Dr. Gabrielle Lyon [00:00:01]

Welcome to the Dr. Gabrielle Lyon Show where I believe a healthy world is based on transparent conversations. I’m very excited to bring you this special episode of The Dr. Gabrielle Lyon Show in which I sit down with Dr. Scott Smith, who leads the nutritional biochemistry lab at NASA Johnson Space Center. This group is charged with keeping crews healthy with respect to nutrition, including nutrition to optimize astronaut health and safety. This work includes ground-based and spaceflight research to understand how nutrition can mitigate the risks of spaceflight. Smith has ongoing research projects on the International Space Station. His past projects have been flown on the space station, space shuttle, and the Russian Space Station. Smith has also led several ground-based research projects to the bottom of the ocean, not to mention studies of vitamin D in crews in Antarctica.

Smith is a member of the American Society for Nutrition, the American Physiological Society, and a whole bunch more. He is one amazing individual. I found this episode really interesting. We talked all about the biomarkers measured in an astronaut. What are the biomarkers that we see that vary from space to Earth and the oxidative stress that the astronaut will face? What are the nutritional strategies that one can use to mitigate this? What are the implications of vitamins and minerals, particularly vitamin D, as it relates to immune function, both in space and on Earth? We talk all about the nutritional needs of the astronaut as well as the nutritional needs of the Earthbound human. I hope you like this episode. Again, it was such an honor to talk with Dr. Scott Smith. Please take a moment to rate, subscribe, share it. There’s always something that we can learn. Thank you so much for listening.

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Scott Smith, although I would love to call you Dr. Scott Smith, tell me, what do you do you for NASA?

Dr. Scott Smith [00:05:21]

I’m a nutritionist, and I lead the nutritional biochemistry lab here at the Johnson Space Center.

Dr. Gabrielle Lyon [00:05:28]

Do people often make jokes about Houston having a problem?

Dr. Scott Smith [00:05:35]

Occasionally.

Dr. Gabrielle Lyon [00:05:37]

Only really bad jokes. Thank you so much for taking the time to be on the show. I’m really excited to interview you and hear all about some of the potential changes that happened in space. Please, correct me if I’m wrong, you did a wonderful review in Cell Press in 2020. It stated that a principal goal of NASA, which is National Aeronautics and Space Administration, has historically been to expand scientific knowledge for humankind’s benefit. This includes a greater understanding of the universe as well as repurposing space-relevant research to advance science and technology on Earth.

Dr. Scott Smith [00:06:21]

Indeed, and that’s in the macroscopic level. Again, the knothole I look out of is nutrition, then in short, how do we keep astronauts healthy from a nutrition point of view to allow mission success.

Dr. Gabrielle Lyon [00:06:37]

That is a very noble endeavor. I’m sure keeping astronauts healthy is not an easy task. By the way, you’re very well published. Thank you for that. I’m so interested in, in particular, the potential of the genetic profile of an astronaut as it relates to having challenges, for example, ocular issues, or potentially, you could lay out a handful of challenges that the astronaut is going to encounter, and then the genetic predisposition that is going to potentially worsen that problem.

Dr. Scott Smith [00:07:19]

Indeed. Spaceflight is pretty hard on the human body. We see changes in almost every system. We see bone loss, muscle loss, cardiovascular changes, and immune changes. We found changes in the FFIs, you name it, all sorts of things. Nutrition, being a cross-cutting science, touches many of those things. For most of those cases or almost all those cases, I wouldn’t presume to tell you that if we just fed them the right thing, none of those changes would occur. It’s not that simple. But what we know is that nutrition plays a significant role in disease risk on Earth and on human adaptation in any environment. By feeding the right things, or the wrong things, we can make the risk of those pathologies better or worse. What we found with the ocular changes– it is probably the most striking thing I’ve ever seen. Around 12 to 14 years ago, we realized that some astronauts were coming back with changes in their eyes. There’s some nuance to it, but in simple terms that I understand, we had some people that went up with perfect vision, and came back and needed glasses, and still five, six, seven years later. There’s a very long story behind this, and about 12 years of work, but we found differences in the blood chemistry of the astronauts that develop those eye problems, and we found differences in their blood chemistries before flight.

We did some research and followed up on that. We did a lot of work and found that some astronauts are genetically predisposed to develop ocular problems during spaceflight and that specifically, the genetics are affecting one of the biochemical pathways in the body that involves B vitamin metabolism, so things like folate, B12, B6, and riboflavin. What we’re about to test is whether or not we can give supplements to overcome that genetic effect to prevent at-risk astronauts from developing this problem.

Dr. Gabrielle Lyon [00:10:06]

That’s so fascinating. What you’re referring to is a homocysteine level. I’m curious, I’m sure that there’s a whole host of biomarkers, but you’re exactly right. I found it very fascinating that these vision changes preflight were much different than post flight. It’s so profound that you were able to identify this pathway of one carbon metabolism as it relates to homocysteine because as a physician in my practice, we test homocysteine routinely. I’m curious as to did you find a common polymorphism? Was there a certain gene mutation? How high was there homocysteine? As it relates to homocysteine and folate, were there certain numbers that you saw that put those individuals at risk, or was it more just the mutation in and of itself?

Dr. Scott Smith [00:11:02]

Those are several great questions; let me see if I can break it down. First of all, the homocysteine levels that we saw were not that high. But when we looked at again, affected astronauts to not affected astronauts, we saw statistically significant differences. But the homocysteine levels that we were seeing were at the point where they were within normal limits, so if somebody showed up in your office and you measure the homocysteine, you can shrug it off until you’re at the high end of normal, but it’s not a big deal. The fact that they were consistently higher, and the fact that they were different before flight, is what led us to look at genetics. We did an initial study back in 2012 where we picked a handful, literally five, single nucleotide polymorphisms that we felt were well documented to be associated with changes in the homocysteine. At the time, we were criticized by our friends and by the reviewers that we should be looking at hundreds of these snips, that we were going way too narrow. Our response back was this was NASA’s first ever look at individual genetic data, and we weren’t sure the IRB was going to approve it. We weren’t sure the crew was going to go along with it. We said look, we’ll pick our best five and hope for the best.

What came of that initial study was, again, we found statistically significant relationships between the genetics or the forms of those five snips and the incidence of these ocular issues. We then spun from that to do a broader study looking at the 500 snips, and we’re still following up on that. In short, there were one or two snips when we looked at them specifically that we were seeing some unique patterns. But as I often say, we didn’t find a smoking gun. We didn’t expect to find a smoking gun. We never expected we’d find one snip that would cause that. We found a couple snips we looked at. One, everybody that had the minor form of that snip developed ocular problems. That was pretty striking. But there were a lot of people that had ocular problems that didn’t have that snip.

Again, what we think is happening is that there are hundreds of snips that impinge upon this biochemical pathway, and your specific mix of genetics at some point will lead to a tipping point where it will affect your B vitamin metabolism, blood vessel function, nitric oxide synthases, and endothelial function at the point at which your blood vessels don’t work as well as they could. That is somehow leading to changes in the eye when put in the spaceflight environment, that it really is a multiple hit phenomena that if you have the same set of genetics here on Earth, it’s probably not an issue. But if we were to put you in head down till bedrest, if we were to fly you in space where the fluid will move from your lower extremities in your head, with those extra triggers, those can cause these problems.

Dr. Gabrielle Lyon [00:15:06]

It’s such a fascinating thing to think of because eventually, again, we’ll probably be on other planets and certain individuals will likely tolerate that better than others. Do you know what it is about? Is it the homocysteine? Is it because of that metabolite? Do you guys have a sense of what is it about space that is creating just a rapid change in potentially, oxidative capacity? Is there something particular about space?

Dr. Scott Smith [00:15:46]

This one, we simply don’t know. I don’t think homocysteine in and of itself is causing the effect. We actually think that it’s more related to blood vessel function, endothelial function, and again, nitric oxide synthases. We know that if you are fully deficient, for example, you will have endothelial dysfunction. We think it’s more related to the blood vessel function associated with the fluid shift of spaceflight that is probably causing this problem. But that’s all hypothetical. We really do not know what causes this problem.

Dr. Gabrielle Lyon [00:16:34]

When the astronauts are on earth, it sounds weird saying on Earth, do you supplement them with B6, B12, and folate to lower their homocysteine? Have you looked at the implications of supplementation, and if it actually lowers their homocysteine levels?

Dr. Scott Smith [00:16:54]

We just started an experiment where we will give people a combination of B6, B12, riboflavin, and folate to see if we can mitigate the eye problems during spaceflight. Our first crew member is going to launch next month. We did her second set of preflight testing this morning, and she’ll be the first of 16 people that will participate in our study. I have to say that historically, NASA has been rather squeamish about genetic data because whenever you talk about genetics, the first question is always well, you could use that to ground people, to select people. It’s literally against the law to do that. We’re by no means looking to do that. But one of the things that does for our experiment is we will open the experiment up to the first 16 people that sign up. We will not look at their genetics before they sign up, and we will not base their participation in the study on their genetics. Again, that’s a very odd way of laying things out. But given the situation, given where we work, and given the population we work with, those are some of the protections we have to go through to make sure that we don’t accidentally out that somebody’s got a certain set of genetics, which obviously can have an effect on their family, on their on their children’s disease risk and things like that. We tend to be even more careful than in general.

Dr. Gabrielle Lyon [00:18:51]

Yes. Actually, it was prior to the interview, for the listener, I definitely had to contact your team and submit a whole thing, give them a retinal scan. No, just kidding. It wasn’t that bad. I had a few questions regarding homocysteine, and one of the reasons I’m talking about homocysteine and MTHFR is many of the listeners in clinical practice, oftentimes, people do test for mutations, whether it’s challenges with pregnancy or vascular risk factors. MTHFR is something that many physicians do test for. In lowering homocysteine, just a few thoughts, have you looked at perhaps a lower methionine diet, potentially increasing cysteine, anything like that?

Dr. Scott Smith [00:19:43]

We’ve not done either of those things. Again, what we think is happening is that the genetics are affecting the biochemical pathway, and as a result of that, or as an artifact of that, homocysteine concentrations are a little bit higher. Again, I don’t know for sure, but based on our data, I do not think that homocysteine in and of itself is the bad actor, if you will. So, if we could magically suck all the homocysteine out, if we could magically remove all the homocysteine from the blood, I don’t think that would change the overall situation. I think it’s more complex than that. So we have not looked at other ways to lower homocysteine because I don’t think that’s the problem, and I think if by giving the vitamins in and of themselves, we think that’s going to fix the issue.

Dr. Gabrielle Lyon [00:20:50]

That’s interesting. What about aspects of oxidative stress, and how do you recreate those environments before sending them off to space? Do you look at ways that there’s an increase in oxidative stress, for example, lower vitamin D levels, impaired immunity? What are some of the things that you impart on the astronauts or potentially, these control groups? What are some of the implications?

Dr. Scott Smith [00:21:18]

Oxidative stress is a is a serious concern. That’s one of the things that we worry about quite a bit, not only because of the typical spacecraft environment, but secondary to radiation exposure in which in low Earth orbit where the space station is, they get significant higher radiation doses then on Earth. But as we’re looking at missions to go back to the moon, as we look long term in missions to go to Mars, the radiation profile gets even greater the further away you get from Earth. Again, I can’t argue that diet alone is going to protect against that, but we know that dietary components, things like fruits and vegetables, sources of flavonoids, lycopene, and other antioxidants can help to mitigate that, if not prevent it, period.

One of the things that we’re always looking for are ways to simulate aspects of spaceflight here on Earth. Spaceflight research is always very exciting, and nothing beats doing research with astronauts on board a space station. But the reality is, it’s very challenging to do those studies. The amount of time and subjects you have and the nature of the studies is very constrained. We’re always looking for ways on Earth that we can mimic elements of that. If we want to look at bone loss or muscle loss or eye changes, we put people to bed for a month or two or three. We can look at changes in those systems there. We’ll be wanting to look at oxidative stress. One of things we’ve done is we piggyback on some studies that were being done at a habitat off the coast of Florida that is about 50 feet below the surface of the ocean, and crews were living there for about two weeks.

We did studies looking at changes in vitamin metabolism, changes in iron metabolism, and red blood cell metabolism. When we want to look at vitamin D and how much vitamin D to give to astronauts that don’t see the sun for six months, we did studies in Antarctica where the sun doesn’t come up for six months. We were actually doing two follow-up studies on that right now, working with colleagues in Europe and colleagues in the immune lab here, looking at the impact of Antarctic isolation and stress on immune system function, and the ability of diet and nutrition to help mitigate some of those stresses.

There’s a lot of different analogues that we use depending on what it is we’re trying to study. None of them are perfect, but they’re all very valuable in their own way and contribute not only to our understanding of elements of how things change during spaceflight, but they often have implications for people here on Earth.

Dr. Gabrielle Lyon [00:24:28]

Are there particular biomarkers that you look at for oxidative stress when individuals are underwater?

Dr. Scott Smith [00:24:37]

There’s a number of things we look at. We’ll look at dopamine oxygen capacity. We’ll look at PGF2alpha in the urine, which is an oxidative stress marker. We’ll look at 8-hydroxy-2′-deoxyguanosine, which is a DNA damage marker. We’ll look at vitamins like vitamin E. We’ll look at glutathione and other nutrients. Depending on the study, we do a pretty wide swath of biochemistry trying to understand as many factors as we can. One of the ways that we overcome the fact that we can’t do what I would call epidemiological-grade studies, we study a very small number of individuals typically, but we look at a large number of markers. What that does is it gives you confidence. If you’re seeing three, four, five, or six different markers show the same patterns even though you only have 10 or 12 subjects, it allows you to make inferences on the overall situation that’s going on.

Dr. Gabrielle Lyon [00:25:45]

Are you able to supplement, for example, if someone has low glutathione status? Are you able to offer that to the astronauts? Or do they all have different individual protocols?

Dr. Scott Smith [00:25:58]

We do a nutritional assessment workup on the space station crew members, and we will work with them or work with our flight surgeons. We evaluate their nutritional status twice before flight, once around 18 months before flying, once about three months before flight. We will make recommendations to the flight surgeon of here’s what their data are, here’s what we think, and here’s what we would recommend.

Dr. Gabrielle Lyon [00:26:26]

Would you say that it’s very conservative in terms of what you would be able to prescribe or offer, whether it’s supplementation, because the supplement landscape is always changing? There are new things. For example, there’s a compound, Urolithin A with gut microbiome. It’s been studied for 20 years or so, and it’s now just making it to more of the mainstream, which obviously, is not your population, but we’re seeing human studies, and it’s validated in animals first and then brought to the public. Are there challenges bringing new supplementation to the astronaut, to this population, maybe something that you find very valuable, but perhaps isn’t enough data behind it yet?

Dr. Scott Smith [00:27:17]

Absolutely. We are probably considered extremely conservative. The number of emails I get from people with suggestions of this week’s supplement, I get a lot of those emails. We typically are extremely conservative, and we don’t move out unless there’s really solid evidence of effectiveness and that not only effectiveness, but that there’s no other concerns, that there’s no concerns of risks of excess amounts because as you know, especially a lot of the nuanced vitamins and supplements can have very high levels of certain nutrients. Again, we don’t have the kind of population that we can afford to find out that oops, there was too much of something in there; we shouldn’t have done that, or oops, in certain individuals, they don’t respond well to this. We took a very slow, conservative approach.

Dr. Gabrielle Lyon [00:28:29]

That would not be ideal, especially if an individual is on their way to Mars. I think that’s what, 1,000 days. I could think that would be definitely an issue. As it relates to vitamin D status, do you see changes in immunity? Have you looked at immune function when you’re dropping individuals off in Antarctica or looking at periods of time where they have no sun exposure for six months? What are some of the changes that you see? How did you get to the current recommendation that you are at for the astronauts?

Dr. Scott Smith [00:29:05]

We did two studies in Antarctica; this was a little over 10 years ago now. One of them was in collaboration with our colleagues in the immune lab. One of the things that we found was an interactive relationship between vitamin D status and stress and viral reactivation. More simply put, what we found is that individuals that had lower vitamin D status, that had higher stress markers, were more likely to reactivate latent viruses. That fits very well with our understanding of nutrition and vitamin D and immune system function. We published that paper, I think, back in 2011. When the pandemic started, we actually looked back at those data and published an editorial paper in, I think, July of 2020 positing that based on our data, it was plausible to think that the reason some people had a much harder course of infection of COVID might be interrelated with those data that vitamin D status and stress might help explain why some people had a much harder course than other people that did not. That was in the first months of the pandemic, and I think at this point, there’s a lot of papers out there where people have looked at nutritional status and vitamin D status and shown that indeed, those are contributing factors to infection in general, and COVID infection in specifics.

Dr. Gabrielle Lyon [00:30:57]

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Is there a particular dose of vitamin D, or do you just go with the standard recommendation?

Dr. Scott Smith [00:33:48]

We when we started flying crews to the space station, we knew that we needed vitamin D. We were providing 400 IU supplements. After a few years when we started looking at the data, we realized that a lot of crews’ vitamin D cells was dropping after flight. At that point, we took the simple approach of we were flying 400 IU tablets, and we said, take two. When we started to do some of the work in Antarctica, we looked at 400 IU, 1,000 IU, and 2,000 IU. What we found was that there really was no difference in the response. There was a slightly faster reaction to a higher dose of vitamin D, but after about a month or two, they all got to the same point and leveled off. When we then started to look at the results of crews that were taking 800 IUs on orbit, their vitamin D levels were good when they started, and they stayed there during flight. So, we firmly believe that about 800 IUs, plus a little bit in the diet, is plenty to maintain vitamin D levels at what most people consider to be optimal vitamin D.

Dr. Gabrielle Lyon [00:35:15]

It’s interesting to see the crossover between what is valuable on Earth and in space, and I suppose that that’s because human beings are human beings. Was there anything that was just so surprising to you, just changes within the astronaut from Earth to space that you didn’t expect, that perhaps that their needs were much greater or, again, different? For example, satiation, being able to eat to capacity, that’s probably different in spaceflight than it is when you’re eating on a gravity-based planet.

Dr. Scott Smith [00:35:55]

Indeed, and a couple of things there, one, we did some studies a ways back documenting that energy expenditure is the same during flight as is on earth. If it’s not the same, it’s higher depending how much they exercise. The immediate assumption is that you’re going to spaceflight, you’re not walking around to the same degree, you’re not working to the same degree, so you probably need fewer calories. The reality was that’s not the case, that for reasons we don’t fully understand, your body is burning the same number of calories as it did on Earth. To that end, you need to consume the same number of calories to maintain body mass. Historically, we’ve seen a lot of crews lose weight during flight. When we meet with astronauts before flight, I always tell them that if I can only tell you one thing is that you need to eat enough, you need to get enough calories, and you need to maintain your weight. If you’re losing weight during spaceflight, you’re losing more bone than you need to, you’re losing more muscle than you need to, your cardiovascular system doesn’t like it, your oxidative stress goes up, and this is not the place to lose weight. We’ve seen a lot of crew members that we said, look, you’re not eating enough. You need to get more of this. They said look, I’m eating, so I’m full; I’m fine. We said, look, if you look at your body mass, it’s going down, so there’s something not right.

I don’t have data to back it up, but what I think is happening is that satiety signals are different during flight, and that food settles in your stomach differently. In essence, your stomach tells your brain that you’re full before you are. We encourage crews all the time that you need to– we have an iPad app up there that they’re using to track their intake, and the crews have really responded well to that. They enter the food as they’re eating it, so at lunchtime, they can see where they are relative to their energy requirements, and they know how much more they need to eat at dinner to round out that day. I tell them all the time, either you need to push more food into meals, you need to snack more, it doesn’t matter; the job one is to get those calories in.

Dr. Gabrielle Lyon [00:38:28]

Do you find that the microbiome of the crews resembles each other, if it’s something that you looked at?

Dr. Scott Smith [00:38:35]

There have been a few microbiome studies during spaceflight. At this point, I don’t think we know enough about microbiome in terms of acting on it really, on Earth or in flight. We know that microbiome is very important. We know that your diet will affect it. But we don’t really know yet what to tell you to eat to make your microbiome do something that will turn around and help your overall health. We know things like more fruits and vegetables, a better diet, more omega-3 fatty acids will produce a more beneficial microbiome. We haven’t been able to do a study on orbit that could prove that, although we have one that is ongoing where we’re testing providing better foods to see health outcomes, and microbiome is one of those. But again, we don’t really have that data yet. Nonetheless, we know that the microbiome is important. We know that there’s reasons to be concerned about that during flight, but being able to act on that in a concrete way, we haven’t had to do that yet.

Dr. Gabrielle Lyon [00:39:58]

Have you looked at omega-3 fatty acids in the brain and protection during flight?

Dr. Scott Smith [00:40:05]

We haven’t looked in relation to the brain, but we have looked at bone health. What we showed is that crews that ate more fish lost less bone. We actually did ground-based studies where we showed the same thing that more omega-3 fatty acids were protective of bone in bedrest subjects, and we did cell culture studies where we took cells and put them into a microgravity-type environment, and if you had an omega-3 fatty acids, they would be less osteoclast-inducing. Again, they would suppress the bone breakdown mechanisms in themselves.

Dr. Gabrielle Lyon [00:40:47]

We’re definitely seeing fatty acid effects on skeletal muscle from preventing sarcopenia, changes in or at least mitigating atrophy. That is very important, of course, as individuals age. Do you feel that individuals age exponentially during spaceflight?

Dr. Scott Smith [00:41:12]

I don’t know about exponentially. I know there have been a lot of people that have made the argument that when you look at the changes that we’re seeing in astronauts, that they look a lot like aging, so muscle loss, bone loss, cardiovascular deterioration. I suppose you can make the argument that spaceflight appears to be accelerating aging, sure. I look at it another way is that a lot of our research has been done looking at diet and bone health and bone loss during spaceflight, and again, those changes will mimic some of the things that we see in people on Earth. What to me is fascinating is that we can study astronauts that are up there for about six months, and looking at either dietary changes or exercise changes, we can see things in generally very healthy people put in a very strange environment, and we see changes in bone in six months that you would see on the order of about five years on Earth. I think of it as it’s almost like time lapse photography where you see things happening much faster. The work that we’re doing in spaceflight, even though we’re trying to prevent bone loss in a relatively small population, the work that we do helps to inform the scientists on Earth that are trying to study osteoporosis in a much larger group of people. I wouldn’t go as far as to say we’re going to cure osteoporosis, but as with every other bone researcher out there, we’re all contributing pieces to the science that, when you step back from all those pieces of research, allows you to see the picture of bone health and bone metabolism and its effectors that can help to ultimately mitigate disease.

Dr. Gabrielle Lyon [00:43:15]

Do astronauts utilize osteoporosis medications prior to going into space? Is that something that you have looked at?

Dr. Scott Smith [00:43:24]

There have been studies of bisphosphonates in particular, to see whether or not those would be viable countermeasures, and to a degree, the jury’s still out. They did help those individuals to degree. Those studies were done at the same time that we flew a new resistive exercise device on station. We had some astronauts that ate well, a good vitamin D status, and exercised really hard but they were the resistive exercise that had the same level of bone change as people that took the drugs. Do we need to be giving everybody antiresorptive medications? I don’t think so. Could antiresorptives be an alternative if the excess devices break or on missions where we can’t have resistive exercise? I think that’s something that needs to be considered.

Again, I’m not afraid to sound like very biased nutritionist. One of the issues of medications is they always have side effects. Bisphosphonates are a class of drug made for Osteoporotic patients. To give that drug to 70-year-old woman with osteoporosis, you don’t have the same concerns that you would giving that drug to a 45-year-old male that is going to have advanced bone loss for six months or a year. The implications of that drug are such that it blocks the ability to get calcium out of the bone. What we saw in the astronauts that took those medications is, in many cases, we saw low levels of calcium in the blood. That causes as much concern as the overall picture of bone loss because, hypercalcemia comes with some significant risks, and we need to be very careful when we’re giving medication to fix one thing that we keep track of all of the downstream effects that they could be having.

Dr. Gabrielle Lyon [00:45:48]

Regarding exercise, are you involved in their exercise prescription? You’re probably at least aware of some of the things that they’re doing because of managing their nutrition.

Dr. Scott Smith [00:46:03]

That’s correct, and actually, one of the things that I’m really excited about is that we tend to have a model here where indeed, I focus on nutrition, and in many ways, nothing but. We work with a flight surgeon who was the physician taking care of each astronaut. We provide input into what their nutrition is, and the physician then talks to their trainers on what their exercise protocols are and all the different pieces of the healthcare. We recently started working on what I would call a care team approach where all of us are sitting down together to discuss individual astronauts. In those cases, we’re actually sitting down with their strength trainers and can talk to each other over what are they working on? What are they concerned about from an exercise point of view? We can inform the conversation from a nutrition point of view to make sure that we’re all on the same page because as you know, you can’t have one without the other. If your nutrition is not supporting your exercise, the exercise is not going to work. So, we’re putting all those pieces together in a way that really should be done, and that’s one of the things moving forward that I’m really excited about.

Dr. Gabrielle Lyon [00:47:31]

That’s going to be so great. The exercise component, you said that there’s a new machine that individuals are using, do they use stim suits, blood flow restriction? What are some of the ways in which an astronaut maintains healthy skeletal muscle?

Dr. Scott Smith [00:47:50]

They’ve looked at things like blood flow restriction on the ground; I’m not aware if we’ve done that in-flight. If we have, it’s been experimental, not programmatic. The astronauts have essentially three key exercise devices on space station; one is a treadmill, one is a cycle, and the other is, what we call, a resistive exercise device or a weight machine, if you will, that uses hydraulics to allow them to do resistive exercise. As on Earth, different types of exercise provide different benefits. For aerobic health, the treadmill and the cycle are very beneficial. For bone health, you need loading, which means you need resistive exercise.

Dr. Gabrielle Lyon [00:48:42]

That is absolutely right, and we definitely see that here on Earth. What is happening with supplementation as it relates to protocols for sleep, circadian rhythm? Do astronauts use melatonin? Are there certain protocols that are put into place?

Dr. Scott Smith [00:49:02]

Sleep is obviously of significant concern. There’s a behavior performance group that helps the physicians operationally. Then there are a number of individuals doing research to try to better understand circadian changes during flight, lighting issues during flight, and sleep. It is extremely challenging to sleep up there. There’s a lot of noise. There’s a lot of things going on. There’s a lot of side issues. Indeed, the astronauts are getting consultation where their flight surgeons have a number of mechanisms that they can work with to do it to make sure they’re getting a good night’s sleep. We actually just started a study working with colleagues out in California at the Ames Research Center to look at the relationship between the sleep data that they have the dietary intake data that we have to see if we can link things like caffeine intake and some other nutrients that might be related to sleep to see if we can put some data to make some dietary changes to help improve sleep, too.

Dr. Gabrielle Lyon [00:50:18]

So, melatonin is not something that’s utilized for sleep.

Dr. Scott Smith [00:50:23]

I don’t know specifically. The short answer is I don’t know. But it wouldn’t surprise me if they don’t use melatonin. It’s not all the time, but occasionally. But again, that’s out of my–

Dr. Gabrielle Lyon [00:50:35]

Probably no alcohol up there either from a nutritional standpoint, probably.

Dr. Scott Smith [00:50:41]

I do know that. There’s no alcohol up there.

Dr. Gabrielle Lyon [00:50:46]

What do you feel is really exciting for the future as it relates to optimizing these astronauts?

Dr. Scott Smith [00:50:54]

Not specifically to optimizing astronauts, but one of the most exciting things that we got going on literally right now is we just started what we’re calling a Mars simulation study. It’s a ground analogue. It’s a habitat that we built. It’s a 1,700 square foot space that was 3D printed out of cement. We put four crew members in there, I think, 17 days ago. They’re at the very beginning of a 378-day mission where they will be confined in this Mars-like habitat. There’s a number of things that they’re being required to do including a 22-minute communication delay as you would have on Mars. When they want to talk to Earth, they send an email, then 22 minutes later, the people in Mission Control will get it. They will find the answer and type it back, and 22 minutes later after they hit send, they receive it in the habitat.

They’ve got mission-realistic timelines. They’ve got logistics constraints. They’re eating space food. They’re doing experiments. They’re growing plants. There’s a 1,200 square foot sandbox with red sand next door that they will do spacewalks. They’ll have to go out. There’s a treadmill out there where they will have to walk to simulate traversing away from the habitat to go dig in the sand and find Martian rocks. There’s again, structures they’ll have to deploy. They’ll be at this for a year, and we’re looking at their performance, behavior, nutrition, and dietary intake. We’re looking at things like menu fatigue, all the different facets of what you can do on a ground-based analog. This is a major step forward to our understanding of the end-to-end issues of a Mars-based mission. This, to me, is one of the biggest steps forward to our ability to someday soon put people off on the way to Mars.

Dr. Gabrielle Lyon [00:53:23]

That’s super cool. You must just love your job thinking you are doing the job that probably there’s so many people that wish they could do that. I’m curious, how did you get to NASA? Is this something that you’ve always wanted to do?

Dr. Scott Smith [00:53:37]

To your first point, I have an incredible job. But I often say that it must be like working at Disney World that there’s a lot of hard work going on underneath those streets to make it the happiest place on earth. The exciting things we do are very exciting. It comes with an awful lot of work and an awful lot of challenges. We just started this study. We’ve been working towards this for about six years now. There was an awful lot of planning, work, effort, and struggling and trying to get this thing to come to reality. When you step back from it, when I give you the nutshell view of what we’re doing, it’s all incredible. But again, there’s a lot of work by a lot of people making this happen.

How did I get here? I did my bachelor’s degree in biology. I had initially thought about going to med school. When that didn’t work out the first year, I decided to go spend a year in grad school and reapply to med school and started in a graduate program in nutrition and in simple terms, fell in love with nutrition. I’ve always been fascinated by physiology and understanding how the body works. I took a nutrition and disease class my last semester as an undergrad and came to realize that nutrition is the underpinning of physiology. When you look at things like diabetes, obesity, kidney disease, or heart disease, you can look at the underlying biochemistry and nutrition for those diseases and how those happen and why they happen, and how you can work on fixing them.

After about three months in grad school, I asked if I could switch from the master’s program into the PhD program, and they were quite happy for that. I went off and got my PhD. To be honest, I knew NASA was here. The Space Shuttle was flying at that time. There were a lot of things going on. There was not a nutrition lab at NASA when I was in graduate school. I went off and did a postdoc with the USDA up in North Dakota and was looking for a job. There was an ad for a position at the Johnson Space Center, and I thought that’d be interesting. I sent off a CV, got a call for the interview, and 31 and a half years later, here I am.

Dr. Gabrielle Lyon [00:56:28]

That’s tremendous, 31 years. You’ve worked at Johnson Space Center at NASA for 31 years. You know a lot of astronauts. What’s so amazing is that when things go well, they probably really go well, and when things don’t go well, it’s likely catastrophic from the astronauts’ perspective.

Dr. Scott Smith [00:56:59]

Indeed. I’ve been here a long time; I’ve seen a lot of things. I’ve seen everything from the incredible to being able to do your experiments and then get to fly things in space, to work with some of these astronauts which are simply phenomenal human beings. They are human. They live in our neighborhood. My kid went to dance class with their kids. You see them at the grocery store. They’re human just like us. But they have incredibly interesting jobs. They’re all very bright. They’re all very dedicated. They have extremely challenging jobs. I’ve seen everything from the amazement of watching crews launch, watching crews land, watching crews do our experiments in space, which is hard to describe.

On the other side, when we lost the Columbia crew back in 2003, that was one of our biggest moments at that time, that we had a major experiment on that flight. We’d worked on that flight for about four years. The crew was deemed to have flied about two and a half years prior to launch, so we worked with them for a long time. I was one of the people in Florida staring up at the sky waiting for them to come home so we can do our post flight data collection. It’s staggering. It’s hard to put into words even literally 20 years later. It is one of the things that never leaves you. It’s one of the things that they teach a lot of things in graduate school, but they don’t teach you how to deal with something like that. I still have a lot of elements of my work and things that I do that are in the backdrop that remind me constantly of their sacrifice and that what we do is a tribute to them. I know in the wake of Columbia, Jon Clark, Laurel Clark’s husband, spoke to our group; he worked in our division. Two days after the accident, he talked to us and he said flat out, you’ve got to keep going. That’s what the crew would want. That’s what they would demand. You’ve got to keep going. I’d looked at that, and to this day, I use that to keep me moving forward. So, again, I’m honored and amazed to have the job that I do. But I never lose sight of the reality of where we are and the importance and the implications of what we’re doing.

Dr. Gabrielle Lyon [01:00:18]

A loss like that is definitely devastating, I can only imagine. My husband was former military for a decade, and he experienced, well, not exactly the same thing, but something very similar. Given the chance, would you go to space knowing what you know?

Dr. Scott Smith [01:00:46]

Yes, to a degree.

Dr. Gabrielle Lyon [01:00:49]

I don’t think you can go partially to space.

Dr. Scott Smith [01:00:55]

No, but I go for a short time. I might be able to handle a week or two up there; I’m not going to space shuttle mission. I don’t have the right stuff for a lot of reasons. I don’t have the right stuff from my glasses being one of them. But the challenge of being away from friends and family for six months or a year, I couldn’t do it. It’s just not for me. There are people that thrive on that. People that are doing this, do very well with that. I’m the kind of person as soon as you tell me I can’t do something, I got to do it. If you tell me I can’t leave, it gets really challenging. So I leave it to the brain people to go. But would I like to be one of these people that get to go up for a couple of days and look out the window? Yeah, I’d be happy to do that.

Dr. Gabrielle Lyon [01:01:55]

Well, I do know a place where you can potentially look like you’re doing that. That would be the Johnson Space Center, which we love, which I have seen some of those simulations. Dr. Scott Smith, thank you so much for being on the show. Thank you for all the great work that you’re doing and the important role that you play, really for everybody. Thank you so much.

Dr. Scott Smith [01:02:19]

Thank you. I appreciate the time and the opportunity to share a little bit of what we’re doing here with you.

Dr. Gabrielle Lyon [01:02:25]

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