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Eating foods that some experts believe are harmful to health — particularly processed and unprocessed red meat — damages the environment, the study also found. Credit: Photo by José Ignacio Pompé on Unsplash

Eating foods that promote good health — particularly nuts, fruits, vegetables and whole grains — benefits the environment, according to a study published in the Proceedings of the National Academy of Sciences (PNAS).

Eating foods that some experts believe are harmful to health — particularly processed and unprocessed red meat — damages the environment, the study also found.

The authors of the study, a team of researchers from the University of Minnesota and Oxford University, say their study offers the first comprehensive look at the effects of specific foods on both human health and the environment.

“This study shows that eating healthier also means eating more sustainably,” said David Tilman, the study’s senior author and a professor of ecology, evolution and behavior at the University of Minnesota, in a released statement.

“Normally, if a food product is good for one aspect of a person’s health, it’s better for the other health outcomes as well. The same holds for environmental outcomes,” he added.

Study details

For the study, Tilman and his colleagues explored the impact on human health and the environment of 15 foods commonly found in a Western diet: chicken, dairy, eggs, fish, fruits, legumes, nuts, olive oil, potatoes, processed red meat, refined grain cereals, sugar-sweetened beverages, unprocessed red meat, vegetables and whole-grain cereals.

Using data from previous research  — 19 meta-analyses of the impact of different foods on health, as well as life-cycle analyses of the natural resources needed to grow those foods — the researchers calculated how eating one extra serving a day of each of the 15 foods to the average American diet would affect five different health outcomes (type 2 diabetes, stroke, heart disease, colorectal cancer and early death) and five aspects of environmental harm (the amount of water and land required, greenhouse gas emissions, and water and soil pollution).

They then looked to see how those two outcomes compared across all the foods.

They found that most foods linked to a lower risk of disease — primarily nuts, fruits, vegetables, legumes, whole grains and olive oil — had the lowest impact on the environment.

Similarly, most foods often linked to a higher risk of disease — primarily beef, pork and other unprocessed and processed red meat — were found to have the highest impact on the environment. In fact, the researchers estimated that the environmental impact of the production of a serving of unprocessed or processed red meat was 10 to 100 times larger than that of a serving of plant-source foods.

But not every food fit neatly into those patterns. Fish was one example. Although generally considered a healthful food, some methods of fish production (such as bottom-trawling fisheries) emit more greenhouse gases than other methods and thus have a moderate impact on the environment, the researchers explain.

On the other hand, sugar-sweetened beverages, which pose a significant risk to health, were found to have a relatively low environmental impact.

A call for change

To help reduce the devastating effects of climate change, the United Nations recommended earlier this year that populations around the world reduce their meat consumption and adopt plant-based diets.

By cutting back on meat, more land can be used to store the greenhouse gases emitted through human behaviors, the UN experts explained.

“It’s important that all of us think about the health impacts of the foods we eat,” said Jason Hill, one of the current study’s co-authors and a biosystems engineer at the University of Minnesota, in a released statement.

“We now know that making our nutrition a priority will pay dividends for the Earth, as well,” he added.

FMI: You’ll find the study on the PNAS website.

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15 Comments

  1. Methodologically, this study seems profoundly flawed. Is red meat harmful to the “environment”, or is it the vast landscapes of GMO corn everywhere we can grow it, bad for the earth?

    Ruminants are important to the health of ecosystems. They keep growth in check while fertilizing – much like fire, which we have also removed from the former grasslands. The illness isn’t eating ruminants, it is crowding them into feedlots and feeding them corn they aren’t evolved to eat.

    Is there anything worse for the land and waters in America than GMO industrial corn and soybeans? These commodities are also ruinous to human health – the idea that sugary drinks with high fructose corn syrup are not bad for ecosystem health in the macro or the micro is laughable. Commodity corn and soybeans are a foundation of the process foods in America, exterminating pollinators while making so many Americans so obese and health care costs as obese.

    Eating less red meat is a fine idea, but that is not anything like a solution for ecosystem health. If we want healthier foods we need to quit subsidizing commodity crops, focus less on corporations and high finance, and more on land access for more people, smaller farms and more local production, mandating carbon capture, soil fertility and water quality.

    Our ill health and high health care costs are a direct reflection of our ill treatment of the land and waters, of farm policy generally. If we want to be healthier, we need to make food production healthier for all life.

    1. I agree, William, with what you’re saying about animals being important for the environment as they graze. That is proven. As (maybe a poor) example, just look at the goats grazing in California to save the Reagan library. I even agree somewhat with what you say about ill health being related to ill treatment of land. I believe, though, the blame is not with GMO corn but rather in poor dietary habits of people and a farm policy that barely recognizes good environmental setasides and Best Management Practices of farming that conserve soil and minimize pollution of water and air.

      1. With respect Greg, the problem with GMO corn is the widespread use of glyphosate. In the late 90’s, we spread about 10 million gallons of it. Now, we use about 300 million gallons, which has devastated plant habitat diversity, leading to the near extinction of many pollinator species. In addition, because glyphosate is sprayed on grains to dry them after harvest, studies have found high levels in bread and breakfast cereals (heresy I know, in the land of General Mills and Pillsbury).

        Also, people buy what they can afford, and industrial commodity crops produce the cheapest, and also the least healthy foods.

          1. With respect Rachel, General Mills in that link wants to promote regenerative, sustainable agriculture on 1 million acres by 2030. That is the equivalent size of the Boundary Waters Wilderness. The total acerage of corn, soybeans and wheat each year in America is about 230 million acres. Statistically, that would make General Mills efforts more like corporate marketing and less like the systemic change we truly need.

  2. Here’s a quick quiz: Two people want to reduce greenhouse gas emissions by changing their consumption patterns: A junks her car and buys and electric car. B goes vegetarian. Which tactic had the greatest effect? The answer is B. Greenhouse gas emissions from meat production are huge.

    But all meats are not equally damaging; it’s especially beef that we should focus on. The environmental impact of a pound of beef is many times greater than the impact of a pound of chicken. Beef is at least twice as damaging as pork.

    So if you don’t want to quit eating meat, you can still make a significant difference just by substituting almost any other meat for beef. (Lamb is actually a bit worse per pound, but most people don’t buy it often.)

    1. The thing is, greenhouse gases are like a red herring for ecological destruction generally. Factoring in all variables, an electric car is considerably worse for the health of the earth than a herd of morally and ethically raised dairy and beef cattle. And with strict vegetarianism, in the north country, in the winter, your veggies are likely traveling a very long ways – as opposed to say, the homesteading omnivore producing most of his or her food.

      1. Yes, greenhouse gasses are a poor shorthand for overall environmental destruction, but it’s no red herring. I agree that a herd of morally and ethically raised beef or dairy cattle aren’t much of a problem. But they’re not large part of a solution either. The problem is that most of our agriculture system is geared toward producing lots of cheap beef and dairy.

        The price difference between commodity beef and ethical beef is so great that as long as the average consumer assumes that beef has to be “what’s for dinner” — and also what’s for lunch — the public has a huge incentive to support our current agricultural system. You won’t change it much by inviting people to pay twice as much to switch to ethical beef. You have to use other tactics as well. A lot of other tactics.

        Driving past the corn and soybean fields in Minnesota and Wisconsin you consider the vast quantities of food that we produce, almost none of which is for human consumption, apart from the corn syrup for soft drinks, etc. It’s all for feed, and most of that is for the very least efficient use of feed, which is commodity beef cattle. (It’s amazingly wasteful!) It’s a highly capital intensive, resource intensive, environmentally destructive and lucrative business. And it’s spreading around the world. It’s a major driver of the destruction of rain forests in the Amazon basin.

        If you could magically make everyone switch from commodity beef to commodity pork, you instantly lose half the problem. Half the feed required, half the water use, half the water pollution, half the herbicide dumped into our soil. (Yeah, I know, you’d have to regulate pork production carefully.)

        It just seems like encouraging any kind of switch from consuming commodity beef (switch to ethical beef, switch to any other meat, etc.) is the low-hanging fruit for an individual looking to painlessly decrease their personal contribution to environmental degradation. So much cheaper and tastier than a Prius.

        1. I agree in the main, John. In fact I think what we need is a far more radical departure from the status quo. The main problem in agriculture is the focus on markets of scale, ie, consolidation and monopoly. If we treated food more like the foundation of the economy, the cities would be surrounded by thousands of family farms practicing rotational grazing and regenerative, sustainable ag. That would eliminate much of the problem of scale, making for greater parity in the cost of food between true organic and industrial, stronger communities and healthier ecosystems.

  3. Everything would be wonderful, if only we weren’t omnivores.

    (Screams at the sky) Damn you evolution!!

    1. They used to tell us about the Cradle of Civilization, and now they talk about 6 or 7 places on earth where civilizations sprang up independently: in Mesopotamia, Egypt, China, India, the Andes, Mesoamerica (Mexico). Sometimes they add Chokia, on the Mississippi near St. Louis.

      Jared Diamond points out that those in the Western Hemisphere had no consistent source of domesticated meat. That’s because there were no domesticable meat animals on our side of the planet, apart from the Guinea Pig.

      So maybe beef cattle aren’t a necessary part of the character of our species.

      1. Yes, and he opined it was that wonderful omnivorous diet which allowed Eurasians to expand their civilization at the expense of their less well fed neighbors.

        Make mine medium rare, please.

        1. Both these comments are so woefully wrong, and contain so many historical accuracies. The turkey was domesticated in Mesoamerica for one. Additionally, half of the domesticated crops in worldwide production trace their lineage to the Western hemisphere. If it were not for the export of new world crops like corn, beans and potatoes, the impoverished expanses of Europe could never have attained a population surplus which set about colonizing the new world.

          Don’t believe my word. Rather, read the primary accounts of Europeans who all were in shock at how well fed the original inhabitants were. The ethnocentrism in these comments, though unsurprising, is tragic. Unless we as a society can implement some of the effective food production strategies practiced by the original inhabitants, our way of life is doomed.

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