Scientists find that ISS-grown lettuce is just as nutritious as Earth-grown lettuce

Research shows that ISS lettuce is just as nutritious as Earth-grown lettuce

If humans are ever going to permanently live away from Earth then growing and harvesting food is a key step in the process. After all, shipping goods from Earth to the moon, Mars, or a space station is too expensive and difficult to do forever. Moreover, as the global population rises Earth won’t be able to spare the resources to support an entire space colony.

Fortunately, growing food in space is looking more viable than ever. Researchers who analyzed lettuce grown aboard the International Space Station (ISS) recently discovered that it is just as nutritious as Earth-grown lettuce. That’s a huge breakthrough for the future of space food.

Healthy Eating

The lettuce in question was grown on the ISS between 2014 and 2016. It is the red romaine variety and grew from seeds to produce entire heads that astronauts were able to harvest. The experiment was part of NASA’s Vegetable Production System, also known as “Veggie” for short.

After harvesting it, astronauts froze samples of the lettuce and sent it back to Earth so it could be analyzed. Researchers Christina Khodadad and Gioia Massa of the Kennedy Space Center were in charge of the study. Their findings were published in the journal Frontiers in Plant Science.

To compare the nutritional value of space lettuce versus Earth lettuce, they also grew a test batch here under the same conditions. Several heads of lettuce were cultivated with LED lighting and the same watering system used aboard the ISS.

After analyzing both lettuce samples the researchers found that they are essentially comparable. Both types are equally nutritious and are free of dangerous microbes like E. coli and Salmonella.

Interestingly, the ISS lettuce had more microorganisms living on it. While it would seem like crops grown in a highly-synthetic environment would be cleaner, the opposite is true. Nonetheless, the microbes found in the sample aren’t harmful to humans and don’t compromise the quality of the lettuce.

Life in Space

Although lettuce alone won’t be enough to sustain astronauts living in space, the results of this study are encouraging. If nutritious lettuce can grow safely in microgravity then scientists believe other produce items can as well.

To test that hypothesis, NASA also sent kale and cabbage to the ISS. Meanwhile, to add some spice to their diet, the ISS crew is currently growing the Espanola chili pepper.

For those living in space and eating prepackaged meals every day, menu fatigue can quickly become a problem. Researchers believe that supplementing astronauts’ diets with freshly harvested fruits and vegetables could alleviate it.

Meanwhile, Khodadad and Massa say, “In the long term, if we ever want to have space colonization, growth of crops will be crucial for establishing any level of sustainability and self-sufficiency.”

They go on to note that growing crops can help make space communities more efficient. The duo says, “In addition to providing food, plants may also play a role in future Life Support Systems needed for long-duration missions. Plants generate oxygen as well as remove and fix carbon dioxide, which is critical in closed systems like the ISS or future moon/Mars facilities.”

Although such facilities are a long way off, knowing that space crops are nutritious is a huge positive factor that will enable their development.


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