Astronauts aboard the International Space Station (ISS) are striving to provide an insight into Parkinson's disease, the chronic neurodegenerative disease that affects more than five million people worldwide, NASA has revealed.

The team, comprising astronauts Serena Aunon-Chancellor from NASA and Alexander Gerst from the European Space Agency (ESA), are studying a group of protein crystals associated with Parkinson's growth and may help researchers find a way to slow it.

For the study, the team grew protein crystals of Leucine-rich repeat kinase 2 (LRRK2) on the space station.

While growing LRRK2 crystals on Earth is difficult and does not produce high quality samples, the extreme low-gravity environment in space spurs them to grow larger and more uniformly, the team said in a blog post on Tuesday.

People with Parkinson's have been found to experience increased function of LLRK2, and genetic studies link mutations in the LRRK2 gene to an increased risk of developing Parkinson's disease.

Although "medications that inhibit LRRK2 are in development, but without knowing the precise structure of this enzyme, such work is like making a key without knowing the shape of the keyhole it must fit," the blog post said.