Fossil Fuels and the Carbon Cycle
The Whole Individual Adequate Energy Intake is Critical
Nutrients are delivered through foods. When foods are digested, nutrients are disbursed and absorbed into all parts of the body not just our site of interest, such as muscle or the colon. Thus, we must be concerned with the effect of any single countermeasure on ALL systems, not just our system of interest. For example, some preliminary data suggest that an amino acid supplement provided to enhance muscle protein synthesis may exacerbate bone loss. Certain amino acids produce a lower metabolic pH in the body, which, in turn, can cause reabsorption of calcium from bone. This issue must be considered. In contrast, fish oil, which we have shown to protect against radiation—enhanced colon cancer, also may enhance muscle mass through an effect on decreasing protein breakdown.
The single most important overall effect of suboptimal nutrition is inadequate energy intake—not eating enough food—which is characteristic of individuals in space. Inadequate food intake results in inadequate nutrition. We saw this in the Tufts bed rest study, where energy intake was intentionally kept 15% lower than required (to mimic the intake observed in spaceflight). As we saw, under these conditions, the amino acid supplement was not effective in protecting against loss of muscle mass. The amino acids probably were being used for energy instead of protein synthesis. Finding a solution to promote adequate energy intake is an important goal of our team.
- NASA. Nutrition in space. Retrieved 09-19-2007 from http://www.nasa.gov/multimedia/imagegallery/index.html.
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Funded by the following grant(s)
My Health My World: National Dissemination
Grant Number: 5R25ES009259
The Environment as a Context for Opportunities in Schools
Grant Number: 5R25ES010698, R25ES06932
Foundations for the Future: Capitalizing on Technology to Promote Equity, Access and Quality in Elementary Science Education