On Earth we don’t often think about how we eat, however, in space great consideration needs to be made before one can eat! Eating in space poses many challenges for astronauts, however, with the development of full kitchens with ovens and hot water in Skylab it is now possible for astronauts to eat similar foods to those on Earth! Prior to such inventions, eating in space was less Earth like; in 1962 John Glenn was the first astronaut to eat in space; he squeezed apple sauce into his mouth from an aluminium shaped toothpaste like tube. 1 What Glenn ate was thermostabalized- meaning heat is applied to the food to destroy enzymes and microorganisms that may cause harm. 1 Later, freeze-drying was developed by squeezing water out of food via dehydration in a vacuum chamber. 1 Freeze-dried food didn’t need to be refrigerated, only added with water to make an edible meal and liquid drinks are still dehydrated, however, are in special pouches to eliminate issues associated with gravity. 5 Gravity poses a large challenge for space travellers, so to ensure food doesn’t float around, special trays with velcro can be attached to their food. 1 While astronauts can’t avoid gravity, new research is emerging to help astronauts avoid flavourless foods, and instead eat foods similar to those grown at home. In 2014 NASA successfully grew the ‘Outredgeous’ red romaine lettuce and this is an exciting concept for nutrition to be consumed naturally in space. 7 While there are many exciting advancements in space research, there is still a long way to go before space travellers don’t have to give thought to the way they eat.
Not only do space travellers need to think about how they eat, serious attention needs to be paid to what they are eating. To evaluate this, a food frequency questionnaire can be utilised. 3 This tool estimates food intake and a doctor will be notified to adjust the food intake of an astronaut who is not meeting nutrient standards in space. 7 Complications for poor nutrition in space include reduced body mass, bone health and radiation. 4 These complications can lead to body weight loss, reduced loose fat and lean muscle mass. 4 Did you know, after only 15 days into a mission 10% of intrinsic lumbar region muscle volume is lost? 3 Even when nutrient conditions are ideal, in some Skylab missions astronaut nitrogen levels are off balance. 3 This negatively comprises the body’s ability to make proteins in muscles, skin and blood- imagine how important this nutrient would be when an astronaut’s body is put under stress in space. 3 Some research suggests that a high protein diet will improve protein synthesis to support muscle mass and function. 3 As you can imagine, with there being no sunlight in space, vitamin D levels are of concern to an astronaut’s health. 3 This often means that an astronaut’s ability to synthesis vitamin D is reduced. 3 Like a reduced protein diet compromises bone health, a lack of vitamin D does the same. 3 Even with taking vitamin D supplements, vitamin D levels are still surprisingly abnormal for space travellers. 3 With food frequency questionnaires becoming more readily available, it is now easier to evaluate food consumption in astronauts and thereby support strong muscle health in astronauts.
While you may be thinking astronauts are completely depleted in nutrients-think again. Down here on Earth, health professionals draw attention to low iron levels that women and vegetarians may experience. You may be thinking astronauts experience the same problem. Think again. Blood volume contracts during a space mission causing an increase in iron levels, in addition, when blood volume is reduced an increase in iron storage becomes available to the body. 6 This increase in iron does not advance the body, rather it leads to poor bone health. 8 What basically happens is that bone break down exceeds bone production and upon return to Earth this may increase the individual’s chance of bone fracture. 8 It’s pretty scary to think that when you come back from space your bones are more fragile than your grandmas! This is because an astronaut loses 1% to 2% of bone density a month, compared to their grandma who is losing 1% to 2% a year. 6
While food in space has changed dramatically over the last 45 years, dehydrated and thermostabilized foods will have to support astronaut nutrition until home cooked meals become available. Long missions need to be clearly monitored to ensure that all dietary needs are met to preserve one’s health. Bone health complications may arise from a diet low in protein and vitamin D, furthermore due to changes in blood volume, iron levels may increase, which also contribute to bone health. Food Frequency Questionnaires have greatly benefited the health of space travellers by allowing careful analysis to be made of their daily intake and adjustments to be made accordingly.
Eating in space has improved and there is still a long way to go to make eating easier and more flavourful for space travellers. The discovery of the ‘Outredgeous’ Red Romaine Lettuce has been a very exciting discovery for space researchers as it allows space travellers to connect to home food and the prospect that more fresh food will be available in space. A new space race exists- to grow more nutrient dense foods in space. However, due to limited volume, water and power, growing foods that have a high nutrient profile in space is a challenge. While it is exciting that research about food consumption and its effect in spaceflight is emerging, there needs to be a greater push for more to ensure that we truly can understand the difference in nutrient requirements compared to Earth and space. There is more to a space mission than just bringing back research- we need to bring back healthy astronauts.
1.Food for Space Flight. Retrieved from http://spaceflight.nasa.gov/shuttle/reference/factsheets/food.html
2.Kinberg, S, Scott, R, Schaefer, M, Sood, A, and Huffam, M (Producer) and Ridley,S. (Director). (2015). Martian [Motion picture]. United States: Fox
3.Lane, H., Kloeris, V., Perchonok, M., Zwart, S., & Smith, S. M. (2007). Food and nutrition for the moon base: What we have learned in 45 years of spaceflight. Nutrition Today, 42(3), 102-110.
4.Smith, S. M., & Zwart, S. R. (2008). Nutrition issues for space exploration. Acta Astronautica, 63(5), 609-613.
5.What do astronauts eat in space?. Wonderopolis. Retrieved from http://wonderopolis.org/wonder/what-do-astronauts-eat-in-space
6.Wyrick, J.(2013, September 5). 30 under 30. Scientific American. Retrieved from http://blogs.scientificamerican.com/food-matters/30-under-30/
7.Ziv, S. (2015, October 8th). INTERNATIONAL SPACE STATION ASTRONAUTS EAT RED ROMAINE LETTUCE GROWN IN SPACE. Newsweek. Retrieved from http://www.newsweek.com/international-space-station-astronauts-eat-red-romaine-lettuce-grown-space-361612
8.Zwart, S.R., Morgan, J.L., & Smith, S.M. (2013) Iron status and its relations with oxidative damage and bone loss during long-duration space flight on the International Space Station. Am J Clin Nutr. 98 (1), 217-223.
9. Unoosa. A history of space [Image]. Retrieved from www.unoosa.org