With all due repect to Dr. Heaney in the above letter, his claims critical of meatless diets are not factually correct. For writings by doctors who are knowlegeable about these issues, I would recommend the work of Neal Barnard, M.D., Dean Ornish, M.D., John McDougall, M.D., Michael Klaper, M.D., and others.
As was mentioned in the comment above, even the very mainstream American Dietetic Association, the main professional association for registered dieticians in the United States, acknowledges the safety and many health benefits of vegetarian/vegan diets. They state:
"It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the life cycle, including pregnancy, lactation, infancy, childhood, and adolescence, and for athletes.... The results of an evidence-based review showed that a vegetarian diet is associated with a lower risk of death from ischemic heart disease. Vegetarians also appear to have lower low-density lipoprotein cholesterol levels, lower blood pressure, and lower rates of hypertension and type 2 diabetes than nonvegetarians. Furthermore, vegetarians tend to have a lower body mass index and lower overall cancer rates. Features of a vegetarian diet that may reduce risk of chronic disease include lower intakes of saturated fat and cholesterol and higher intakes of fruits, vegetables, whole grains, nuts, soy products, fiber, and phytochemicals."
For the full ADA statement, see the PDF link at http://www.eatright.org/about/content.aspx?id=8357
I'm an online subscriber, yet unable to access the full article, Made for Meat or Food for Thought. Hopefully, I'll be able to read them in the future.
Meanwhile, as a vegetarian for 10 years and a vegan since 2006, I can say with confidence that a nutritious plant food diet is quite healthy. if not healthier than a diet that includes animal products. The American and Canadian Dietetic Associations have found that vegetarian and vegan diets can meet recommendations for protein and nutrients: http://www.ncbi.nlm.nih.gov/pubmed/12826028
With all due repect to Dr. Heaney in the above letter, his claims critical of meatless diets are not factually correct. For writings by doctors who are knowlegeable about these issues, I would recommend the work of Neal Barnard, M.D., Dean Ornish, M.D., John McDougall, M.D., Michael Klaper, M.D., and others.
As was mentioned in the comment above, even the very mainstream American Dietetic Association, the main professional association for registered dieticians in the United States, acknowledges the safety and many health benefits of vegetarian/vegan diets. They state:
"It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases. Well-planned vegetarian diets are appropriate for individuals during all stages of the life cycle, including pregnancy, lactation, infancy, childhood, and adolescence, and for athletes.... The results of an evidence-based review showed that a vegetarian diet is associated with a lower risk of death from ischemic heart disease. Vegetarians also appear to have lower low-density lipoprotein cholesterol levels, lower blood pressure, and lower rates of hypertension and type 2 diabetes than nonvegetarians. Furthermore, vegetarians tend to have a lower body mass index and lower overall cancer rates. Features of a vegetarian diet that may reduce risk of chronic disease include lower intakes of saturated fat and cholesterol and higher intakes of fruits, vegetables, whole grains, nuts, soy products, fiber, and phytochemicals."
For the full ADA statement, see the PDF link at http://www.eatright.org/about/content.aspx?id=8357
Some further considerations: B12 is synthesized by bacteria in the digestive systems of humans and nonhuman animals. We don't make enough B12, so we need to get it from another source. Most people rely on animal products. But how much B12 is in these products is questionable, since farm animals who lack sufficient amounts of cobalt in their diets and in the soil, may develop B12 deficiencies.
http://www.vetsweb.com/diseases/cobalt-vitamin-b12-deficiencyd263.html#causes
B12 is also found on unwashed plant foods. We wash produce, but for eons our ancestors didn't, which means meat was not their only source of B12. Human anatomy more closely resembles herbivores, than either carnivores or omnivores. http://www.theveganlife.com/articles/comparative-anatomy.html We also make our own cholesterol and some other important nutrients.
For these reasons, I don't think we evolved to eat meat.
Nina Planck is not a dietician -- she's a farmer's market entrepreneur, in the business of selling animal products. The dairy products she claims people can't live without are not free of suffering and they very much involve slaughter. http://www.humanemyth.org