Why does food taste so bland in space? The answer may be loneliness

A recent, world-first study looking into common food aromas may explain why astronauts claim meals taste bland in space and find it difficult to fulfill their nutritional needs. 

Researchers at the Royal Melbourne Institute of Technology (RMIT) in Australia found that spatial perception can greatly impact how people smell different aromas and, in turn, taste various flavors. Amongst astronauts, a greater sense of loneliness and isolation while on the International Space Station (ISS) can influence how they smell and taste their food, the study reported.

“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,” Gail Iles, former astronaut instructor and co-researcher from RMIT School of Science, said in a statement from the university.

Previous studies examined the phenomenon of fluid shift, which states that astronauts experience taste differently due to the lack of gravity. This causes bodily fluids to move upwards towards the head rather than flow down towards the feet, thus causing a blocked nose along with facial swelling which obstructs one's sense of smell and taste.

Now, researchers are saying there may be more reasons why meals taste so bland in space. The study, published in the International Journal of Food Science and Technology, sampled 54 adults and looked at how their perception of lemon essential oil, vanilla and almond extracts changed from normal environments on Earth to a space environment — simulated using virtual reality goggles. Researchers found that vanilla and almond aromas were perceived as more intense in the ISS-simulated environment, while the lemon scent remained unchanged.

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Both the vanilla and almond extracts contain an organic compound called benzaldehyde, which researchers said could explain the change in perceptions and an individual’s sensitivity to particular smells. 

“A greater sense of loneliness and isolation may also play a role, and there are implications from this study around how isolated people smell and taste food,” said Dr. Julia Low, a fellow co-researcher on the study. 

“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%,” she added. “The results of this study could help personalize people's diets in socially isolated situations, including in nursing homes, and improve their nutritional intake.”