Loneliness is linked to food tasting bland in space, finds world-first study

The food options in space are limited. Astronauts mostly fuel up with pre-made meals packed in pouches. These meals are freeze-dried, dehydrated, or heat-treated for long shelf life. Astronauts simply add water for a hot or cold meal.

However, these meals taste bland and astronauts often struggle to eat enough during their stay at the International Space Station (ISS).

Now, a first-of-a-kind study from RMIT University has suggested that food aromas might be the key to understanding why astronauts struggle to enjoy their meals. The study found that the environment itself can change how humans perceive aromas and flavors.

“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 Julia Low, the lead researcher.

Aroma of vanilla, almond, lemon

We all know that smell is a big part of taste. But how do vanilla, almond, and lemon smell in space? To find out, researchers put 54 participants to the test.

This unique study used virtual reality (VR) to see how the perception of common food aromas changes in space. VR was used to simulate the ISS for participants.

The researchers discovered that vanilla and almond scents turned out to be “more intense” in the simulated space station. However, the lemon scent “remained unchanged.”

The culprit behind the stronger vanilla and almond smells could be a sweet chemical called benzaldehyde. This, combined with individual sensitivity to smells, could explain the changes in perception.

“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%,” Low said.

The science behind

Loneliness and isolation may also play a role in how astronauts experience food. This study is the first to explore aroma and taste perception in large groups (54 people) under isolated conditions.

The lack of gravity pulls fluids from the lower body to the upper body. This can cause facial swelling and nasal congestion, similar to a bad head cold. As a result, astronauts’ sense of smell and taste become less sensitive.

However, these effects are usually temporary, fading within a few weeks aboard the space station.

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

With missions like Artemis going to the Moon, astronauts will be in space for longer durations. Proper nutrition is crucial for their health. The new findings suggest that future space food might need adjustments to account for this.

“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,” said Gail Iles, former astronaut instructor and co-researcher from RMIT.

On Earth, this research holds promise for improving the diets of people facing isolation in nursing homes, and other isolated settings.

The findings were published in the International Journal of Food Science and Technology.