Of Fish, Astronauts, and Bone Health on Earth

This week, comments from guest blogger Dr. Scott M. Smith as he reflects on recent space station research, which connects a diet rich in fish intake and omega-3 fatty acids to a reduced rate of bone loss.

Scientists spend a lot of time discussing their work in proposals, manuscripts, and meetings, but Eureka! or light-bulb-going-off moments are amazingly rare. Our Nutritional Biochemistry Lab at NASA Johnson Space Center, however, was fortunate enough to have one of these moments recently.

Our lab’s Eureka! moment actually started a few years ago when we submitted a proposal to look at omega-3 fatty acids as a countermeasure for the muscle loss caused by space flight. Omega-3 fatty acids have been shown to help stop muscle loss in cancer patients; we believed the sub-cellular mechanisms of the two types of muscle loss are similar. In theory, if it works for cancer, it should work for space travelers. Although that proposal was well scored, funding was short that year and our experiment did not make the cut.

 

NASA Johnson Space Center Nutritional
Biochemistry Lab Logo

    Image courtesy of NASA

 

The data suggesting that omega-3 fatty acids would help slow or stop muscle loss was pretty convincing, but some softer evidence hinted that omega-3 fatty acids might also help slow bone loss. We proceeded to do a cell culture study—long story short, we added omega-3 fatty acids to bone cells and it suppressed the activation of cells that break down bone; bone breakdown is the process that is accelerated during spaceflight and during disuse here on Earth. This was pretty exciting in and of itself, but not the moment of epiphany.

The Eureka! came when we were in a meeting reviewing another bone loss countermeasure that was tested during bed rest. Unfortunately, despite high hopes going into the study, this method was not working. As I rolled this around in my head, it seemed to me that nothing to date had worked at slowing bone loss. We had tried exercise and other physical countermeasures with limited success and, although drugs are available, there is not a drug out there without side effects.

It was during this reflection that the light bulb went on. Eureka! I realized that our bed rest studies had included a menu that was pretty loaded with fish, which is a great source of omega-3 fatty acids. This was done to help increase the vitamin D content of the diet, a very important factor. As I thought of ways to investigate my hypothesis, I realized I had some challenges to face in gaining specific data on omega-3 fatty acid intake. It is not easy to find volunteers to literally spend a few months in bed, let alone subjects who are willing to participate in the bed rest and also forego eating fish.

Driving home that night, I called my colleague Dr. Sara Zwart and suggested we look at the omega-3 fatty acid intake in the existing bed rest subjects and compare it to the bone data from the same subjects. The next morning, Sara had the graph, which clearly showed a relationship between omega-3 fatty acids and N-telopeptide—a marker of bone breakdown that appears in the urine. Specifically, and statistically significantly, the more omega-3 fatty acids the subjects ate, the less bone breakdown marker they excreted, which was pretty cool!

We then took the next logical step, to see if the diet of astronauts was related to their bone breakdown. We track dietary intake of astronauts during space flight using a food frequency questionnaire or FFQ. This tool monitors the intake of seven key nutrients: energy, fluid, protein, calcium, iron, sodium, potassium. The FFQ is designed to measure only these specific things, so if we wanted to measure anything else, we would typically have to modify how we grouped the foods in the questionnaire.

Instead of redesigning the tool, we took a leap and looked at fish intake in the diet of the International Space Station crewmembers. Given that we did not have the detailed omega-3 fatty acid content of all space station foods, and given that we did not sort out the fish by those rich or poor in omega-3 fatty acid content, this was admittedly a stretch. When we compared the relationship between reported fish intake in crewmembers and their bone loss after flight, however, we found another significant relationship. Those who ate more fish lost less bone. This was awesome stuff! It was one of those rare times in a scientist’s career when unrelated pieces of information actually built into a complete story.

This story did not end, though, with these findings. What we had at this stage was what is called correlational evidence. The two factors—fish intake and bone loss—were related. This does not directly prove a causal relationship, however, and could be nothing more than coincidence or indirect effect. For example, those who ate more fish probably ate less meat, which we also conjecture is bad for bone health. What we need now is a controlled study, where we track and control intakes throughout a space mission, with one group eating a high omega-3 fatty acid diet and others consuming a low or “control” omega-3 diet. By comparing the data from such a study, we can detect differences in bone loss. We have submitted this proposal and hope an opportunity arises in the near future to carry out the experiment.

This research not only has clear benefits for astronauts, but also significant implications for those of us on Earth. These types of relationships—between fish and bone—have been observed. Given the much slower rate of bone loss on Earth, however, makes effects more difficult to pinpoint. Microgravity research can amplify the impacts, providing new knowledge that may benefit those suffering from bone loss. This is just another example of where the space station provides an out-of-this-world platform for human research!

 

Astronaut Suni Williams eats a meal that includes salmon, a fish rich in omega-3 fatty acids,
while on orbit aboard the International Space Station.

Image courtesy of NASA: ISS014E13728

 

Dr. Scott Smith and his colleague Dr. Sara Zwart lead NASA’s Nutritional Biochemistry Lab at Johnson Space Center. The research discussed above was published in the Journal of Bone and Mineral Research (Volume 25, pages 1,049-57, 2010). In addition to ground-research studies, they lead two space station experiments: Nutritional Status Assessment and Pro K, which investigate the roles of animal protein and potassium in mitigating bone loss. In today’s blog Dr. Smith shares his thoughts and experiences as a scientist with the readers of A Lab Aloft.

A Teacher’s View of the International Space Station

This week, comments from guest blogger Susan Mayo with observations about the value of the International Space Station in inspiring students.

As a former high school chemistry and physics teacher, I am pleasantly surprised by the focus on education linked to research in space. For example, I was just at the American Society for Gravitational and Space Biology (ASGSB) annual meeting in Washington, D.C. This gathering included a hands-on workshop and panel geared towards education and I was inspired by the positive, exciting, next-generation focus of this group of professionals. The ASGSB meeting is the first conference I have been to in a long time where they planned to build partnerships with classroom teachers, rather than trying to “fix” them as educators. This, in turn, better enables those teachers to share their knowledge and enthusiasm with their students.

Inspiring the next generation of innovators is an essential component of K-12 education. Children can truly aspire to be anything they want to be if, and only if, they are willing to work for it. Educators have a responsibility to provide students with the tools to guide them through the difficult process of determining where their skills and interests will lead them in the future. Students do not understand the importance of having a strong background in math and science as they progress through their education. With the nationwide focus on testing students to determine knowledge, rather than developing critical thinking skills, we are forcing an entire generation of students to concentrate on becoming test takers and not innovators.

This is where partnerships between industry and educators can truly initiate a difference via collaboration. Well over 31 million students worldwide participated in hands-on activities related to space station research from 2000 to 2006. Now, in 2010, as the International Space Station moves to assembly complete and full utilization, the opportunities for reaching the next generation grow radically.

The new technological developments and scientific research taking place on station are not only cutting edge, but also applicable to our everyday lives. Many of the future careers our students will seize do not even exist today. Educators and students have a unique opportunity with the space station to participate in science while it is happening, rather than teaching about it later on as a history lesson. While speaking at the conference, former astronaut and explorer Dr. Scott Parazynski, Challenger Center for Space Science Education, stated, “NASA is in the business of taking the impossible and making it look easy.” I believe this is what educators do every day in the classroom.

The space station gives teachers an amazing forum for their students. If you are an educator or student who wants to be part of some of our ongoing outreach programs, like EarthKAM, Kids in Micro-g, or the Zero Robotics Challenge, just click on the imbedded links here.

Susan Mayo is a scientist and educator specialist for the International Space Station Office of the Program Scientist. Her background includes experience as a high school chemistry and physics teacher in Idaho and a scientist with a background in biochemistry, chemistry, waste management and environmental science. In today’s blog she shares her thoughts and experiences from the 2010 American Society for Gravitational and Space Biology conference with the readers of A Lab Aloft.

When will we know if research on the ISS has paid off?

I often have the opportunity to do interviews with reporters who are interested in the kind of research happening on the International Space Station. Sometimes they are veteran space reporters, other times they are new and just learning about space research for the first time.

 

Regardless of their past experience, they often ask me for evidence that research on the space station is worth the cost. It is a simple question, but a misleading one. This is because it counts every penny on the cost side, but fails to account for the multiple benefits in addition to research results: international cooperation, engineering accomplishments, and research accomplishments.

 

The space station already benefits the country and the world through its construction and operation—even if it were never used as a laboratory, this would still hold true. We should not lose track of the power of daily international cooperation in constructing, operating and using the space station. The fact that this cooperation is on the cutting edge of space technology and for peaceful purposes amazes the previous generation, but is business as usual for us today. I work closely with colleagues at the main partner agencies, including Russia, the European Space Agency, Japan, and Canada; over 59 countries have participated in space station research or education activities through 2010.

 

Crewmembers from ISS Expedition 20 represent five nations and the five partners in building the International
Space Station: Belgium (European Space Agency), Canada, Japan, Russia, and the United States.
                                                                                                   
Image courtesy of NASA: ISS020e008898

 

The value of the space station as an engineering accomplishment should also not be underestimated. Common standards allow parts manufactured all over the world to interchange and connect flawlessly the first time they meet in orbit. Year round operations, 24 hours a day, 7 days a week, have now extended for 11 years, and we have more than a decade ahead of us. The various life support technologies developed for station provide redundant capabilities to ensure the safety of the crew. They also provide technology advances that benefit people right here on Earth—for example, new compact technologies provided water purification after earthquakes in Pakistan and Haiti.

 

Water filtration plant set up in Balakot, Pakistan, following the earthquake
disaster in 2005. The unit is based on space station technology and processes
water using gravity fed from a mountain stream.

                                       Image courtesy of the Water SecurityTM Corporation

 

Even if we could place a monetary value on peaceful international cooperation and engineering advances from building and operating spacecraft, finding the true long-term payoffs of scientific research is very challenging. Some items could be tabulated as direct benefits from space station research—things such as new materials and products that can have a measurable market impact. Beyond the obvious items, however, the calculations get fuzzy. New products can lead to long-term economic value by making safer vehicles, by extending human life, and even by advancing the quality of life. What might appear as esoteric knowledge may indeed be the first critical steps on the path to a high-value breakthrough. Let us not forget indirect benefits from educational activities, job creation, and economic growth, as well. Colin Macilwain wrote a great critical review of the general challenges of valuing the worth of science in Nature last June, Science Economics: What Science is Really Worth, which I recommend for those interested in the challenge of valuing science.

 

In the coming weeks I will share with you stories of some of the direct benefits that I see coming from space station research. These developed from the modest research throughput during the station assembly period, prior to the full use of the finished laboratory we have today. Based on publications so far, most space station experiments take 2-5 years post-laboratory to publish results. New products related to these results take another 5-10 years or more to transition to a direct benefit. In fact, the space station will be deorbited before an accounting can be completed.

 

Along this journey, there are some really exciting possibilities emerging. I invite you to browse developments from space station research via our key results Web site, as we monitor the progress from knowledge to direct benefits.

 

Julie A. Robinson, Ph.D.

ISS Program Scientist

 

Who will be the Carl Sagan for the International Space Station?

(Originally published October 19, 2010)


At the 2010 meeting of the International Astronautical Congress, I moderated a session of international investigators talking about the importance of the International Space Station for their disciplines: ISS Research—A Decade of Progress and a Decade of Promise. As part of a wide-ranging discussion, Professor Urade from Japan shared an amazing video summarizing tests for a new treatment for Duschenne’s muscular dystrophy, which were developed using information from space station research. The crowd collectively caught their breath at the possibility and potential impacts on human lives.

 

One of the first questions from the audience inspired my title for this post: Who will be the Carl Sagan for the International Space Station? It is a great question—how do we get the message about this amazing research platform out to the world?

 

I grew up with Carl Sagan and Cosmos—everyone understood his simple message: with “billions upon billions” of stars, other life is out there and astronomy is the key to our future in the universe. He made astronomy popular and respected. His work is one of the reasons we are so moved by the deep-space images from Hubble. Carl prepared us to understand them.

 

It is a tall order to do the same for a platform with the potential to touch dozens, even hundreds of research disciplines.

 

As scientists, we are taught that good experiments control each variable in turn. Centuries of scientific research, however, have never controlled gravity as such a variable. How many errors in scientific theory trace back to our assumptions about gravity? What breakthrough will result from completing one of these ultimate experiments in orbit—with the effects of gravity removed? Buckle up, because we are about to find out!

 

This is the first entry of an ongoing blog on space station research and results. We will have no single spokesperson and no single catchphrase, because the potential for discovery on the station is much larger than that. Working with my team of scientists, our research community, and our international colleagues, we will bring you the stories of the people and the discoveries as they unfold.

 

Please join us on our journey into uncharted territory by following our blog: A Lab Aloft.

 

Julie A. Robinson, Ph.D.

International Space Station Program Scientist