Causes of Astronaut Bone Loss Unraveled in New ISS Study

In space, astronauts lose bone mineral density. However, researchers are still unsure exactly why this is. Now, they're investigating the phenomenon a bit more closely as space agencies prepare for longer-term space travel.

Previous studies into bone loss have suggested that microgravity activates osteoclasts. These are cells that control the breakdown of bone tissue.

In this latest study, the researchers reared small, freshwater fish aboard the International Space Station for 56 days. They then examined the animals' jawbones and teeth for any potential effects from microgravity.

So what did they find? There was indeed an increased volume and activity of osteoclasts, and significant reduction of bone mineral density in the fish aboard the station. The scientists also used electron microscopes and found that there were abnormalities in osteoclast mitochondria. Mitochondria are round or rod-shaped organelles inside most of our cells that produce enzymes for converting food to energy.

Genetic analysis also revealed significant increase in activity in two genes that may be involved in mitochondria function. This suggests that osteoclast activation might be linked to the reaction of mitochondria to microgravity.

The findings could mean that medicines that target mitochondria dysfunction could help prevent bone loss in space. The new research could be extremely useful for preparing astronauts for long-term space travel, when conditions like bone loss could be severe over time.

The findings are published in the journal Scientific Reports.

Related Stories

The 'Big Bang' May be Confirmed with a New Method Examining the Beginning of the Cosmos

Milky Way Galaxy Has Dark 'Noodles' Moving Around

For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).