20 January 2008

Meat, Cancer, and the Cumulative Case for Ethical Vegetarianism

Ethical vegetarianism is the thesis that killing and eating animals is morally wrong whenever equally nutritious plant-based alternatives are available. The case for ethical vegetarianism starts with several uncontroversial premises. Virtually everyone agrees that:

(1) It is wrong to cause a conscious sentient animal to suffer for no good reason.
Causing an animal to suffer for no good reason is cruel, and our ordinary commonsense morality tells us in no uncertain terms that cruelty is wrong. A brief look at the public outcry concerning Michael Vick’s dog-fighting ring shows just how widely accepted premise (1) is. It is not just a few outspoken animal rights fanatics who hold this view. We all do. Animal abuse is a crime in all fifty states, and rightly so.

Similarly, most people also agree that:

(2) It is wrong to kill a conscious sentient animal for no good reason.
Even the most ardent defenders of the morality of using animals for food and as “tools” in scientific experiments admit that premises (1) and (2) are true and acknowledge that (1) and (2) capture something central to our moral relationship to animals. For example, Carl Cohen, who has argued at length that animals don’t have rights, admits:

If animals feel pain (and certainly mammals do, . . .), we humans surely ought cause no pain to them that cannot be justified. Nor ought we kill them without reason. (Cohen, The Animal Rights Debate, p. 46) [To see Cohen’s commitment to (1) here, we need only recognize that justification proceeds in terms of reasons. We are justified in causing an animal pain if and only if we have a good reason for doing so. If there is no good reason to cause an animal pain, then causing that animal pain cannot be justified.]
Elsewhere, Cohen reiterates his commitment to (1) and (2):

Our obligations to animals arise not from their rights, I believe, but from the fact that they can feel pain and from the fact that we, as moral agents, have a general obligation to avoid imposing needless pain or death” (Cohen, The Animal Rights Debate, p. 226).
Similarly, Peter Carruthers acknowledges that sentient animals deserve moral consideration when he explicitly endorses (1):

. . . it will be useful to have a rough idea at the out-set of what our common-sense morality tells us about the status and appropriate treatment of animals. . . . Most people hold that it is wrong to cause animals unnecessary suffering. Opinions will differ as to what counts as necessary. . . . But all will agree that gratuitous suffering—suffering caused for no good reason—is wrong. (Carruthers, The Animals Issue, p. 8)
The argument for the immorality of eating meat continues with two additional, undeniable premises:

(3) The animals that become that meat are killed.
No one disputes premise (3). There is also little dispute concerning the following premise:

(4) The animals that become that meat are reared in ways that subject them to intense pain and suffering for much of their lives.
Premise (4) is widely acknowledged. It is not in dispute that, in modern factory farms, animals are raised in massively overcrowded, unnatural warehouses. In these intensive confinement facilities, the animals are forced to stand on inappropriate surfaces that cause foot and leg injuries. They are also forced to stand in their own waste. The noxious fumes from the accumulated urine and feces cause lung problems in many of the animals. In addition, the animals are subjected to excruciating mutilations – including branding, dehorning, debeaking, tooth pulling, tail docking, and castration – all performed without anesthesia. Even those actively involved in the industry typically admit that these modern animal rearing practices cause animals severe pain and stress. At the time of slaughter, these frightened animals are inhumanely loaded onto trucks and shipped long distances to the slaughterhouse without food or water or protection from the elements. No one disputes that these actions cause the animals an enormous amount of pain and distress. [For more detailed descriptions of the conditions in which farm animals are raised, see here, here, and here. Those who have doubts as to the accuracy of these descriptions can view the graphic but accurate documentary "Meet Your Meat" here or here. Running time: 12 Minutes. If you do view the documentary, I suspect that you will agree that "raising," transporting and slaughtering animals in this way is, indeed, prima facie wrong and ought not be supported, absent a very compelling reason for doing so.]

Premises (1) – (4) are true, and together they entail:

(5) Raising animals inhumanely and killing them is morally wrong, unless there is a good reason for doing so.
Premise (5) leaves open the possibility that there might be circumstances in which it is permissible to inflict pain and suffering on an animal. Nevertheless, when considering (5), it is important to realize that not just any reason will do. We accept premises (1) and (2) is because we think that (i) unnecessary suffering is intrinsically bad and (ii) unnecessary killing is prima facie wrong. So, for a reason to be good enough to justify raising animals inhumanely and killing them, it must be sufficiently weighty to override both the intrinsic badness of their suffering and the prima facie wrongness of killing them. Trivial or insignificant reasons won’t do.

To derive the immorality of raising, killing, and eating animals from (1) – (5), one needs the following additional premise:

(6) The pain, suffering and killing of farm animals that inevitably results from meat production is gratuitous, i.e., it is done for no good reason.
How might one defend premise (6)? One could begin by noting that, in modern agriculture societies, no one needs to eat meat to survive, since all of our nutritional needs can easily be met with a plant-based diet. So, in support of (6), one can offer the following premise:

(7) In modern societies, meat consumption is in no way necessary for human survival.
Premise (7) is clearly true, but don’t take my word for it. Consider instead what the American Dietetic Association’s position paper on vegetarian diets has to say:

It is the position of the American Dietetic Association (ADA) that appropriately planned vegetarian diets are healthful, are nutritionally adequate, and provide health benefits in the prevention and treatment of certain diseases. (p. 748)
This same ADA position paper points out that:

Well-planned vegan, lacto-vegetarian, and lacto-ovo-vegetarian diets are appropriate for all stages of the life cycle, including during pregnancy and lactation. Appropriately planned vegan, lacto-vegetarian, and lacto-ovo-vegetarian diets satisfy nutrient needs of infants, children, and adolescents and promote normal growth. (p. 754-5)
Perhaps, eating meat, while not strictly necessary for our survival, is necessary for us to thrive and be optimally healthy. If we needed to eat animals in order to be optimally healthy, that would constitute a good reason to raise and kill them for food. [It wouldn’t be a good reason to cause them to suffer in the process, but it would be a good reason to raise and kill them for food.] The crucial question is this: Do we need to eat animals in order to be optimally healthy? The answer, according to the ADA, is “No.” Here is what the ADA position paper finds:

Vegetarians have been reported to have lower body mass indices than nonvegetarians, as well as lower rates of death from ischemic heart disease; vegetarians also show lower blood cholesterol levels; lower blood pressure; and lower rates of hypertension, type 2 diabetes, and prostate and colon cancer. (p. 748)
Consequently, not only is premise (7) above true, so is the following premise:

(8) In modern societies, not only is meat consumption not necessary for optimal human health, meat consumption is a contributing factor to the degenerative diseases (i.e., heart disease, stroke, diabetes, obesity, and prostate and colon cancers) that are the leading causes of death in such societies.
If the diseases associated with meat consumption as identified by the ADA don't convince you that there is no good reason to raise animal inhumanely and kill them for food, perhaps a few other meat-related diseases will do the trick. A recently published peer-reviewed study conducted by Amanda J. Cross and Michael F. Leitzmann (both from the Nutritional Epidemiology Branch of the Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland, United States of America) entitled “A Prospective Study of Red and Processed Meat Intake in Relation to Cancer Risk” suggests that we can now add lung cancer, esophageal cancer, and liver cancer to the list of health problems associated with meat consumption—in this case red meat (defined in the study as: beef, pork, and lamb) and processed meat (defined in the study as: bacon, red meat sausage, poultry sausage, luncheon meats [red and white meat], cold cuts [red and white meat], ham, regular hot dogs, and low-fat hot dogs made from poultry) were the culprits. The study was published in the December 2007 issue of the Public Library of Science’s journal PLOS Medicine.

The researchers analyzed data from the NIH-AARP Diet and Health study cohort which consisted of approximately 500,000 people aged 50–71 years at baseline (1995–1996), none of whom had previously had cancer at the time they entered the study. The researchers used a Cox proportional hazards regression analysis to estimate hazard ratios. Their findings:

Statistically significant elevated risks (ranging from 20% to 60%) were evident for esophageal, colorectal, liver, and lung cancer, comparing individuals in the highest with those in the lowest quintile of red meat intake. Furthermore, individuals in the highest quintile of processed meat intake had a 20% elevated risk for colorectal and a 16% elevated risk for lung cancer. (p. 1973)

According to the Editor’s Summary of the study:

These findings provide strong evidence that people who eat a lot of red and processed meats have greater risk of developing colorectal and lung cancer than do people who eat small quantities. They also indicate that a high red meat intake is associated with an increased risk of esophageal and liver cancer, and that one in ten colorectal and one in ten lung cancers could be avoided if people reduced their red and processed meat intake to the lowest quintile. (p. 1984)
One can not only meet one’s nutrition needs without eating meat, one can meet them better without eating meat. Consequently, there is no good reasonno sufficiently weighty reason – to raise animals in inhumane conditions and kill them for food. Consequently, premise (6) above is true.

Taken together, premises (1) – (8) provide a compelling argument for the conclusion that it is morally wrong to raise animals inhumanely and kill them for food, and that, as a result, vegetarianism is morally required (whenever equally nutritious plant-based alternatives are available, which in modern societies is almost always).

The Bottom Line:

The cumulative case for ethical vegetarianism is all the stronger when we realize that not only are there no good reasons to raise and kill animals for food, there are good reason not to. Keith has made the point before that the case for vegetarianism is overdetermined. He’s right. There are environmental reasons for becoming vegetarian. There are health reasons for becoming vegetarian. And there are ethical reasons for becoming vegetarian. What I have argued here is that the compelling health reasons for vegetarianism serve to strengthen the moral argument for vegetarianism by undermining the only reasons potentially good enough to override the prima facie wrongness of harming and killing animals for food. Absent such an overriding reason, the prima facie case for ethical vegetarianism provides us with an all-things-considered ultima facie reason for the immorality of eating meat. What’s good for us is good for the animals. Ethical synergy at work.