Why space foods aren’t just for space

When it comes to food, the difficulties faced by astronauts, older people and those affected by disaster are more similar than you might think.

Space agencies worldwide are rolling out plans to build bases on the Moon. One challenge is how to nourish astronauts by growing fresh food in the extreme conditions on the lunar surface — in soils with few nutrients and where there is scarce water and no air. It’s too expensive to send supplies from Earth regularly, and long-term storage is difficult because foods decay.

Without healthy food, astronauts on long missions might face malnutrition, just like people on Earth do. They lose bone and muscle mass when working in low gravity¹, mirroring changes that occur naturally during ageing. Food systems for any future missions need to be sustainable and resilient — as does food production on Earth in the face of climate change.

Here, we highlight four areas of common ground between space and Earth-bound nutrition research programmes that need exploring.

Maintaining food supplies

In the aftermath of disasters, affected people need access to food. With water, electricity and gas supplies often cut off, there are parallels with remote operations in space. In Japan, earthquakes, tsunamis, typhoons and floods occur frequently, and the country has been learning from these parallels for the past decade.

As in space, disaster food supplies for emergencies must be stable when stored at room temperature in the absence of power and refrigeration². They must come in durable packaging that protects against damage and contamination. Meals must require minimal preparation and be easy for anyone to eat with limited equipment. And they must be prepared and packed in hygienic environments to prevent foodborne illnesses. In Japan, pre-cooked and dried rice, dried noodles, fermented products such as miso, sweets and jelly drinks, and fish or meat stored in cans or sterile plastic pouches are used in both disaster settings and space.

The Tōhoku earthquake in Japan in 2011 led to changes in how disaster foods are managed. Emergency shelters saw food-supply disruptions as well as problems with limited dietary diversity and hygiene^3,4. Recognizing that many of the stringent space-food standards set by the Japan Aerospace Exploration Agency (JAXA) were applicable to disaster contexts, the Japan Disaster Food Society launched its Disaster Food Certification System in 2015.

In 2022, the society introduced a streamlined cross-certification process, allowing JAXA-approved Japanese space foods to be certified as disaster food. This reduces duplicate product development and, in large-scale emergencies, means that foods earmarked for space missions can be diverted to humanitarian use (although these are not stored in large amounts).

Japan has developed about 53 space foods through JAXA’s programme — some have been stockpiled for disaster preparedness by local governments and deployed in emergency situations, including in earthquake-affected regions.

Now, one of us (N.T.-K.) is working with experts to develop an international standard for emergency and disaster foods. This could simplify food-aid coordination between governments and non-governmental organizations by standardizing stockpiling conditions, hygiene protocols and food labelling. Shared protocols could also help countries to adopt advanced food-production and preservation technologies originally developed for space for their own emergency and disaster food supplies.

The next step is to build consensus among food-safety authorities, humanitarian organizations and space agencies. Implementation of pilot projects in disaster-prone regions of Asia is under consideration. Challenges include aligning diverse national regulations, encouraging private-sector participation in dual-use product development and demonstrating cost-effectiveness in resource-limited settings.

Optimizing nutrition

Japan’s government recommends⁴ that food provided to emergency shelters should contain five elements: energy, protein and vitamins B₁, B₂ and C. Together, these factors prevent deficiency-related diseases such as beriberi, ariboflavinosis and scurvy, and help to sustain basic physiological functions.

As part of JAXA’s Lunar Food System Working Group 2023–25, one of us (N.T.-K.) is evaluating whether a set of eight staple crops — rice, potatoes, sweet potatoes, soya beans, tomatoes, cucumbers, lettuce and strawberries — can provide these five elements and other crucial nutrients. These crops are rich in carbohydrates, dietary fibre and certain vitamins.

The working group is using nutritional modelling, simulations of human dietary intake and cultivation studies under controlled environmental conditions to assess how much of astronauts’ daily nutritional requirements could be met using just these eight crops, and to identify any nutritional gaps that would require supplements.

Antioxidant compounds have anti-inflammatory and other effects that might help to prevent muscle deconditioning caused by microgravity in space and in people who are confined to bed rest on Earth because of illness or age. The French, German and Canadian space agencies are examining whether a cocktail of antioxidant supplements — polyphenols, vitamin E, selenium and omega-3 fatty acids — could prevent muscle deconditioning. Although there is no firm evidence yet⁵, the agencies are planning to assess these compounds’ benefits in space.

Supplements generated using soya might also help to prevent the wasting of astronauts’ muscles and bones. One of us (T.N.), together with colleagues, has conducted experiments in space using rats⁶ and cells grown in culture⁷ to reveal that muscle atrophy comes about when microgravity induces oxidative stress in muscle tissues. The process activates enzymes that alter cell signalling such that protein synthesis ceases and degradation increases. The same changes were subsequently shown to occur in adults under bed-rest conditions, and a clinical trial found that oral intake of soya proteins, especially Cblin-like peptides — which prevent this protein-degradation pathway from being activated — increases the quadricep strength of people on bed-rest⁸.

We are now testing whether similar Cblin peptides can also help astronauts, through experiments in cultured muscle cells aboard the International Space Station (ISS).

Specialists who can take a high-level view of micronutrient function, delivery methods and physiological needs under stress could vastly improve our ability to build resilience into future food systems — on Earth and beyond.

Alternative protein sources

Sustainable sources of alternative protein are urgently needed to avoid widespread food insecurity and malnutrition on Earth. A 2019 survey of Japanese citizens found that, on average, more than 50% of a person’s protein intake was derived from animal-based sources such as meat, dairy and fish (see go.nature.com/44xwmyn). But with the global population projected to reach nine billion by 2050, there is concern that current protein sources will be insufficient to meet global nutritional needs⁹.

Alternative protein sources are a focus of research for space agencies, too. Conventional animal agriculture requires large amounts of water, land and feedstock — resources that are unavailable in space. Protein-production systems involving plants, cultured cells or insects are more viable options.

Soya protein is of interest to JAXA, because of its high yield, relatively complete amino-acid profile and long shelf life, and because it is widely consumed in Japan. One of us (T.N.) has been involved in developing a compact soya-bean cultivation system. It uses programmable LED lighting and supplies nutrients through a mist infused with rhizobia — bacteria that convert inert nitrogen into forms that plants can use to grow¹⁰. Next, we hope to test its applicability aboard the ISS.

Meat produced from animal cells grown in the laboratory could give astronauts some of the nutrients that soya protein lacks — particularly branched-chain amino acids, which muscles need to generate energy during exercise. Cultured meat can be produced under sterile conditions, reducing the risk of foodborne illness¹¹. However, this technology is in its infancy. Cells need to be coaxed to keep proliferating so that they form large, structured tissue pieces. Getting oxygen to the core of thick cultures is tricky. The liquids in which the cells need to be grown are expensive to produce and transport. And there isn’t a good way to generate cultures with meat-like textures, which are important for psychological satisfaction.