Exposing leafy vegetables grown during spaceflight to a few bright pulses of light daily could increase the amount of eye-protecting nutrients produced by the plants, according to a new study by researchers at the University of Colorado Boulder.
One of the concerns for astronauts during future extended spaceflights will be the onslaught of eye-damaging radiation they'll be exposed to. But astronauts should be able to mitigate radiation-induced harm to their eyes by eating plants that contain carotenoids, especially zeaxanthin, which is known to promote eye health.
Zeaxanthin could be ingested as a supplement, but there is evidence that human bodies are better at absorbing carotenoids from whole foods, such as green leafy vegetables.
Already, NASA has been studying ways to grow fresh produce during deep space missions to maintain crew morale and improve overall nutrition. Current research into space gardening tends to focus on getting the plants to grow as large as possible as quickly as possible by providing optimal light, water and fertilizer. But the conditions that are ideal for producing biomass are not necessarily ideal for the production of many nutrients, including zeaxanthin.
"There is a trade-off," said Barbara Demmig-Adams, professor of distinction in the Department of Ecology and Evolutionary Biology and a co-author of the study published in the journal Acta Astronautica. "When we pamper plants in the field, they produce a lot of biomass but they aren't very nutritious. If they have to fend for themselvesif they have to defend themselves against pathogens or if there's a little bit of physical stress in the environmentplants make defense compounds that help them survive. And those are the antioxidants that we need."
Plants produce zeaxanthin when their leaves are absorbing more sunlight than they can use, which tends to happen when the plants are stressed. For example, a lack of water might limit
|Contact: Barbara Demmig-Adams|
University of Colorado at Boulder