by Jack Dini
New research from Carnegie Mellon University shows that consuming more fruits, vegetables, diary and seafood is more harmful to the environment because these foods have relatively high resource uses and green gas emissions per calorie. (1)
Eating the recommended 'healthier' foods—a mix of fruits, vegetables, dairy and seafood—increased the environmental impact in all three categories: energy use went up by 38 percent, water use by 10 percent and greenhouse gas emissions by 6 percent.
“Eating lettuce is over three times worse in greenhouse gas emissions than eating bacon,” said Paul Fischbeck, professor of social and decision sciences. “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.” (1)
And speaking of lettuce, here's what Tamar Haspel reports: “Salad vegetables are pitifully low in nutrition. The biggest thing wrong with salads is lettuce, and the biggest thing wrong with lettuce is that it's a leafy-green waste of resources. Salad is one food that has almost nothing going for it. It occupies precious crop acreage, requires fossil fuels to be shipped refrigerated around the world, and adds nothing but crunch to the plate.” (2)
Researchers Charles Benbrook and colleague Donald Davis developed a nutrient quality index—a way to rate foods based on how much of 27 nutrients they contain per 100 calories. Four of the five lowest ranking vegetables (by serving size) are salad ingredients: cucumbers, radishes, iceberg lettuce, and celery. The fifth is eggplant. (2)
Then there are nitrates which concern some folks. As far as humans are concerned, most of the nitrates we receive come from vegetables, about 80 percent. About 10 to 15 percent come from water. (3)
Beets, celery, lettuce, and spinach provide us between 75 and 100 mg of nitrates a day, while vegetarians get more than 250 mg. (4)
So, should one stop being a vegetarian? No, says Ross Pomeroy who cites the following reports. In a 2009 review, the Academy of Nutrition and Dietetics, the largest organization of food and nutrition professionals in the US, declared that 'appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases.' More recently, a 2012 review published in the Journal of Public Health Nutrition found that vegetarian diets have not shown any adverse effects on health. (5)
So in spite of higher greenhouse gas emissions, low nutrition salads, and higher nitrate contents, choice of vegetarianism is supported by some studies. Take your pick.
1. Shilo Rea, “Vegetarian and healthy diets could be more harmful to the environment,” cmu.edu/news, December 14, 2015
2. Tamar Haspel, “Why salad is so overrated,” The Washington Post, August 23, 2015
3. Jean-Louis L'Hirondel, “Are dietary nitrates a threat to human health?”, in Fearing Food, Julian Morris and Roger Bate, Editors, (Oxford, Butterworth Heinemann, 1999), 38
4. Bjorn Lomborg, The Skeptical Environmentalist, (Cambridge, Cambridge University Press, 2001), 202
5. Ross Pomeroy, “Large study finds vegetarians have poorer health, lower quality of life than meat eaters,” realclearscience.com, April 4, 2014