A healthy diet and a healthy environment seem to go hand in hand. It’s not often you meet a vegan that throws her trash out the car window. You also don’t see many environmentalists at McDonald’s. As healthy eaters, we seem to have a natural tendency to care about the environment, and it just seems to make sense that way. Right? Well, maybe not. There is a new study that may give us cause to pause and wonder: Could eating healthy foods have a negative impact on the environment?
A recent study by Carnegie Mellon Institute shows that the two might not coexist in the way we think. According to the research, if all Americans followed accepted dietary guidelines, the planet might be in trouble. The study imagines a scenario in which all Americans followed the guidelines of the United States Department of Agriculture. The USDA guidelines are an accepted standard through which normal Americans judge the nutritional benefits of their food.
The USDA recommends a diet that is heavy on fish, vegetables, dairy and seafood. While this sounds ideal to many people, increased production and consumption of these foods would have significant global impact. Larger consumption and more production of these foods would increase green house gas emissions. It could also increase our energy usage and our blue water impact, or the amount of fresh water used by humans.
Now, this is not an excuse to give up your healthy lifestyle and head for the nearest bakery. This study presents scenarios in which ALL Americans began to eat properly. Let’s face it, that’s never going to happen. However, it does present some interesting possibilities that should be considered.
- Scenario One: The first scenario presented in the Carnegie Mellon Research actually shows a better world. In this situation, Americans simply follow USDA guidelines to reduce caloric intake and achieve normal weight. There is not so much of a change in actual food production as a general shifting of current diets. Were this to occur, greenhouse gas emissions would actually be reduced by approximately nine percent globally. So far, so good.
- Scenario Two: In this scenario, American food production and consumption is shifted towards USDA guidelines, but caloric reductions do not occur. These changes would include reduced intake of solid fats, meats and added sugar. Were this to become reality, energy use would increase by 43 percent; blue water footprint would increase by 16 percent; and greenhouse gas emissions increase by 11 percent. This would be bad.
- Scenario Three: This is a combination of Scenarios 1 and 2 in which caloric intake is decreased AND the Americans’ diets are shifted towards healthier foods. While this may seem ideal, it would negatively effect our environment as well. In this scenario, energy use goes up by 38 percent; blue water footprint up by ten percent; and greenhouse gas emissions increase by six percent
Needless to say, no scenario in which all Americans strictly follow dietary guidelines is realistic. However, these are the types of diets for which many of us are striving. If it is the goal of the USDA to have a world of healthy Americans, it is important for us to understand the possible global impact it would create.
A main factor in the scenarios presented would be the increased production of vegetables. The production of more vegetables would require more fresh water, thus increasing our blue water footprint. More vegetables would also create more greenhouse gas emission.
“Eating lettuce is over three times worse in greenhouse gas emissions than eating bacon,” said Paul Fischbeck, professor of social and decisions sciences and engineering and public policy at Carnegie Mellon. Dr. Fischbeck was one of the main contributors to the research in the study. “Lots of common vegetables require more resources per calorie than you would think. Eggplant, celery and cucumbers look particularly bad when compared to pork or chicken.”
Dr. Fischbeck, Michelle Tom, a Ph.D., student in civil and environmental engineering, and Chris Hendrickson, professor of civil and environmental engineering at Hamerschlag University, actually began this study with other intentions. They had planned to study the relationship between the environment and the American obesity epidemic.
They began by examining how processing, growing, selling, and transporting all the food we Americans love affect resources in the form of greenhouse gas emissions, energy use and fresh water usage. They found that our current designs towards combating and eliminating obesity would actually have greater negative impact.
“There’s a complex relationship between diet and the environment,” Tom said. “What is good for us health-wise isn’t always what’s best for the environment. That’s important for public officials to know and for them to be cognizant of these tradeoffs as they develop or continue to develop dietary guidelines in the future.”
Foods that negatively effect the environment
While this study focused on hypothetical situations, there are currently real issues in the food world that affect the whole world. The production and consumption of many popular foods is already increasing water and energy uses as well as creating extra greenhouse gas emissions. Although this does not mean these foods are necessarily bad, we thought it would be good to at least be more aware of how what we eat affects where we live. Here are a few foods that currently have the most negative environment impact.
- Bananas: If anyone tries to sell you a locally-grown banana, you probably shouldn’t buy it. This is because they don’t grow here. Almost all of the world’s supply of bananas comes from either Columbia, Costa Rica, Ecuador, Honduras and Guatemala. They are then transported to all corners of the globe which produces a large amount of carbon dioxide.
- Avocados: Unfortunately the world’s trendiest fruit requires much larger amounts of water than its more common, less cool counterparts. Per pound, avocados require around 74 gallons of fresh water. Their growing popularity could increase our blue water footprint, but then you couldn’t brag to your friends about how to pick out a good one.
- Soybeans: The increased production of soybeans has caused massive devastation in the form of deforestation. We normally only think of deforestation as being a problem in terms of wood, but the harvesting of plants like these can be just as harmful. They grow in rain forests and already fragile environment and then are shipped around the world, causing more greenhouse effects.
- Rice: Rice and other grains are one of the leading culprits in our increased blue water footprint. According to Oxfam, rice alone accounts for almost one third of our annual use of fresh water. Recently, farmers have been developing new methods of producing rice with greatly reduced amounts, but most of the world’s rice is still drawing greatly on the water supply.
- Beef: Many readers are already familiar with some of the negative impact that America’s lust for meat causes. However, if you look further into into it, it is probably worse than you even imagined. For example, according to the U.N. Food and Agricultural Organization:
- 18 percent of all greenhouse gas emissions come from livestock. That is more than the emission caused by all forms of transportation.
- The livestock sector is responsible for the world’s largest source of fresh water pollution
- 70 percent of deforestation in the Amazon occurred to clear room for pasturing livestock
- One cow produces up to 120 kilograms of methane per year. Methane is approximately 23 times more harmful to the environment than carbon dioxide.
- Salmon: Recent awareness and actions have gone a long way to slow down the over-fishing that drove many species near extinction. However, our love of salmon and other fish has not diminished and now are now come from fish farm. While this is a preferable alternative, the technique creates problems of its own. Fish farms create waste, chemicals and parasites that are then released into our natural water supplies.
While these few foods represent harm to our environment, the biological repercussions of farming methods are even more harmful. Although many of us try to eat organic, much of the world’s food supply still consists of genetically modified foods. Many plants are now modified to deter pests, but this could also be poisonous to the animals that use them as a food source. Not to sound too paranoid, but there could also be many unforeseen problems that arise from GMFs. Some experts believe that the modified bacteria used to create GFMs could adapt and become something far more dangerous.
Don’t give up
I know this may not be the most encouraging article for someone who is trying hard to stay healthy. By no means should you give up on eating healthy foods. These examples are real, but with more awareness and conversation about the negative impact of our food, we will only be playing a positive role in diminishing it. You don’t have to give up a healthy lifestyle to avoid betraying your environmental responsibility. We also don’t hope to ruin bananas or avocados for you, but it is important to always remember the impact we have on our planet.
Humans will always have an effect on the environment and vice-versa. Co-author of the Carnegie Melon study Michelle Tom said it well:
“There’s a complex relationship between diet and the environment. What is good for us health-wise isn’t always what’s best for the environment. That’s important for public officials to know and for them to be cognizant of these tradeoffs as they develop or continue to develop dietary guidelines in the future.”