Blog | Monday, June 15, 2015

The family dinner

The family dinner may itself be an endangered species in this modern era of fast food, electronic distractions, and isolated eating on-the-fly. The composition of that meal may be among the reasons other species are endangered, and that confluence is today's harangue. But we may begin with our own species.

We know what Homo sapiens should eat.

In this context, “should” has no moral implications, despite our tendency to think of diet and health as expressions of virtue, and the vexing modern proclivity to defend competing dietary dogmas with nearly religious zeal. There is a basic way Homo sapiens should eat, just as there is a way that koala bears, giant pandas, and spiny anteaters should eat. All creatures should eat some variant on the theme of the dietary pattern to which they are adapted. A diet in accord with adaptations tends to foster health; a diet at odds with native requirements tends to conspire against it. Lions must eat meat; caribou cannot.

The basic dietary pattern to which our species is adapted is reasonably clear. Clearer still are the variations and theme of optimal eating decisively associated with human health and longevity. Despite our penchant for emphasizing, in books and television segments and daily headlines, the minor differences among contenders for best diet laurels, and our comparable predilection for exaggerating the importance of each isolated study to issue, the fundamentals of healthy eating are both clear and consistent. They are the product of scientific research spanning decades, diverse methods, and widespread populations. They are validated by real-world experience in large populations. They are the product of both science and sense, evidence and consensus, cultural traditions and time-honored practices. We are not clueless about the basic care and feeding of Homo sapiens.

Our species is constitutionally omnivorous, and has been so since even before our species became one. According to the best anthropological evidence and thinking, Homo sapien antecedents, such as Homo erectus, were hunter-gatherers as well. If our ancestry is extended back far enough, we become vegetarian or very nearly so, as are most of our extant primate cousins. But we clearly have physiologic adaptations for a mixed diet, and perhaps even specific adaptations for the ingestion of cooked meat.

Exactly how important hunting has been to our lineage remains a contentious area for paleoanthropologists. Some use the traditional appellation, “hunter-gatherer,” to place emphasis on hunting in the first position, and the relative primacy of animal foods in our native diet. Others, however, flip that order, and contend that gathering was the greater brace for our Stone Age sustenance.

As is true of so much else in nutrition, that discord masks the greater and more salient accord. Expert paleoanthropologists debate whether plants provided the majority of our calories, or just half, but all agree that our native diet was comprised principally of wild plants and the flesh of wild animals. Domestication of other species had not yet been invented.

So, our traditional diet is limited to real foods, direct from nature. There were no added sugars- other than what little honey we wrestled from the bees. There were no artificial sweeteners. There were no food chemicals. There was no trans fat.

As for meat, it was obtained from animals that in turn had recourse to their native conditions. They were wild animals that roamed their native, wild spaces; exercised their muscles in the various imperatives of survival; and ate their own diet, generally wild plants. There were no factory-farmed animals, fed an expediently non-native diet, denied space to move, dosed with antibiotics and hormones as profits dictate, or subject to indifference or even brutality during incarceration or at slaughter.

The familiar expression, “you are what you eat,” has a corollary we all too often ignore: what we eat is what it eats. In light of this consideration, the meat that predominates today in the typical American diet is nearly as different from its native lineage as is high-fructose corn syrup from that apple in Eden. By means of illustration, the flesh of grain-fed, sedentary cattle may provide as much as 35% of calories from fat, much of it saturated. In contrast, the flesh of antelope, thought to resemble that of our Stone Age prey animals, provides as little as 7% of calories from fat, nearly all of it unsaturated, and some of it omega-3. So-called “fish oil” only became that once we had domesticated it out of other animals.

Whatever the arguments for meat in the human diet, they should pertain to the kind of meat that is native to that diet. The meat intake of modern cultures is a marked departure.

But there is another, more radical distinction between the dining of modern humans and that of our Stone Age forebears. They did theirs in scattered, isolated clans surrounded by vast, wild spaces. We do ours as members of a voracious, planet-wide horde. For the current population of over seven billion Homo sapiens to make a living the Stone Age way would require roughly 15 times the surface area of our planet, and even that assumes we could hunt and gather over every square foot of it, from the South Pole to the Sahara.

Eating is more than just sustenance, of course; it is a medium of social exchange as well. Food has always been central to human concourse. In modern context, as social traditions are anachronized with increasing expedition, we have evidence to suggest advantages in going occasionally back to our future. Family meals, for instance, are associated with better dietary practices and health than eating in distracted isolation.

There is cause now to expand the definition of that family, as the concerns of public health and conservation converge. Sustainability is, rightly, a consideration in dietary guidance. Climate change may now be so salient a menace to humanity that the infamous imperium of chronic diseases may need to surrender to it. That does not suggest we should choose between them, but rather look for strategies that can address both.

Among such strategies is the adoption of the very dietary pattern most decisively associated with human longevity and vitality: wholesome foods close to nature, predominantly plants, in various, time-honored, sensible combinations. A more plant-based, and less hyper-processed diet offers advantages far beyond chronic disease prevention, extending to sustainability of food sources; reduced environmental degradation; less propagation of antimicrobial resistance; reduced fresh water depletion; kinder, gentler treatments of any animals we do raise for food; and conservation of wild spaces required to protect biodiversity.

That last consideration may seem to be more about them- those other species- and less about us. But there is no meaningful distinction. The forests that produce our oxygen are in turn dependent on animal species that are sustained by them, and pay it back in various ways, such as by dispersing seeds. The vast interdependence of life is a bedrock principle of biology, from bees to buffalo to banyan trees. As glaciers melt and sea levels rise, our fellow species and we will sink or swim together.

E.O. Wilson, a Harvard biologist and Pulitzer Prize winner, puts it compellingly well in The Social Conquest of Earth:

The obliteration of biodiversity in the living world has received much less attention than climate changes, depletion of irreplaceable resources, and other transformations of the physical environment. It would be wise to observe the following principle: if we save the living world, we will also automatically save the physical world, because in order to achieve the first, we must also achieve the second. But if we save only the physical world, which appears our current inclination, we will ultimately lose them both.

How Homo sapiens choose to eat has profound implications for our own medical destinies. But what's for dinner and who has a seat at the table reverberates beyond the years in our lives and the life in our years, to the fate of virtually every other species as well. That, in turn, has implications for our own survival as a species, and any hope we have of bequeathing to our children and grandchildren a world in which they may hope to thrive.

All of life is an extended family, at 1 remove or another. As is the case for the nuclear family with which we share our daily intimacies, members of this extended family are interdependent, and the family dinner has implications for us all.

We should chew on it accordingly.

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.