The sky is no limit: a soup of supplements to mitigate space hazards
by Imogen Allen, Technical Document Controller
Last November, SpaceX’s ongoing Crew-1 mission delivered four astronauts to the International Space Station (ISS)— the company’s first operational crewed flight, and the longest crewed mission ever launched from US soil. This spring, Crew 2 will be trading places with them.
Trips to the ISS are becoming less and less of a novelty. Since its launch in 1998, the ISS has welcomed 242 individuals from 19 countries around the world. What is so special about this trip?
Well, according to Business Insider, SpaceX’s Crew-2 mission ‘is a precursor to the permanent moon space station, the lunar Gateway, that NASA hopes to build’ in the 2020s.
This is, in turn, a vital ‘part of NASA’s deep space exploration plans’, as the knowledge imparted through experiences on the moon will assist astronauts in taking their next giant leap – to Mars: the only potentially inhabitable planet which is close enough to us.
One gap in our knowledge that visiting the moon may shed some light on is the extent of certain health hazards. Such health hazards include the risks that astronauts encounter beyond the protection offered within the lower earth orbit (LEO), and more importantly the type of countermeasures required.
Unless appropriate countermeasures are developed prior to a Mars mission, it is likely that crew members will experience the following:
· ‘debilitating losses of bone mass, muscle strength, cardiovascular fitness, and endurance;
· changes in sensorimotor functions (e.g. impaired balance control);
· swelling of vertebral disks; and
· an impaired ability to heal bone fractures’.
Cancer, anxiety, impaired cognition and increased susceptibility to infectious disease are other inevitable hazards.
This is because travel outside the LEO – where the ISS is located – involves astronauts being subject to reduced gravitational loading in confined spaces over longer periods of time, as well as solar and cosmic radiation.
With current technology, it is likely astronauts will be redder in the face than the Red Planet itself by the time they arrive at their destination, or worse even, dead.
Nevertheless, if humanity’s first steps on the moon in 1969 proved one thing, it was that the sky is no limit. NASA remains committed to discovering ‘the best methods and technologies to support safe, productive human space travel’ of which nutrition may play an important role.
What are current astronaut diets like?
Muscle groans and weak bones have always been a concern since the beginning of spaceflight. This is because in a microgravity environment, bones and muscles don’t have to support the body’s mass (weight on Earth) and as a result atrophy occurs leading to a loss of strength.
In order to counteract these effects, astronauts now take 800 IU vitamin D/day, in conjunction with a strict exercise regime. These countermeasures, alongside an adequate energy intake during 4-6 month missions have been proven to be satisfactory at maintaining bone mass.
To date, it seems like astronaut diets don’t appear to differ much from earthling diets; whilst calorie recommendations are higher, astronauts eat a varied diet that is similar to what we eat on Earth. However, in the future this could all change and reliance on nutritional supplements could increase.
Below I describe some of the negative physiological consequences of spaceflight and types of nutritional countermeasures that could be used to tackle them.
Radiation-induced oxidative stress
As mentioned, in space, beyond LEO, astronauts have to endure a stiff dose of radiation. This in turn induces oxidative stress, a term used to describe the ‘biological damage of DNA, lipids and proteins’ caused by free radicals, which in turn leads to numerous health conditions ranging from poor eyesight to cancer.
In an attempt to counteract the high levels of oxidative stress astronauts encounter, researchers have been busily trying to determine whether supplementing diets with antioxidants can reduce the rate of oxidative stress and the onset of related health conditions including cancer.
Current studies are limited, they often use either mice or rats as the subjects and that can mean the radiation types and doses used simply do not accurately represent the complexity of the space environment astronauts will be exposed to. Nevertheless, there is promising evidence that a combination of antioxidants, protease inhibitors, retinoids and fruit extracts could be the rocket fuel needed to prevent or mitigate space radiation induced carcinogenesis.
In flight, astronauts develop ophthalmic changes including: optic disc edema, globe flattening, hyperopic shifts, choroidal folds and cotton wool spots. This has been linked to space radiation and increased intracranial pressure due to microgravity and high cabin levels of carbon dioxide. However, as environmental pressures are consistent, this link alone doesn’t explain why only 20% of ISS astronauts are affected.
Interestingly, research has revealed that some astronauts may be more prone to visual damage than others due to genetic differences in metabolic enzymes resulting in higher concentrations of homocysteine, an amino acid, and lower levels of folate. This low folate is in turn thought to exaggerate astronaut’s susceptibility to environmental pressures in space because of the protective role folate plays in scavenging free radicals, thereby counteracting oxidative stress.
If this mechanism holds true, it could be deemed advantageous for these astronauts to be intaking levels of folate higher than what is typically recommended. Astronauts need their vitamin B to see!
Suitable nutritional countermeasures could include folic acid (Vitamin B9) supplements or meals made from folic acid rich foods such as broccoli and leafy green vegetables. This is particularly important because it could also be that these astronauts are more at risk of other health conditions as a result of increased susceptibility to oxidative stress and that their loss of visual acuity is just the first warning sign.
Immune system dysfunction
In space, the incidence of infectious diseases, allergies and persistent skin hypersensitivity reactions are higher. As mentioned above, this is another consequence of increased oxidative stress. Negative shifts in gut microbiota may also play an etiological role.
Spaceships are typically sterile places. Afterall, NASA was the first to come up with HACCP – the industry standard that benefits consumers globally by keeping food free from ‘chemical, physical and biological hazards’.
Whilst it remains important to prevent certain categories of dangerous micro-stowaways from boarding missions, there may be reason to begin welcoming gut-positive micro-friends on board. Studies suggest that space flight may be bad for the “good” bacteria that live in our gut and help us stay healthy. For example here, examinations of mice being sent to the ISS, and of astronaut Scott Kelly, have revealed that spaceflight ‘causes significant changes to the diversity of the bacteria in the gut microbiome’, with microgravity being cited as the ‘primary factor at play’. This has caused concern as terrestrial studies show that many of the maladies experienced by astronauts including – GI distress, respiratory illness, skin irritation and infections – could be being caused or exacerbated by microbiome dysfunction.
If this is the case, it may be that probiotics (live bacteria and yeasts) play an important role in correcting negative microbial shifts in the gut and preventing related health conditions. Studies have identified ‘a space associated reduction’ of bacterial genera Akkermansia in the guts of astronauts which is known to have anti-inflammatory properties. Therefore, it could be beneficial to treat them with A. muciniphila (a type of Akkermansia species) in order to moderate chronic inflammatory responses to spaceflight.
Another countermeasure that may be effective in boosting the immune system function of astronauts might be the fermented mushroom extract AHCC (Active Hexose Correlated Compound).
Studies of cancer patients and mice subjected to microgravity, have shown that AHCC can increase the activity of certain types of white blood cells and pro-inflammatory cytokines such as interleukin-12. Studies also show that they may increase nitric oxide production, a toxic defence molecule against infectious microorganisms, and reduce the action of certain immune-suppressing hormones such as corticosterone.
Clearly, space travel is no holiday for the human body. Whilst perhaps not a primary line of defence, there are a myriad of nutritional supplements that could help astronauts survive the harsh environmental pressures of space travel.
But perhaps most importantly, a taste of space can help you too:
Our colourful range of herbals, my favourite being the galaxy coloured Haskap Berry Fruit Powder (Lonicera caerulea L.), are packed with antioxidants. On our earlier blog you’ll find that they contain 30 times more cyanidin-3-glucoside (a major antioxidant) than even blackcurrants. We also have a very fine selection of Vitamin B9 Folic Acid supplements in synthetic or natural form – whatever your preference!
Furthermore, our probiotic supplements such as Bfidobacterium Bfidum, as well as our fermented mushroom extracts (including Reishi and Chaga) are a great way to boost gut health which studies have shown to be intrinsically related with a healthy immune system. As we are in the midst of global pandemic – what could be more important to take!
What’s more – there are already a few pioneers promoting the benefits of “out of this world nutrition” and beginning to make space foods more mainstream such as The Space Foods Company and Astronaut Foods. Why not get ahead of the curve and reach for the stars by producing your own trailblazing space-food range now!
TO INFINITY AND BEYOND!