Military Strategies for Sustainment of Nutrition and Immune Function in the Field (1999) / Chapter Skim
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4 Why is the Army Interested in Nutrition and Immune Function?
4 Why is the Army Interested in Nutrition and Immune Function?
Pages 139-162
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From page 139... ...
Combined stressors may reduce the normal ability of soldiers to resist pathogens, increase susceptibility to biological threat agents employed against them, and reduce effectiveness of vaccines intended to protect them. Some immunological impairments may be prevented by ensuring adequate nutrition (e.g., preventing substantial energy or protein deficits)
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From page 140... ...
The infectious disease problem in Ranger students appears largely to have been corrected through a nutritional intervention. Immune function deficits were attenuated with increased feeding, and dramatic reductions in infection (25% prevalence reduced to 2%)
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From page 141... ...
IMMUNE SUPPRESSION AND INFLAMMATORY RESPONSES TO OPERATIONAL STRESSORS A current objective of Army operational medicine research is to identify the effect of operational stressors and other battlefield hazards on soldiers' immunological and/or inflammatory host defenses. Problems must be defied in relevant models of operational stress and in terms of actual disease susceptibility (Kusnecov and Rabin, 1994~; research to develop nutritional countermeasures is appropriate after problems have been clearly identified.
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From page 142... ...
, and this has an impact on immune function that may be distinctly different from anxiety stress effects. Acute sleep restriction produces a reduction in natural immune responses (e.g., natural killer [NK]
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From page 143... ...
, in a multistressor paradigm that includes strenuous exercise, followed by dramatic changes in immunological indices (see Wiik, Chapter 6~. However, this stressful training does not result in a significant increase in infection rates (B0yum et al., 1996~.
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From page 144... ...
For example, during the Vietnam War, John Mason and his colleagues examined endocrine stress responses of helicopter air ambulance crews and Special Forces A-teams under attack (Bourne et al., 1967; Rose et al., 1969~; also a Navy aeromedical research team studied stress responses of carrier pilots in combat (Lewis et al., 1967~. Unfortunately, these studies preceded the recent advances in immune function testing and current understanding of the associations between stress and disease susceptibility.
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From page 145... ...
1988~. A primary recommendation, which came out of the North Atlantic Treaty Organization workshop on "The Effect of Prolonged Exhaustive Military 4 Since this workshop, a study involving hepatitis A vaccine administered to Ranger students has been designed and started (October 1997)
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From page 146... ...
The methodology, including a whole blood method of lymphocyte proliferation measurement, and the challenges to carefully control field sample collection and handling are reviewed later in this report by Kramer (see Chapter 10~. These data suggest that the degree of immune function suppression, as indicated by stimulated lymphocyte proliferative response, is proportional to the degree of energy deficit.
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From page 147... ...
The Special Forces Assessment and Selection (SFAS) course was only 3 weeks long, compared with 8 weeks for Ranger training and for Army basic training, and energy density of weight loss is likely to vary over time within a protracted energy deficit.
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From page 148... ...
A modest increase in caloric intake and a 20 percent reduction in energy deficit across the course may have been responsible for the marked reduction in infection rates noted between the first and the second Ranger study (Table 4-2~. It is also possible that the attenuation of the immune function deficits observed in the in vitro tests offers a mechanism for the reduction in infection rates (Kramer et al., 1997~.
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From page 149... ...
, there was a suppression of immune function indices, although smaller than in the Ranger studies (Table 4-1~. The in vitro lymphocyte responses cannot be compared directly between the glutamine study and the original study because of the timing of a DTH test at the end of the glutamine study; however, similar results were obtained for both treatment and control groups in the glutamine study.
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From page 150... ...
This exercise model was shown previously to produce suppression of immune function indices in men (Singh et al., 1994~. The intervention study with women produced no differences in stress responses (e.g., serum levels of IL-6, cortisol, and adrenocorticotropic hormone)
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From page 151... ...
Multiple studies show increased T-lymphocyte counts, enhanced wound healing, increased strength of immune responses to mitogens, and other immune enhancements. Ten grams a day may keep you forever out of the dangerous hands of medicine.
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From page 152... ...
Key technological barriers in nutritional immunology include an understanding of the relationship between immune function indices and disease susceptibility, a better understanding of the central role of cytokines in stress-induced suppression of immunological function, and a more complete understanding of the biological effects and modulation of oxidative stress. Practical limitations include diminishing resources and limited available expertise in the multiple disciplines required to accomplish this research.
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From page 153... ...
1994. Leukocytosis and natural killer cell function parallel neurobehavioral fatigue induced by 64 hours of sleep deprivation.
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From page 154... ...
Army Ranger students in a multistressor f~eld environment. Workshop on the Effect of Prolonged Exhaustive Military Activities on Man-Physiological and Psychological Changes Possible Means of Rapid Recuperation.
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From page 155... ...
Army Ranger Training Class 11/91. A brief report of the Committee on Military Nutrition Research, Food and Nutrition Board, March 23.
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From page 156... ...
Vogel 1992. Changes in soldier nutritional status and immune function during the Ranger training course.
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From page 157... ...
1995. Effects of glutamine supplementation on immunological responses of soldiers during the Special Forces Assessment and Selection Course.
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From page 158... ...
1993. The effect of light, moderate and severe bicycle exercise on lymphocyte subsets, natural and lymphokine activated killer cells, lymphocyte proliferative response and interleukin-2 production.
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From page 159... ...
We captured it in those infection rates. When we looked at why people dropped out, the dropouts were not people who were having problems with infections.
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From page 160... ...
The question relates to the infection rates in the women who were undergoing basic training. Was that similar to the infection rates in the men?
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From page 161... ...
[as demonstrated by the tine test] at the end of the study compared with the beginning of the study, but not in the second Ranger study, where individuals were knocked out early in the trial because of medical problems.
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