A large, long-term study from Harvard School of Public Health published last week confirmed what we already know – red meat is a disease-promoting food whose consumption leads to premature death.1 This is an important study because of its lengthy follow-up time, distinction between unprocessed and processed red meats, and findings of a dose-response relationship between red meat intake and risk of death – in short, the authors concluded each daily serving of unprocessed red meat increased risk by 13% and processed meat by 20%. However, the bottom line “red meat increases risk of mortality” certainly isn’t news. This is not the first study to link meat consumption to premature death, and it certainly will not be the last.1-5
Of interest though, is the accompanying commentary by Dean Ornish, M.D., a respected and widely known figure in lifestyle medicine. In his comment, Dr. Ornish leaves the physician-sanctioned territory of human health and nutrition makes a call to action to reduce red meat consumption to protect the health of our planet, not just ourselves:6
“In addition to their health benefits, the food choices we make each day affect other important areas as well. What is personally sustainable is globally sustainable. What is good for you is good for our planet...
… choosing to eat more plant-based foods and less red meat is better for all of us—ourselves, our loved ones, and our planet. In short, don't have a cow!”>6
We already know that red meat is a contributory factor in the development of cancer7 – plus, we know from epidemiologic findings from rural areas that the etiology of this relationship will not be negated by eating grass-fed beef.8-13 We know that heme iron is an oxidant that accumulates in the body over time, contributing to cardiovascular disease and dementia.14,15 We know that heme iron and proteins in meats form N-nitroso compounds in the digestive tract that can damage cellular DNA, potentially leading to stomach and colorectal cancers.16-18 We know that cooking meats (all meats, not just red meat) at high temperatures forms carcinogens called heterocyclic amines.19 Plus, we are now finding that chronic inflammation results from newly discovered compounds such as Neu5Gc, which accumulate from eating red meat.20 Furthermore, higher levels of meats (animal protein) lead to higher circulating levels of IGF-1 that promote cell division and fuel growth of cancerous cells.21,22 These issues related to heme iron and animal protein will also not be resolved by simply switching to grass-fed beef.
The “red meat is good for you” slogan is dead – its proponents don’t have a scientific leg to stand on. Atkins, Dukan, Sugar Busters, Weston Price, and all the other meat-promoting and protecting people need to keep out of this discussion and finally stop protesting and promoting death. Now, the new question has become: are red meat consumers and promoters destroying our environment also?
There is certainly no need to debate the health issues any further. With global livestock production expected to double by 2050,23 now is the time for the public to become better aware of the environmental impact of consuming meat. Dr. Ornish brings up these important points regarding the impact of animal agriculture on our environment:
- Greenhouse gas emissions: The livestock sector generates more greenhouse gas emissions than transportation – about 18% of total emissions; emissions include carbon dioxide and to a greater extent, methane and nitrous oxide, which are considered to be more harmful than carbon dioxide.
- Deforestation: Currently, animal agriculture uses 30% of the Earth’s land surface, and 70% of forests in the Amazon are no longer forests – they have become grazing land for livestock, resulting in depletion of wildlife and natural ecosystems.
- Use of resources and energy: Almost 40% of the world’s grain (and over 50% in the U.S.) is fed to livestock and 33% of arable land on Earth is devoted to growing feed for livestock. The production of 1 pound of beef requires almost 20,000 liters of water, and is a significant contributor to water pollution.6,23
What do you think?
Especially considering red meat is harmful to human health, and to our environment do you agree with Dr. Ornish? Should all of us, including informed physicians make it our responsibility to promote dietary change for environmental reasons as well, or should we doctors stick to health and medical topics?
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2. Sinha R, Cross AJ, Graubard BI, et al: Meat intake and mortality: a prospective study of over half a million people. Arch Intern Med 2009;169:562-571.
3. Major JM, Cross AJ, Doubeni CA, et al: Socioeconomic deprivation impact on meat intake and mortality: NIH-AARP Diet and Health Study. Cancer Causes Control 2011;22:1699-1707.
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18. Kuhnle GG, Story GW, Reda T, et al: Diet-induced endogenous formation of nitroso compounds in the GI tract. Free Radic Biol Med 2007;43:1040-1047.
19. Zheng W, Lee S-A: Well-Done Meat Intake, Heterocyclic Amine Exposure, and Cancer Risk. Nutr Cancer 2009;61:437-446.
20. Padler-Karavani V, Yu H, Cao H, et al: Diversity in specificity, abundance, and composition of anti-Neu5Gc antibodies in normal humans: potential implications for disease. Glycobiology 2008;18:818-830.
21. Thissen JP, Ketelslegers JM, Underwood LE: Nutritional regulation of the insulin-like growth factors. Endocr Rev 1994;15:80-101.
22. Kaaks R: Nutrition, insulin, IGF-1 metabolism and cancer risk: a summary of epidemiological evidence. Novartis Found Symp 2004;262:247-260; discussion 260-268.
23. Livestock's Long Shadow: Environmental Issues and Options. Food and Agriculture Organization of the United Nations; 2006.