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Serum cholesterol and cognitive functions: the Lothian Birth Cohort 1936

Published online by Cambridge University Press:  15 July 2014

Janie Corley ,
John M. Starr  and
Ian J. Deary
Janie Corley
Affiliation:
Department of Psychology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK
John M. Starr
Affiliation:
Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK Royal Victoria Building, Western General Hospital, Porterfield Road, Edinburgh EH4 2XU, UK
Ian J. Deary*
Affiliation:
Department of Psychology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK
*
Correspondence should be addressed to: Ian J. Deary, Department of Psychology, Centre for Cognitive Ageing and Cognitive Epidemiology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, Scotland, UK. Phone: +44-131-650-3452. Email: I.Deary@ed.ac.uk.
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Abstract

Background:

We examined the associations between serum cholesterol measures, statin use, and cognitive function measured in childhood and in old age. The possibility that lifelong (trait) cognitive ability accounts for any cross-sectional associations between cholesterol and cognitive performance in older age, seen in observational studies, has not been tested to date.

Methods:

Participants were 1,043 men and women from the Lothian Birth Cohort 1936 Study, most of whom had participated in a nationwide IQ-type test in childhood (Scottish Mental Survey of 1947), and were followed up at about age 70 years. Serum cholesterol measures included total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides, and cholesterol:HDL cholesterol ratio. Cognitive outcome measures were age 70 IQ (using the same test as at age 11 years), general cognitive ability (g), processing speed, memory, and verbal ability.

Results:

Higher TC, higher HDL-C, and lower triglycerides were associated with higher age 70 cognitive scores in most cognitive domains. These relationships were no longer significant after covarying for childhood IQ, with the exception a markedly attenuated association between TC and processing speed, and triglycerides and age 70 IQ. In the fully adjusted model, all conventionally significant (p < 0.05) effects were removed. Childhood IQ predicted statin use in old age. Statin users had lower g, processing speed, and verbal ability scores at age 70 years after covarying for childhood IQ, but significance was lost after adjusting for TC levels.

Conclusions:

These results suggest that serum cholesterol and cognitive function are associated in older age via the lifelong stable trait of intelligence. Potential mechanisms, including lifestyle factors, are discussed.

Keywords

cholesterolcognitive functionchildhood IQaging
Type
Research Article
Information
International Psychogeriatrics , Volume 27 , Issue 3 , March 2015 , pp. 439 - 453
Copyright
Copyright © International Psychogeriatric Association 2014 

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References

Abbott, R. D. et al. (1997). Cross-sectional and longitudinal changes in total and high-density-lipoprotein cholesterol levels over a 20-year period in elderly men: the Honolulu Heart Program. Annals of Epidemiology, 7, 417–424.CrossRefGoogle Scholar
Adult Treatment Panel III (2001). Executive summary of the third report of the national cholesterol education program (NCEP) expert panel on detection, evaluation and treatment of high blood cholesterol in adults. Journal of the American Medical Association, 285, 2486–2497.CrossRefGoogle Scholar
Anstey, K., Lipnicki, D. and Low, L. (2008). Cholesterol as a risk factor for dementia and cognitive decline: a systematic review of prospective studies with meta-analysis. American Journal of Geriatric Psychiatry, 16, 343–354. doi:10.1097/JGP.0b013e31816b72d4.CrossRefGoogle ScholarPubMed
Atzmon, G. et al. (2002). Plasma HDL levels highly correlate with cognitive function in exceptional longevity. Journal of Gerontology. Series A, Biological Sciences and Medical Sciences, 57, M712–M715. doi:10.1093/gerona/57.11.M712.Google Scholar
Batty, G. D. and Deary, I. J. (2004). Early life intelligence and adult health. British Medical Journal, 329, 585–586. doi:10.1136/bmj.329.7466.585.Google Scholar
Batty, G. D., Deary, I. J., Schoon, I. and Gale, C. R. (2007). Childhood mental ability in relation to food intake and physical activity in adulthood: the 1970 British Cohort Study. Pediatrics, 119, e38–e45. doi:10.1542/peds.2006-1831.CrossRefGoogle ScholarPubMed
Benito-León, J., Louis, E. D., Vega, S. and Bermejo-Pareja, F. (2010). Statins and cognitive functioning in the elderly: a population-based study. Journal of Alzheimer's Disease, 21, 95–102. doi:10.3233/JAD-2010-100180.CrossRefGoogle ScholarPubMed
Bernick, C. et al.; Cardiovascular Health Study Collaborative Research Group (2005). Statins and cognitive function in the elderly: the Cardiovascular Health Study. Neurology, 65, 1388–1394. doi:10.1212/01.wnl.0000182897.18229.ec.Google Scholar
Berry, J. D. et al. (2008). Association of traditional risk factors with cardiovascular death across 0 to 10, 10 to 20, and >20 years follow-up in men and women. American Journal of Cardiology, 101, 89–94. http://dx.doi.org/10.1016/j.amjcard.2007.07.079.Google Scholar
Beydoun, M. A. et al. (2010). Statins and serum cholesterol's associations with incident dementia and mild cognitive impairment. Journal of Epidemiology and Community Health, 65, 949–957. doi:10.1136/jech.2009.100826.Google Scholar
Brescianini, S. et al.; ILSA Group (2003). Low total cholesterol and increased risk of dying: are low levels clinical warning signs in the elderly? Results from the Italian Longitudinal Study on Aging. Journal of the American Geriatrics Society, 51, 991–996. doi:10.1046/j.1365-2389.2003.51313.x.CrossRefGoogle ScholarPubMed
Brownell, K. D., Bachorik, P. S. and Averle, R. S. (1982). Changes in plasma lipid and lipoprotein levels in men and women after a program of moderate exercise. Circulation, 65, 477–484.Google Scholar
Calvin, C. et al. (2011). Intelligence in youth and all-cause-mortality: systematic review with meta-analysis. International Journal of Epidemiology, 40, 626–644. doi:10.1093/ije/dyq190.CrossRefGoogle ScholarPubMed
Carlsson, C. M. et al. (2008). Effects of simvastatin on cerebrospinal fluid biomarkers and cognition in middle-aged adults at risk for Alzheimer's disease. Journal of Alzheimer's Disease, 13, 187–197.Google Scholar
Cook, Z. (2005). Diet will help reduce cholesterol levels. Professional Nursing, 20, 44.Google Scholar
Corley, J., Gow, A. J., Starr, J. M. and Deary, I. J. (2010). Is body mass index in old age related to cognitive abilities? The Lothian Birth Cohort 1936 Study. Psychology and Aging, 25, 867–875. doi:10.1037/a0020301.Google Scholar
Coscina, D. V., Yehuda, S., Dixon, L. M, Kish, S. J. and Leprohon-Greenwood, C. E. (1986). Learning is improved by a soybean oil diet in rats. Life Sciences, 38, 1789–1794. http://dx.doi.org/10.1016/0024-3205(86)90130-X.Google Scholar
Cox, B. D., Huppert, F. A. and Whichelow, M. J. (1993). The Health and Lifestyle Survey: Seven Years On. Aldershot, UK: Dartmouth.Google Scholar
de Freitas, E. V. et al. (2011). Importance of high-density lipoprotein-cholesterol (HDL-C) levels to the incidence of cardiovascular disease (CVD) in the elderly. Archives of Gerontology and Geriatrics, 52, 217–222. doi:10.1016/j.archger.2010.03.022.Google Scholar
Deary, I. J., Der, G. and Ford, G. (2001). Reaction times and intelligence differences: a population-based cohort study. Intelligence, 29, 389–399. doi:10.1016/S0160-2896(01)00062–9.CrossRefGoogle Scholar
Deary, I. J., Weiss, A. and Batty, G. D. (2010). Intelligence and personality as predictors of illness and death: how researchers in differential psychology and chronic disease epidemiology are collaborating to understand and address health inequalities. Psychological Science in the Public Interest, 11, 53–79. doi:10.1177/1529100610387081.CrossRefGoogle ScholarPubMed
Deary, I. J., Whalley, L. J., Lemmon, H., Crawford, J. R. and Starr, J. M. (2000). The stability of individual differences in mental ability from childhood to old age: follow up of the 1932 Scottish Mental Survey. Intelligence, 28, 49–55. doi:10.1016/S0160-2896(99)00031-8.CrossRefGoogle Scholar
Deary, I. J., Whalley, L. J. and Starr, J. M. (2009). A Lifetime of Intelligence: Follow-up Studies of the Scottish Mental Surveys of 1932 and 1947. Washington, DC: American Psychological Association.Google Scholar
Deary, I. J. et al. (2004). The functional anatomy of inspection time: an event-related fMRI study. NeuroImage, 22, 1466–1479. doi:10.1016/j.neuroimage.2004.03.047.Google Scholar
Deary, I. J. et al. (2007). The Lothian Birth Cohort 1936: a study to examine the influences on cognitive ageing from age 11 to age 70 and beyond. BMC Geriatrics, 7, 28. doi:10.1186/1471-2318-7-28.CrossRefGoogle ScholarPubMed
Delgado-Rodríguez, M. et al. (2002). Cholesterol and serum albumin levels as predictors of cross infection, death, and length of hospital stay. Archives of Surgery, 137, 805–812. doi:10.1001/archsurg.137.7.805.CrossRefGoogle ScholarPubMed
Dyker, A. G., Weir, C. J. and Lees, K. R. (1997). Influence of cholesterol on survival after stroke: retrospective study. British Medical Journal, 314, 1584–1588. doi:http://dx.doi.org/10.1136/bmj.314.7094.1584.Google Scholar
Elias, P. K., Elias, M. F., D’Agostino, R. B., Sullivan, L. M. and Wolf, P. A. (2005). Serum cholesterol and cognitive performance in the Framingham Heart Study. Psychosomatic Medicine, 67, 24–30. doi:10.1097/01.psy.0000151745.67285.c2.CrossRefGoogle ScholarPubMed
Ellison, R. C. et al. (2004). Lifestyle determinants of high-density lipoprotein cholesterol: the National Heart, Lung, and Blood Institute Family Heart Study. Investigators of the NHLBI Family Heart Study. American Heart Journal, 147, 529–35. doi:10.1016/j.ahj.2003.10.033.Google Scholar
Folsom, A. R. et al. (1994). Body mass, fat distribution and cardiovascular risk factors in a lean population of south China. Journal of Clinical Epidemiology, 47, 173–181. doi.org/10.1016/0895-4356(94)90022-1.Google Scholar
Folstein, M. F., Folstein, S. E. and McHugh, P. R. (1975). “Mini Mental State”: a practical method for grading the cognitive state of patients for the clinician. Journal of Psychiatric Research, 12, 189–198.CrossRefGoogle ScholarPubMed
Formiga, F. et al. (2011). Serum high-density lipoprotein cholesterol levels, their relationship with baseline functional and cognitive status, and their utility in predicting mortality in nonagenarians. Geriatrics and Gerontology International, 11, 358–364. doi:10.1111/j.1447-0594.2010.00681.x.CrossRefGoogle ScholarPubMed
Formiga, F. et al. (2012). Serum high-density lipoprotein cholesterol levels correlate well with functional but not with cognitive status in 85-year-old subjects. Journal of Nutrition, Health and Aging, 16, 449–453. doi:10.1007/s12603-012-0018-z.Google Scholar
Gaziano, J. (2012). Should we fast before we measure our lipids? Archives of Internal Medicine, 172, 1705–1706. doi:10.1001/jamainternmed.2013.1771.Google Scholar
Gottfredson, L. S. (2004). Intelligence: is it the epidemiologists’ elusive “fundamental cause” of social class inequalities in health? Journal of Personality and Social Psychology, 86, 174–199. doi:10.1037/0022-3514.86.1.174.Google Scholar
Hagger-Johnson, G., Mõttus, R., Craig, L. C., Starr, J. M. and Deary, I. J. (2012). Pathways from childhood intelligence and socioeconomic status to late-life cardiovascular disease risk. Health Psychology, 4, 403–412. doi:10.1037/a0026775.CrossRefGoogle Scholar
Henderson, V.W., Guthrie, J. R. and Dennerstein, L. (2003). Serum lipids and memory in a population based cohort of middle age women. Journal of Neurology, Neurosurgery and Psychiatry, 74, 1530–1535. doi:10.1136/jnnp.74.11.1530.CrossRefGoogle Scholar
Hertzog, C., Kramer, A. F., Wilson, R. S. and Lindenberger, U. (2009). Enrichment effects on adult cognitive development: can the functional capacity of older adults be preserved and enhanced? Psychological Science in the Public Interest, 9, 1–65. doi:10.1111/j.1539-6053.2009.01034.x.Google Scholar
Ingelsson, E. et al. (2007). Clinical utility of different lipid measures for prediction of coronary heart disease in men and women. Journal of the American Medical Association, 298, 776–785. doi:10.1001/jama.298.7.776.CrossRefGoogle ScholarPubMed
Jia, X., Craig, L. C., Aucott, L. S., Milne, A. C. and McNeill, G. (2008). Repeatability and validity of a food frequency questionnaire in free-living older people in relation to cognitive function. Journal of Nutrition Health and Aging, 12, 735–741. doi: 10.1007/BF03028622.Google Scholar
Karlamangla, A. S., Singer, B. H., Reuben, D. B. and Seeman, T. E. (2004). Increases in serum non-high-density lipoprotein cholesterol may be beneficial in some high-functioning older adults: MacArthur studies of successful aging. Journal of the American Geriatrics Society, 52, 487–494. doi:10.1111/j.1532-5415.2004.52152.x.Google Scholar
Kilgour, A. H. M., Starr, J. M. and Whalley, L. J. (2010). Associations between childhood intelligence (IQ), adult morbidity and mortality. Maturitas, 65, 98–105. doi.org/10.1016/j.maturitas.2009.09.021.Kilgour.Google Scholar
Kivipelto, M. and Solomon, A. (2006). Cholesterol as a risk factor for Alzheimer's Disease – epidemiological evidence. Acta psychiatrica et neurologica Scandinavica Supplementum, 185, 50–57. doi:10.1111/j.1600-0404.2006.00685.x.Google Scholar
Langsted, A., Freiberg, J. J. and Nordestgaard, B. G. (2008). Fasting and nonfasting lipid levels: influence of normal food intake on lipids, lipoproteins, apolipoproteins, and cardiovascular risk prediction. Circulation, 118, 2047–2056. doi:10.1161/CIRCULATIONAHA.108.804146.Google Scholar
Law, M. R., Wald, N. J. and Thompson, S. G. (1994). By how much and how quickly does reduction in serum cholesterol concentration lower risk of ischaemic heart disease? British Medical Journal, 308, 367–372.Google Scholar
Lee, Y. et al. (2010). Systematic review of health behavioral risks and cognitive health in older adults. International Psychogeriatrics, 22, 174–187. doi:10.1017/S1041610209991189.Google Scholar
Li, G. et al. (2005). Serum cholesterol and risk of Alzheimer disease: a community-based cohort study. Neurology, 65, 1045–1050. doi:10.1212/01.wnl.0000178989.87072.11.Google Scholar
Luciano, M. et al. (2009). Cognitive ability at age 11 and 70 years, information processing speed, and APOE variation: the Lothian Birth Cohort 1936 Study. Psychology and Aging, 24, 129–138. doi:10.1037/a0014780.Google Scholar
McNeill, G., Winter, J. and Jia, X. (2009). Diet and cognitive function in later life: a challenge for nutritional epidemiology. European Journal of Clinical Nutrition, 63, S33–S37. doi:10.1038/ejcn.2011.2.Google Scholar
Mielke, M. M. et al. (2005). High total cholesterol levels in late life associated with a reduced risk of dementia. Neurology, 64, 1689–1695. doi:10.1212/01.WNL.0000161870.78572.A5.Google Scholar
Mielke, M. M. et al. (2008). Baseline serum cholesterol is selectively associated with motor speed and not rates of cognitive decline: the Women's Health and Aging Study II. Journal of Gerontology. Series A, Biological Sciences and Medical Sciences, 63, 619–624.CrossRefGoogle Scholar
Muldoon, M. F., Ryan, C. M., Matthews, K. A. and Manuck, S. B. (1997). Serum cholesterol and intellectual performance. Psychosomatic Medicine, 59, 382–387.Google Scholar
Nelson, H. E. and Willison, J. R. (1991). National Adult Reading Test (NART) Test Manual (Part II). Windsor, UK: NFER-Nelson.Google Scholar
Office of Population Censuses and Surveys. (1980). Classification of Occupations 1980. London, UK: Her Majesty's Stationery Office.Google Scholar
Onder, G. et al. (2003). Serum cholesterol levels and in-hospital mortality in the elderly. American Journal of Medicine, 115, 265–271. http://dx.doi.org/10.1016/S0002-9343(03)00354-1.Google Scholar
Panza, F. et al. (2009). Higher total cholesterol, cognitive decline, and dementia. Neurobiology of Aging, 30, 546–548. doi:10.1016/j.neurobiolaging.2007.10.019.Google Scholar
Parale, G. P., Baheti, N. N., Kulkarni, P. M. and Panchal, N. V. (2006) Effects of atorvastatin on higher functions. European Journal of Clinical Pharmacology, 62, 259–265. doi:10.1007/s00228-005-0073-z.Google Scholar
Piguet, O. et al. (2003). Vascular risk factors, cognition and dementia incidence over 6 years in the Sydney Older Persons Study. Neuroepidemiology, 22, 165–171. doi:10.1159/000069886.Google Scholar
Prospective Studies Collaboration (2007). Blood cholesterol and vascular mortality by age, sex, and blood pressure: meta-analysis of individual data from 61 prospective studies with 55 000 vascular deaths. Lancet, 370, 1829–1839. http://dx.doi.org/10.1016/S0140-6736(07)61778-4.Google Scholar
Reitz, C., Luchsinger, J., Tang, M. X., Manly, J. and Mayeux, R. (2005). Impact of plasma lipids and time on memory performance in healthy elderly without dementia. Neurology, 64, 1378–1383. doi:10.1212/01.WNL.0000158274.31318.3C.Google Scholar
Reitz, C., et al. (2008). Plasma lipid levels in the elderly are not associated with the risk of mild cognitive impairment. Dementia and Geriatric Cognitive Disorders, 25, 232–237. doi:10.1159/000115847.CrossRefGoogle Scholar
Reitz, C. et al. (2010). Association of higher levels of high-density lipoprotein cholesterol in elderly individuals and lower risk of late-onset Alzheimer disease. Archives of Neurology, 67, 1491–1497. doi:10.1001/archneurol.2010.297.CrossRefGoogle ScholarPubMed
Reynolds, C. A., Gatz, M., Prince, J. A., Berg, S. and Pedersen, N. L. (2010). Serum lipid levels and cognitive change in late life. Journal of the American Geriatrics Society, 58, 501–509. doi:10.1111/j.1532-5415.2010.02739.x.CrossRefGoogle ScholarPubMed
Rockwood, K. et al. (2002). Use of lipid-lowering agents, indication bias, and the risk of dementia in community-dwelling elderly people. Archives of Neurology, 59, 223–227. doi:10.1001/archneur.59.2.223.Google Scholar
Sacker, A., Schoon, I. and Bartley, M. (2002). Social inequality in educational achievement and psychosocial adjustment throughout childhood: magnitude and mechanisms. Social Science and Medicine, 55, 863–880. http://dx.doi.org/10.1016/S0277-9536(01)00228-3.Google Scholar
Sacks, F. (1994). Dietary fats and coronary heart disease. Overview. Journal of Cardiovascular Risk, 1, 3–8.Google Scholar
Schalk, B. W., Visser, M., Deeg, D. J. and Bouter, L. M. (2004). Lower levels of serum albumin and total cholesterol and future decline in functional performance in older persons: the Longitudinal Aging Study Amsterdam. Age and Ageing, 33, 266–272. doi:10.1093/ageing/afh073.Google Scholar
Schatz, I. J. et al. (2001). Cholesterol and all-cause mortality in elderly people from the Honolulu Heart Program: a cohort study. Lancet, 358, 351–355. http://dx.doi.org/10.1016/S0140-6736(01)05553-2.Google Scholar
Schubert, C. M. et al. (2006). Lipids, lipoproteins, lifestyle, adiposity and fat-free mass during middle age: the Fels Longitudinal Study. International Journal of Obesity, 30, 251–260. doi:10.1038/sj.ijo.0803129.Google Scholar
Scottish Council for Research in Education. (1933). The Intelligence of Scottish Children: A National Survey of an Age Group. London, UK: University of London Press.Google Scholar
Scottish Council for Research in Education. (1949). The Trend of Scottish Intelligence: A Comparison of the 1947 and 1932 Surveys of the Intelligence of Eleven-year-old Pupils. London, UK: University of London Press.Google Scholar
Shepherd, J. et al.; PROSPER Study Group (2002). Prospective study of pravastatin in the elderly at risk. Pravastatin in elderly individuals at risk of vascular disease (PROSPER): a randomised controlled trial. Lancet, 360, 1623–1630. doi.org/10.1016/S0021-9150(00)80775-3.Google Scholar
Simons, L. A., Simons, J., Friedlander, Y. and McCallum, J. (2001). Cholesterol and other lipids predict coronary heart disease and ischaemic stroke in the elderly, but only in those below 70 years. Atherosclerosis, 159, 201–208. doi.org/10.1016/S0021-9150(01)00495-6.Google Scholar
Siri-Tarino, P. W., Sun, Q., Hu, F. B. and Krauss, R. M. (2010) Saturated fatty acids and risk of coronary heart disease: modulation by replacement nutrients. Current Atherosclerosis Reports, 12, 384–390. doi:10.1007/s11883-010-0131-6.Google Scholar
Solomon, A. et al. (2007). Serum cholesterol changes after midlife and late-life cognition: twenty-one-year follow-up study. Neurology, 68, 751–756. doi:10.1212/01.wnl.0000256368.57375.b7.Google Scholar
Solomon, A. et al. (2009) Serum total cholesterol, statins and cognition in non-demented elderly. Neurobiology of Aging, 30, 1006–1009. doi.org/10.1016/j.neurobiolaging.2007.09.012.CrossRefGoogle ScholarPubMed
Starr, J. M. et al. (2004). Life long changes in cognitive ability are associated with prescribed medications in old age. International Journal of Geriatric Psychiatry, 19, 327–332. doi:10.1002/gps.1093.Google Scholar
Thorsson, B. et al. (2013). Changes in total cholesterol levels in Western societies are not related to statin, but rather dietary factors: the example of the Icelandic population. European Heart Journal, 34, 1778–1782. doi:10.1093/eurheartj/ehs395.Google Scholar
Tilvis, R. S., Valvanne, J. N., Strandberg, T. E. and Miettinen, T. A. (2011). Prognostic significance of serum cholesterol, lathosterol, and sitosterol in old age: a 17-year population study. Annals of Medicine, 43, 292–301. doi:10.3109/07853890.2010.546363.CrossRefGoogle ScholarPubMed
Trompet, S. et al. (2010). Pravastatin and cognitive function in the elderly. Results of the PROSPER study. Journal of Neurology, 257, 85–90. doi:10.1007/s00415-009-5271-7.Google Scholar
van den Kommer, et al. (2009). Total cholesterol and oxysterols: early markers for cognitive decline in the elderly? Neurobiology of Aging, 30, 534–545. doi:10.1016/j.neurobiolaging.2007.08.005.Google Scholar
van Exel, E. et al. (2002). Association between high-density lipoprotein and cognitive impairment in the oldest old. Annals of Neurology, 51, 716–721. doi:10.1002/ana.10220.Google Scholar
van Vliet, P. (2012). Cholesterol and late-life cognitive decline. Journal of Alzheimer's Disease, 30 (Suppl. 2), S147–S162. doi:10.3233/JAD-2011-111028.Google Scholar
van Vliet, P., van de Water, W., de Craen, A. J. and Westendorp, R. G. (2009). The influence of age on the association between cholesterol and cognitive function. Experimental Gerontology, 44, 112–122. doi:10.1016/j.exger.2008.05.004.Google Scholar
Wechsler, D. (1998a). WAIS–IIIUK Administration and Scoring Manual. London, UK: Psychological Corporation.Google Scholar
Wechsler, D. (1998b). WMS–IIIUK Administration and Scoring Manual. London, UK: Psychological Corporation.Google Scholar
Weverling-Rijnsburger, A. W. et al. (1997). Total cholesterol and risk of mortality in the oldest old. Lancet, 350, 1119–1123. http://dx.doi.org/10.1016/S0140-6736(97)04430-9.Google Scholar
Whalley, L. J. and Deary, I. J. (2001). Longitudinal cohort study of childhood IQ and survival up to age 76. British Medical Journal, 322, 819. http://dx.doi.org/10.1136/bmj.322.7290.819.Google Scholar
Whalley, L. J., Fox, H. C., Whale, K. W., Starr, J. M. and Deary, I. J. (2004). Cognitive aging, childhood intelligence and the use of food supplements: possible involvement of n-3 fatty acids. American Journal of Clinical Nutrition, 80, 1650–1657.Google Scholar
Whalley, L. J. et al. (2003). Plasma vitamin C, cholesterol and homocysteine are associated with grey matter volume determined by MRI in non-demented old people. Neuroscience Letters, 341, 173–176. http://dx.doi.org/10.1016/S0304-3940(02)01452-0.Google Scholar
Whitehead, T. P., Robinson, D. and Allaway, S. L. (1996). The effects of cigarette smoking and alcohol consumption on blood lipids: a dose related study on men. Annals of Clinical Biochemistry, 33, 99–106.Google Scholar
Whitmer, R. A., Sidney, S., Selby, J., Johnston, S. C. and Yaffe, K. (2005). Midlife cardiovascular risk factors and risk of dementia in late life. Neurology, 64, 277–281. doi:10.1212/01.WNL.0000149519.47454.F2.Google Scholar
Willett, W. C. (2012). Dietary fats and coronary heart disease. Review. Journal of Internal Medicine, 272, 13–24.Google Scholar
Xiong, G. L., Benson, A. and Doraiswamy, P. M. (2005). Statins and cognition: what can we learn from existing randomized trials? CNS Spectrums, 10, 867–874.Google Scholar
Yaffe, K., Barrett-Connor, E., Lin, F. and Grady, D. (2002) Serum lipoprotein levels, statin use, and cognitive function in older women. Archives of Neurology, 59, 378–384. doi:10.1001/archneur.59.3.378.Google Scholar