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There are so many different types of lettuce on the market these days. You can whip up a crisp Caesar salad with Romaine lettuce, a tangy wedge salad with iceberg lettuce, or an artisanal salad with a nifty head of hydroponic lettuce that comes with the root ball still attached! With all these choices, not to mention kale, arugula, and other leafy vegetables, you may wonder how sustainable lettuce is and which variety to buy.
Plastic Bags vs. Plastic Boxes
If you are buying lettuce from a grocery store, you will easily find whole heads of lettuce, triple-washed leaves, and salad kits with chopped greens. Most of these will probably come in some type of plastic packaging. The plastic used in bags of lettuce contains additives to keep the greens fresh. According to Association of Plastic Recyclers, these polymer barriers may help protect the food and extend its shelf life but recyclers consider them to be contaminants in the recycling bin. You’ll often find hydroponic lettuce and mixed spring greens sold in clear plastic boxes made from #1 polyethylene (a.k.a. PET), and these are totally recyclable. If you are buying lettuce in plastic, it’s more sustainable if you go with the plastic box instead of the plastic bag and then recycle the box.
Hydroponic Lettuce
Hydroponics is a system for growing plants indoors without any soil. Hydroponic farming uses around 90% less water, grows crops at any time of year, and yields more harvests in concentrated areas in shorter spaces of time. With climate-controlled greenhouses, producers can grow pretty much anywhere, even in “food desert” cities, which means they can also stay local and generate less carbon emissions from transportation. Disadvantages to hydroponics include high start-up costs and excessive amounts of energy required for indoor operations unless they use renewable generated power (not unlike vertical farming).
Whole Head Lettuce vs. Chopped Lettuce
According to FDA spokesperson Peter Cassel, lettuce that is pre-cut and pre-packaged is handled along the supply chain way more than whole head lettuce is, so there are more opportunities for it to become contaminated along the way. While salmonella and listeria can be removed through careful washing, E. Coli is nearly impossible to rinse off and can make you quite sick. Buying from a farmers’ market is preferable to buying from a grocer because less time has transpired from farm to fridge, and there are fewer opportunities for contamination from human handling and other foods during processing and transportation.
It’s also no secret that you’ll pay more for the convenience of having produce that is washed, chopped, wrapped, or processed in any way. For Romaine lettuce, Safeway charges $3.49 for one whole head, $4.49 for a 7 oz. plastic box of leaves, and $4.99 for a 10oz plastic bag of triple-washed chopped lettuce.
Nutritionally speaking
According to Jo Robinson, author of Eating on the Wild Side, bagged and boxed lettuce is usually almost two weeks old from the time it is harvested to the time it goes into your fridge, often with a couple of extra days in storage before it reaches your plate. Produce is never as fresh as when it was first picked and nutritional values plummet with each passing day. Water-soluble vitamins B and C are easily washed away during commercial cleaning and processing. The more fresh and intact your lettuce is when you buy it, the more you will reap its nutritional benefits. This Business Insider article ranks 10 different lettuces according to their nutritional value. It’s no surprise that iceberg lettuce ranked the lowest, with one cup having only 7% of daily vitamin A and only 3% of daily vitamin C. Even the Chick-fil-A chain of restaurants banned iceberg for its low nutritional value. In contrast, the CDC ranks Romaine lettuce among top 10 "powerhouse foods" that reduce your risk for chronic diseases. One cup of Romaine lettuce is only eight calories and has 81% of daily vitamin A. Here are tips on storing lettuce.
Footprints
Lettuce is cultivated only part of the year and has a relatively low water footprint. It takes about 28 gallons of water to produce one pound of lettuce. By comparison, it takes 1,800 gallons of water to produce one pound of beef! The average carbon footprint of beef, excluding methane, is 10 to 100 times the footprint of most plant-based foods. In 2018, a comprehensive study by Oxford University found that animal farming provides 18% of calories but takes up 83% of farmland. It concluded that avoiding meat and dairy was the single biggest way to reduce one’s impact on earth.
There were surprising and controversial reports back in 2015 that claimed lettuce had a larger carbon footprint than bacon. The reasoning was that bacon surpassed lettuce for protein and caloric intake, therefore, it had more value and relatively less impact on the planet. Fortunately, Scientific American debunked this claim and pointed out that we don’t eat lettuce for protein but rather for fiber, hydration, nutrients, and vitamins (and, of course, for the enjoyment of eating delicious and healthy food!). It’s a well-established fact that on the scale of best and worst foods for the environment, beef, pig, and lamb farming are the worst burdens on the planet, partly due to the methane they produce.
Ethics
The world’s top lettuce producers are China, the USA (70% from California and 30% from Arizona), and India. The health and safety of farm laborers vary from farm to farm and country to country. Agriculture in general is a dangerous industry for farmworkers due to poor working and living conditions that include exposure to toxic chemicals and pesticides, unsafe machinery, dehydration, heat stroke, migrant worker abuse, job loss, employer mistreatment, and wage violations, to name a few. This is another reason it pays to know where your food comes from and to shop at your local farmers’ market. Sustainability is not just about environmentalism but also about keeping communities healthy and thriving while responsibly managing ecological, social, and economic resources. Be sure to buy pesticide-free varieties of produce whenever possible. Finally, it’s obvious but worth stating – no animals are harmed or killed in the production of lettuce.
Bottom line: For lettuce that is cheaper, less processed, safer, and more ethically produced, choose organically grown whole heads of lettuce from your local farmer.
Sources and further reading:
https://www.shelfengine.com/blog/best-worst-foods-for-environment/
https://www.healabel.com/water-footprints-of-food-list/
https://www.trees.com/gardening-and-landscaping/advantages-disadvantages-of-hydroponics
https://www.bonappetit.com/story/best-lettuce-to-buy
https://www.sgaonline.org.au/the-pros-and-cons-of-hydroponic-growing/
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