Acknowledgments Supported by grants from the National Institute on Aging of the National Institutes of Health (P01AG022064 and P01AG017553) and by the Louisiana Board of Regents through the Millennium Trust Health Excellence Fund [HEF(2001-06)-02]. We thank the people of Louisiana and Georgia for participation in our study. We acknowledge the valuable recruitment, data acquisition, data management, and fiscal management efforts of M. Cervantes, D. Rouzan, T. Beard, M. Burgess, K. Grier, E. Jackson, E. McCarthy, K. Shaw, L. Strong, S. Reynolds, S. Anderson, E. Cassidy, M. Janke, T. Savla, and M. Poon. Additional authors include for The Louisiana Healthy Aging Study: M. Allen, I.E. Antikainen, A.M. Arce, J. Arceneaux, Mark A. Batzer, E.O. Boudreaux, L. Byerley, P.A. Callinan, C.M. Champagne, H. Cheng, Y.-W. Chiu, L. Cosenza, M.E. Cress, J.P. DeLany, J.Denver, A.Deutsch,M.J.deVeer,D.A.Dobrosielski,R.Ellis,A.Ermolao,M.Erwin,J.Fabre,E.Fontham,MSurvey for Assessing Physical Activity Among Older Adults. Med Sci Sports Exerc (): Duca M, Vekhoff P, Oussedik K, Halby L, Arimondo PB () The Triple Helix: Years Later, the Outcome. Nucleic Acids Res (): Flachsbart F, Croucher PJ, Nikolaus S, Hampe J, Cordes C, Schreiber S, Nebel A () Sirtuin (SIRT) sequence variation is not associated with exceptional human longevity. Exp Gerontol (): Folstein MF, Folstein SE, Mugh PR () Mini-Mental State: A Practical Method for Grading the Cognitive State of Patients for the Clinician. J Psychiatr Res (): Friedrich U, Griese E, Schwab M, Fritz P, Thon K, Klotz U () Telomere length in different tissues of elderly patients. Mech Ageing Dev (): Gabriel SB, Schaffner SF, Nguyen H, Moore JM, Roy J, Blumenstiel B, Higgins J, Delice M, Lochner A, Faggart M, Liu-Cordero SN, Rotimi C, Adeyemo A, Cooper R, Ward R, Lander ES, Daly MJ, Altshuler D () The structure of haplotype blocks in the human genome. Science (): Goni JR, de la Cruz X, Orozco M () Triplex-forming oligonucleotide target sequences in the human genome. Nucleic Acids Res (): Grodstein F, van Oijen M, Irizarry MC, Rosas HD, Hyman BT, Growdon JH, De Vivo I () Shorter telomeres may mark early risk of dementia: preliminary analysis of participants from the Nurses Health Study. PLoS One (): Guarente L., Kenyon C () Genetic pathways that regulate ageing in model organisms. Nature (): Harley CB () Telomere loss: Mitotic clock or genetic time bomb? Mutat Res (): Hastie ND, Dempster M, Dunlop MG, Thompson AM, Green DK, Allshire RC () Telomere reduction in human colorectal carcinoma and with ageing. Nature (): Iwama H, Ohyashiki K, Ohyashiki JH, Hayashi S, Yahata N, Ando K, Toyama K, Hoshika A, Takasaki M, Mori M, Shay JW () Telomeric length and telomerase activity vary with age in peripheral blood cells obtained from normal individuals. Hum Genet (): Jazwinski SM, Kim S, Dai J, Li L, Bi X, Jiang JC, Arnold J, Batzer MA, Walker JA, Welsh DA, Lefante CM, Volaufova J, Myers L, Su LJ, Hausman DB, Miceli MV, Ravussin E, Poon LW, Cherry KE and Welsch MA () HRAS and LASS with APOE are associated with human longevity and healthy aging. Aging Cell (): Jeong J., Juhn K., Lee H., Kim SH., Min BH., Lee KM., Cho MH., Park GH., Lee KH () SIRT promotes DNA repair activity and deacetylation of Ku. Exp Mol Med (): Kimura M., Gazitt Y., Cao X., Zhao X., Lansdorp PM., Aviv A () Synchrony of telomere length among hematopoietic cells. Exp Hematol (): Lamarche BJ., Orazio NI., Weitzman MD () The MRN complex in double-strand break repair and telomere maintenance. FEBS Lett (): Li R., Yang Y., An Y., Zhou Y., Liu Y., Yu Q., Lu D., Wang H., Jin L., Zhou W., Qian J., Shugart YY () Genetic polymorphisms in DNA double-strand break repair genes XRCC1, XRCC2 and susceptibility to hepatocellular carcinoma. Carcinogenesis (): Libby BJ, Reinholdt LG, Schimenti JC () Positional cloning and characterization of Mei1, a vertebrate-specific gene required for normal meiotic chromosome synapsis in mice. Proc Natl Acad Sci USA (): Liu Y., Zhang H., Zhou K., Chen L., Xu Z., Zhong Y., Liu H., Li R., Shugart YY, Wei Q, Jin L, Huang F, Lu D and Zhou L () Tagging SNPs in non-homologous end-joining pathway genes and risk of glioma. Carcinogenesis (): Ludlow AT, Zimmerman JB, Witkowski S, Hearn JW, Hatfield BD and Roth SM () Relationship between physical activity level, telomere length and telomerase activity. Med Sci Sports Exerc (): Mather KA, Jorm AF, Parslow RA and Christensen H () Is telomere length a biomarker of aging