Factors affecting flavor perception in space: Does the spacecraft environment influence food intake by astronauts?

Abstract

The intention to send a crewed mission to Mars involves a huge amount of planning to ensure a safe and successful mission. Providing adequate amounts of food for the crew is a major task, but 20 years of feeding astronauts on the International Space Station (ISS) have resulted in a good knowledge base. A crucial observation from the ISS is that astronauts typically consume only 80% of their daily calorie requirements when in space. This is despite daily exercise regimes that keep energy usage at very similar levels to those found on Earth. This calorie deficit seems to have little effect on astronauts who spend up to 12 months on the ISS, but given that a mission to Mars would take 30 to 36 months to complete, there is concern that a calorie deficit over this period may lead to adverse effects in crew members. The key question is why astronauts undereat when they have a supply of food designed to fully deliver their nutritional needs. This review focuses on evidence from astronauts that foods taste different in space, compared to on Earth. The underlying hypothesis is that conditions in space may change the perceived flavor of the food, and this flavor change may, in turn, lead to underconsumption by astronauts. The key areas investigated in this review for their potential impact on food intake are the effects of food shelf life, physiological changes, noise, air and water quality on the perception of food flavor, as well as the link between food flavor and food intake.

The taste of the pandemic—contemporary review on the current state of research on gustation in coronavirus disease 2019 (COVID‐19)

“…Flavor perception includes the integration of gustatory, olfactory, and trigeminal information 63 . Even though their afferents enter the CNS through different channels, these senses share distinct brain projection areas and integrative processing 40,64–66 . They mutually amplify each other and do not exhibit strong compensation for the impairment of other chemical senses, as is known for other senses such as vision and hearing 67 …”

Scent in Motion: On the Multiple Uses of Ambient Scent in the Context of Passenger Transport

“…The starting point is not good, given that reports from astronauts describing space as smelling like: "gunpowder, hot metal, welding" (New York Hall of Science, 2016). The repeated recycling of limited air can potentially lead to the build-up of volatile pollutants (Taylor et al, 2019(Taylor et al, , 2020. At the same time, however, the lowered gravitational pull also leads to the build up of blood in the head, and this may constrict the nasal airways (NPR, 2012), leading to what is known as "space anosmia" (Varma et al, 2000).…”

“…This is what is sometimes referred to as dashboard dining or cup-holder cuisine (Hill, 2005 ; see also Morrison, 2021 , for one view of the future of dining in autonomous cars). Designed food experience for passengers on other forms of transport has also occupied the minds of many researchers' (e.g., Horwitz and Singley, 2004 ; Muecke, 2004 ; Spence, 2017a , b ; Taylor et al, 2019 , 2020 ). Returning to a theme that was mentioned earlier in this review, it has been suggested by de Syon ( 2008 ) that the provision of food on airplanes may also be one means of helping passengers to manage their anxiety (though more could certainly be done in this regard; e.g., Delahaye, 2017 ).…”

Persisting olfactory dysfunction in post-COVID-19 is associated with gustatory impairment: Results from chemosensitive testing eight months after the acute infection

“…For chronic non-COVID-19 hyposmia a secondary gustatory impairment has been suggested [ 34 – 37 ]. As the processing of chemical information from olfaction, gustation, and trigeminal input uses overlapping brain regions and amplifies each other, a secondary hypogeusia could be explained through reduced amplification of gustation on a central nervous level [ 38 – 40 ]. Prolonged olfactory dysfunction after COVID-19 may also be associated with secondary hypogeusia as it has been shown for pre-COVID hyposmia of various etiologies [ 37 ].…”