The grand sham: eating meat is not killing you or the planet
A mainstream narrative of our times is that eating red meat is damaging human health and jeopardizing the existence of Earth. From meatless Mondays to proposals on meat taxation, eating red meat, something that homo sapiens has done for hundreds thousands of years, and which allowed homo sapiens to become what we are now, is being demonized. But if we look into the evidence, there is no clinical or sound statistical proof that eating red meat is the cause of disease; on the contrary, meat provides plenty of essential nutrients. On the other hand, while it is imperative that meat production is done more optimally from an ethical and environmental perspective, the claims that ranching and meat industry are killing the planet (as if the planet, a gigantic rock with molten magma on its core and plenty of salty water, was a living organism) are based on simplistic assumptions and first dimensional thinking that omits systems.
On the this article, we will look into the evidence that red meat is “bad”, both from a health and an environmental perspective, and show that reducing or stopping the consumption of red meat not only will not improve the health of human beings or minimize the impact of food procurement on Earth’s ecosystems and natural resources, but it could actually have a negative effect on both. People should be free to choose whichever diet they want, but policy (or lack of) should be based on facts.
Health
The World Health Organization (WHO) published a report in 2015 where the intake of processed and red meat was associated to colon cancer. In 2018, The Eat-Lancet Commission on Healthy diets published their recommendation of one-size-fits-all 14 grams of red meat per day person based on “ extensive literature on foods, dietary patterns, and health outcomes”. Both reports went mainstream and have influenced policy makers and consumers alike into thinking that there is solid scientific evidence that red meat is inherently dangerous. However, taking a look at the evidence both reports cite, we will see there is not.
In the medical field, there are two kinds of evidence: clinical data and epidemiological data. Clinical data is based on experiments where subjects are applied treatment, and assessed based on randomized trials whether the treatment/intervention has any effect. Epidemiological data, on the other hand, is based on observations: the statistical association between different level of exposures of groups of people with specific outcomes. These exposures are wide and range from diet to lifestyle, drug intake, sleep patterns or even sex. Yet it seems that the popular mantra of “correlation is not causation” does not seem to resonate enough. While there is a particular field of statistics devoted to investigate causality, removing biases is still hard.
These studies must rely on high quality data to be reliable. The implication is that even if the mathematical models are sound and have a strong signal of causality, if the underlying data is flawed we end up with “garbage in garbage out”. Imagine then, how difficult it is to design a clinical study on human beings and follow them for a long period of time, especially for behavioral traits like nutrition. For this reason, most diet-related studies are observational and not clinical. And while some traits like age, death, weight, sex are easily measurable and thus available in databases, for diet, researchers must rely on surveys or self-assessments. And if recent years haven’t taught you anything on surveying, read this paper on the Validity of US Nutritional Surveillance. The majority of the studies referenced in the reports above rely on survey-based epidemiological evidence.
The Eat-Lancet commission uses, amongst many others, a study based on a survey of over 73 thousand Adventist men and women participants who followed a vegan, octo-lacto-vegetarian or pesco-vegetarian diet, followed over a period of less than 6 years, to assess that plant-based diets are associated with lower mortality. Let’s assume that indeed, 73 thousand individuals were able to fill a survey with their appropriate energy intake, their precise amount of consumption of food, and respond truthfully to their daily amount of sleep and exercise; yet, the study compares only Adventist Church members, who might share a peculiar set of costumes. Given such a large sample, it is expected that results will be statistically significant (secondary school math: what happens when you divide by a very large number?). A more appropriate label for this study would be mortality statistics for a particular group of religious people with self-reported unverifiable claims about their diet and lifestyle. Even so, Eat-Lancet says that fish intake should be low despite the fact that in this study pesco-vegetarians had the lowest relative risk of mortality compared to non vegetarians. Moreover, the authors mention that the very low risk gap between vegetarians and non vegetarians decreases when body mass index is introduced as a control. They also compare it to another similar study from Britain, which found no association between a plant-based diet and lower mortality. The authors discuss that British and American vegetarians eat differently, primarily because the former do it for ethical and environmental issues while the latter based on perceived health superiority of plant-based diets. The obvious inference is that if the results are not replicated across different studies, a balanced diet and healthy lifestyle are what make a person live longer and not the exclusion of animal protein.
The report uses another reference that links plant-based diets to lower risk of Type-2-Diabetes (T2D). The report is obviously based on a survey, and they exclude implausible energy intakes, which they consider to be <600 and >3500 kcal for women. Let’s assume again that this survey is valid, and some people in the United States are living on a 601 kcal diet. The study found again that when controlling for body mass index (BMI), the relative risk difference of developing T2D between plant-based versus omnivore diets reduces significantly. They also do a distinction between healthy and unhealthy plant-based diets, finding that when adjusting for BMI unhealthy vegetarian diets are as risky as omnivore diets of developing T2D. It looks once again that there is something else dominating these effects, especially considering they do not look into a healthy omnivore diet.
Eat-Lancet also mentions that red meat is associated to higher cardiovascular disease (CVD), citing amongst many other studies a metha-analysis of 13 cohort studies on the subject. Again, these are survey-based studies. The metha-analysis concludes on their main findings that red meat intake is associated to a 16% higher risk of CVD relative to not consuming it. This is just roughly the average across the 13 cohort studies analyzed, but they acknowledge that the results should be taken with caution given the huge heterogeneity of the results. In metha-analysis, the heterogeneity of the results is meant to demonstrate how much the variability within the studies goes beyond what would be expected due to chance or measurement errors, i.e., how consistent are the results across the studies analyzed. It is measured by a score I², which in the case of association between red-meat and mortality and CVD were 95% and 82.5% respectively. The highest score possible is 100%. The pooled studies are thus very variable, and in some cases, red meat is associated to lower CVD mortality.
For colorectal cancer, another metha-analysis of 28 cohort studies was used. In this case, the heterogeneity was moderate (I²=60%) but still present. The associated risk of developing colorectal cancer by consuming risk was 24%. But this can be thought of an “average” across studies which does not tell the full story, in their own words:
“Studies adjusted for age and energy only showed a stronger association than studies with higher level of adjustments. However, after the exclusion of the studies adjusted only for age and energy intake from the analysis, moderate unexplained heterogeneity persisted.[…] the associations of red meat and processed meat and colon cancer were attenuated after better adjustment for confounders and longer follow-up”.
Chan, Doris S M et al. “Red and processed meat and colorectal cancer incidence: meta-analysis of prospective studies.” PloS one vol. 6,6 (2011): e20456. doi:10.1371/journal.pone.0020456
Moreover, this metha-analysis estimates a dose-response function where they claim the risk for red meat and processed meat has a non-linear response that starts at 100g/day. Nonetheless, they omitted some studies in the creation of this dose-response due to what they claim is insufficient information. Interestingly, many of the studies omitted show no association or reduced risk between red meat consumption and colorectal cancer.
We could go on, but all of the studies have weak evidence as shown above. Let’s assume that indeed, the surveys are reliable, and ignoring heterogeneity of the studies and the lack of proper controls, these relative risks exist. Relative risk (RR) is the measure of how much the exposed group is more likely to develop an outcome relative to the control group. This does not mean that the control group does not have a risk, rather than theirs is different to the treatment/exposure group. RR may be misleading due to ergodicity or other factors as explained here. The RR for the studies above range between 1.1 to 1.3, meaning that consumption of red meat or animal protein is at much associated to a 1.3 higher chance of having any adverse outcome described above relative to diets without red meat. How does this compare to other factors? Family history of cancer is associated to a 2.2 RR of developing cancer. Obesity to a 5.5 RR of T2D. Smoking to a 7.3 RR of lung cancer. Thus, even if the red meat RR were robust, their effect is weak.
Eat-Lancet does not provide a compelling case or clinical studies to back their claims. Incredibly, after writing that most reports have been performed in an American or European setting and that studies in Asia contradict those findings by demonstrating lower mortality associated to consumption of meat and poultry, they “conclude that a low range of intake, 0 to approximately 28 grams/day, is desirable and have used a midpoint of 14 g/day for the reference diet’’. They also acknowledge that the intake of red meat in low-income country helps alleviates nutritional deficiencies and has metabolic benefits yet fail to be agnostic on their main conclusions. Another contradiction is that they speculate the associated meat lower risks of mortality in Asia are due to correlations with higher income while saying at the same time that because these countries recently became affluent the long-term consequences are not fulfilled, as if red meat were something new. I can think of many adjectives to describe this, but at least one which is definitely not fit is rigorous scientific evidence so I will let the reader decide.
Moving on from Eat-Lancet, the WHO report is basically another metha-analysis of several cohort studies, of which the vast majority are survey-based observational studies. There is a large overlap with those evaluated by Eat-Lancet, thus it is not worth revising them since they have the same flaws. I strongly encourage the reader to ignore any advice based on such studies, whichever the field. Even more so with many embarrassingly poor-researched documentaries; never let the TV think for you. Let’s then investigate the six clinical studies available.
The first reference shows “promotion of experimental carcinogenesis by dietary meat”… on rats…. fed a low-calcium diet and treated with azoxymethane, a potent carcinogenic. The second clinical reference shows that intake of calcium reduces rate of ACF, lesions in the colon that rarely evolve to cancer… in rats fed beef alongside a plethora of substances. The third experiment showed that by eating processed meat alongside two carcinogenic, vegetable oil and a high glucose diet for 14 days, the colon develops lesions which might lead to cancer… in rats. The fourth reference finally included a few human volunteers, which were fed 180 g of cured meat with six additives for four days and whose stool found two compounds which might be associated to cancer. The fifth reference was a 4-week-long experiment of 23 human volunteers consuming 300 g per day of lamb or beef alongside orange juice, milk, with and without fiber to analyze mutations in the colon, showing that the diet with no fiber increased 20% mutations that are mostly repaired by the body. The sixth study showed that consumption of 400 g of beef plus processed carbs like bread and cereal plus sugar and butter increase mutations in the colon that are mostly repaired by the body on a 15-day study with 21 human volunteers.
Inexplicably, WHO decided to categorize red meat based on this information on the same group of carcinogenic as tobacco and asbestos. The clinical evidence is limited and not indicative of anything. Epidemiological evidence is based on flawed methods, unreliable data and faulty assumptions. Somewhere on the middle of the report, they are actually honest and scientific and assess the true message: there is no medical evidence that proves red meat is dangerous for human health.
“Chance, bias, and confounding could not be ruled out with the same degree of confidence for the data on red meat consumption, since no clear association was seen in several of the high quality studies and residual confounding from other diet and lifestyle risk is difficult to exclude. The Working Group concluded that there is limited evidence in human beings for the carcinogenicity of the consumption of red meat.”
Bouvard, Véronique and Loomis, Dana and Guyton, Kathryn… [et al.]. Carcinogenicity of consumption of red and processed meat. (2015) The Lancet Oncology, 16 (16). 1599- 1600. ISSN 1474–5488
It is misleading to masquerade propaganda as scientific evidence and state red meat is dangerous for human health. Red meat provides protein and many essential nutrients that are more bioavailable compared to other food. It contains the eight essential amino acids for optimal health as well as many other nutrients like vitamins A & B12, Iron, Zinc, Phosphorus and Magnesium. Moreover, consumption of meat provided early hominids a comparative advantage that lead us to where we are. The more bioavailable protein as well as the improved net energy intake freed early humans from the constraints that are usually associated to larger mammals in terms of mobility and diet needs; eventually shaping our kinetics and making our brain larger.
Ultimately, time is the greatest judge. Fossil evidence dates back meat consumption as far as back as at least 2.6 million years. If red meat was detrimental for human health, natural selection would have wiped us out, but, despite the WHO or Eat-Lancet claims, here we are. Eating red meat is not going to kill you.
Environment
There are nearly 7.8 billion of us now. We humans, unlike plants, are not autotrophs, and hence must rely on external sources for all of our energetic needs. And in order to fulfill our most basic functions we need food, and this food comes from Earth like any natural resource. Every single food source then will have soil, water and energy as input, whether it’s plant-based, animal-based, or even for industrial garbage marketed as processed food. It is expected that a not insignificant share of our footprint on Earth, based on those three metrics of land, water and energy, will come from food procurement. The notion that any diet will save Earth is false. All food production has an impact on our natural resources, and some means are more or less efficient.
Red meat production, hence, does have an impact on several issues of concern: water scarcity, emissions, land use, antibiotic resistance, biodiversity loss, soil and water pollution. But this is not unique to beef, let alone any kind of food. Yet the media continuously claims that if the world stopped eating red meat those issues would disappear. This is a fallacy that does not consider the benefits of red meat and looks beyond the statistics, without thinking of second order effects. Before reviewing each, let’s state that we are ignoring the fact that animal protein includes far more biodigestible protein and essential aminoacids than plant protein in the forthcoming analyses. For instance, a gram of red meat contains more useful protein than a gram of wheat, peas, lentils, beans or nuts.
Greenhouse gas emissions
Many academics, policymakers, entrepreneurs and journalists believe that red meat is causing global warming and eliminating it from our diets will prevent it. Not only is it that this is false, but that the effect of beef and other ruminant meat on climate change is overestimated. And while for transportation they suggest electric vehicles instead of driving less and walking more (which would actually be better), for electricity switching to low-emitting sources instead of dropping electricity, or for industry using low-carbon fuels and inputs instead of not producing, it’s only for red meat where they suggest elimination and substitution. Ironically, amongst those substitutions advocated is artificial and processed protein that requires many industrial and energetic inputs, and which only an over-educated person would conceptualize as being able to replicate millions of years of evolution.
It’s true that red meat procurement does have an impact on the carbon cycle and other greenhouse gases, such as nitrous oxide, but the footprint that red meat itself has on climate change is overstated and the resulting effects of not consuming it would yield very modest emission reductions or even increases. Main greenhouse gases emitted are: methane, carbon dioxide, and nitrous oxide. Emissions associated to meat can mainly come from three sources: enteric fermentation, feed production, and manure. The Food and Agriculture Organization of the United Nations (FAO) estimates that 14.5% of total greenhouse gas emissions are associated to livestock, including pork and poultry, with 65% of that total being cattle (including both beef and dairy). This means that red meat is roughly responsible for less than 10% of total reported greenhouse gas emissions. If cattle were to disappear by magic in any given year, you would still have 90% of existing emissions, clearly not a solution to global warming. Still, the reduction would be far less than 10%, and the 10% itself is actually misleading.
Let’s break out the main gas: methane. Methane from red meat comes from enteric fermentation: a digestive process by which organic plant matter is broken down by microorganisms in the gut of ruminants for absorption into their bloodstream. All ruminants, therefore, large or small, wild or domesticated, convert feed that is indigestible for us into high quality protein. This follows mostly a natural cycle, since methane is a short-lived gas that gets broken down in the atmosphere in a short time and gets converted into carbon dioxide. This carbon dioxide is then absorbed by plants and then eaten again by animals.
Humans have decimated the population of many wild ruminants in the past, including during the ice age, to the present day for food production. This is certainly an ecological disaster, but the impact on the methane cycle itself has been overestimated. It is hard to assess historically the magnitude of methane emissions globally from wild ruminants as opposed to today since the number of both domestic and wild animals in the past is uncertain. But some studies suggest that, for example, in pre European-settlement North America methane emissions from wild ruminant was equivalent to 86% of today’s. And even though wild ruminants populations declined precipitously in the 18th and 19th centuries, primarily bison (though elk and deer were not spared), a period known as the Little Ice Age in the Northern Hemisphere still had large populations of wild ruminants at least in North America. So, where was the warming?
The answer to this apparent paradox is that the impact of methane from agriculture is overestimated. Methane, as said before, is more potent than carbon dioxide in terms of warming, but it is also short-lived. It gets oxidized in the atmosphere, i.e., destroyed, and converted to carbon dioxide. While methane concentration in the atmosphere has risen steadily, scientist are still trying to understand the steep changes over the last few decades, either due to changes in the atmospheric hydroxil radical that destroy methane, increased tropical wetland emissions, or geological and fossil fuel emissions. Certainly cattle is not to blame since it has remained relatively flat over the last decade.
Moreover, as a short-lived but more potent gas, it’s not easy to compare the impact of methane on the radiative forcing on the surface compared to other gases like carbon dioxide. It’s very common to see the use of tons of CO2-equivalent, by assigning a factor of how much more another potent gas warms relative to a ton of CO2 emitted. In the case of methane, the differentiation over a shorter time period -20 years- to a longer time period -100 years- is important because of the shorter lifetime. It is usually assumed that over 20 years a ton of methane has a warming effect 84 times larger than a ton of CO2, and 28 times larger over a period of 100 years. While this is useful for accounting purposes, it is not very reflective of the physics and chemistry involved. A new proposal by John Lynch et al 2020 labeled GWP* deals with this by differentiating between rate and stock. CO2 is a stock gas because it is cumulative, which means that warming will accrue over thousands of years. Methane, on the other hand, has a stronger pulse over a shorter lifespan but eventually decays. For methane stock effect, they recommend multiplying by 0.25 for a period of 100 years.
The implication is that if the rate of methane keeps constant, there is no further warming, and that on a cumulative or stock basis for a 100 year period, methane is being overestimated by a factor of 4.
According to the FAO, of the 7.1 Gt of CO2eq that livestock contributes on a global level, accounting for for 14.5% of global GHG emissions, 39% is attributed to enteric fermentation. Correcting using GWP*, the true impact of livestock as a whole is 10%, and of red meat 5%. So, if red meat were to disappear by magic, emissions would still be 95% of what they are today. This leaves us with the rest of emissions associated to cattle: carbon dioxide and nitrous oxide.
Carbon dioxide comes from use of fossil fuels in the production and processing of feed, as well as coming from land use changes. When forests , peat lands or any natural ecosystems that serve as carbon sinks are replaced by crops or grazing, carbon dioxide is emitted by clearing the wild flora with fire and/or in terms of lost carbon storage. Then, for the growth of feed and crops, when artificial fertilizers are used, which need natural gas as an input, the process releases carbon dioxide (and some methane leaks which are negligible for the total), as well as the fossil fuels needed for the processing and transportation of the feed for cattle, and the processing of cattle itself. From the total footprint of livestock, 20% is associated to fossil fuel use. So even if red meat was to be replaced with food that requires less energy (grains, for example, can be transported in trains and ships and do not need refrigeration), there would still be emissions attributed to processing and transport.
As far as feed production, it is true that cattle require massive amounts of food and are directly the major land users (and hence displacers of other ecosystems), which leads to carbon dioxide emissions from land use changes. However, most fail to acknowledge that 86% of the global livestock feed intake in dry matter is inedible for humans, and that only a third of the grasslands surface covered by livestock is suitable for cropland. Livestock is thus a user of marginal land and uptakers of organic matter inedible for humans, so even assuming that the area suitable for cropland currently allocated to livestock could meet the nutritional requirements of the entire world population, more ecosystems would be threatened. This is location-specific, but in many cases, without livestock, the pressure on other ecosystems that overlap with arable land would increase, leading to more carbon dioxide emissions.
Moreover, in places like Brazil, 80% of land clearance is attributable to grazing and the rest to cultivation, primarily from soybeans. Soybeans are used in both feed and for producing biofuels, yet, despite the usage of soy for oil comprises less than 20% in terms of weight, it accounts for more than 40% in terms of value. Would soybeans be cultivated in the Amazon or Pantanal without ethanol mandates? Grazing can definitely be improved and be more sustainable, but the priority should be that the people who inhabit those areas make a living and improve their quality of life, if farming would be banned would they turn to logging or mining, which would have the same effect? In the US, as another example, roughly 35%-40% of corn production is used in ethanol, yet no one is suggesting to use this as food for humans. If this is seen as recycling carbon, why is red meat not being spared the same logic?
Nitrous oxide, on the other hand, a much more potent gas than both methane and carbon dioxide, accounts for roughly the same amount of GHG emissions from livestock as carbon dioxide. It comes mostly from the application of fertilizers in feed production, and from manure. Given that we have exposed that most feed is inedible, these emissions would remain largely unaffected since you would need to increase fertilizer use for increase human-edible crops. The results are mixed to determine whether organic or synthetic fertilizer have higher nitrous oxide emissions. Manure storage and processing accounts for 10% of total live stock footprint, which means that is negligible. Manure deposited on soils or left on pastures accounts for roughly 20%. However, the majority of the emissions comes from developing areas, which means that if such countries adopt the measures of others there is potential for emissions reduction. It’s a problem of practices more than a feature of the product. Still, empirical research suggest this problem has been overestimated as well.
Moreover, manure can be used as an organic fertilizer. Manure increases soil health as opposed to the application of synthetic fertilizer, and has a function of increasing fertility and organic matter. Not only it is beneficial, but given that half of the population does not have access to synthetic fertilizers, the elimination of livestock would put millions under food insecurity or potentially starvation.
Note that we have been saying that red meat would disappear by magic. This is because there are 1.4 billion heads of cattle, 0.2 of buffaloes, 1 of goat, and 1.2 of sheep. If red meat was banned or eliminated, what would happen to these animals? Would they be slaughtered? Of course not, but even if some of then would be slaughtered, what would be the environmental effect of this action and their disposal? If they were to return to wilderness, they would still burp methane and produce manure, they could even displace other herbivores specially considering the lack of predators. Even if half of them disappeared within a few years, you would still have a significant amount of methane and nitrous oxide from enteric fermentation and manure.
The United States is the country with the highest consumption per capita of meat in the world. White and Hall (2017) modelled the elimination of animal products (not only red meat) in the food system in the US, and found that the reductions of total GHG would be equal to 2.5%. Thus, if the highest consumer of meat in the world sees a nimble decrease in GHG from changing their diet, the notion that eating red meat is causing global warming must be discarded. Besides, the study does not takes into consideration the fact that methane emissions are overestimated and that cattle have many byproducts which would needed to be replaced with artificial processes. If we also consider as mentioned above that animals would not disappear, it might be the case that not only would emissions changes would be null, but that there could be an increase.
Land use
Since our planet is mostly water, land is one of our most precious and limited resources. Livestock is the major user of land: 25%. But as mentioned on the GHG subsection, livestock dwells mostly on marginal land: land which has limited potential for growth of crops. Hence, the impact of livestock on land is not an easy answer, and just removing cattle won’t make our impact on land dissipate so easily.
When compared to other sources, cattle does have a higher footprint per unit weight. A tool to compare the impact of different products is Life-Cycle-Assessments (LCA), which measures the footprint of products and services across their entire supply chain based on any desirable metric, from greenhouse gas emissions, to water, to cost, to labor or more. However, LCAs are dependent on assumptions and the functional unit (FU). The FU is the denominator of the footprint and change how products are measured. In the case of food, one could judge by weight, or grams of nutrient, calories, etcetera. Poore and Nemecek (2018) did a very comprehensive LCA of different food sources to asses their sustainability. Like many other studies, they found that beef had a higher footprint per 100 g of protein relative to other food sources, but let’s focus only on land.
The authors gathered ~38,700 regional or farm level inventories in 119 countries. Observations are concentrated in Europe, North America, Oceania, Brazil, and China, but limited in Africa and Central Asia. The land use data for red meat were heavily skewed, 25% of producers accounted for 60% of beef impact and 80% of goat. Even considering this, the impact on land is indeed 15 to 20 larger compared to nuts and peas. Even though, the interesting result which is not highlighted on the main results, is that elimination of red meat would reduce total land use of food production by ~50%, but total arable land would only be reduced by 5%. With the complete elimination of animal products, total arable land would only be reduced by 20%. And while the study does allocate the byproducts for both crops and livestock, it does not mention that most feed for livestock is inedible for humans. Given the heavily skewed distribution of red meat, this result is overestimated, and due very likely to the data from developing economies. If such regions get as efficient as North America and Europe, the impact on land (and many other metrics) would be reduced widely.
The image above shows how constrained our land is for food productivity; removing of cattle from areas where there is no potential for anything else than grazing would make the system more fragile. Using mean or median values is a terrible idea for it obscures the local context; the United States, with the highest meat and calorie intake per capita of the world, has managed to do so with 44.5% of its land dedicated to agriculture, while being able to feed more than 350 million people, exporting food and using crops for other energy uses. Brazil does not have the same consumption, but has 2.5 the number of cattle than the USA and uses also lots of crops for ethanol, yet its share of land dedicated to agriculture is only 33%. Some countries in Sub-Saharan-Africa and Scandinavia, in contrast, have less than 10%.
Hence, any claims that extrapolate the environmental impact of the American diet to the entire world is meaningless. First of all, it would be remarkable if such a feature was possible, it would mean that the entire world becomes rich! And that obesity, diabetes and cardiovascular diseases are now the major causes of concerns, not famine and poverty. But then, if the entire world were like the USA, then it wouldn’t need to exceed the land use by 100% of habitable land as usually acknowledged because developing countries would be as efficient as the USA. And then, the environmental impact would come from driving SUVs, having big houses and flying often for vacations and work. But this is actually desirable.
Let’s stress out as well that the study uses 100 g of protein as their functional unit. The FU chosen can widely change the scope and results; whether it’s weight, or calorie per gram, or calorie itself, or essential aminoacids would give different answers. For example, the study above attributes higher GHG and land use for dairy as opposed to soy milk per liter. But research that utilized a nutrition index instead of protein (remember not all grams of protein are equal) or weight, found that dairy has half the greenhouse gas emissions intensity of soy milk and a fifth of oat milk per unit of nutritional index. While the precise number for land use would be different, bottom-line is land use impact from animal protein is a complex issue taken out of context, and the effect of changing the diet is exaggerated. Well managed livestock systems provide human-digestible protein more efficiently than crops.
Antibiotic resistance
Antimicrobial resistance (AMR) is one of the most concerning global threats in this century. Antibiotics are used in the production of red meat to maintain health and productivity, but this practice contributes to the spread of pathogens resistant to treatment in both humans and livestock. However, this is not an issue unique to red-meat but all livestock: poultry and pork have higher consumption of antibiotics than cattle per unit weight. Intensive farming has made food production to be possible at a lower cost, and reduce the footprint on other metrics such as land ,water, or emissions, but it has had other secondary effects. Thus, AMR is not an inherent feature of red meat or animal source food, it’s rather related to modern agricultural techniques and practices.
The ecological interactions and the transmission dynamics make the causal link between human-infections and antibiotic use in livestock very complex. Even so, in recent years avian or swine influenza have emerged. Obviosuly, the likelihood of another deadly pandemic due to AMR attributed to farming is high and must be adressed, but removing red meat won’t make the issue disappear. AMR is a complex problem and is attributed also to misuse of medication, or infections on communities and hospitals. It is hence a problem attributed to medical practices, and whose solution lies on the medical field as well. For livestock, AMR mitigation is possible by reducing antibotic usage with improved management, hygiene, alternative treatment, preventive vaccines and proper waste management. The emergence of zoonotic diseases is a function of the frequency and nature of human-animal interactions, and the animal species from where the pathogen comes. Elimination of red-meat is not a guarantee that such complex dynamics are dissipated, especially considering many pathogens are linked to species like rodents and activities like bush-meat hunting, which would very likely increase without livestock.
Water Scarcity
Another very common misconception is that red meat is inherently water intensive. Cattle does require larger amounts of water than humans or crops, but the key difference is that the majority of the water that cattle uses is green water. Green water is the water that comes from the rain, while blue water is water used in irrigation. Blue water is the one that puts stress on freshwater resources, either surface or groundwater. And just like in the case of previous metrics, this is context and location specific. In some areas, cattle might be more water intensive than in others, and the impact on water scarcity depends on the water stress of the region. An average is misleading, especially considering as seen from the arable land map above that in many countries livestock is the only viable food source.
Going again to the widely cited Poore and Nemecek (2018) study, we find that water-scarcity is even more heavily skewed. 5% of beef producers create 67% of the water impact. In this case, the authors did add a metric to weight by water stress: they weighted the impact by the stress of the region where the farm-level data comes. A caveat is that they assume that all irrigation water is evapo-transpired or embedded in the product and none is returned to the watershed through percolation. This is sometimes true, and many times an overestimation, which means there is still further research to be done. Using these methods, nuts, poultry and pork have higher impact on water scarcity than beef and goats, and rice and wheat have also much higher impact than it on a weight basis without providing the same amount of protein. Thus, it is actually the case that eating red meat saves more water relative to other food sources, and if it were eliminated from our diets water consumption would increase.
Soil and water pollution
The main environmental problem with red meat is pollution of soil and water. This happens through acidification of the soil due to feed production and eutrophication of water resources because of manure and feed. The application of fertilizer for feed leaks ammonia and NOx which leads to acidification of the soil, while some of it also comes from use of fossil fuels for processing and transportation or residue burning. But in the case of cattle, the main problem arises from feed. But as explained before, cattle uptakes mostly inedible feed; so the assessment that just by eliminating cattle the problem disappears is false. It can’t be assumed to allocate the same rate of acidification of crops to cattle since cattle uses waste or residues. On the other hand, without cattle, there would be less organic fertilizer, which means that more synthetic fertilizer would be applied. Synthetic fertilizer creates more acidification than organic, which would then very likely offset the reduced acidification from lower crops allocated for livestock feed.
This leaves us with eutrophication: excess runoff of nitrogen and phosphorous which finds its way to waterways and creates pollution. The excess of these nutrients can lead overgrowth of algae which in turn depletes water of oxygen and dissipates life. Both fertilizers and manure have an effect on this, but if red meat is gone, neither of both will disappear. Poore and Nemecek (2018) found that if red meat was eliminated at a global level, the reduction of this problem would be trivial. The solution is thus to improve efficiency and management. Proper application of both fertilizer and manure has potential to improve the soil pH and increase organic content, and thus the elimination of red meat would come with tradeoffs that would not improve the environment or mitigate nitrogen and phosphorous runoff. Well managed agricultural systems can improve nutrient efficiency.
Biodiversity loss and animal welfare
Cattle spend only four to six months on feedlot, before being sent to processing plants. In countries with good standards such as the USA, inspectors verify the health and animal welfare conditions. Death and violence are part of life, and humans need to get food from other living organisms, there is no other way. Hence, any diet will have an impact on sentient beings and biodiversity. Food production, with or without cattle as highlighted above, needs massive amounts of land and inputs. This leads to death of many species.
It is hard to assess with precision which food system produces more or less deaths of species. But cattle grazing has the potential to conserve nature and reduce biodiversity losses. It’s rather simple: monocrop agriculture requires clearing the native flora, the use of pesticides and other techniques that reduce soil fertility and kill insects, reptiles, small mammals and birds. The greatest threats to biodiversity loss are crop expansions, especially in the tropics. Removing red meat from diet hence means that all food comes from crops, even if some of the land use for feed is reduced. This means that not eating red meat won’t have an effect on lower deaths of species of flora and fauna. Moreover, smart grazing provides semi-natural habitats which serve as replacement for lost ecological roles. Without red meat producers, there is no guarantee that such role will continue.
Conclusion
Food production and consumption is an inherently complex system with many interactions. Assessing that red meat is unsustainable based on simplistic assumptions underscores the dynamics and go against common sense. It’s illogical to say that red meat consumption is creating health problems for human beings when it has been consumed for millions of years. Red meat provides many essential nutrients and bioavailable protein. On the other hand, all food production, animal or plant sourced, has an impact on our environment. But saying that removing red meat from our diets is going to eliminate those problems is not true, and it is based on statistics that do not consider second order effects nor go beyond the surface of the dynamics involved. Improved cattle systems have the potential to restore many ecological imbalances and improve the environment.
The local and cultural context and geographical constraints of food production must be considered before making deterministic global recommendations. Red meat provides a livelihood for millions of people, suggesting that it’s inherently bad also omits the benefits it provides. In many areas, red meat is the only viable source of food procurement. Eliminating red meat would create economic harm and increase food insecurity, all for negligible and debatable environmental gains. It wouldn’t improve our health, on the contrary, it could increase physical and mental diseases. Red meat is not going to kill you or the planet.
