Over-the-counter osteoporosis drug appears to keep astronauts from losing bone density on long space flights

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Big news: New research on ISS now shows that the standard over-the-counter osteoporosis drugs used by millions on Earth appears to keep astronauts from losing bone density during long space flights.

Beginning in 2009, the group administered the drug to five long-stay astronauts on the International Space Station (ISS), including Koichi Wakata, 48, and Soichi Noguchi, 46. The five took the drug — an over-the-counter bisphosphonate used to treat osteoporosis — once a week starting three weeks before they lifted off until they returned to Earth. The researchers then monitored the astronauts’ bone mass over time and compared the results to those for 14 astronauts that had never taken the drug.

The results showed that the 14 who had never taken the drug had average bone density loss of 7 percent in the femur, and 5 percent in the hip bone. The five astronauts on bisphosphonate, however, only had average bone density loss in the femur of 1 percent, and even a 3 percent increase in the hip bone. Calcium levels in their urine, which rise the more bone mass is lost, were also very low.

If these results hold up, they might very well solve one of the biggest challenges faced by any interplanetary traveler. Up until now, bone loss during long weightless missions never seemed to average less than 0.5 percent per month. After spending three years going to and from Mars, an astronaut could thus lose about almost 20 percent of their bone mass in their weight-bearing bones, and would probably be unable to return to Earth.

Thus, a mission to Mars seemed impossible, unless we could build a ship with some form of artificial gravity, an engineering challenge we don’t yet have the capability to achieve.

If these already tested drugs can eliminate this problem, then the solar system is finally open to us all. All that has to happen now is to do some one to two year manned missions on ISS to test the drugs effectiveness for these long periods of weightlessness.



  • Craig Beasley

    This is great news. The only disagreement that I have is in regards to artificial gravity and our technological incapability generate such an environment. All we really need is an acceleration bearing down on the human body, though we don’t know exactly how much is required to keep bone and muscle density within a normal range.

    Space missions with constant thrust would provide such an acceleration. VASIMR Rocket missions, that sort of thing. If we can use these medications to bolster the beneficial effects of any induced accelerations to simulate a gravity vector, then we have indeed removed one of the major impediments to long-term, deep-space crewed missions.

  • Patrick Ritchie

    It continues to boggle my mind that more research into artificial gravity isn’t going on. Gemini 11 proved the basic principle (albeit only generating 0.00015 g…), but since then I’m not aware of any experiments being flown.

    Even if the bone loss issue can be addressed with drugs, weightlessness has plenty of other undesirable effects on the human body.

    Also, without variable gravity research we have no way of knowing what the effects 1/3rd or 1/6th gravity (Mars or Moon) might have.

  • Kelly Starks

    Agree Patrick, zero G hurts muscle, immune function, cardio vascular, etc. So bone loss alone is just window dresing.

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