It takes between 150-300 days to get to Mars (1). The time it takes depends on the speed of the launch, the alignment of Earth and Mars, and how much fuel is used. Regardless of how long it takes, it’s a very, very long journey. And one of the challenges for astronauts is staying healthy. In fact, there are many obstacles that get in the way of maintaining health during long space missions.
A little less spinach please
In one respect, it is not a nutritional deficiency that astronauts have to worry about during the long-haul flight to Mars, but nutritional excess. In an analysis of 23 astronauts’ blood and urine samples, researchers found that extended spaceflight resulted in too much iron (2). This is because during spaceflight your blood volume contracts, which increases iron storage.
In the analysis, authors discovered that all of this extra iron may be the culprit for the bone loss that astronauts experience. The study showed that an increased storage of iron correlated with increased bone loss in astronauts on missions ranging from two to eight months. Of course, if a Mars mission takes up to 10 months, then there is a higher risk of bone loss causing issues.
Image credit: Wikipedia
Astronauts lose bone density at an average rate of 1-2% a month (3). This may seem minor at first. But consider the rate at which an elderly person loses bone – 1-2% a year. Decreased bone density means an increased risk of bone fracture. Trying to colonise Mars with broken bones will not be an easy task!
NASA astronaut Scott Kelly says that “the effect of diet on bone is likely greater the longer you’re up there” (4). If we’re going to get to Mars safely, then special attention must be paid to nutrition.
A carefully planned astronaut diet
Long-duration missions need the right amount of nutritional requirements for protection against the effects of microgravity (5). Weightlessness affects almost every system in the body, including those of the muscles, heart and blood vessels, and nerves.
The mental health effects of space missions (6), such as those caused by an increased sense of isolation, could also be addressed by nutrition. For example, omega-3 fatty acids (7) and vitamin D (8) play an important role in maintaining good mental health. Poor mental health during space flights is an issue, because it can result in less productive missions and decreased crew morale.
In addition, environmental factors (including radiation and spacecraft and spacesuit atmospheres) can change the nutritional requirements of space flight (9).
Little research has been done on differences in food components (i.e. protein, carbohydrate and fat) during space flight, or other factors (e.g. vitamins) relating to energy utilisation. But it is worth highlighting what evidence has been gathered so far (10).
Adequate energy intake is considered to be the single most important aspect of astronaut nutrition. This is not only because energy is more important than nutritional factors, in and of itself, but also because if enough food is consumed to meet energy needs, then generally other nutrients will be consumed in reasonable amounts.
High-energy foods include complex carbohydrates, spinach, sweet potatoes, fruit, nuts, soybeans and pumpkin seeds. Also, B vitamins play a crucial role in the conversion of food into energy (11). So ensuring an adequate intake of B vitamins is important.
One study found that heavy resistance exercise plus adequate intake of vitamin D reduced the loss of bone mineral density on long-duration International Space Station (ISS) missions (12). Given the serious risks posed by bone loss, eating foods high in vitamin D or taking a vitamin D supplement may be advisable.
As SpaceX gets busy with its plans to colonise Mars, all of these considerations (and more) will need to be taken into account. If we can’t overcome the health challenges posed by long-duration flights, and existence on another planet, then the Mars colony will not be sustainable.
About the author: Sam Woolfe @samwoolfe
I’m currently a Writer at The Canary, covering issues relating to the food industry, drugs, health, well-being and nutrition. I’m also a Blogger for Inspiring Interns, where I offer careers advice for graduates. If you have a story you want me to cover, drop me a message on Twitter (@samwoolfe). You can also check out my travel blog (samreflectsontravel.com) and personal blog (www.samwoolfe.com) to read my articles on philosophy, psychology, and more opinion-related content.