Before I move on to some of the environmental and ethical questions that always surround this topic, I want to mention that last week NPR's Fresh Air featured a story about Dr. Kevin Patterson, a young internist who has spent a good portion of his career in the Arctic circle, as well as Afghanistan with the Canadian army. Over the years he noticed that while doing surgeries on Afghani patients, there was a virtual absence of body fat, both externally and internally surrounding their organs - which is a pervasive characteristic of western patients (both fat and thin). The typical Afghani male weighed about 140 pounds and were pastoralists who lived primarily on food they grew and animals they raised. He also saw an absence of any signs of diabetes, cardiovascular disease, or any arterial thickening that is also characteristic of even young Americans and Europeans. And while working in the Canadian Arctic, he watched the Inuit's (native people of the Arctic) health degenerate as they transitioned from their traditional diets of caribou, whale blubber, seal meat, and occasional berries (during their short season) to a North American based diet of simple carbohydrates and processed foods. He said that obesity, diabetes, and heart disease began to soar in these places where it was once absent.
This is just another testament to why many believe that traditional foods are the healthiest - and when I say traditional, I mean mostly a hunter/gatherer diet. Animal/plant based diets have sustained civilizations for millions of years, while modern agriculture has only existed for less than 10,000 years - coinciding with the rise of chronic diseases. The human body evolved over millions of years to digest animal foods and assimilate the proper nutrition from these foods. Our bodies have not yet adapted to cereal grains, pulses, and some other agricultural products, which is why so many people suffer from food allergies, digestive disturbances, inflammatory conditions like chrohn's and celiac disease, and chronic diseases like diabetes and cancers. This is also why you will see many semi-traditional cultures ferment these foods - so they can be made more digestible. Sourdough breads, fermented soy, soaked and sprouted grains, and soured dairy products - were all ways in which people made foods that weren't exactly natural for humans, more digestible and less harmful to the body.
But aren't vegetarian/vegan diets traditional? Well, no - except for perhaps the Jainists and some early Buddhists - although few historical texts are available from that time to provide evidence of large movements. There were many cultures that practiced abstinence of animal foods for religious and spiritual purposes, such as the Hindu practice of Ahimsa (nonviolence), and some forms of asceticism. But even today there are few cultures that practice pure vegetarianism. The Jains drink milk and dairy products, the Okinawans (contrary to popular perception) eat a lot of plant-based foods but also a great deal of fish and pork, the Mediterranean diet consists of vegetables, olive oil, fish, and guess what else? Meat! Lamb, pork, beef, chicken… are all dishes you will find on any Italian, Greek, or other Mediterranean country's plate. In poor countries, wealthier people eat meat and are taller, stronger, and live longer. Those in poor countries who live on grains (corn, rice, wheat), beans, and a few vegetables are shorter, have more developmental problems throughout their lives, and have shorter life expectancies due to malnutrition and infectious diseases. Anyone who has lived or traveled anywhere in Central and South America, Africa, and in parts of Asia have witnessed this first-hand.
So while I believe that vegetables and fruits are healthy and an important aspect to a healthy diet, they are not the whole picture. The latest articles which tout vegetarians feeling better, losing weight, and living longer also don't tell the whole story. Many of these people make big lifestyle changes that go hand-in-hand with becoming a vegetarian: more physical activity, a more spiritual outlook on life (less stress), eating more whole foods rather than processed foods, quitting smoking, drugs, alcohol, etc... Many of these factors are not taken into account when these stories are published, therefore implicating meat and animal fats as the culprit of all that is unhealthy has not been proven. In fact, it may be quite the contrary.
So while I, too, love the idea of being vegan/vegetarian, and never having to kill another sentient being for my food, I realize that this may be an unrealistic and over romanticized ideal that is frankly, a western privilege. It's easy for those of us who have had normal body and brain development as a result of our good lifelong nutrition to make a stand against eating animals when we have an overabundance of food in our lives and hundreds of meal choices. But are we really going to tell the native Alaskan who has subsisted on Caribou and whale meat, that their livelihoods are cruel and they should switch to eating tofu and bok choy? How about in south Sudan where a whole family can subsist on a cow, a goat, and growing some yams and cassava? Are you going to convince them that imported rice and beans from the Americas is the right way to go? It isn't very sustainable and sounds a bit evangelical, doesn't it.