A commentary just out in JAMA says many reasonable things about diet and health. The author notes that the overall low quality of the prevailing American diet is an anchor on life expectancy itself. Amen to that. No, multicolored marshmallows are NOT part of a (sane) complete breakfast. Really.
The commentary begins with, and was apparently provoked by, new CDC data suggesting that age-adjusted mortality rates for major diet and lifestyle-related diseases ticked up in 2015. The author and I agree: this is ominous.
To be clear, we have known for a long time that lifestyle practices in our culture militate against the full measure of both longevity, and vitality. We heard about the "actual causes of death in the United States," also in JAMA, all the way back in 1993. We've had plenty of time, every opportunity, and ample reason to do more than count the cost.
We have known as well, and also for years, that reversing the lifestyle practices that conspire against lifespan and healthspan alike -- tobacco, poor diet, lack of physical activity to name only the top three -- works just as hoped. Eating well and being active is reliably, if imperfectly, associated with lasting weight control, and when those four factors are combined -- not smoking, eating well, being active, and maintaining a healthy weight -- they dial down the risk for all major chronic disease by a stunning 80%.
We have seen this verified by the diverse yet kindred cultures of the Blue Zones, and the blessings of longevity and vitality they confer. We have seen this demonstrated in population-wide interventions across a generational expanse. We have seen this demonstrated in randomized controlled trials. A repetitive drumbeat of publications in the peer-reviewed literature has rapped out this message for years with remarkable, nearly metronomic consistency.
These are, or should be, drums of war. The enemy -- a culture that willfully places profit ahead of the life expectancy of your daughter, and my son -- is inside the gates. If such a clear and omnipresent menace does not inspire our passions, and unity of purpose, it's hard to imagine what would. The skin in this game is that of the people we love most in the world. What are we waiting for?
The commentary author and I, as best I can tell, agree about all this. But we do seem to disagree about what will help us, at long last, overcome our apparent deafness to the invitation of those drums.
My answer is: stop arguing long enough to hear them. We have missed the common invitation of the drums for decades in the persistent noise of our perpetual discord.
I can't help but think in terms of an analogy. We might imagine we are actual soldiers, and I am from New York, say, and you are from Chicago. We argue over which of the two is the greater city, and miss the warning hiss of artillery, incoming. We might instead be Americans together, acknowledge the greatness of both cities, and take the next hill.
In the world of diet, details are the stuff of such dangerous diversion. There is a veritable cottage industry these days in pointing out the relative advantages of diets higher in total fat. Such arguments, like the case for Chicago over New York or vice versa, are invariably selective -- reliably omitting any study that shows an advantage in the other direction. The real-world evidence implies that macronutrient levels are effectively irrelevant. When cultures eat wholesome foods in sensible combinations, they do just fine whether their fat intake is high, or low.
Similarly, endless debate about the esoterica involved in the burning of calories tends to play out by the light of fires burning arguments of straw. Allegedly, those of us who maintain that calories do, in fact, count are oblivious to consideration of the quality of food choice. The JAMA commentary even implies that the 2015 Dietary Guidelines Advisory Committee went awry by noting the relevance of calories to weight -- despite the explicit emphasis of their report on wholesome foods, not calorie counting, as the essential means to desired ends.
There is -- so far as I know -- no law obligating a choice between the importance of calorie quantity, and quality. To the contrary, we have abundant reason -- and have had such reason for longer than many may realize -- to respect the indelible links between the two. One of the defining virtues of high "quality" food is that it tends to fill us up on fewer calories. One of the defining features of "junk" food, and intentionally so, is that... nobody can eat just one.
Simple, wholesome, minimally processed or unprocessed foods tend to have many virtues, satiety among them. There is no need to make a choice between the quantity and quality of calories; eat high quality foods, and quantity tends to take care of itself, with at times astonishing benefit. Nor is there a need here to line up behind the banner of one macronutrient or another. People readily over-consume calories from high-sugar, fat-free sodas; we also readily over-consume French fries, which get their calories almost equally from fat and carbohydrate -- or, for that matter, honey-roasted almonds, which get almost 75 percent of their calories from fat. What these items have in common is not macronutrient distribution, but processing in the service of... certainly not health.
In contrast, plain, unprocessed, high-fat nuts are very satiating. So are high-carb beans, and lentils, and apples for that matter. So are baked potatoes, naked and unadorned. Simplicity is the common theme here.
There's no need to choose -- this nutrient or that, quantity or quality -- and there's certainly no value in endless argument that forestalls collective action. Discord lends comfort only to the enemy. Ancel Keys no more meant, "eat Snackwells," than Robert Atkins meant, "eat low-carb brownies." Having seen both such variants on the follies of history, and others besides, the only question now is: do we learn from them and move on, or just keep repeating them?
There are, and there will long be, many unanswered questions about the particulars of nutrition. Good will surely come of plugging those gaps in our knowledge, but not from plugging our ears to all but the opinions we already own. Not if we squander the opportunities in what we already know between now and then. I am sure there are many interesting metrics as yet untallied that would allow for refined comparisons among the great cities in America. We don't need them to know that all such cities are on the common ground of this country.
John Donne warned us centuries ago about the common implications of the bell. It rings true today, and of drums as well.
The threat to life expectancy is present and more than sufficiently clear to give us common cause. The lives in question are those of our children, and grandchildren, establishing our common interest. We certainly have questions left to answer, but have enough answers already to protect our loved ones robustly.
But we do need to stop arguing long enough to hear, and heed that percussive taunt -- and rally to the common battle, in defense of our common ground.
-fin
Director, Yale University Prevention Research Center; Griffin Hospital
President, American College of Lifestyle Medicine
Founder, The True Health Initiative