A few years ago, astronauts first ate lettuce grown on the International Space Station (ISS),media New Atlas reported. It has now been determined that the nutritional value of “space lettuce” is at least as good as the likeplants grown on Earth. Between 2014 and 2016, the red-leafed lettuce “Outredgeous” plant grew on the International Space Station for 33 to 56 days, in NASA’s Veggie zero-gravity greenhouse. Among other things, the setup includes LED planting lights and automatic watering systems.
When the three astronauts each ate several leaves, the rest of the crops were frozen and transported back to Earth. Scientists at the Kennedy Space Center conducted chemical and biological analysis of it and compared it to Outredgeous, a red leaf lettuce grown by the center’s laboratory during the same period. The growth conditions of the “Earth lettuce” match the temperature, carbon dioxide level and humidity in the Veggie greenhouse.
Overall, scientists found that the earth and ISS plants are very similar in composition. In some cases, however, space lettuce is actually rich in potassium, sodium, phosphorus, sulfur and zinc. It also contains higher levels of phenolic substances, which have been shown to be antiviral, anti-cancer and anti-inflammatory.
Interestingly, the diversity and homogeneity of the microbes present in the two groups of plants were similar – assuming that the types of organisms in ISS lettuce were reduced. Importantly, no harmful bacteria (such as E. coli or salmonella) have been found on any plant. Therefore, based on these and other findings, space dates are considered edible (and safe).
“The International Space Station is serving as a test ingester for future long-term missions, and these types of crop growth tests are helping to expand the number of candidates that can grow effectively in microgravity,” said study co-author Dr. Gioia Massa of the Kennedy Space Center. Future tests will look at other types of leafy crops, as well as fruits and vegetables such as peppers and tomatoes, to help provide fresh produce to the astronauts’ diet. “
The paper was recently published in the journal Frontiers in Plant Science.