High-profile opinion and commentary about the value of nutrient supplementation, whether directed to the general public, or health professionals is in bountiful supply, and just keeps coming. To some extent, the cadence of such commentary may be likened to the swing of a pendulum: excesses of support (primarily from those marketing supplements) are followed by excesses of opposition (that toss out the baby with the bathwater), until the extremes of action and reaction settle toward a more temperate middle ground.
But there is a surprising deficit in nearly all of this commentary, and it’s not so much an expert answer, as an obvious question: nutrients, supplemental to what?
The very word “supplement” clearly denotes “in addition to,” rather than something that stands on its own. The whole idea of supplementation is meaningless without accounting for what is being supplemented.
The answer is as obvious as the question is neglected: diet. Nutrient supplements are intended to “add to” the nutrients we get from what remains the principal, and until very recently in history was the only, place to get nutrients: food.
Perhaps one of the reasons this question is neglected is because we have often treated supplements as substitutes, and that is certainly a mistake. While I believe the case is strong for judicious use of nutrient supplements, there is no evidence at all that any combination of supplements can do for health what diet and lifestyle can do. What I have previously termed supplemenstitution is potentially a tendency of both those selling supplements too aggressively and implying they can do far more for health than has ever been proven; and those buying them in the hope that the ease of taking a pill can replace the benefits of eating well, being physically active, getting enough sleep, managing stress, and so on. But no pill can do any such thing, so let’s just get it out there: healthy living – there is no substitute!
There is, though, another potential reason why “supplemental to what?” has mostly fallen out of the dialogue about nutrients, and that’s the difficulty in determining the nutrients people are getting from food. Dietary intake assessment methods, like food frequency questionnaires, and diet diaries, are tedious, time-consuming, and labor-intensive. They are certainly not a step manufacturers would pitch, or consumers would tend to practice, before choosing supplements.
Fortunately, that can change. I happen to have inside knowledge on this matter, because I invented a new method of dietary intake assessment and founded a company to develop it. The DietIDÔ method can establish a baseline dietary pattern, and approximate levels of roughly 150 nutrients, in less than a minute, and on a mobile device. I am not writing to promote it to you- merely to point out that new methods are needed to make “supplemental to what?” a question we can both ask and conveniently answer, and those methods are coming.
This is also, in my view, the right way into considerations of “personalization.” That is a salient theme in modern medicine, and is attracting the attention of supplement manufacturers, too. Knowing that consumers want personalized prescriptions, supplement makers are shopping the new-age means of customizing clinical care: tailoring based on genetic profiling, metabolic markers, and variations in the microbiome, to name a few. But while all of these measures are still in their relative infancy, with uncertain implications for nutrient supplementation, the relevance of nutrient intake from food to supplementation is both obvious and mature. That, in fact, is where the study of so-called “micronutrients” began: as an approach to redressing any gaps left by diet. Perhaps we are poised to go back to the future.
There are a few other important considerations that tend not to get the attention they deserve as the pros of supplementation are aired by proponents, the cons by opponents. The benefits of supplementation can be real, but very hard to prove. Consider, for instance, attempting to show that omega-3 fats are good for the heart. How would you do it?
You might randomize healthy people to omega-3s or matched placebos, but just think of how many people you would need to enroll, and how long your study would need to be, before that one difference translated into a measureable difference in the rate of, say, heart attacks. So, instead, you might do the same in people with heart disease, where events happen more often, and you thus need fewer people and less time to show a change. But now, the participants are all taking state-of-the-art medication, so the observable effects of nutrients are limited to what is “left over” to fix, after drugs do all they can. After all, it would be unethical to withhold drugs known to be effective while hoping nutrients can do the same job. The result is that real, and even potent therapeutic effects of nutrients, can be very elusive for a long time.
Related to the above is that nutrients may be less studied than drugs in the first place, because research is expensive, and patented drugs are far more lucrative than unpatentable nutrients. Much as we all like to think we are beneficiaries of evidence-based medicine, we only have the evidence we generate- and profitability plays a role in those decisions. So, to some extent, we have profit-based-evidence, and are well advised to remember that absence of evidence (i.e., a useful study that no one has yet done) is not the same as evidence of absence (i.e., actual proof that something does not work).
Yet another matter of importance is the distinction between nutrient supplements, and nutriceuticals. Supplements are intended to fill gaps; any kind of “ceutical,” whether pharma-, or nutri-, is meant to exert a therapeutic effect. So, for example, niacin in a multivitamin is a B vitamin supplement; high-dose niacin used to bring down triglycerides is a nutriceutical. There are many examples of nutrients known to exert therapeutic effects, and for that matter, many drugs and nutriceuticals are close cousins. Aspirin, a pharmaceutical, is derived originally from willow bark; the cardiac drug digoxin is derived from foxglove; just as the nutriceutical coenzyme Q10 is derived from plant sources.
Another topic often neglected in debates about the value of supplementation is the established role of fortification in public health. Fortification really is a means of supplementation that uses food rather than a pill as the delivery vehicle. It makes sense when deficiencies would otherwise be very common, when supplementation is of clear benefit, and when there are few concerns about anyone overdosing. Examples include iodine in salt, vitamin D in milk, and folate in grains. When experts contend that supplements have “no value,” they are obviously overlooking the established value of fortification as a mainstay in modern public health.
Finally, nutrients in foods work in concert, not alone- and that, too, introduces challenges. If a diet is deficient in vegetables and fruits, and thus in the plant-derived nutrients we measure routinely, is it better to supplement just certain nutrients, or the entire suite of nutrient compounds native to those foods? Standard supplements do the former job; a class of products called “whole food concentrates” do the latter. We simply don’t yet have the research needed to answer this question decisively.
Nutrient supplements are not a one-size-fits-all proposition. We will start doing a much better job of determining what makes sense for whom, and separating baby from bathwater, when we begin by asking: “supplemental to what?” You can get ahead of the curve by thinking that way now, and considering the supplements that may benefit you based on your dietary pattern and lifestyle. In case you are wondering, I supplement my rather optimal, plant-predominant diet with vitamin D; omega-3 from algae; and a probiotic. I use a few nutriceuticals selectively as well.
But this above all: even the best chosen supplements are in addition to, not instead of, the most healthful dietary pattern you can adopt. Remember that when it comes to lifestyle as medicine, there simply is no substitute.
David L. Katz, MD, MPH, FACPM, FACP, FACLM, is the Founding Director (1998) of Yale University’s Yale-Griffin Prevention Research Center, and former President of the American College of Lifestyle Medicine. He has published roughly 200 scientific articles and textbook chapters, and 15 books to date, including multiple editions of leading textbooks in both preventive medicine, and nutrition. He has made important contributions in the areas of lifestyle interventions for health promotion; nutrient profiling; behavior modification; holistic care; and evidence-based medicine. David earned his BA degree from Dartmouth College (1984); his MD from the Albert Einstein College of Medicine (1988); and his MPH from the Yale University School of Public Health (1993). He completed sequential residency training in Internal Medicine, and Preventive Medicine/Public Health. He is a two-time diplomate of the American Board of Internal Medicine, and a board-certified specialist in Preventive Medicine/Public Health. He has received two Honorary Doctorates.