Space travel missions to Mars are usually very challenging and of high importance, especially for scientific purposes. To this end, astronauts usually pursue training courses to learn the effects that Mars mission may cause and part of their scientific education is using dietary supplements that would minimize the negative effects of space travel.

In an effort to study the impact of space travel on the human health, scientists studied the effects of radiation encountered in space on blood stem cells function and regeneration. They performed lab experiments with transplanted human cells in mice models and concluded that simulated solar energetic particles (SEP) and galactic cosmic ray (GCR) radiation adversely affected human hematopoetic stem cells (HSC). These stem cells comprise less than 0.1% of the bone marrow of adults, but produce the many types of blood cells that circulate through the body and work to transport oxygen, fight infection, and eliminate any malignant cells that arise.

Radiation exposure at these levels was highly deleterious to HSC function, reducing their ability to produce almost any type of blood cells, often by 60-80 percent.

Earlier studies by other researchers had already proved that exposure to high doses of earthly radiation, such as from X-rays, can have harmful (even life-threatening) effects on the body's ability to make blood cells, and can significantly increase the likelihood of cancers, especially leukemia. However, the current study was the first to show a damaging effect of low, mission-relevant doses of space radiation.

This study is significant because it shows that radiation affected cells at the stem cell level. It caused mutations in genes involved in the hematopoietic process, and it dramatically reduced the ability of HSCs to give rise to mature blood cells. Consequently this genetic damage led to leukemia.

Despite solar energetic particles (SEP) and galactic cosmic ray (GCR) radiation, weightlessness/microgravity present during spaceflight can also cause marked alterations in astronaut's immune function, even after short duration missions in low earth orbit, where they are largely protected from cosmic radiation. Taken together, these results indicate that the combined exposure to microgravity and SEP/GCR radiation that would occur during extended deep space missions, such as to Mars, could potentially exacerbate the risk of immune-dysfunction and cancer.
Other than causing elevated risk for leukemia, scientist also found that gravity seems to bevital for normal tissue health, with the forces it generates stimulating and promoting regeneration by stem cells. NASA experiments in microgravity on ISS show sharply reduced ability by mouse embryonic stem cell cultures to develop and generate different tissue types. This is new evidence that gravity mechanical stimulation on Earth promotes stem cell-based tissue regeneration, and that mechanical unloading in microgravity, as well as disuse on Earth, can slow-down normal tissue regeneration. Other studies pointed out that space travel may increase the risk of heart, anxiety and other diseases. 

As we know, the higher the altitude of traveling to the planets, the lower we weigh. Maybe this can give us any clue about new insights in the role of space mission in obesity.

Another intriguing fact is whether a latent genetic/proteinic programming is activated while traveling on Mars and what are molecular changes that occur as long as we travel with aircraft.

These new underexplored insights clearly demonstrates that space travel usually hinders stem cell function and impair regenerative ability as a results of lowering oxygen levels and gravity force reduction while carrying space mission.

All these newly revealed facts may commence the emerge of a new discipline, astro-genetic or genetic astrology that deals with the genetics of life forms out of earth or the impact of space in the human genome. Probably this new discipline will illuminate many unexplained things pertaining regenerative medicine and genetics.


 The article is written by Vedat Sunguri ( Master of Pharmacy, University of Pristina) .