While space travel sucks in red blood cells and weakens bones, microgravity isn’t all lost.
A new study of International Space Station (ISS) astronauts suggests that the fatty tissue inside your bones acts as a temporary buffer against the decline in cell and bone density in a weightless state. Even better, treatments based on this new knowledge may help aging populations, as well as people on Earth who must remain in bed due to medical conditions.
“We found that the astronauts had significantly less fat in their bone marrow about a month after they returned to Earth,” said lead study author Jay Trudel, a rehabilitation physician and researcher at Ottawa Hospital and a professor at the University of Ottawa. Statement August 21. (The study’s lead author is Tammy Liu, who also works at the hospital.)
“We think the body uses these fats to help replace red blood cells and rebuild bones that are lost during space travel,” Trudel added.
Related: Spaceflight causes the body to kill red blood cells and not get better after landing
The new study examined 14 astronauts, each of whom had spent at least six months aboard the International Space Station. It’s part of a group from Science Canada seeking more information about how bone marrow and blood production change in space. One of the functions of the International Space Station in general is to study how long microgravity shifts affect all aspects of health, from balance to bone, which lends itself well to research.
Trudel’s larger study, called Marrow, looks at bone cells that produce fat, red blood cells and white blood cells. The study concluded the active collection of samples in 2020, but continues to push new frontiers in science as the data is analyzed. For example, an investigation published in 2022 tracked changes in red blood cells in space that appear to persist for some time after landing.
Red cell production is fundamental to human health, as healthy red blood cells carry oxygen throughout the body. Without enough of these cells, the body will become anemic and will experience physical and mental health problems. For astronauts tasked with landing on the Moon or Mars, preventing this condition from occurring is essential to helping establish settlements beyond Earth, which NASA wants to do with its Artemis lunar program later this decade.
“Fortunately, anemia is not a problem in space when your body is weightless, but when landing on Earth and possibly on other gravitational planets or moons, anemia will affect energy, stamina and strength and can threaten mission objectives,” Trudel said. . “If we can learn exactly what controls this anemia, we may be able to improve prevention and treatment.”
The new bone marrow study, based on MRI scans on Earth before and after the astronauts’ space missions, shows a slight decrease in fat in the bone marrow: an increase of about 4.2%, on average, just before the astronaut’s flight into space, compared to the sample collection. One month after landing.
However, this deficiency recovers on Earth with an increase in red blood cells and bone density. The study authors noted that younger astronauts may be able to get more energy from fat, while female astronauts saw more fat in their bone marrow than expected a year later.
“Since red blood cells are made in the bone marrow and osteoblasts surround the bone marrow, it makes sense for the body to use local fats in the bone marrow as an energy source to fuel red blood cells and produce bone,” Trudel said. . “We look forward to further investigating this in various clinical situations on the ground.”
A study based on the research is published in Nature Communications on August 9. Funding was provided in part by the Canadian Space Agency, which got science aboard the International Space Station through NASA’s ongoing Canadarm robotics program that exchanges science and astronauts’ time. for devices.