Many of us wanted to be astronauts when we were kids. Some of us may even still daydream about it. While we lionize pioneers like Neil Armstrong and Buzz Aldrin, we now know that prolonged time in space comes with some serious health consequences. We are, after all, creatures whose anatomy evolved with gravity weighing us down. Astronauts’ nutrition and cardiovascular system can be greatly affected, and a particular risk is the loss of bone density in reduced gravity.
Here’s some fun news: A chemical engineering team from the University of California, Davis has developed a transgenic — genetically modified — lettuce that would be able to give astronauts the chemicals they need to stop their bone density loss.
Parathyroid hormone (PTH)
Astronauts can take PTH to counteract their bone density loss in space. On earth, our bones are usually in a balanced state between growth and resorption, helping us to recover from injuries. PTH helps to maintain this balance in reduced gravity, by pushing bones toward the resorption side of the spectrum. The problem is that a drug supply of PTH would eventually expire on a long space voyage.
Growing PTH lettuce in space
The UC Davis team genetically modified lettuce to express a fusion protein mixing PTH with a human antibody protein. This would be safe and stable in the blood, and it would give the astronauts the PTH they need from lettuce they can grow themselves using LED lighting. The team is still working out the dosages, as in how much PTH they can introduce into the lettuce to allow astronauts to monitor their intake just by biting off the leaves.
Being able to grow their own plants and crops would be helpful for peace of mind and morale on long space journeys. More importantly, though, a space garden would give the astronauts a means to produce food with PTH and in the future, potentially, other necessary drugs for their bodies to live in space.
Here’s to daydreaming about being an astronaut the next time you’re eating a salad. Gotta eat your space greens!