Meat and cheese may be as bad for you as smoking

“Crucially, the researchers found that plant-based proteins, such as those from beans, did not seem to have the same mortality effects as animal proteins. Rates of cancer and death also did not seem to be affected by controlling for carbohydrate or fat consumption, suggesting that animal protein is the main culprit.”



That chicken wing you’re eating could be as deadly as a cigarette. In a new study that tracked a large sample of adults for nearly two decades, researchers have found that eating a diet rich in animal proteins during middle age makes you four times more likely to die of cancer than someone with a low-protein diet — a mortality risk factor comparable to smoking.

“There’s a misconception that because we all eat, understanding nutrition is simple. But the question is not whether a certain diet allows you to do well for three days, but can it help you survive to be 100?” said corresponding author Valter Longo, the Edna M. Jones Professor of Biogerontology at the USC Davis School of Gerontology and director of the USC Longevity Institute.

Not only is excessive protein consumption linked to a dramatic rise in cancer mortality, but middle-aged people who eat lots of proteins from animal sources — including meat, milk and cheese — are also more susceptible to early death in general, reveals the study to be published March 4 in Cell Metabolism. Protein-lovers were 74 percent more likely to die of any cause within the study period than their more low-protein counterparts. They were also several times more likely to die of DIABETES.

But how much protein we should eat has long been a controversial topic — muddled by the popularity of protein-heavy DIETS such as Paleo and Atkins. Before this study, researchers had never shown a definitive correlation between high protein consumption and mortality risk.

Rather than look at adulthood as one monolithic phase of life, as other researchers have done, the latest study considers how biology changes as we age, and how decisions in middle life may play out across the human lifespan.

In other words, what’s good for you at one age may be damaging at another. Protein controls the growth hormone IGF-I, which helps our bodies grow but has been linked to cancer susceptibility. Levels of IGF-I drop off dramatically after age 65, leading to potential frailty and muscle loss. The study shows that while high protein intake during middle age is very harmful, it is protective for older adults: those over 65 who ate a moderate- or HIGH-PROTEIN diet were less susceptible to disease.

The latest paper draws from Longo’s past research on IGF-I, including on an Ecuadorian cohort that seemed to have little cancer or DIABETES susceptibility because of a genetic mutation that lowered levels of IGF-I; the members of the cohort were all less than five-feet tall.

“The research shows that a low-protein diet in middle age is useful for preventing cancer and overall mortality, through a process that involves regulating IGF-I and possibly insulin levels,” said co-author Eileen Crimmins, the AARP Chair in Gerontology at USC. “However, we also propose that at older ages, it may be important to avoid a low-protein diet to allow the maintenance of healthy weight and protection from frailty.”

Crucially, the researchers found that plant-based proteins, such as those from beans, did not seem to have the same mortality effects as animal proteins. Rates of cancer and death also did not seem to be affected by controlling for carbohydrate or fat consumption, suggesting that animal protein is the main culprit.

“The majority of Americans are eating about twice as much proteins as they should, and it seems that the best change would be to lower the daily intake of all proteins but especially animal-derived proteins,” Longo said. “But don’t get extreme in cutting out protein; you can go from protected to malnourished very quickly.”

Longo’s findings support recommendations from several leading health agencies to consume about 0.8 grams of protein per kilogram of body weight every day in middle age. For example, a 130-pound person should eat about 45-50 grams of protein a day, with preference for those derived from plants such as legumes, Longo explains.

The researchers define a “HIGH-PROTEIN” diet as deriving at least 20 percent of CALORIES from protein, including both plant-based and animal-based protein. A “moderate” protein diet includes 10-19 percent of calories from protein, and a “low-protein” diet includes less than 10 percent protein.

Even moderate amounts of protein had detrimental effects during middle age, the researchers found. Across all 6,318 adults over the age of 50 in the study, average protein intake was about 16 percent of total daily calories with about two-thirds from animal protein — corresponding to data about national protein consumption. The study sample was representative across ethnicity, education and health background.

People who ate a moderate amount of protein were still three times more likely to die of cancer than those who ate a low-protein DIET in middle age, the study shows. Overall, even the small change of decreasing protein intake from moderate levels to low levels reduced likelihood of early death by 21 percent.

For a randomly selected smaller portion of the sample – 2,253 people – levels of the growth hormone IGF-I were recorded directly. The results show that for every 10 ng/ml increase in IGF-I, those on a HIGH-PROTEIN diet were 9 percent more likely to die from cancer than those on a low-protein diet, in line with past research associating IGF-I levels to cancer risk.

The researchers also extended their findings about HIGH-PROTEIN diets and mortality risk, looking at causality in mice and cellular models. In a study of tumor rates and progression among mice, the researchers show lower cancer incidence and 45 percent smaller average tumor size among mice on a low-protein diet than those on a high-protein diet by the end of the two-month experiment.

“Almost everyone is going to have a cancer cell or pre-cancer cell in them at some point. The question is: Does it progress?” Longo said. “Turns out one of the major factors in determining if it does is is protein intake.”




The Paradigm Shift Requires Clarity About the Moral Baseline

If we are ever going to see a paradigm shift, we have to be clear about how we want the present paradigm to shift.

We must be clear that veganism is the unequivocal baseline of anything that deserves to be called an “animal rights” movement. If “animal rights” means anything, it means that we cannot morally justify any animal exploitation; we cannot justify treating animals as human resources, however “humane” that treatment may be.

We must stop thinking that people will find veganism “daunting” and that we have to promote something less than veganism. If we explain the moral ideas and the arguments in favor of veganism clearly, people will understand. They may not all go vegan immediately; in fact, most won’t. But we should always be clear about the moral baseline. If someone wants to do less as an incremental matter, let that be her/his decision, and not something that we advise to do. The baseline should always be clear. We should never be promoting “happy” or “humane” exploitation as morally acceptable.

The notion that we should promote “happy” or “humane” exploitation as “baby steps” ignores that welfare reforms do not result in providing significantly greater protection for animal interests; in fact, most of the time, animal welfare reforms do nothing more than make animal exploitation more economically productive by focusing on practices, such as gestation crates, the electrical stunning of chickens, or veal crates, that are economically inefficient in any event. Welfare reforms make animal exploitation more profitable by eliminating practices that are economically vulnerable. For the most part, those changes would happen anyway and in the absence of animal welfare campaigns precisely because they do rectify inefficiencies in the production process. And welfare reforms make the public more comfortable about animal exploitation. The “happy” meat/animal products movement is clear proof of that.

We would never advocate for “humane” or “happy” human slavery, rape, genocide, etc. So, if we believe that animals matter morally and that they have an interest not only in not suffering but in continuing to exist, we should not be putting our time and energy into advocating for “humane” or “happy” animal exploitation.

Welfare reforms and the whole “happy” exploitation movement are not “baby steps.” They are big steps–in a seriously backward direction.

There are some animal advocates who say that to maintain that veganism is the moral baseline is objectionable because it is “judgmental,” or constitutes a judgment that veganism is morally preferable to vegetarianism and a condemnation that vegetarians (or other consumers of animal products) are “bad” people. Yes to the first part; no to the second. There is no coherent distinction between flesh and other animal products. They are all the same and we cannot justify consuming any of them. To say that you do not eat flesh but that you eat dairy or eggs or whatever, or that you don’t wear fur but you wear leather or wool, is like saying that you eat the meat from spotted cows but not from brown cows; it makers no sense whatsoever. The supposed “line” between meat and everything else is just a fantasy–an arbitrary distinction that is made to enable some exploitation to be segmented off and regarded as “better” or as morally acceptable. This is not a condemnation of vegetarians who are not vegans; it is, however, a plea to those people to recognize their actions do not conform with a moral principle that they claim to accept and that all animal products are the result of imposing suffering and death on sentient beings. It is not a matter of judging individuals; it is, however, a matter of judging practices and institutions. And that is a necessary component of ethical living.

If we take the position that an assessment that veganism is morally preferable to vegetarianism is not possible because we are all “on our own journey,” then moral assessment becomes completely impossible or is speciesist. It is impossible because if we are all “on our own journey,” then there is nothing to say to the racist, sexist, anti-semite, homophobe, etc. If we say that those forms of discrimination are morally bad, but, with respect to animals, we are all “on our own journey” and we cannot make moral assessments about, for instance, dairy consumption, then we are simply being speciesist and not applying the same moral analysis to nonhumans that we apply to the human context.

When we discuss veganism with vegetarians or other consumers of animal products, we should never convey the message that we think that they are “bad” people. We should instead focus on how any form of animal exploitation is inconsistent with the moral principle that they themselves claim to hold: namely, that animals are members of the moral community and that the imposition of suffering and death on any member of that community–human or nonhuman–requires a compelling justification. And whatever constitutes a compelling justification, taste preferences, conveneience, fashion sense, etc., do not.

Finally, we should always be clear that animal exploitation is wrong because it involves speciesism. And speciesism is wrong because, like racism, sexism, homophobia, antisemitism, classism, and all other forms of human discrimination, speciesism involves violence inflicted on members of the moral community where that infliction of violence cannot be morally justified. But that means that those of us who oppose speciesism necessarily oppose discrimination against humans. It makes no sense to say that speciesism is wrong because it is like racism (or any other form of discrimination) but that we do not have a position about racism. We do. We should be opposed to it and we should always be clear about that.

Veganism is about nonviolence. It is about not engaging in harm to other sentient beings; to oneself; and to the environment upon which all beings depend for life. In my view, the animal rights movement is, at its core, a movement about ending violence to all sentient beings. It is a movement that seeks fundamental justice for all. It is an emerging peace movement that does not stop at the arbitrary line that separates humans from nonhumans. Changing a hierarchical paradigm of pervasive exploitation that has dominated for millenia requires a great deal of hard work. And that hard work requires clarity.

Gary L. Francione
Professor, Rutgers University