Food as Medicine: The Case for Measuring What We Intend to Manage

The Food-as-Medicine movement - a movement I applaud, in which I am involved, and arguably to which my whole career has been devoted – is gaining momentum.? As it does, we are duty bound to ask: what, exactly, is “food as medicine” intended to treat??

Hold that thought as we invite an analogy to get some of the heavy lifting out of the way.

Imagine a world - perhaps before the invention of the blood pressure cuff, or perhaps even in the early days after its invention, when the House of Medicine still opposed the adoption of this new-fangled thing - suddenly rallying around “anti-hypertension as medicine.”? This world would know that high blood pressure was implicated in heart attack, stroke , kidney disease and failure, visual impairment and blindness, heart failure, and more.? A movement to “fix” high blood pressure to lessen or eliminate its many consequences would not only make sense, but rightly count among the urgent imperatives of medicine and public health.? Failure to address so salient a cause of harm- a siphon of years from lives, and life from years- would simply not be an option.

One surmises, then, that such a world would reach for all pertinent evidence regarding the management of blood pressure, and bring it to bear on the problem.? Such efforts would span aspects of lifestyle from diet to exercise to stress management and the avoidance of toxins; would rightly at least consider environmental factors, both physical and social; and would, of course, strive for advances in pharmacotherapy.

There would be concomitant efforts to use all that was already known , and to advance the bounds of that knowledge with research.? We would be well within our rights and tethered to reason to expect and demand no less; best therapeutic efforts with all we knew even as we probed what we did not, because the urgency of the threat would not justify delay.? There would be heart attacks and strokes, blindness and kidney failure to prevent.

In this world, as the “anti-hypertension as medicine” movement gained momentum, what should be the primary measure of its efficacy?? The answer all but screams itself at us: changes in blood pressure .

But recall the premise; this is a world before the invention of the blood pressure cuff, or a world in which the hide-bound traditionalism of medicine opposes its adoption .? In other words: this is our world.

There was a time- in our world- when the many harms of hypertension were well known and catalogued, but the measurement of blood pressure remained rather daunting.? Intra-arterial catheters could be used with a very high cost in time, technical expertise, the risks of serious bleeding and infection, and intense pain.? The measurement would be reliable, but the aggregate price of its acquisition- very, very high.? Let us call this option valid, but not scalable.

At the other end of the spectrum, we have the pre-sphygmomanometer mucking about that passed for adjudication of blood pressure: examination of the tongue, palpation of the eyeballs.? These “guestimates” of blood pressure in eyeball-palpation-units or some such fatuous fluff were scalable, but utterly invalid.? When the blood pressure cuff was adopted, it quickly impugned the deficiencies of the methods that formerly passed for the state-of-the-art, and the standard-of-practice.?

So, Houston, and Boston, and Rochester; New York City, Los Angeles, San Diego, and Cleveland- we have a hypothetical problem in our thought-experiment world.? We are looking to launch “anti-hypertension as medicine,” but seemingly without plans, or means, to measure blood pressure.?

Two aphorisms come to mind.? The first, from the world of business, and generally attributed to Peter Drucker, is that we don’t tend to manage (at least not well) what we do not measure.? The second, of unknown origin, is that in medicine, management without measurement is malpractice.? One might debate either in the realm of edge cases, but they prevail as general truisms.

In the absence of blood pressure measurement, “anti-hypertension as medicine” would be left to look downstream, attempting to garner data for heart attacks and strokes that did not occur.? Such data capture would be better than nothing to be sure, but with grave liabilities.? There would be a long delay before validating data were in hand.? There would be a need for very large samples, and very long time horizons- and capturing absences would still prove challenging.? Most importantly, absent direct measure of the putatively “causal” factor, there would be nominal to no capacity for attribution.? In other words, if we didn’t measure blood pressure, we could not know that blood pressure improved.? Our efforts might be hinting at more strokes, or fewer strokes, but we could not, with any confidence, say how or why.?

Fewer strokes would, of course, be a good thing no matter the “how” or the “why,” but this state is very problematic nonetheless.? How does one build on gains- in scale, scope, and intensity- if one can’t tell to what those gains are attributable?? Absent the ability to gauge the particular effects of our movement, all movement tends to stop.?

The simple fact is, an “anti-hypertension as medicine” campaign absent measurement of the very thing it directly aims to ameliorate- blood pressure- would be misguided at best, at worst- a boondoggle.? Programs, potions, and practices doing nothing to improve blood pressure might all find sanctuary under the halo of an “anti-hypertension as medicine” banner, provided that the measurement of blood pressure was not required.? These would mount up until dirty bathwater prevailed, and we all lost our baby.

But of course, the measurement of blood pressure is required.?

The maturation of “anti-hypertension as medicine,” from thiazide diuretics to ACE inhibitors, exercise to the DASH diet, occurred and accelerated after the early opposition to the blood pressure cuff was overcome, and the objective measurement of blood pressure became a vital sign.? Measurement was an essential catalyst of effective management, leading to where we are today: many, many fewer preventable heart attacks and strokes .? A clear understanding of the direct impact of blood pressure on these and other outcomes.? An established ability to differentiate effective and ineffective treatments of hypertension, and to disseminate widely those that work best.? An elevation of the state of the art, and the standard or practice.

Leading, as well, back to the question with which we began: what, exactly, is “food as medicine” intended to treat?

The answer is exactly analogous to blood pressure.? Anti-hypertension-as-medicine would be preventing bad outcomes by treating “bad” blood pressure.? Improvement in blood pressure would be the one, true, direct measure of its efficacy.? Food-as-medicine is aimed at preventing bad outcomes by treating “bad” diets.? Improvement in diet quality would be the one, true, direct measure of its efficacy.

We are in the world we imagined if we replace “blood pressure” with “diet quality.”

Robust, validated measures of overall diet quality exist and are in wide use- but the House of Medicine has yet to embrace such a measure as the vital sign it deserves to be.? Why “deserves”?? Because diet quality measured objectively is not merely a predictor of chronic disease and premature death; it is THE leading predictor of chronic disease and premature death in the United States , and dozens of other countries.??

There are means of capturing these measures that vary in performance characteristics.? Suffice to say here that among those are methods that are scientifically validated ; perform reliably ; are fast and easy and inexpensive ; and scale with ease.? Leaving aside my strong personal inclinations about the preferred approach , we may simply note that if had the will to measure what food-as-medicine is aimed at fixing, there are ways readily at our disposal.

Which leads, ipso facto, to the implications of our thought experiment.?? Food-as-medicine programming that does not measure change in diet quality is exactly analogous to anti-hypertension-as-medicine programming that fails to measure blood pressure.? Grave liabilities prowl and tend to prevail, and understanding is on shaky ground, wherever attempted management parts ways with standardized measurement of the essential.

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-fin

Dr. David L. Katz is a board-certified specialist in Preventive Medicine/Public Health, and past president of the American College of Lifestyle Medicine .??He is the founder of Diet ID, Inc , which has developed and validated a fundamentally new and infinitely scalable way to conduct comprehensive dietary intake assessment, including instantaneous generation of overall diet quality by means of the Healthy Eating Index 2020.? He serves as Chief Medical Officer for Tangelo , a leading food-as-medicine company focused preferentially on the needs of underserved and food insecure populations.