Aged care residents and people living on their own may end up enjoying tastier meals and better nutrition thanks to research that helps explain why food seems bland in space. 

A study led by scientists at RMIT University in Melbourne, published in the International Journal of Food Science and Technology, has broad implications for improving the diets of isolated people – ranging from astronauts to care residents – by personalising aromas to enhance the flavour of their food.

Scientists already know that aroma plays a big role in the way we taste our food. 

The challenge for the RMIT team began with the observation that astronauts in the International Space Station (ISS) had poor nutrition linked to the fact that they didn’t like their food. 

The researchers tested how people perceived vanilla and almond extracts and lemon essential oil changed from normal environments on Earth to the confined setting of the ISS, which was simulated using virtual reality goggles. 

Lead researcher Dr Julia Low said vanilla and almond aromas were more intense in the ISS-simulated environment, while the lemon scent remained unchanged. 

The team found that a particular sweet chemical in the aromas of vanilla and almond, called benzaldehyde, could explain the change in perceptions, in addition to an individual’s sensitivity to a particular smell. 

It is known that weightlessness causes fluid to shift from the lower to the upper parts of the body, which creates facial swelling and nasal congestion that affects astronauts’ sense of smell and taste. 

These symptoms typically begin to disappear within a few weeks, but astronauts have reported still not enjoying their food after this fluid shift occurs. 

“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,” Dr Low said. 

“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%.” 

Former astronaut instructor and co-researcher Associate Professor Gail Iles said, despite carefully designed diet plans, astronauts were not meeting their nutritional needs. This posed a danger for long-term missions, such as proposed journeys to Mars. 

Dr Low said the study could also have implications for people living in socially isolated environments on Earth. 

“The results of this study could help personalise people’s diets in socially isolated situations, including in nursing homes, and improve their nutritional intake,” she said. 

Related reading: RMIT, Yahoo! News