The US Office of Disease Prevention and Health Promotion, Department of Health and Human Services, has issued a report recommending that Americans eat less meat. The executive summary of the report is here (pdf), and the web site for the report is here. It says,
The overall body of evidence examined by the 2015 DGAC identifies that a healthy dietary pattern is higher in vegetables, fruits, whole grains, low- or non-fat dairy, seafood, legumes, and nuts; moderate in alcohol (among adults); lower in red and processed meat; and low in sugar sweetened foods and drinks and refined grains. Vegetables and fruit are the only characteristics of the diet that were consistently identified in every conclusion statement across the health outcomes. Whole grains were identified slightly less consistently compared to vegetables and fruits, but were identified in every conclusion with moderate to strong evidence. For studies with limited evidence, grains were not as consistently defined and/or they were not identified as a key characteristic. Low- or non-fat dairy, seafood, legumes, nuts, and alcohol were identified as beneficial characteristics of the diet for some, but not all, outcomes. For conclusions with moderate to strong evidence, higher intake of red and processed meats was identified as detrimental compared to lower intake. Higher consumption of sugar-sweetened foods and beverages as well as refined grains was identified as detrimental in almost all conclusion statements with moderate to strong evidence.
I’m thinking it will be the food you eat that gets you. Here’s why.
Humans eat a wide variety of foods; as a species, the diversity of species we eat is greater than any other animal by a very large margin, with the only quirky exception being the animals that we take along with us, the commensals such as rats and cockroaches. Most primates eat a high diversity of foods, but about two million years ago or a bit less, according to the “Cooking Hypothesis” (which a lot of people think is correct) we took an already diverse primate diet and added to it anything we might encounter in the environment that could be made edible with heat and added that to our diet. More recently, beginning about 10,000 years ago, we applied additional technology and the new practice of plant husbandry to convert other foods, some edible some not, into more useful items for our diet. Humans around the world did this independently over several thousand years, in parallel.
Then we got boats that were capable of doing magical things like sailing up wind, and navigation technologies that allowed humans to be less lost when doing so over great distances. Some humans had done this much earlier at a smaller scale, but by the 15th century there were big wooden boats criss crossing the seas, bringing people to places they had never been before, and along with them the foods people ate all over the world.
Have you looked at photographs of traditional people living in traditional, seemingly timeless, ways in places like Africa, the Amazon, or New Guinea? Look again, and focus on the things that form the backdrop for the scenes shown in those photographs. One of the things you’ll see in many pictures is the plantain, or the banana. You might notice the huge elephant ear leaves of taro plants. If you look closely you might notice cassava growing in the fields, or maize.
Maize was domesticated in Mexico, taro, plantains, and bananas in various different locations across south and southeast Asia. Cassava comes from the lowlands of South America, and potatoes come from the Andes. Some Yams come from Africa, some from South America (I oversimplify a bit). You can’t find a modern traditional diet, as it were, that does not include ingredients from continents other than where the traditional diet lives today, except perhaps in Ethiopia. Everybody eats everybody else’s food all the time. The main determinant of where food is grown is not where it was first domesticated, but rather, the limitations of seasons, rainfall, heat and cold. And even there, the limitations are relaxed. Maize only grows in the colder regions because varieties have been developed to do so, and many plants are grown in regions normally too arid for them, by virtue of irrigation.
Adding all this up – the diverse primate diet, the addition of cooked foods otherwise not edible, the artificially selected crops, and the global exchange of horticultural goods and practices – and you get a huge variety of food, the largest variety of food any species has ever managed to include in its diet. (Other than the rats and cockroaches, of course.)
Despite all this diversity, something has remained more or less the same all along. The “traditional” diet for humans, though much altered with cooking, is relatively low quality. I use the term “low quality” in the way an ecologist uses it. How many usable calories do you get out of a kilo of the food item under consideration? Or, related, how much work do you, using food preparation, chewing, and digestion (including the work done by the friendly microbes living in your gut) to convert that kilo of food into energy?
It is easy to see how our traditional diets are low quality by comparing them to the diets of a handful of primates that live almost entirely off of insects, or tree sap, or nectar. If we look at birds, we see the same thing; many species of birds eat pure sugar of one form or another. A few other animals have very high quality diets. Generally, carnivores have higher quality diets than herbivores. There are no carnivores that use multiple stomachs or habitually regurgitates and re-consume their animal prey in order to digest it. Herbivores that eat grass or leaves spend a lot of time feeding, have massive digestive systems designed by natural selection to digest the hell out of the food, and sometimes they have to “eat” the same food multiple times to get enough energy out of it to survive. Humans are somewhere in between. Some of our digestion is done pre-consumption by cooking and processing, but for the most part our natural, traditional diet takes a fair amount of work to process. We don’t live off of sugar water like hummingbirds and many insects do.
And this is why the leading cause of death in the United States and some other countries has shifted from the usual panoply of causes – infectious disease, accident, homicide, etc. – to our diets. Our diet is the most likely thing to kill us, and lately, the primary mediating factor in this particular cause of death is obesity and/or diabetes.
The “traditional” diet of any group of people, as I’ve already outlined, is relatively recent historically, being the result of 10,000 years of developing plants and a few hundred years of transferring crops and growing methods across the world. That traditional diet was prominent globally through the 19th century and well into the 20th century. The food came from farms, and although many amazing novel technologies were being applied on those farms, such as better plows and various other things that could be drawn behind oxen, a team of ponies or horses, or a small tractor, those technologies did not change the diets too much.
But as technologies developed, farms began to scale up. This is the reason that the New England countryside is graced with young forests criss-crossed with quaint stone walls. Those stone walls were field boundaries in the old days. But as farming scaled up, it became economically inviable to have small fields on small farms. A few other things went wrong on some of these New England farms as well, including some climate glitches and some other economic effects that drove farmers off the land and in some cases into cities where there were jobs working in mills. But some of those farmers took part in the great Westward Migrations, as the country grew, and established a new kind of agriculture in the vast regions of the midwest and plaines.
Add a growing urban market for foods, government help in the form of extension and agricultural colleges, more technology such as combines, railroads to move produce to market, mills to process the produce, add some water (irrigation) as needed and salt to taste. It took decades, but we went from an agrarian economy where the same traditional diet we had been eating was produced on a somewhat larger scale, to an agricultural economy that produces mostly one single thing. This product:
OK, I’m exaggerating there. It isn’t really true that the entire US agricultural system has been converted over to the production of sugary drinks. But sometimes it seems that way. Vast expanses of corn are grown in the midwest and plains, and that corn is used to produce vast amounts of ethanol (as fuel), alcoholic beverages, sugary substances including cola, feed for animals, and some of it even makes it to the table as … well, corn. But lets step back to the original comparison of “traditional diet” and the diet many Americans eat today.
When you eat a traditional meal, a good amount of that food is low quality, relatively hard to digest, carbohydrates with a mix of proteins. There will be a little simple sugar here and there and a bit of fat here and there.
The simple sugars go right away to the liver, where they supplement the body’s immediate energy stores. The complex sugars, the carbohydrates that consist of much larger and more involved molecules, take time to digest and break down to eventually use as fuel. So the sugar gives you a small amount of immediate energy and the complex carbohydrates give you energy over the coming hours.
The fats are simply stored up. If you eat fat, the fat molecules are minimally processed, moved to your hips or wherever, and are pasted there for later use. Or, forever, depending.
When you eat a modern diet, it will have two major difference from the traditional diet. The foods at the two ends of that spectrum of availability will be in greater proportion. Instead of having a bunch of low quality food in the middle, with a little fat (for later) on one end of the spectrum, and a little simple sugar (for immediate use) on the other end of the spectrum, the modern diet will have piles of fat and piles of simple sugar and not much in between.
So, what happens? The fat goes where fat goes, as stated already, but there is more of it. The sugar overloads the liver, which detecting an overabundance of energy, converts the sugar to some form of storage, and some of that is fat that joins up with the other fat. There is also a kind of molecule the liver converts some of that sugar into, stored in your liver, for in case you get hungry between meals. That molecule reduces the chance your body will use any of that stored up fat as energy.
Two thousand traditional calories provides you with energy for now, energy for the next several hours, and a bit of energy for much later. Two thousand modern calories provides you with way more energy than you need for now, and a huge amount of fat that you’ll never use because you are never going to let much time go between meals. Because there is a fast food joint just down the street. And your refrigerator and cabinets are full of junk food.
And that’s not all. Our system of agriculture has all sorts of other negatives as well. The following is from the Food and Agriculture page of the Union of Concerned Scientists:
Food and Agriculture: Toward Healthy Food and Farms
Our agricultural system has lost its way.
Millions of acres of corn, soybeans, and other commodity crops, grown with the help of heavy government subsidies, dominate our rural landscapes.
To grow these crops, industrial farms use massive amounts of synthetic fertilizers, herbicides and pesticides, which deplete our soil and pollute our air and water.
Much of this harvest will end up as biofuels and other industrial products—and most of the rest will be used in CAFOs (confined animal feeding operations) or in heavily processed junk foods, which seem cheap only because their hidden costs don’t show up at the cash register.
Industrial agriculture is unhealthy — for our environment, our climate, our bodies, and our rural economies.
A Better Way: Sustainable Agriculture
There’s a better way to grow our food. Working with nature instead of against it, sustainable agriculture uses 21st-century techniques and technologies to implement time-tested ideas such as crop rotation, integrated plant/animal systems, and organic soil amendments.
Sustainable agriculture is less damaging to the environment than industrial agriculture, and produces a richer, more diverse mix of foods. It’s productive enough to feed the world, and efficient enough to succeed in the marketplace—but current U.S. agricultural policy stacks the deck in favor of industrial food production.
Yesterday, I went to a symposium hosted at the Humphrey Institute at the University of Minnesota and organized by the Center for Science and Democracy at the Union of Concerned Scientists. A description of the symposium is here and the entire thing was “taped” and will be available. I’m not going to tell you anything major about the symposium now; I’ll wait until the video is available, then I’ll provide you with my thoughts on it. For now I’ll just say it was quite good, eye-opening, and that you’ll definitely want to watch it. In fact, you should feel a little bad that you weren’t there.
Somebody tipped over a bag full of a white powdery substance. Most of what fell out splayed across the dirty wooden table, but about a cup poured onto the dirt floor of the open-air Baraza at our research site in a remote part of the Congo’s Ituri Forest. Embarrassed about tipping onto the ground more of this valuable substance than most people living within 50 kilometers would ever see in one day, the tipper started to push loose dirt onto the powder to cover it up. But the spill had been noticed by two children lounging nearby; in what seemed like a fraction of a second, the boys were face down on the ground licking up the spilled material, taking with it mouthfuls of dirt and who knows what parasites and other kooties. It was a sudden and short lived fiasco and a scene etched hard into my mind. To this day, decades later, when I think of this I breathe a sigh of relief that it was not me who tipped over the bag of white sugar.
These kids and everyone else in the Baraza that day were very familiar with sugarcane. Everyone grew at least a little. Sugarcane was to the Ituri Forest villagers what Hastas is to urban gardeners in the US. Everyone grew at least a little where it would fit and not get trampled or take up extra gardening space for real food.
The sugarcane was eaten raw. You would use a machete to cut a off a long section of the giant grass plant, and carry it around. With your teeth or with the help of a knife you would slice open a section of the cane and chew on it, sucking out the sweet water inside. When the sugarcane was ripe, the pathways and, really, any open surface would be littered with spent wadges. But still, not much sugarcane is grown in the Congo compared to other crops then or now. Sugarcane, originally from the Pacific and India, was, however, grown for centuries in large quantities where it was transplanted in the New World. You probably know of it as one of the vertices of the Triangle Trade (sugarcane = rum). But there is still a connection to these kids, the two who scarfed up the dirt and sand and sugar spilled on the baraza floor.
No sense sugar-coating it. The story of sugar is the story of slavery. The Congo was probably not the biggest source of slaves for the Caribbean and South America. The eastern Congo, especially, was on the Indian Ocean slave route. But generally speaking, West and Central Africa supplied millions of people, captured, owned and sold, to the sugar plantations of the Caribbean. Over the centuries since its introduction to West Asia and Europe, and by extension, the New World, sugar grew in importance from a rarity to a common element in the diet, often carrying with it symbolic importance as an indicator of class or by its use in food art. Sugar is distilled and concentrated solar energy that preserves well and is easily transported. The production and distribution of sugar is one of a handful, maybe the most important of engines for the rise of Immanuel Wallerstein’s global system (that I almost did my PhD on by the way).
You’ve got to love it when a molecule changes history. Primates (and a few other groups of animals) lost their ability to synthesize and use ascorbic acid because fruit producing plants had evolved to have their seeds dispersed in exchange for Vitamin C rich pulp. Therefore, the British Mercantile System. Similarly, C12H22O11, one of a class of molecules used by plants to store energy (and sometimes entice monkeys or ants to do their bidding) drove the most momentous of historical changes and its production, in one form or another, makes up an inordinate percentage of the effort expended to feed our species.
Nobody really questions the importance of sugar, but how aware is the average person of the details of its sweet success? More so than before for those who have read Elizabeth Abbott’s “Sugar: A Bittersweet History.” Before you go check and yell at me for not restricting my writing to things that happened during the last five minutes, I’ll admit that the book came out in 2010 and I’ve only just now noticed it. I was focusing on other things, I promise. But I am pretty sure that no major revisions of history of the last thousand years or so have been made that would make this engaging book out of date or less relevant.
We all like to consume knowledge, but if you also like knowledge of what you consume you should read this book. It will make you feel bad, and likely awed, but also, a lot smarter, hopefully enough to offset the shame.
One of the most important things that ever happened in history is really a category of things and took a few centuries. This was the transplantation of crops and to a lesser extent horticultural technologies across the globe beginning with the Portuguese and extending at a quickened pace with all the major colonial ventures. This is probably more pervasive than you think. The lifeways and culture of the Yanomamö were greatly transformed, in my opinion, buy the introduction of south and southeast Asian (and possibly African) crops, mainly the plantain. The earliest records suggest that the Yanomamö were foragers, but all the later ethnography shows them as horticulturalists. The difference between “typical” equatorial foragers and the Yanomamö may well be the inclusion in their economy and society of a key crop that is also a highly vulnerable resource. Vulnerability of one’s resource base can shape one’s attitude at the socio-cultural level. What crops are mainly grown in swidden fields in Africa? South American ones. There would have been no Irish potato famine had there been no potatoes. They come from the Andes. And as mentioned sugar/rum was one of the vertices of the Triangular Trade and along with a few other crops (like Cotton) formed the agricultural structure of the slave-based economy that made up the largest single capital component of the rise of the United State’s economy. If the modern US economy is the fat bank account, slavery was the first big deposit in that account and New World Slavery happened because of this small number of transported crops.
By the twentieth century, sugarcane had circled the globe, traveling north and west from New Guinea then back again to the Pacific, and its legacies mark its global passage even where it is no longer grown… In the Caribbean, where King Sugar is now expiring as a major industry … and where most former colonies have become independent, political and commercial unions remain skewed along historical lines. Sugar culture is at the root of why Afro- and Indo-Trinidadians and Guyanese are mired in political enmity, why Hawaii and Fiji endure perpetual conflict between their Native and their Asian populations and why the official currency fo Mauritius, off the coast of Africa, is the rupee and its population is primarily Indian…
It is a good book. Overlook Publishers, available for the Kindle. I am probably going to work this into this week’s lecture in Intro to Archaeology.