health and live better -- it's my pleasure as well as my job to do so.
The same basic mentality pertains outside the clinic walls, where the means of reaching people change. Rather than hand or stethoscope on skin, it reverts to words or images on screens, fingers on keypads, and/or a voice from the podium. But the objectives are the same: to empower people with reliable means to better ends. Mostly, it's a very good gig, and the many attendant rewards of it keep me enthusiastically engaged.
I also appreciate well-reasoned criticism. I am more likely to learn something from those who disagree than agree with me, so the thoughtful, courteous dissenter is a great connection. I attend closely to what they have to say, engage in debate with them, and suspect we both emerge the better for it, whether or not either of us converts the other. Just agreeing to disagree is broadening and constructive.
But there is a very different kind of criticism, which in this age of cyberspatial anonymity, social polarization, and shoot-first-then-aim reactionism seems increasingly to prevail. It's criticism of the rush to judgment, ad hominem, we-disagree-so-you-must-be-a-moron variety, and to be honest, it is very tiresome.
I hear routinely from people who, by their own admission, have gone no further than the headline -- yet feel fully qualified to critique publicly content they haven't bothered to read. I hear routinely from people who have formed an opinion, selectively read the work of only those who support that opinion, and conclude I am an uninformed ignoramus for expressing a different opinion. The possibility that I have a different opinion because I have read more, rather than less, apparently never crosses their mind.
Anti-elitist attitudes make sense. Anti-elite attitudes do not. I'm pretty sure we all want our Special Forces to be special; our pilots to be highly skilled; and our neurosurgeons to be equally deft of mind and hand. In the areas that actually impact our collective health the most, diet prominent among them, we really need to stop pretending that all opinions are created equal, and espousing each with religious fervor. We need to stop indulging in the notion that an expert stops being an expert when they disagree with something we know is true after reading the first three lines of the three blogs we like the best.
I will be very honest with you -- sometimes the obstreperous, presumptuous, obnoxious stupidity I run into does make me think: if we are this foolish, maybe we deserve to be so fat and sick.
Yes: whole fat milk is better than soda. But better still is: get your liberal intake of fat from walnuts, salmon, avocado and olive oil -- and consume your dairy with little or no fat. This contributes to a shift in your diet toward the pattern of fat intake most decisively linked to good health outcomes. Of course, if you eat little dairy -- it may not matter if it's low-fat or full-fat. But if you eat little dairy, why the fuss? If you eat a lot of dairy and it's full fat, that saturated fat may not be harmful in the ways once thought, but it's not helpful either -- and the more of it you eat, the less room you have in your diet for the fats that are apt to do you genuine good.
At least I think so, for now. To be totally and permanently certain -- I will need to confer with fools and fanatics.
Follow David Katz, M.D. on Twitter: www.twitter.com/DrDavidKatz