I have been privileged this past week to preside one final time as President over the annual meeting of the American College of Lifestyle Medicine, held at a lovely venue in Naples, Florida. The venue is special not just because the hotel did such a fine job hosting us and satisfying our demands for delicious, nutritious, plant-based fare, nor just because of the long boardwalk through mangroves to the beautiful, powdery beach on the Gulf of Mexico. This area, with leadership from local healthcare systems, is a Blue Zones Project, working to turn the habits of the longest-lived, most vital people on the planet into blue prints for new, local norms. What a perfect place to celebrate the primacy of lifestyle in health!
At my initial suggestion, our conference theme this year was Healthy People, Healthy Planet. I wanted to showcase to our membership, and learn more myself about, the implications of human lifestyle choices for not just our own health, but that of everything around us.
My hopes in this area were richly fulfilled, as leading experts from around the world gave illuminating talks on chronic disease, emerging infections, climate change, water supply, biodiversity, soil quality, sustainable agriculture, and more- and how they all relate to the behavior, and in particular dietary choices, of the roughly 7.5 billion Homo sapiens currently on the planet.
This particular professional college traces its lineage to faculty at Loma Linda University, home to the famous Seventh Day Adventist Study, and has always placed a very strong emphasis on plant-based diets for preventing, treating, and reversing chronic disease. I have respected this for the simple reason that it is just where the weight of evidence inclines. But, I have also pushed back against the tendency, whenever and wherever I've seen it, to make claims past the margins of that evidence.
I won't belabor that case here- I've made it many times before, in columns, in peer-reviewed papers and invited commentaries, in an entire textbook, and in the best of company. The evidence regarding diet for human health extends to variations on a broad theme of minimally processed foods, mostly plants, in sensible combinations that are often time-honored, and rooted in heritage and cultural practices.
But this is just the evidence related directly to human health. There is a critical, indirect consideration at one nominal remove: what about the health of the planet? There is, quite simply, no human health left to worry about on a planet no longer hospitable to our species.
That danger truly looms, and more proximally than most of us care to admit. The case was made in its alarming particulars by a veritable parade of luminaries to our conference podium.
Dr. Samuel Myers, director of the Planetary Health Alliance, talked about the many interactions between human lifestyle choices and the health of ecosystems. He then completed the circle in several vivid examples from fieldwork around the world, showing how perturbations of ecosystems often translate into human health threats, from emerging infectious disease, to respiratory disease- a salient issue in Indonesia as rich forests are felled for palm oil production, and the smoke chokes Singapore. Perhaps the greatest surprise in Dr. Myers' presentation was elegantly gathered evidence showing that higher carbon levels in the air, regardless of effects on climate, translate directly to lower nutrient levels in plants- including nutrients already consumed at inadequate levels by millions of people around the world, notably iron and zinc.
Refreshingly, Dr. Myers also called out the routinely overlooked elephant in the room: the size of the global human population. The combination of a growing human population, and growing access to ever more manufactured goods by each of us, is a formula for catastrophe. We must do all we can to stabilize the global population at current levels, and shift our demands for goods and services to those that do not ravage the planet in the making.
In passing, Dr. Myers also noted that animals raised in human agriculture outnumber people by at least 10 to 1. So as we assault the planet by the billions, they do so at our behest in the tens of billions.
Danielle Nierenberg, founder of Food Tank, took us on a worldwide tour of small-scale, agricultural innovations that show promise in defending us against food insecurity, soil degradation, and the civil unrest that ensues when people are hungry and thirsty. All such roads around the world lead to an emphasis on plant foods, grown in variety. They also lead, it's worth noting, to an emphasis on parity and respect and empowerment for women across all cultures, as women figure so prominently in food production where it's needed most, yet face considerable disadvantages in accessing the needed resources.
Dr. Richard Oppenlander took these worries up a notch, highlighting the confluence of immediately urgent threats to the stability of natural systems around the world. The simple message is the most inconvenient of all truths: our species, so good at propagating extinction, could certainly be the architect of our own.
Even as the planetary issues were elaborated, talks in our customary purview- human health- reaffirmed the principles of healthy living to which the College, and the True Health Initiative, are pledged.
We were honored to host Dr. Erkki Vartiainen, Director of the National Institute of Health and Welfare in Finland, and co-director of the rightly famed North Karelia project. Dr. Vartiainen took us through nearly 50 years of data, showing how interventions to reduce saturated fat intake and blood cholesterol levels, salt intake and blood pressure, and tobacco use have translated into stunning improvements in health and life expectancy. With the most recent data, however, he revealed that as the North Karelians buy into some of the currently popular memes, like “butter is back,” with attendant changes in diet, heart disease rates are creeping back up for the first time in decades.
Dr. Christopher Gardner, Director of the Prevention Research Center at Stanford University, shattered myths about the need to eat meat to get adequate protein, and highlighted the opportunity to put the joy of delicious food in the vanguard of efforts to move toward health-promoting, planet-friendlier, plant-predominant diets.
Dr. Michael Greger made a compelling case (with customary lilt and panache) for the capacity of the status quo to deny what in time become self-evident truths, using the history of tobacco to illustrate. Caught up in the denial of tobacco's terrible harms were not just the obvious industries and usual suspect, including athletes, actors, and individual doctors- but the formal structures of medicine, like the AMA. The evidence was available, but lots of money was in play- and the weight of evidence was long disregarded, as people died.
The parallels with food today are striking. Big Soda uses money to fight soda taxes, obscure the obvious connection of their signature product with obesity and diabetes, and try to influence our understanding of energy balance itself. Big Sugar has, we learned recently, has long fought to limit the list of crimes against human health for which they are held to account.
Big Dairy has long made sure there is a wedge of cheese in every formal dietary recommendation. Big Beef not only fights to include meat in all dietary guidelines, but against all reason and decency, fought effectively to expunge any consideration of sustainability. And again, the major health organizations, from the USDA to the NIH, to the AHA, are somewhat complicit in denial of the truth.
That simple, environmental truth is that we must eat less meat- much less. This is the truth both for those long favorably disposed, and for those who find it monumentally inconvenient. The truth is not a contestant in a popularity contest; it's just the truth. Many of the environmental scientists revealing this truth are not yet vegetarian, and many in this conversation don't want to be- but they are doing what honest scientists do, and following their data where they lead.
The audience of diverse health professionals at our meeting was, by all indications, inspired to do everything in our collective power to propagate the message, and advance the mission: diet and lifestyle can, and therefore must, change at scale to help save the planet. In case you want in on it right away, two direct substitutions would make an excellent start: drink plain water instead of soda, and eat more beans and lentils in the place of all varieties of meat, but especially beef.
There has, indeed, long been a reasonably broad theme representing “the” optimal diet for human health, couched within a small portfolio of other lifestyle practicesdiverse authorities call by different names, but prioritize in common. The planet's many imminent perils, and unchecked population growth may, however, be narrowing down our dietary options rather rapidly. This is directly analogous to human health threats. When a person is still mostly healthy, there tend to be many ways to stay that way. The treatments for advanced disease are much more narrowly circumscribed. What happens to patients in ICUs is generally unpleasant, and highly protocolized. The planet is fast headed toward the ICU.
Fortunately, the imperatives of lifestyle for our own health promotion are highly confluent with the needs of the planet. Experts tell us, however, that the needs of the planet may be more urgent, and less accommodating. For now, we can address both by moving our diets away from processed foods, soda, and animal foods, and toward ever more vegetables, fruits, beans, lentils, nuts, seeds, whole grains, and plain water. It may not be too long, though, before a planet of both the starving and the obese, of parched fields and rising seas, of rising temperatures and dwindling aquifers, of dying birds and bats and bees- leaves us no choice at all.
Epilogue: I recognize the above may seem a bit gloomy, and rightly so; but all is not lost. We are, alas, very late to this party- and even now willing to consider, at least, electing a President of the United States who overtly denies climate change is even happening. That we will undo enough to reverse our calamitous momentum seems all but impossible. But we are an ingenious species, and along with what we fix by undoing our mistakes, I am hopeful, and even optimistic, that we will fix much more by exploiting our inclination to invent. I am admittedly non-expert in this area, but I envision new technologies, and soon, running on carbon-neutral, renewable energy sources already available, that are used to sequester and repurpose atmospheric carbon; desalinate our rising seas and produce abundant fresh water; systematically divert food waste into constructive use; and more. To borrow a line from The Martian, in the face of overwhelming odds, we are going to have to “science the sh#@ out of this,” and I believe we can. I believe we will. But as we count on our engineers to “science” us out of this mess of our own devising, none of us should spend another day blithely propagating the problem; it's plenty big enough already to test the limits of our ingenuity.
David L. Katz, MD, FACP, MPH, FACPM, is an internationally renowned authority on nutrition, weight management, and the prevention of chronic disease, and an internationally recognized leader in integrative medicine and patient-centered care. He is a board certified specialist in both Internal Medicine, and Preventive Medicine/Public Health, and Associate Professor (adjunct) in Public Health Practice at the Yale University School of Medicine. He is the Director and founder (1998) of Yale University's Prevention Research Center; Director and founder of the Integrative Medicine Center at Griffin Hospital (2000) in Derby, Conn.; founder and president of the non-profit Turn the Tide Foundation; and formerly the Director of Medical Studies in Public Health at the Yale School of Medicine for eight years. This post originally appeared on his blog at The Huffington Post.