Skip to main content
SpringerLink
Log in

Role of Dietary Fats and Exercise in Immune Functions and Aging

  • Chapter
Book cover Fatty Acids

Part of the book series: Nutrition and Health ((NH))

  • 333 Accesses

Abstract

Immunosenescence is a complex remodeling of the immune system that may contribute significantly to morbidity and mortality in the elderly. Much evidence suggests an association between immune function and well-being during aging and longevity. Despite several studies on the immune system in the elderly, little is known of the biological basis of immunosenescence in humans. Undoubtedly, some diseases to which the elderly are particularly susceptible, such as infections and autoimmune and neoplastic pathologies, include dysregulation of several immune functions in their pathogenesis. On the other hand, recent studies in healthy centenarians suggest that the immunological changes observed during aging are consistent with a reshaping, rather than a generalized deterioration, of the main immune functions. The infection rate and severity increase with aging as a result of decrease in immune function with aging. The primary changes of the aged host are in the T-lymphocytes, perhaps because of the involution of the thymus. Secondary changes (environmental) may be the result of changes in diet, drug intake, physical activity, and so forth or, alternatively, the result of underlying diseases (Wick and Grubeck-Loebenstein, 1997). There is a paradoxical increase in autoimmunity, and the responsiveness to exogenous antigens and tumors are reduced and may play a proinflammatory role in the development of many pathological conditions (Weyand et al., 1998). Recurrent stress, infections, and inflammation over the life-span play a significant role in producing age-associated changes in all systems. Genetic selection for infections has been implicated in coronary heart disease (McCann et al., 1998), early onset of Parkinson’s following influenza encephalitis, and Alzheimer’s disease (Stoessl, 1999).

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Log in via an institution
Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 189.00
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 249.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info
Hardcover Book
USD 249.99
Price excludes VAT (USA)
  • Durable hardcover edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  • Barnett YA, Barnett CR. DNA damage and mutation: contributors to the age-related alterations in T cell-mediated immune responses? Mech Ageing Dev 1998; 102: 165 - 175.

    Article  PubMed  CAS  Google Scholar 

  • Beere PA, Russell SD, Morey MC, Kitzman DW, Higginbotham MB. Aerobic exercise training can reverse age-related peripheral circulatory changes in health older men. Circulation 1999; 100: 1085 - 1094.

    Article  PubMed  CAS  Google Scholar 

  • Bodnar, AG, Ouellette M, Frolkis, M, Holt SE, Chiu CP, Morin GB, et al. Extension of life span by introduction of telomerase into normal human cells. Science 1998; 279: 349 - 352.

    Article  PubMed  CAS  Google Scholar 

  • Bouchard C, An P, Rice T, Skinner JS, Wilmore JH, Gagnon J, et al. Familial aggregation of Vo2cm) response to exercise training: results from the HERITAGE Family study. J Appl Physiol 1999; 87: 1003 - 1008.

    PubMed  CAS  Google Scholar 

  • Burns EA, Goodwin JS. Immunodeficiency of aging. Drugs Aging 1997; 11: 374 - 397.

    Article  PubMed  CAS  Google Scholar 

  • Byun DS, Venkatraman JT, Yu BP, Fernandes, G. Modulation of antioxidant activities and immune response by food restriction in aging Fischer-344 rats. Aging: Clin Exp Res 1995; 7: 40 - 48.

    Article  CAS  Google Scholar 

  • Calder PC. Immunoregulatory and anti-inflammatory effects of n-3 polyunsaturated fatty acids. Braz J Med Biol Res 1998; 31: 467 - 490.

    Article  PubMed  CAS  Google Scholar 

  • Calles-Escandon J, Poehlman ET. Aging, fat oxidation and exercise. Aging 1997; 9: 57 - 63.

    PubMed  CAS  Google Scholar 

  • Catania A, Airaghi L, Motta P, Manfredi MG, Annoni G, Pettenati C, et al. Cytokine antagonists in aged subjects and their relation with cellular immunity. J Gerontol: Biol Sci 1997; 52A: B93 - B97.

    Article  CAS  Google Scholar 

  • Ceddia MA, Price EA, Kohlmeier CK, Evans JK, Lu Q, McAuley E, et al. Differential leukocytosis and lymphocyte mitogenic response to acute maximal exercise in the young and old. Med Sci Sports Exerc 1999; 31: 829 - 836.

    Article  PubMed  CAS  Google Scholar 

  • Chaet MS, Garcia VF, Arya G, Ziegler MM. Dietary fish oil enhances macrophage production of nitric oxide. J Surg Res 1994; 57: 65 - 68.

    Article  PubMed  CAS  Google Scholar 

  • Chandrasekar B, Troyer DA, Venkatraman JT, Fernandes G. Dietary co-3 lipids delay the onset and progression of autoimmune lupus nephritis by inhibiting transforming growth factor 13 mRNA and protein expression. J Autoimmun 1995; 8: 381 - 393.

    Article  PubMed  CAS  Google Scholar 

  • Cinader B, Doria G, Facchini A, Kurashima C, Thorbecke GJ, Weksler ME. Aging and the immune system: Workshop 4 of 8th International Congress of Immunology, Budapest, Hungary. Aging: Immunol Infec Dis 1993; 4: 47 - 53.

    Google Scholar 

  • Doria G, Frasca D. Genes, immunity, and senescence: looking for a link Immunol Rev 1997; 160: 159 - 170.

    CAS  Google Scholar 

  • Ernst DN, Hobbs MV, Torbett BE, Glasebrook AL, Rehse MA, McQuitty DN, et al. Differences in the subset composition of CD4+ T cell population from young and old mice. Aging: Immunol Infec Dis 1990; 2: 105 - 109.

    Google Scholar 

  • Ernst DN, Weigle O, Hobbs MV. Aging and lymphokine gene expression by T cell subsets. Nutr Rev 1995; 53: S18 - S26.

    Article  PubMed  CAS  Google Scholar 

  • Fabris N, Mocchegiani E, Provinciali M. Plasticity of neuroendocrine-thymus interactions during aging. Exp Gerontol 1997; 32: 415 - 429.

    Article  PubMed  CAS  Google Scholar 

  • Fernandes, G. Effects of calorie restriction and omega-3 fatty acids on autoimmunity and aging. Nutr Rev 1995; 53: S72 - S79.

    PubMed  CAS  Google Scholar 

  • Fernandes A, Venkatraman JT, Tomar V, Fernandes G. Effect of treadmill exercise and food restriction on immunity and endocrine hormone levels in rats. FASEB J 1990; 4: 751A.

    Google Scholar 

  • Fernandes G, Venkatraman JT. Effect of food restriction on immunoregulation and aging. In R. R. Watson (Ed.), Handbook of Nutrition in the Aged. 2nd ed. CRC, Boca Raton, FL, 1993, pp. 331 - 346.

    Google Scholar 

  • Fernandes G, Bysani C, Venkatraman JT, Tomar V, Zhao W. Increased TGFß and decreased oncogene expression by co-3 lipids in the spleen delays autoimmune disease in B/W mice. J Immunol 1994; 152: 5979 - 5987.

    PubMed  CAS  Google Scholar 

  • Fernandes G, Chandrasekar B, Mountz JD, Zhao W. Modulation of Fas apoptotic gene expression in spleens of B/W mice by the source of dietary lipids with and without calorie restriction. FASEB J 1995; 9: 4559.

    Google Scholar 

  • Fernandes G, Troyer DA, Jolly CA. The effects of dietary lipids on gene expression and apoptosis. Proc Nutr Soc 1998; 57: 543 - 550.

    Article  PubMed  CAS  Google Scholar 

  • Fernandes G, Venkatraman JT, Turturro A, Attwood VG, Hart RW. Effect of food restriction on life span and immune functions in long-lived Fisher-344 x Brown Norway Fl rats. J Clin Immunol 1997; 17: 85 - 95.

    Article  PubMed  CAS  Google Scholar 

  • Grounds MD. Age-associated changes in the response of skeletal muscle cells to exercise and regeneration. Ann NY Acad Sci 1998; 854: 78 - 91.

    Article  PubMed  Google Scholar 

  • Guidi, L.,Tricerri A, Frasca D, Vangeli M, Errani AR, Bartoloni C. Psychoneuroimmunology and aging. Gerontology 1998; 44: 247 - 261.

    Article  Google Scholar 

  • Hakkinen K, Pakarinen A, Newton RU, Kraemer WJ. Acute hormone responses to heavy resistance lower and upper extremity exercise in young versus old men. Eur J Appl Physiol Occup Physiol 1998; 77: 312 - 319.

    Article  PubMed  CAS  Google Scholar 

  • Han SN, Meydani SN. Vitamin E and infectious diseases in the aged. Proc Nutr Soc 1999; 58: 697 - 705.

    CAS  Google Scholar 

  • Haydar ZR, Blackman MR, Tobin JD, Wright JG, Fleg JL. The relationship between aerobic exercise capacity and circulating IGF-1 levels in healthy men and women. J Am Geriatr Soc 2000, 48: 139 - 145.

    PubMed  CAS  Google Scholar 

  • Hayek MG, Han SN, Wu D, Watkins BA, Meydani M, Dorsey JL, et al. Dietary conjugated linoleic acid influences the immune response of young and old C57BL/6NCr1BR mice. J Nutr 1999; 129: 32 - 38.

    PubMed  CAS  Google Scholar 

  • Hirokawa K. Reversing and restoring immune functions. Mech Ageing Dev 1997; 93: 119 - 124.

    Article  PubMed  CAS  Google Scholar 

  • Hirokawa K, Utsuyama M, Kasai M, Kurashima C, Ishijima S, Zeng YX. Understanding the mechanism of the age-change of thymic function to promote T cell differentiation. Immunol Lett 1994; 40: 269 - 277.

    Article  PubMed  CAS  Google Scholar 

  • Jill, Leeuwenburgh C, Leichtweis S, Gore M, Hollander J, Bejm J. Oxidative stress and aging. Role of exercise and its influences on antioxidant systems. Ann NY Acad Sci 1998; 854: 102 - 117.

    Article  Google Scholar 

  • Kasch FW, Boyer JL, Schmidt PK, Wells RH, Wallace JP, Verity LS, et al. Aging of the cardiovascular system during 33 years of aerobic exercise. Age Ageing 1999; 28: 531 - 536.

    Article  PubMed  CAS  Google Scholar 

  • Krause D, Mastro AM, Handte G, Smiciklas-Wright H, Miles MP, Ahluwalia, N. Immune function did not decline with aging in apparently healthy, well-nourished women. Mech Ageing Dev 1999; 112: 43 - 57.

    Article  PubMed  CAS  Google Scholar 

  • Laganiere S, Yu BP, Fernandes G. Studies on membrane lipid peroxidation in omega-3 fatty acid-fed autoimmune mice: effect of vitamin E supplementation. In: Bendich A, Phillips M, Tangerdy RB, eds. Adv Exp Med Biol, Vol. 262, Plenum Press, New York, 1990, pp. 95 - 103.

    Google Scholar 

  • Lesourd BM. Nutrition and immune in the elderly: modification of immune response with nutritional treatments. Am J Clin Nutr 1997; 66: 4785 - 484S.

    Google Scholar 

  • Lesourd BM. Immune response during disease and recovery in the elderly. Proc Nutr Soc 1999; 58: 85 - 98.

    Article  PubMed  CAS  Google Scholar 

  • Makinodan T. Studies on the influence of age on immune response to understand the biology of immunosenescence. Exp Gerontol 1998; 33: 27 - 38.

    Article  PubMed  CAS  Google Scholar 

  • Makinodan T, Chang MP, Norman DC, Li SC. Vulnerability of T cell lineage to aging. In: Goidl E, ed. Aging and Immune Response: Cellular and Humoral Aspects. Marcel Dekker, New York, 1987, pp. 27 - 39.

    Google Scholar 

  • Marcell TJ, Wiswell RA, Hawkins SA, Tarpenning KM. Age-related blunting of growth hormone secretion during exercise may not be due to increased somatosatatin tone. Metab: Clin Exp 1999; 48: 665 - 670.

    Article  CAS  Google Scholar 

  • Marsh GD, Paterson DH, Govindasamy D, Cunningham DA. Anaerobic power of the arms and legs of young and older men. Exp Physiol 1999; 84: 589 - 597.

    Article  PubMed  CAS  Google Scholar 

  • Mazzeo RS, Rajkumar C, Rolland J, Blaher B, Jennings G, Eshler M. Immune response to a single bout of exercise in young and elderly subjects. Mech Ageing Dev 1998; 100: 121 - 132.

    Article  PubMed  CAS  Google Scholar 

  • Mazzoccoli G, Correra M, Bianco G, De Cata A, Balzanelli M, Giuliani A, et al. Age-related changes of neuro-=endocrine-immune interactions in healthy humans. J Biol Regul Homeostat Agents 1997; 11: 143 - 147.

    CAS  Google Scholar 

  • McCann SM, Licinio J, Wong ML, Yu WH, Karanth S, Rettorri V. The nitric oxide hypothesis of aging. Exp Gerontol 1998; 33: 813 - 326.

    Article  PubMed  CAS  Google Scholar 

  • Morio B, Barra V, Ritz P, Fellmann N, Bonny JM, Beaufrere B, et al. Benefit of endurance training in elderly people over a short period is reversible. Eur J Appl Physiol Occup Physiol 2000; 81: 329 - 336.

    Article  CAS  Google Scholar 

  • Mountz JD, Wu J, Zhou T, Hsu H-C. Cell death and longevity: implications of Fas-mediated apoptosis in T-cell senescence. Immunol Rev 1997; 160: 19 - 30.

    Article  PubMed  CAS  Google Scholar 

  • Nieman DC, Henson DA, Gusewitch G, Warren BJ, Dotson RC, Butterworth DE, Nehlsen-Cannarella SL.

    Google Scholar 

  • Physical activity and immune function in elderly women. Med Sci Sports Exerc 1993; 25: 823 - 831.

    Article  Google Scholar 

  • Pendergast DR, Horvath PI, Leddy JJ, Venkatraman JT. The role of dietary fat on performance metabolism and health. Am J Sports Med 1997; 24: S53 — S58.

    Google Scholar 

  • Phelouzat MA, Arbogast A, Laforge T, Quadri RA, Proust JJ. Excessive apoptosis of mature T lymphocytes is a characteristic feature of human immune senescence. Mech Ageing Dev 1996; 88: 25 - 38.

    Article  PubMed  CAS  Google Scholar 

  • Pierpaoli W. Neuroimmunomodulation of aging. A program in the pineal gland. Ann NY Acad Sci 1998; 840: 491 - 497.

    Article  PubMed  CAS  Google Scholar 

  • Potestio M, Caruso C, Gervasi F, Scialabba G, D' Anna C, Di Lorenzo G, et al. Apoptosis and ageing. Mech Ageing Dev 1998; 102: 221 - 237.

    Article  PubMed  CAS  Google Scholar 

  • Prioux J, Ramonatxo M, Hayot M, Mucci P, Prefaut C. Effects of ageing on the ventilatory response and lactate kinetics during incremental exercise in man. Eur J Appl Physiol Occup Physiol 2000; 81: 100 - 107.

    Article  CAS  Google Scholar 

  • Reddy Avula CP, Zaman AK, Lawrence R, Fernandes G. Induction of apoptosis and apoptotic mediators in Balb/c splenic lymphocytes by dietary n-3 and n-6 fatty acids. Lipids 1999; 34: 921 - 927.

    Article  Google Scholar 

  • Rink L, Cakman I, Kirchner H. Altered cytokine production in the elderly. Mech Ageing Dev 1998; 102: 199 - 209.

    Article  PubMed  CAS  Google Scholar 

  • Robinson LE, Field CJ. Dietary long-chain (n-3) fatty acids facilitate immune cell activation in sedentary, but not exercise-trained rats. J Nutr 1998; 128: 498 - 504.

    PubMed  CAS  Google Scholar 

  • Rumyantsev SN. Constitutional and non-specific immunity to infection. Rev Sci Tech 1998; 17:26-42. Shephard PJ, Rhind S, Shek PN. Exercise and the immune system. Natural killer cells, interleukins and related responses. Sports Med 1994; 18: 340 - 369.

    Google Scholar 

  • Shephard RJ, Shek PN. Exercise, aging and immune function. Intl J Sports Med 1995; 16: 1 - 6.

    Article  CAS  Google Scholar 

  • Shinkai S, Konishi M, Shephard RJ. Aging and immune response to exercise. Can J Physiol Pharmacol 1998; 76: 562 - 572.

    Article  PubMed  CAS  Google Scholar 

  • Solana R, Pawelec G. Molecular and cellular basis of immunosenescence. Mech Ageing Dev 1998; 102: 115 - 129.

    Article  PubMed  CAS  Google Scholar 

  • Stoessl AJ. Etiology of Parkinson's disease. Can J Neuro Sci 1999; 26:S5—S 12.

    Google Scholar 

  • Thoman ML, Weigle WO. The cellular and sub-cellular bases of immunosenescene. Adv Immunol 1989; 46: 221 - 261.

    Article  PubMed  CAS  Google Scholar 

  • Tsuji I, Tamagawa A, Nagatomi R, Irie N, Ohkubo T, Saito M, et al. Randomized controlled trial of exercise training for older people (sendai Silver Center Trial; SSCT): study design and primary outcome. J Epidemiol 2000; 10: 55 - 64.

    Article  PubMed  CAS  Google Scholar 

  • Venkatraman JT, Chu W. Effects of dietary w-3 and w-6 lipids and vitamin E and on proliferative response, lymphoid cell subsets, production of cytokines by spleen cells and splenic protein levels for cytokines and oncogenes in MRL/MpJ-/pr mice. J Nutr Biochem 1999; 10: 582 - 597.

    CAS  Google Scholar 

  • Venkatraman JT, Chu W. Effects of dietary w-3 and w-6 lipids and vitamin E on serum cytokines, lipid mediators and anti-DNA antibodies in a mouse model for rheumatoid arthritis. J Am Coll Nutr 1999; 18: 602 - 612.

    CAS  Google Scholar 

  • Venkatraman JT, Fernandes G. Modulation of immune function during aging by dietary restriction. In: Yu BP, ed. Modulation of Aging Processes by Dietary Restriction. CRC, Boca Raton, 1994, pp. 193 - 219.

    Google Scholar 

  • Venkatraman JT, Fernandes G. Exercise, immunity and aging. Aging: Clin Exp Res 1997; 9: 42 - 55

    CAS  Google Scholar 

  • Venkatraman JT, Attwood VG, Turturro A, Hart RW, Fernandes G. Maintenance of virgin T-cells and immune functions by food restriction during aging in long-lived B6D2F1 female mice. Aging: Immunol Infect Dis 1994; 5: 13 - 25.

    Google Scholar 

  • Venkatraman JT, Bysani C, Kim JD, Fernandes G. Effect of n-3 and n-6 fatty acids on activities and expression of hepatic antioxidant enzymes in autoimmune-prone NZB/NZWF1 mice. Lipids 1994; 29: 561 - 568.

    Article  PubMed  CAS  Google Scholar 

  • Venkatraman JT, Fernandes G. w-3 lipids in health and disease. Nutr Res 1993; 13: 19S - 45S.

    Article  Google Scholar 

  • Venkatraman JT, Pendergast DR. Effects of the level of dietary fat intake and endurance exercise on plasma cytokines in runners. Med Sci Sports Exerc 1998; 30: 1198 - 1204.

    Article  PubMed  CAS  Google Scholar 

  • Venkatraman JT, Horvath PJ, Pendergast DR. Lipids and exercise immunology. In: Nieman DC, Pedersen B, eds. Nutrition and Exercise Immunology. CRC, Boca Raton, 2000, pp. 43 - 74.

    Google Scholar 

  • Venkatraman JT, Leddy JJ, Pendergast DR. Dietary fats and immune status in athletes: clinical implications. Med Sci Sports Exerc 2000; 32: S1 — S7.

    Article  Google Scholar 

  • Venkatraman JT, Rowland JA, DeNardin E, Horvath PJ, Pendergast DR. Influence of the level of dietary lipid intake and maximal exercise on immune status in runners. Med Sci Sports Exerc 1997; 29: 333 - 344.

    Article  PubMed  CAS  Google Scholar 

  • Walford RL. MHC regulation of aging: an extension of the immunologic theory of aging. In: Warner HR, Butler RN, Sprott RL, Schneider EL, eds. Modern Biological Theories of Aging. Raven, New York, 1987, pp. 243 - 255.

    Google Scholar 

  • Wander RC, Hall JA, Gradin JL, Du SH, Jewell DE. The ratio of dietary (n-6) to (n-3) fatty acids influences immune system function, eicosanoid metabolism, lipid peroxidation and vitamin E status in aged dogs. J Nutr. 1997; 127: 1198 - 205.

    CAS  Google Scholar 

  • Weiss C, Kinscherf R, Roth S, Friedmann B, Fischbach T, Reus J, et al. Lymphocyte subpopulations and concentrations of soluble CD8 and CD4 antigen after anaerobic training. Intl J Sports Med 1995; 16: 117 - 121.

    Article  CAS  Google Scholar 

  • Weyand CM, Brandes JC, Schmidt D, Fulbright JW, Goronzy JJ. Functional properties of CD4 CD28T-cells in the aging immune system. Mech Ageing Dev 1998; 102: 131 - 147.

    Article  PubMed  CAS  Google Scholar 

  • Wick G, Grubeck-Loebenstein B. The aging immune system: primary and secondary alterations of immune reactivity in the elderly. Exp Gerontol 1997; 32: 401 - 13.

    Article  PubMed  CAS  Google Scholar 

  • Woods JA, Ceddia MA, Wolters BW, Evans JK, Lu Q, McAuley E. Effects of 6 months moderate aerobic exercise training on immune function in the elderly. Mech Ageing Dev 1999; 109: 1 - 19.

    Article  PubMed  CAS  Google Scholar 

  • Yehuda AB, Friedman G, Wirtheim E, Abel L, Globerson A. Checkpoints in thymocytopoiesis in aging: expression of the recombination activating genes RAG-1 and RAG-2. Mech Ageing Dev 1998; 102: 239 - 247.

    Article  PubMed  CAS  Google Scholar 

  • Zaccaria M, Varner M, Piazza P, Noventa D, Ermolao A. Blunted growth hormone response to maximal exercise in middle-aged versus young subjects and no effect of endurance training. J Clin Endocrinol Metab 1999; 84: 2303 - 2307.

    Article  PubMed  CAS  Google Scholar 

  • Zouhal H, Gratas-Delamarche A, Rannou F, Granier P, Bentue-Ferrer D, Delamarche P. Between 21 and 34 years of age, aging alters the cateholamine responses to supramaximal exercise in endurance trained athletes. Intl J Sports Med 1999; 20: 343 - 348.

    Article  CAS  Google Scholar 

Download references

Authors
  1. Jaya T. Venkatraman
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. David Pendergast
    View author publications

    You can also search for this author in PubMed Google Scholar

Editor information

Editors and Affiliations

  1. Department of Psychology, Boston University, Boston, MA, USA

    David I. Mostofsky PhD

  2. Psychopharmacology Laboratory, Bar Ilan University, Ramat Gan, Israel

    Shlomo Yehuda PhD

  3. National Institute on Alcohol Abuse and Alcoholism, Rockville, MD, USA

    Norman Salem Jr. PhD

Rights and permissions

Reprints and permissions

Copyright information

© 2001 Springer Science+Business Media New York

About this chapter

Cite this chapter

Venkatraman, J.T., Pendergast, D. (2001). Role of Dietary Fats and Exercise in Immune Functions and Aging. In: Mostofsky, D.I., Yehuda, S., Salem, N. (eds) Fatty Acids. Nutrition and Health. Humana Press, Totowa, NJ. https://doi.org/10.1007/978-1-59259-119-0_5

Download citation

  • DOI: https://doi.org/10.1007/978-1-59259-119-0_5

  • Publisher Name: Humana Press, Totowa, NJ

  • Print ISBN: 978-1-61737-265-0

  • Online ISBN: 978-1-59259-119-0

  • eBook Packages: Springer Book Archive

Publish with us

Policies and ethics

Search

Navigation