Higher Groundwater Selenium Exposure Is Associated with Better Memory: A Project FRONTIER Study

James Hall, Melissa Edwards, Robert Barber, Leigh Johnson, Gordon Gong, Sid E. O’Bryant

Department of Neurology, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
Department of Psychology, Texas Tech University, Lubbock, TX, USA.
F. Marie Hall Institute for Rural and Community Health, Texas Tech Health Sciences Center, Lubbock, TX, USA.
Texas Tech University Health Sciences Center, Laura W Bush Institute for Women’s Health & Department of Family and Community Medicine, Lubbock, TX, USA.
University of North Texas Health Science Center, Department of Pharmacology and Neuroscience, Ft Worth, TX, USA.
University of North Texas Health Science Center, Department of Psychiatry, Ft. Worth, TX, USA.

DOI: 10.4236/nm.2012.31004                

Abstract

Background: Exposure to elements in groundwater (toxic or beneficial) is commonplace yet, outside of lead and mercury, little research has examined the impact of many commonly occurring exposures on mental abilities during the aging process. Selenium has antioxidant properties as part of the glutathione peroxidase system and may have protective effects on memory abilities. Objectives: To investigate the relationship of groundwater selenium exposure to neuropsychological status. Method: Analysis of data from 484 participants (148 men and 336 women) of Project FRONTIER, a community-based participatory research study of the epidemiology of health issues of rural-dwelling adults and elders. Results: Estimated selenium exposure (current and long-term) was specifically related to memory functioning without relation to other neurocognitive domains. The significant, positive link between selenium and memory (Immediate and Delayed) scores held regardless of APOE4 status as well as when the sample was restricted to only those without cognitive dysfunction. Current selenium was also associated with significantly reduced risk of cognitive decline prospectively. Conclusions: Higher selenium levels were associated with better memory functioning as well as reduced risk of cognitive decline among this community-based sample. Given the antioxidant properties of selenium, and the well-documented link between oxidative stress and the development of cognitive dysfunction and Alzheimer’s disease, additional research is necessary to determine the utility of groundwater selenium monitoring as a potential population-wide prevention effort against Alzheimer’s disease.

Keywords

Environmental Exposure; Cognition; APOE4; Selenium; Groundwater

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	K. Bandeen-Roche, T. A. Glass, K. I. Bolla, A. C. Todd and B. S. Schwartz, “Cumulative Lead Dose and Cognitive Function in Older Adults,” Epidemiology, Vol. 20, No. 6, 2009, pp. 831-839. doi:10.1097/EDE.0b013e3181b5f100
[2]	C. Liao, H. H. Shen, C. L. Chen, L. I. Hsu, T. L. Lin, S. C. Chen and C. J. Chen, “Risk Assessment of Arsenic-Induced Internal Cancer at Long-Term Low Dose Exposure,” Journal of Hazardous Ma-terials, Vol. 165, No. 1-3, 2009, pp. 652-663. doi:10.1016/j.jhazmat.2008.10.095
[3]	A. Navas-Acien, E. K. Silbergeld, R. Pastor-Barriuso, et al., “Arsenic Exposure and Prevalence of Type 2 Diabetes in US Adults,” JAMA, Vol. 300, No. 7, 2008, pp. 814- 822. doi:10.1001/jama.300.7.814
[4]	Arsenic in Drinking Water, Subcommittee on Arsenic in Drinking Water National Research Council, Washington DC, 1999.
[5]	Arsenic in Drinking Water, Subcommittee to Update the 1999 Arsenic in Drinking Water Report National Research Council, 2001 Update, Wash-ington DC, 2001.
[6]	J. Weuve, S. A. Korrick, M. A. Weiss-kopf, L. M. Ryan, J. Schwartz, H. Nie, et al., “Cumulative Exposure to Lead in Relation to Cognitive Function in Older Women,” Environmental Health Perspectives, Vol. 117, No. 4, 2009, pp. 574-580.
[7]	S. Gao, Y. Jin, K. S. Hall, C. Liang, F. W. Unverzagt, R. Ji, et al., “Selenium Level and Cognitive Function in Rural Elderly Chinese,” American Journal of Epidemiology, Vol. 165, No. 8, 2007, pp. 955-965. doi:10.1093/aje/kwk073
[8]	A. Flatt, N. Pearce, C. D. Thomson, M. R. Sears, M. F. Robinson and R. Beasley, “Reduced Selenium in Asthmatic Subjects in New Zealand,” Thorax, Vol. 45, No. 2, 1990, pp. 95-99. doi:10.1136/thx.45.2.95
[9]	B. R. Cardoso, T. P. Ong, W. Jacob-Filho, O. Jaluul, M. I. D. Freitas and S. M. F. Cozzolino, “Nutritional Status of Selenium in Alzheimer’s Disease Patients,” British Journal of Nutrition, Vol. 103, No. 6, 2010, pp. 803-806. doi:10.1017/S0007114509992832
[10]	T. Finkel and N. J. Holbrook, “Oxidants, Oxidative Stress and the Biology of Ageing,” Nature, Vol. 408, 2000, pp. 239-247. doi:10.1038/35041687
[11]	N. T. Akbaraly, I. Hininger-Favier, I. Carrière, J. Arnaud, V. Gourlet, A. M. Roussel, et al., “Plasma Selenium over Time and Cognitive Decline in the Elderly,” Epidemiology, Vol. 18, No. 1, 2007, pp. 52-58. doi:10.1097/01.ede.0000248202.83695.4e
[12]	A. B. Mendelsohn, S. H. Belle, G. P. Stoehr and M. Ganguli, “Use of Antioxidant Supplements and Its Association with Cognitive Function in a Rural Elderly Cohort: The Movies Project,” American Journal of Epidemiology, Vol. 148, No. 1, 1998, pp. 38-44. doi:10.1016/j.jalz.2008.02.005
[13]	A. J. Perkins, H. C. Hendrie, C. M. Callahan, S. Gao, F. W. Unverzagt, Y. Xu, et al., “Association of Antioxidants with Memory in a Multiethnic Elderly Sample Using the Third National Health and Nutrition Examination Survey,” American Journal of Epidemiology, Vol. 150, No. 1, 1999, pp. 37-44.
[14]	Alzheimer’s Association, “Alzheimer’s Disease Facts and Figures,” Alzheimer’s & Dementia, Vol. 4, No. 2, 2008, pp. 110-133.
[15]	Alzheimer’s Association, “Changing the Trajectory of Alzheimer’s Disease,” Washington DC, 2010.
[16]	N. R. Graff-Radford, J. E. Crook, J. Lucas, B. F. Boeve, D. S. Knopman, R. J. Ivnik, et al., “Association of Low Plasma Abeta42/Abeta40 Ratios with Increased Imminent Risk for Mild Cognitive Impairment and Alzheimer Disease,” Archives of Neurology, Vol. 64, No. 3, 2007, pp. 354-362. doi:10.1001/archneur.64.3.354
[17]	S. Gao, Y. Jin, K. S. Hall, C. Liang, F. W. Unverzagt, F. Ma, et al., “Selenium Level Is Associated with apoE ε4 in Rural Elderly Chinese,” Public Health Nutrition, Vol. 12, No. 12, 2009, pp. 2371-2376. doi:10.1017/S1368980009005102
[18]	L. D. O’Fallon, “Commitment of the National Institute of Environmental Health Sciences to Community-Based Participatory Research for Rural Health,” Environmental Health Perspectives, Vol. 109, Suppl. 3 2001, pp. 469- 473.
[19]	L. Johnson, V. Hobson, M. Jenkins, A. Dentino, M. Ragain and S. E. O’Bryant, “The Influence of Thyroid Function on Cognition in a Sample of Ethnically Diverse, Rural-Dwelling Women: A Project FRONTIER Study,” Journal of Neuropsychiatry and Clinical Neuroscience, Vol. 23, No. 2, 2011, pp. 219-222. doi:10.1176/appi.neuropsych.23.2.219
[20]	S. E. O’Bryant, Y. Zhang, D. Owen, B. Cherry, V. Ramirez, M. Silva, C. Hudson, V. Hobson, P. Grammas, R. B. Schiffer, G. Manning, G. W. Schrimsher, J. A. Lucas, P. B. Sutker and the CCAS Research Team, “The Cochran County Aging Study: Methodology and Descriptive Statistics,” Texas Public Health Journal, Vol. 61, No. 1, 2009, pp. 5-7.
[21]	S. E. O’Bryant, J. Falkowski, V. Hobson, L. Johnson, J. Hall, G. W. Schrimsher, et al., “Executive Functioning Mediates the Link between Other Neuropsy-chological Domains and Daily Functioning: A Project FRON-TIER Study,” International Psychogeriatrics, Vol. 23, No. 1, 2010, pp. 107-113. doi:10.1017/S1041610210000967
[22]	S. O’Bryant, J. R. Hall, K. Cukrowizc, M. Edwards, L. A. Johnson, D. Lefforge, M. Jenkins, A. Dentino, “The Differential Impact of Depressive Symptom Clusters on Cognition in a Rural Multi-Ethnic Cohort: A Project FRONTIER Study,” International Journal of Geriatric Psychiatry, Vol. 26, No. 2, 2011, pp. 199-205. doi:10.1002/gps.2514
[23]	C. Randolph, “Repeatable Battery for the Assessment of Neuropsychological Status,” The Psychological Coporation, San Antonio, 1998.
[24]	K. Duff, L. J. Beglinger, M. R. Schoenberg, D. E. Patton, J. Mold, J. G. Scott, et al., “Test-Retest Stability and Practice Effects of the RBANS in a Community Dwelling Elderly Sample,” Journal of Clinical and Experimental Neuropsychology, Vol. 27, No. 5, 2005, pp. 565-575. doi:10.1080/13803390490918363
[25]	K. Duff, D. Pattern, M. R. Schoenberg, J. Mold, J. G. Scott and R. L. Adams, “Age- and Education-Corrected Independent Normative Data for the RBANS in a Community Dwelling Elderly Sample,” Clinical Neuropsycho- logist, Vol. 17, No. 3, 2003, pp. 351-366. doi:10.1076/clin.17.3.351.18082
[26]	K. Duff, J. D. Humph-reys, S. E. O’Bryant, J. W. Mold, R. B. Schiffer and P. B. Sutker, “Utility of the RBANS in Detecting Cognitive Impairment Associated with Alzheimer’s Disease: Sensitivity, Specificity, and Positive and Negative Predictive Powers,” Archives of Clinical Neuropsychology, Vol. 23, No. 5, 2008, pp. 603-612. doi:10.1016/j.acn.2008.06.004
[27]	E. B. Larson, K. Kirschner, R. Bode, A. Heinemann and R. Goodman, “Construct and Predictive Validity of the Repeatable Battery for the Assessment of Neuropsychological Status in the Evaluation of Stroke Patients,” Journal of Clinical & Experimental Neuropsychology, Vol. 27, No. 1, 2005, pp. 16-32. doi:10.1080/138033990513564
[28]	M. F. Folstein, S. E. Folstein and P. R. McHugh, “Mini-Mental State: A Practical Method for Grading the Cognitive State of Patients for the Cli-nician,” Journal of Psychiatric Research, Vol. 12, No. 3, 1975, pp. 189-198. doi:10.1016/0022-3956(75)90026-6
[29]	E. Strauss, E. M. S. Sherman and O. Spreen, “A Compendium of Neuropsycholog-ical Tests: Administration, Norms, and Commentary,” 3rd Edition, Oxford University Press, Oxford, 2006.
[30]	J. R. Harvan and V. Cotter, “An Evaluation of Dementia Screening in the Primary Care Setting,” Journal of the American Academy of Nurse Practitioners, Vol. 18, No. 8, 2006, pp. 351-360. doi:10.1111/j.1745-7599.2006.00137.x
[31]	G. A. AvRuskin, G. M. Jacquez, J. R. Meliker, M. J. Slotnick, A. M. Kaufmann and J. O. Nriagu, “Visualization and Exploratory Analysis of Epidemiologic Data Using a Novel Space Time Information System,” International Journal of Health Geographics, Vol. 3, 2004, p. 26. doi:10.1186/1476-072X-3-26
[32]	G. Gong and S. E. O’Bryant, “The Arsenic Exposure Hypothesis for Alzheimer’s Disease,” Alzheimer Disease & Associated Disorders, 2010, Epub ahead of print.
[33]	N. I. Khan, G. Owens, D. Bruce and R. Naidu, “Human Arsenic Exposure and Risk Assessment at the Land-scape Level: A Review,” Environmental Geochemistry and Health, Vol. 31, No. 1, 2009, pp. 143-166. doi:10.1007/s10653-008-9240-3
[34]	S. R. Samadder and C. Subbarao, “GIS Approach of Delineation and Risk Assessment of Areas Affected by Arsenic Pollution in Drinking Water,” Journal of Environmental Engineering, Vol. 133, No. 7, 2007, pp. 742-749. doi:10.1061/(ASCE)0733-9372(2007)133:7(742)
[35]	C. C. Su, Y. Y. Lin, T. K. Chang, C. T. Chiang, J. A. Chung, Y. Y. Hsu, et al., “Incidence of Oral Cancer in Relation to Nickel and Arsenic Concentrations in Farm Soils of Patients’ Residential Areas in Taiwan,” BMC Public Health, Vol. 10, 2010, p. 10.
[36]	T. Crook, R. T. Bartus, S. H. Ferris, et al., “Age-Associated Memory Impairment: Proposed Diagnostic Criteria and Measures of Clinical Change: Report of a National Institute of Mental Health Work Group,” Developmental Neuropsychology, Vol. 2, No. 4, 1986, pp. 261-276. doi:10.1080/87565648609540348
[37]	R. C. Petersen, “Mild Cognitive Impairment: Aging to Alzheimer’s Disease,” Oxford University Press, Oxford, 2003.
[38]	D. McKhann, D. Drockman, M. Folstein, et al., “Clinical Diagnosis of Alzheimer’s Disease: Report of the NINCDS- ADRDA Work Group,” Neurology, Vol. 34, No. 7, 1984, pp. 939-944.
[39]	H. C. Chui, J. I. Victoroff, D. Margolin, W. Jagust, R. Shankle, R. Katzman, “Criteria for the Diagnosis of Ischemic Vascular Dementia Proposed by the State of California Alzheimer’s Disease Diagnostic and Treatment Centers,” Neurology, Vol. 42, No. 3, 1992, pp. 473-480.
[40]	J. Chen, M. J. Berry, “Selenium and Selenoproteins in the Brain and Brain Diseases,” Journal of Neurochemistry, Vol. 86, No. 1, 2003, pp. 1-12. doi:10.1046/j.1471-4159.2003.01854.x
[41]	M. P. Rayman, “The Importance of Selenium to Human Health,” Lancet, Vol. 356, No. 9225, 2000, pp. 233-241. doi:10.1016/S0140-6736(00)02490-9
[42]	U. Schweizer, A. U. Br?uer, J. K?hrle, R. Nitsch, N. E. Savaskan, “Selenium and Brain Function: A Poorly Recognized Liaison,” Brain Research Reviews, Vol. 45, No. 3, 2004, pp. 164-178. doi:10.1016/j.brainresrev.2004.03.004
[43]	V. Mostert, P. Selenoprotein, “Properties, Functions, and Regulation,” Archives of Biochemistry and Biophysics, Vol. 376, No. 2, 2000, pp. 433-438. doi:10.1006/abbi.2000.1735
[44]	T. Ishrat, K. Parveen, M. M. Khan, G. Khuwaja, M. B. Khan, S. Yousuf, et al., “Selenium Prevents Cognitive Decline and Oxidative Damage in Rat Model of Streptozotocin-Induced Experimental Dementia of Alzheimer’s Type,” Brain Research, Vol. 1281, 2009, pp. 117-127. doi:10.1016/j.brainres.2009.04.010
[45]	J. Van Eersel, Y. D. Ke, X. Liu, F. Delerue, J. J. Kril, J. G?tz, et al., “Sodium Selenate Mitigates Tau Pathology, Neurodegeneration, and Functional Deficits in Alzheimer’s Disease Models,” Proceedings of the National Academy of Sciences of the United States of America, Vol. 107, No. 31, 2010, pp. 13888-13893. doi:10.1073/pnas.1009038107