Space Team Online Web Chat

Date: July 02, 1997

Featuring: Janis Davis-Street
Nutritionist
NASA Johnson Space Center, Houston, TX

Hello to our Shuttle Team Online participants. Welcome to today's chat with Janis Davis-Street from NASA Johnson Space Center.

Oran/NASA Chat Host: . . . . Wed, Jul 2, 10:29 AM PDT (-0700 GMT). . . Janis is a nutritionist and works in the life sciences. She is part of a team whose job is determining the nutritional requirements for space flight, that is, finding out what foods and nutrients are important for the astronauts as they venture into space.

Oran/NASA Chat Host: . . . . Wed, Jul 2, 10:30 AM PDT (-0700 GMT). . . And now, here is Janis Davis-Street to answer your questions.

Jason/California: . . . . Wed, Jul 2, 10:32 AM PDT (-0700 GMT). . . Janis, what kinds of foods do the astronauts eat in space?

Janis/NBL: . . . . Wed, Jul 2, 10:40 AM PDT (-0700 GMT). . . Jason, astronauts eat 'regular' foods in space - these are usually packaged in special forms - rehydratable, etc., and are reconstituted on-board.

Susan Chase Foundation Argentina: . . . . Wed, Jul 2, 10:33 AM PDT (-0700 GMT). . . Is it true that the intestinal tract is longer for Asian astronauts? What consideration is given for their alimentation and how do their digestive systems vary from that of a "normal" American?

Janis/NBL: . . . . Wed, Jul 2, 10:40 AM PDT (-0700 GMT). . . Susan - I had never heard of intestinal tract differences. Will check on that one.

Janis/NBL: . . . . Wed, Jul 2, 10:42 AM PDT (-0700 GMT). . . Susan, I'm not sure on that one. Japanese astronauts have flown on the shuttle - typically they each many of the American foods - however we frequently will send favorites of the specific crewmembers -these are usually shelf-stable

"STO-Guest": . . . . Wed, Jul 2, 10:34 AM PDT (-0700 GMT). . . Janis: What was the single most important influence that got you where you are today?

Janis/NBL: . . . . Wed, Jul 2, 10:43 AM PDT (-0700 GMT). . . "STO-Guest," I think it would have to be my parents. They have always encouraged me and my siblings to believe that we could achieve anything.

Lovena: . . . . Wed, Jul 2, 10:34 AM PDT (-0700 GMT). . . Janis, with the different nationalities of astronaunts that go into space, are you able to create the many different ethnic dishes for everyone?

Janis/NBL: . . . . Wed, Jul 2, 10:46 AM PDT (-0700 GMT). . . Lovena, ethnic additions to the menus have included Russian food items for crewmembers on the Mir. Most of the astronauts on the shuttle eat the American foods - with special items flown on occasion. To my knowledge - most of the astronauts enjoy the food - especially the shrimp cocktail.

COTF: . . . . Wed, Jul 2, 10:39 AM PDT (-0700 GMT). . . What differences have been found between the nutrional requirements in microgravity vs. Earth's gravity, especially in terms of number of calories and calcium requirements. What problems and solutions with calcium deficiencies are currently being investigated?

Janis/NBL: . . . . Wed, Jul 2, 10:49 AM PDT (-0700 GMT). . . COTF, we are particularly concerned about specific nutrients like iron, sodium, vitamin D, calcium and antioxidants among others. We have done a study on several shuttle missions and have found that caloric requirements are similar in space as on the ground. Calcium is a work in progress. We are looking at calcium metabolism during long-duration space flight - this has important implications for bone health.

David/Purdue: . . . . Wed, Jul 2, 10:42 AM PDT (-0700 GMT). . . Are any of the nutrients absorbed differently in space than they are in gravity conditions?

Janis/NBL: . . . . Wed, Jul 2, 10:51 AM PDT (-0700 GMT). . . David, on nutrient absorption: to date we have information on calcium absorption which appears to be decreased in space flight. The Skylab studies in the 1970s suggest that absorption is generally not a problem - but there are certain nutrients that we worry about: calcium and iron in particular.

Susan /Chase Foundation Argentina: . . . . Wed, Jul 2, 10:43 AM PDT (-0700 GMT). . . What is your project with high school biology?

Janis/NBL: . . . . Wed, Jul 2, 10:53 AM PDT (-0700 GMT). . . Susan, at present I have done some email mentoring with high schools students. I am hoping to have more opportunities to do educational outreach in the community.

Susan/Chase Foundation Argentina: . . . . Wed, Jul 2, 10:56 AM PDT (-0700 GMT). . . Keep us in mind to help you in the high school biology project.

Meri/Classroom of the Future: . . . . Wed, Jul 2, 11:17 AM PDT (-0700 GMT). . . A few people asked about high school projects. Please check out our BioBLAST project. It is a lunar base simulation. We are looking for volunteer high schools for beta-testing beginning in January 1998. Our Internet site is called BioBLAST.

Susan /Chase Foundation Argentina: . . . . Wed, Jul 2, 10:48 AM PDT (-0700 GMT). . . Max and Peanut: Do they get a nutrition health diet base on proteins or what else?

Janis/NBL: . . . . Wed, Jul 2, 10:55 AM PDT (-0700 GMT). . . Max/Peanut, the Foods Lab at NASA packages a well-balanced, nutritional menu. Once up there, the astronauts are free to eat from the 'pantry' as well and often trade food items. The crew members have input as to the foods flown.

COTF: . . . . Wed, Jul 2, 10:52 AM PDT (-0700 GMT). . . Can you give any references, name any experts, or give any URLs for actual results of experiments on calcium deficiency, other than the rat study posted on the Humans in Space Internet page?

Janis/NBL: . . . . Wed, Jul 2, 10:57 AM PDT (-0700 GMT). . . COTF, the calcium data (decreased absoprtion, not deficiency per se) is hot off the press. The data was presented at Experimental Biology this year (Author - Scott M. Smith). Our lab hopes to be publishing more of the data in the very near future.

Meri/Classroom of the Future: . . . . Wed, Jul 2, 10:56 AM PDT (-0700 GMT). . . Why do you think there is no reduction in calories needed in the weightless environment? If you were planning a lunar diet in 1/6 Earth's gravity, would you reduce the daily calories? How would the lunar location change the diet (grow own, fewer choices, etc.)?

Janis/NBL: . . . . Wed, Jul 2, 11:00 AM PDT (-0700 GMT). . . Meri, it may be that baseline energy requirements (resting energy) are increased during space flight, and the energy requirements of activity are decreased. We have not investigated that as yet, but that is a project that we have great interest in. Maybe some time in the future....

Janis/NBL: . . . . Wed, Jul 2, 11:02 AM PDT (-0700 GMT). . . Meri, we would probably try to do a ground-based evaluation at first. But my instinct would be that we would provide similar calories regardless. Great questions!!

Janis/NBL: . . . . Wed, Jul 2, 11:03 AM PDT (-0700 GMT). . . Meri, in the test projects currently in progress,the astronauts will grow much of their foods. Consequently the diet would probably be mostly vegetarian.

Duncan /Chase Foundation Argentina: . . . . Wed, Jul 2, 10:58 AM PDT (-0700 GMT). . . What is the daily consumption estimated for an astronaut? Do they suffer from dehydration effects?

Janis/NBL: . . . . Wed, Jul 2, 11:04 AM PDT (-0700 GMT). . . Duncan, in general it is 3000 kcal. However that will change depending on age, gender and weight.

Janis/NBL: . . . . Wed, Jul 2, 11:06 AM PDT (-0700 GMT). . . Duncan, our guidelines are that the astronauts drink at least two liters of fluid a day. This varies by individual. We do not have a chance to monitor actual intake on all missions, however, it appears that many are able to meet this recommendation.

Robin/Hopkins: . . . . Wed, Jul 2, 11:02 AM PDT (-0700 GMT). . . Janis, how much do your nutritional suggestions influence the choices astronauts make?

Janis/NBL: . . . . Wed, Jul 2, 11:07 AM PDT (-0700 GMT). . . Robin, we do much of the research that goes into the NASA nutrient recommendations. The Foods Lab converts these requirements into menu items and assists the astronauts in selecting foods that meet the guidelines.

Meri/Classroom of the Future: . . . . Wed, Jul 2, 11:03 AM PDT (-0700 GMT). . . If you were planning for a long-term mission (to a lunar or mars or distant space station), how would that influence the choice of foods of the astronauts?

Janis/NBL: . . . . Wed, Jul 2, 11:09 AM PDT (-0700 GMT). . . Meri, we would like them to get a well-balanced menu from the available food items (and that is in development as we speak). High on our wish list would be freezers as that would increase the nutritional quality and variety.

Farm Home Class: . . . . Wed, Jul 2, 11:04 AM PDT (-0700 GMT). . . Farm Home School here from Oregon! We are picking strawberries by the bushel this time of year; what is the choice and process for fruits for astronauts?

Janis/NBL: . . . . Wed, Jul 2, 11:10 AM PDT (-0700 GMT). . . Farm Home School, off the top of my head, fresh fruits are not readily available. However, fruits are featured in such items as the fruit cocktails, etc.

David/Purdue: . . . . Wed, Jul 2, 11:10 AM PDT (-0700 GMT). . . Classrooms here would be interested in email mentoring or other methods of contact with people from NASA. Any leads I can pursue?

Janis/NBL: . . . . Wed, Jul 2, 11:12 AM PDT (-0700 GMT). . . David, I would contact the PAO (Public Affairs Office) here at JSC. Ask for their Education Outreach group (281) 483 2929. Good luck.

Meri/Classroom of the Future: . . . . Wed, Jul 2, 11:13 AM PDT (-0700 GMT). . . What are the major nutritional supplements with which it is expected astronauts would need to be provided on a long-term mission where they would be growing a vegetarian diet?

Janis/NBL: . . . . Wed, Jul 2, 11:20 AM PDT (-0700 GMT). . . Meri, we encourage the use of food items to meet all nutrient needs.

Janis/NBL: . . . . Wed, Jul 2, 11:21 AM PDT (-0700 GMT). . . Meri, on modules on the planetary surface.

Susan /Chase Foundation Argentina: . . . . Wed, Jul 2, 11:06 AM PDT (-0700 GMT). . . What is the time before expiration of dehydrated food used for astronauts?

Janis/NBL: . . . . Wed, Jul 2, 11:14 AM PDT (-0700 GMT). . . Susan, I think it varies, and unfortunately I don't have that information on my finger-tips, however it is more than long enough for the long Mir missions that US astronauts have flown on so far.

Meri/Classroom of the Future: . . . . Wed, Jul 2, 11:11 AM PDT (-0700 GMT). . . How much nutritional value is lost in the storage process? Do nutritionists analyze for calorie and nutrition content at various times after freezing, etc., to see patterns of nutrition loss? What is the appropriate nutritional loss in a frozen as compared to a relatively fresh (picked within two weeks) diet?

Janis/NBL: . . . . Wed, Jul 2, 11:16 AM PDT (-0700 GMT). . . Meri, we have done some micronutrient studies which show that there is no significant loss of nutrients. All foods have been analyzed so that we can tell exactly how much of the nutrients the astronauts are getting.

Janis/NBL: . . . . Wed, Jul 2, 11:17 AM PDT (-0700 GMT). . . Meri, periodic evaluation of the foods have been completed. We are pretty comfortable with our database, especially with the macronutrients.

Janis/NBL: . . . . Wed, Jul 2, 11:18 AM PDT (-0700 GMT). . . Meri, I'll have to pass on that one. Our food scientists would probably have a better handle on that one.

Robin/Hopkins: . . . . Wed, Jul 2, 11:11 AM PDT (-0700 GMT). . . How much lead time was there to prepare for STS94?

Janis/NBL: . . . . Wed, Jul 2, 11:19 AM PDT (-0700 GMT). . . Robin, I think it's four months (but they have been training for 12-18 months).

Farm Home Class: . . . . Wed, Jul 2, 11:13 AM PDT (-0700 GMT). . . Do astronauts still eat some types of food out of tubes, as they did on the first manned space missions?

Janis/NBL: . . . . Wed, Jul 2, 11:22 AM PDT (-0700 GMT). . . Farm Home Class, not the US foods. The Russians still have some tube foods. Our Foods folks have worked real hard to make the foods as 'home'-like as possible.

david: . . . . Wed, Jul 2, 11:16 AM PDT (-0700 GMT). . . Are astronauts allowed to choose the foods they wish to bring?

Janis/NBL: . . . . Wed, Jul 2, 11:23 AM PDT (-0700 GMT). . . David, the astronauts typically select food items from the available foods. The variety is quite wide from shrimp cocktail to various vegetables, beef steak and all. They also do taste panels to see which foods they especially like.

Meri/Classroom of the Future: . . . . Wed, Jul 2, 11:20 AM PDT (-0700 GMT). . . How would a trip to Mars influence the diet of the astronauts on-board?

Janis/NBL: . . . . Wed, Jul 2, 11:24 AM PDT (-0700 GMT). . . Meri, it would probably be high in vegetarian items (probably much like the lunar plans).

Robin/Hopkins: . . . . Wed, Jul 2, 11:23 AM PDT (-0700 GMT). . . Has your Foods team been successful recreating Pepsi and Coke?

Janis/NBL: . . . . Wed, Jul 2, 11:24 AM PDT (-0700 GMT). . . Robin, not to my knowledge - stay tuned though....

david: . . . . Wed, Jul 2, 11:24 AM PDT (-0700 GMT). . . Do astronauts choose the foods they bring? What foods do they bring to MIR. I mean with the Russians eating the same food as us.

Janis/NBL: . . . . Wed, Jul 2, 11:26 AM PDT (-0700 GMT). . . David, I think the menu is 50% Russian and 50% American and I know there is lots of sharing of food items going on.

Farm Home Class: . . . . Wed, Jul 2, 11:25 AM PDT (-0700 GMT). . . OK, the BIG question: Is "Tang" still the number-one drink of US astronauts?

Janis/NBL: . . . . Wed, Jul 2, 11:27 AM PDT (-0700 GMT). . . Farm Home, I think the mango drinks are more popular.

Robin/Hopkins: . . . . Wed, Jul 2, 11:25 AM PDT (-0700 GMT). . . Have any of your hot and spicy foods been added to the shuttle diets?

Janis/NBL: . . . . Wed, Jul 2, 11:28 AM PDT (-0700 GMT). . . Robin, not yet (but maybe I'd volunteer if they were). There are some Mexican spiced items - omelets and all that are popular, in addition to the spicy shrimp cocktail.

Meri/NASA Classroom of the Future: . . . . Wed, Jul 2, 11:25 AM PDT (-0700 GMT). . . Does there seem to be any difference in the sense of taste of astronauts during their missions? Where could I find more information on this?

Janis/NBL: . . . . Wed, Jul 2, 11:30 AM PDT (-0700 GMT). . . Meri, according to the anecdotal evidence, the crew may have some altered taste and odor perceptions, but I don't know of any documented studies in flight to support that. We are working on publication (author Rice, BL) of some ground-based data which may have some more information.

Farm Home Class: . . . . Wed, Jul 2, 11:28 AM PDT (-0700 GMT). . . What is the weight limit to be an astronaut?

Janis/NBL: . . . . Wed, Jul 2, 11:31 AM PDT (-0700 GMT). . . Astronauts have to pass a complete physical. I think the guidelines are probably that they need to be within ideal body weight for their height, etc.

Susan /Chase Foundation Argentina: . . . . Wed, Jul 2, 11:26 AM PDT (-0700 GMT). . . Thank you for this opportunity to allow us to participate in this most interesting and informative chat. -Duncan and Susan Chase.

Oran/NASA Chat Host: . . . . Wed, Jul 2, 11:29 AM PDT (-0700 GMT). . . Thank you to everyone for joining us today for our chat with Janis Davis-Street from NASA Johnson Space Center!!! We hope you are able to join us for our next chat with Dr. Frank Merceret from NASA Kennedy Space Center on Wednesday, July 9, at 10:00 AM, PDT.

Meri/NASA Classroom of the Future: . . . . Wed, Jul 2, 11:32 AM PDT (-0700 GMT). . . When and where may we see the archive of this chat session?

Oran/NASA Chat Host: . . . . Wed, Jul 2, 11:34 AM PDT (-0700 GMT). . . Meri, an archive of this chat session should be available by next week, and may be reviewed by visiting our WebChat archives.