Not all foods taste the same in space as on Earth. A team of scientists from RMIT University is working to change that. The group recently published a study examining how the smell of food changes in space-like environments. Their findings could help improve astronauts’ diets. It could also benefit individuals in isolated conditions on Earth, such as nursing home residents.

“One of the long-term aims of the research is to make better-tailored foods for astronauts, as well as other people who are in isolated environments, to increase their nutritional intake closer to 100%,” said lead researcher Julia Low from the RMIT School of Science.

In space, astronauts often report that their food tastes bland, leading to reduced nutritional intake. The study, published in the International Journal of Food Science and Technology, explores how people perceive familiar food smells in a simulated space environment using virtual reality (VR). The researchers aimed to understand the reasons behind the different perceptions of smell for food in space and its impact on taste.

Participants were immersed in a VR simulation of the International Space Station (ISS) and a neutral environment to compare their perceptions of three food odors: vanilla, almond, and lemon. Using VR goggles, those involved experienced the confined and cluttered conditions of the ISS, complete with floating objects and operational sounds, to mimic the effects of microgravity.

The study involved 54 adults aged 18–39 with no history of motion sickness or vertigo. Researchers found that vanilla and almond odors were perceived as significantly more intense in the VR space simulation compared to the neutral environment, while the perception of lemon odor remained unchanged. This difference was linked to the presence of benzaldehyde, a sweet-smelling compound found in both vanilla and almond aromas.

Low emphasized how individual sensitivity to specific smells and the psychological impact of isolation can alter the perception of odors.

“A greater sense of loneliness and isolation may…play a role, and there are implications from this study around how isolated people smell and taste food,” she said.

The researchers found that participants who were less sensitive to odors in the neutral environment perceived almond odor as significantly stronger in the VR simulation.

Also, weightlessness being what it is, body fluids can shift from the lower to the upper parts of the body, creating facial swelling and nasal congestion, which can also affect the sense of smell and taste. These symptoms typically begin to disappear within a few weeks of being on board the space station. However, Low said there was something else at play as well.

“Astronauts are still not enjoying their food even after fluid shift effects have gone, suggesting that there’s something more to this,” she said.

The study could have significant implications for improving astronauts’ diets on long-term missions. Former astronaut instructor RMIT associate professor Gail Iles emphasized the importance of understanding and addressing the challenges astronauts face with food in space.

“What we’re going to see in the future with the Artemis missions are much longer missions, years in length, particularly when we go to Mars, so we really need to understand the problems with diet and food and how crew interact with their food,” Iles said.

Beyond space travel, this research could benefit those in socially isolated environments on Earth. Low suggested the study’s results might help personalize diets for individuals in nursing homes, potentially enhancing their nutritional intake and overall well-being by tailoring food aromas to improve flavor perception.

The study introduces new possibilities for investigating how digital experiences and sensory perception interact. Iles said she is excited about this VR assistance.

“The incredible thing with this VR study is that it really does go a very long way to simulating the experience of being on the space station. And it really does change how you smell things and how you taste things.”