Re-printed from the April 2010 issue of the Ester Republic.

Eating more vegetables is advice you hear a lot of these days. It is good advice in an age where people consume significantly more animal protein than is necessary, or even rational. Our culture’s unprecedented meat hunger is a top offender among the sustainability-minded, right up there with gas guzzling cars and incandescent light bulbs. As a result, vegetarianism and veganism are experiencing something of a renaissance. Many have long chosen to drop meats and other animal products from their diets, for health or even moral reasons, but many more are now doing so out as a way to “go green.” But is it true that humanity would be more ecologically sustainable if we all became vegetarians and vegans? Holding the arguments of ethics and health aside, my sense is that an entirely plant-based diet would be at least as unsustainable as the meat-heavy diets we all eat today. There are at least three reasons.

Firstly, protein is complicated. We eat food in order to remake ourselves. Our metabolism does this by assembling amino acids into proteins. There are eight ‘essential’ amino acids (11 for infants and children). That they are essential means that they are required for synthesizing proteins, but that we can only get them through diet. They occur in both meats and vegetables, but there’s a catch: not only do we need all eight, we need them in the right quantities and at the right ratios. Think of it like a recipe for chocolate chip cookies. Flour, baking soda, eggs, oil, sugar, chocolate chips, each of these are required in specific measure. Being short on any one means no cookies. In the same way, if our diet is short of any essential amino acid, protein synthesis stops.

Animal-based foods are the only place where we can get all our amino acids in the correct quantities and ratios. Anthropologist Marvin Harris calculated in Good to Eat that a person would in some cases need to eat 8-10 times the amount of some vegetables to match the contribution of meat. The difference is akin to buying a package of pre-prepared cookie dough, or buying a 5lb bag of flour, 10lb bag of sugar, 1 quart bottle of oil, a dozen eggs, and one bag of chocolate chips, to make only one batch of cookies.

To be sure, choosing the right vegetable foods can help to optimize a vegetarian diet, pairing certain grains and legumes, for instance. But few have the necessary knowledge to do so, in our society at least. A related issue is that store-bought vegetarian and vegan foods, in order to provide complete nutrition, are often the most highly processed. Indeed, these primarily soy, wheat, and corn based products are up there with the most energy-intensive foods on the market.

A second issue is that animals and animal products are essential to sustainable agriculture. Natural-systems farming is designed to mimic the function of ecosystems, and animals are a key part of ecosystems, cycling nutrients, disturbing soils, etc. Whether it is to till the soil or to fertilize it, if these new agricultural systems are going to provide sufficient food to support our populations, livestock must play a keystone role. And, with the world running out of the non-renewable resources that drive our tractors and the raw materials that are currently used to provide nitrogen fertilizer and rock phosphate, animal inputs are quite literally our only hope. Too, mimicking natural systems means that even the farmers need to be a part of the ecosystems that they cultivate; every farm family needs to eat, and this means relying on farm animals as food for the reasons described above.

The third reason I am a skeptic of global veganism is that shorter and simpler food chains often make for less resilient ecosystems. Eating down the food chain is a concept that describes a shift in diet to organisms closer to “primary production”—where energy from sunlight is converted to matter (i.e., photosynthesis). Eating smaller fish rather than larger ones, another common recommendation for a more sustainable diet, is another example. There can be unintended consequences with such a shift, however. Eating smaller fish takes the food away from the big fish, for instance, and in all likelihood we could eat our competition to extinction. Such losses are more than unfortunate; where biodiversity decreases and food webs get simpler, they often get more vulnerable to changes in climate or surprises like disease.

A similar argument could be made regarding livestock; eating only plants would be a kind of competition with livestock. Think of the hundreds of breeds of farm animals that would go extinct! And think of the loss of diversity in our food system that would result!

The point to this argument is not to pull the carpet out from under people who are quite admirably trying to bring ethics back into their food culture. I applaud such discourse and believe it an important aspect of the redevelopment of small-scale sustainable food systems. Rather, it is simply to illustrate that there is likely no one best solution. Diversity itself is likely the best principle for designing the food systems of our future. Surely we need to address both the unsustainability and immorality of contemporary industrial agricultural practices and consumptions patterns, but neither vegetarianism nor veganism provide ecological or ideological panaceas for doing so.

This entry was posted on Tuesday, May 11th, 2010 at 3:48 pm by Philip Loring and is filed under Feature Stories. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.