Cows, she believes, can engineer healthier ecosystems, and healthy grass-fed animals provide meat with measurable health benefits over factory-farmed stuff. This sounds reasonable, but the carbon cost of cattle is what troubles most environmentalists today. In her book Defending Beef , Hahn Niman explains how naturalistic cattle grazing adds manure and organic matter to the soil and encourages plants that help draw down carbon.
Unlike crops, which are traditionally cultivated by ploughing the soil and releasing carbon, there is a wealth of evidence showing that carefully grazed grasslands sequester carbon.
The same study calculated that, globally, 1g of protein per person per day comes from grass-fed animals, whereas 32g of protein per person per day comes from all animal sources including fish, with 49g from plant sources. These kinds of big global studies frustrate Hahn Niman because, she argues, they fail to account for the complexity and diversity of land.
So the Nimans are converting arid grassland into sustenance where no other human food could be produced. Many environmentalists argue in response that if diets were to become much less meaty, all such grazing land could be rewilded , sequestering even more carbon, while cropland is farmed more intensively to feed the world. This, responds Hahn Niman, fails to acknowledge the soil erosion and carbon emissions caused by intensive, plough-based farming.
And in modern agriculture and modern human life we tend to ignore what that functionality looks like — where there should be watercourses, grasslands, forests. Where grasslands occur naturally and have been grazed by wild herbivores for millennia, farming with nature is grazing cattle. What is her best estimate of how much those emissions would fall if we only raised grass-fed beef? What you should do on the land is radically specific to that place. I am convinced that grazing, when done well, is probably beneficial everywhere.
If the world switched to eating only grass-fed beef, people would have to eat much less and pay much more. But it only remains in the atmosphere for a relatively short time: half is broken down in nine years. This leads some to argue that maintaining the global cattle herd at current levels — about 1 billion animals — is not heating the planet. The burping cows are just replacing the methane that breaks down as time goes by.
Even if you ignore methane completely, says Poore, animal products still produce more CO2 than plants. His work shows that a transition to a predominantly plant-based flexitarian diet would free up both pasture and cropland. The pasture could instead be used to grow trees and lock up carbon, provide land for rewilding and the restoration of nature, and growing bio-energy crops to displace fossil fuels.
This is true. Furthermore, research shows this carbon storage reaches its limit in a few decades, while the problem of methane emissions continue. The stored carbon is also vulnerable - a change in land use or even a drought can see it released again. That is probably true but misses the real point.
A huge driver of the global wildlife crisis is the past and continuing destruction of natural habitat to create pasture for livestock. Herbivores do have an important role in ecosystems, but the high density of farmed herds means pasture is worse for wildlife than natural land. Eating less meat means less destruction of wild places and cutting meat significantly would also free up pasture and cropland that could be returned to nature. Furthermore, a third of all cropland is used to grow animal feed.
There is no lack of protein, despite the claims. All protein needs can easily be met from plant-based sources, such as beans, lentils, nuts and whole grains. But animals can play a role in some parts of Africa and Asia where, in India for example, waste from grain production can feed cattle that produce milk. In the rest of the world, where much of cropland that could be used to feed people is actually used to feed animals, a cut in meat eating is still needed for agriculture to be sustainable.
If you are worried about the Amazon, not eating meat remains your best bet. Some almond production may well cause environmental problems. But that is because rising demand has driven rapid intensification in specific places, like California, which could be addressed with proper regulation. It is nothing to do with what almonds need to grow.
Traditional almond production in Southern Europe uses no irrigation at all. It is also perhaps worth noting that the bees that die in California are not wild, but raised by farmers like six-legged livestock. But if you are still worried, there are plenty of alternatives, with oat milk usually coming out with the lowest environmental footprint.
Again, the problem here is the rapid growth of production in specific regions that lack prudent controls on water use, like Peru and Chile. Avocados generate a third of the emissions of chicken, a quarter of those of pork, and a 20th of beef. If you are still worried about avocados, you can of course choose not to eat them. The market is likely to solve the problem, as the high demand from consumers for avocados and almonds incentivises farmers elsewhere to grow the crops, thereby alleviating the pressure on current production hotspots.
Quinoa is an amazing food and has seen a boom. But the idea that this took food from the mouths of poor farmers is wrong. Quinoa was never a staple food, representing just a few percent of the food budget for these people. The quinoa boom has had no effect on their nutrition. There is an issue with falling soil quality, as the land is worked harder. The researchers are more worried now about the loss of income for South American farmers as the quinoa supply rises and the price falls.
Palm oil plantations have indeed led to terrible deforestation. A massive review of 20 studies including 1,, individuals found that processed meat was associated with an increased risk of heart disease and diabetes. However, no association was found for unprocessed red meat In the EPIC study, a very large observational study including , people, processed meat increased the risk of death, while no effect was seen for unprocessed red meat The observational studies seem to agree that processed meat not unprocessed red meat is associated with an increased risk of an early death and many diseases.
Some observational studies show a link between meat intake, diabetes, heart disease and death. Other studies suggest this only applies to processed meat, not unprocessed red meat. Many observational studies show that red meat consumption is associated with an increased risk of cancer 12 , 13 , The main type of cancer that red meat is believed to cause is colorectal cancer, the fourth most commonly diagnosed cancer in the world.
A recurrent problem in these studies is that they seem to pool together processed meat and unprocessed red meat. Meta-analyses in which researchers analyze data from many studies show that the increased risk of colorectal cancer is very low. One meta-analysis found a weak effect for men, but no effect for women 15 , Several observational studies show that red meat eaters are at a greater risk of cancer, but larger reviews looking at the evidence as a whole show that the effect is weak and inconsistent.
When you look closely, practically all studies that allegedly prove that red meat causes harm are observational studies. They can tell us that individuals who eat a lot of red meat are more likely to get sick, but they cannot prove that red meat is the cause.
One of the main problems with such studies is that they are plagued by various confounding factors. For example, people who eat red meat are less health-conscious and more likely to smoke, drink excessively, eat more sugar, exercise less, etc. There are many cases in history where randomized controlled trials ended up showing the exact opposite effect.
Later, a randomized controlled trial discovered that it actually increases the risk Observational studies cannot be used to determine cause and effect. There are many confounders in such studies, and higher-quality studies sometimes end up showing the exact opposite effect.
In these studies, people are randomized into groups. For example, one group eats diet A, while the other group eats diet B. Then the researchers follow the people and see which diet is more likely to lead to a particular outcome. As a rich protein source, red meat can also benefit muscle growth in people doing strength exercises.
A study in older women showed that eating grams of red meat six days of the week for four months enhanced muscle growth resulting from strength training, compared to pasta or rice Red meat also decreased the levels of the inflammatory marker IL-6 Keep in mind that all of these studies examined lean red meat.
To date, no studies have examined the health effects of high-fat red meat. However, there are plenty of studies that compare high-fat diets with low-fat diets. These studies have the primary goal of reducing saturated fat , which means that the people in them have to eat less red and processed meats, which happen to be high in saturated fat. One group was instructed to eat a low-fat diet, while the other group continued eating the standard Western diet.
After a period of 7. There was also no difference in the rate of heart disease or cancer 23 , 24 , 25 , One randomized controlled trial compared the Atkins diet high in red meat to the Ornish diet a low-fat vegetarian diet with no red meat. It is called the A to Z weight loss study After one year, the Atkins group had lost more weight and had greater improvements in some of the most important risk factors for disease.
Many other studies compared low-carb high in red meat and low-fat low in red meat diets. In these studies, low-carb diets lead to much better health outcomes 28 , 29 , However, more studies need to examine whether it affects hard endpoints like heart disease and cancer. The roles of cooking methods and processing techniques also need to be studied further. Several randomized controlled trials indicate that the intake of unprocessed red meat does not have negative health effects.
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