The World Health Organization (WHO) recently declared processed meats a cause of colorectal cancer, the second-leading cause of cancer deaths in the United States, and conceivably a cause of stomach cancer. The International Agency for Research on Cancer (IARC), a group of international experts, published this finding and named red meat a “probable” cause of cancer as well. The meat industry, however, poses a myriad of threats to human health beyond its carcinogenic properties. The U.S. food production system uses about 50 percent of the total U.S. land area, approximately 80 percent of the fresh water, and 17 percent of the fossil energy used in the country.
The report by IARC said 50 grams of processed meat a day (less than two slices of bacon) increases the chance of developing colorectal cancer by 18 percent. Processed meat is meat that has been modified to either extend its shelf life or alter its taste. Common processing methods include smoking, curing and adding salt or preservatives. High temperature cooking can also create carcinogenic chemicals. The publication is not unlike past research on the health effects of meat consumption. The Academy of Nutrition and Dietetics found that vegetarians and vegans have a “lower risk of death from ischemic heart disease, lower blood cholesterol levels, lower blood pressure, lower rates of hypertension and type 2 diabetes, lower body mass indexes as well as lower overall cancer rates.”
Meat production also has a marked effect on the environment. Methane produced by cows contributes enormously to air pollution, while grazing animals leave once fertile land barren and unusable. Each cow on average releases between 70 and 120 kg of methane per year. Methane is a greenhouse gas not unlike carbon dioxide (CO2), but its negative effects in terms of climate damage are 23 times higher than that of CO2.
The Worldwatch Institute concluded that 51 percent or more of global greenhouse gas emissions are caused by animal agriculture, making vegetarianism and veganism more efficient methods of reducing pollution than buying hybrid cars. The main sources of emissions are feed production and processing, (45 percent of the total), outputs of greenhouse gases during digestion by cows (39 percent), and manure decomposition (10 percent). The remainder is attributable to the processing and transportation of animal products. Livestock are also responsible for almost two-thirds (64 percent) of anthropogenic ammonia emissions, which contribute significantly to acid rain and acidification of ecosystems.
Around 70 percent of agricultural land and 30 percent of the global land surface are used for animal production. About 60 percent of United States pastureland is subject to accelerated erosion due to overgrazing. U.S. pastures and rangelands are losing soil at an average of six times above the sustainable rate. Bryan Walsh of Time magazine writes, “You may think you live on a planet, but really you live on a gigantic farm, one occasionally broken up by cities, forests and the oceans.”
Meat production also significantly depletes and pollutes scarce freshwater resources. Producing 1 kilogram of animal protein requires about 100 times more water than producing 1 kilogram of grain protein. In addition, discharges of ammonia and nitrous oxides deteriorate water quality regionally. The major sources of water pollution are animal wastes, antibiotics and hormones, fertilizers and pesticides used for feed crops, and sediments from eroded pastures. In the United States, livestock is responsible for an estimated 55 percent of erosion and sediment, 37 percent of pesticide use, 50 percent of antibiotic use, and one-third of the nitrogen and phosphorus pollution in freshwater resources. The livestock sector is also the leading cause of reduction of biodiversity, posing long-term risks for food security.
Information for this article was taken from