LONGVIEW: COGNITIVE CAPITAL OVER THE LAST 50 YEARS

SEMINAR 5 ADULT LIFE CHANCES: HEALTH

Based on work led byDavid Batty, Catherine Gale, Stephani Hatch,

Barbara Jefferis, Diana Kuh, and Marcus Richards

PATHWAYS FROM COGNITIVE CAPITAL TO HEALTH

Mediation

Cognition may mediate early circumstances that influence health:

• material home conditions (wealth)• family interaction (psychosocial)• developing health itself

PATHWAYS FROM COGNITIVE CAPITAL TO HEALTH

Social causation

Cognition can determine the acquisition of factors that influence health:

• material resources (wealth)• psychosocial capital (status, control, wellbeing) • self-care/health literacy (lifestyle, health service use)

PATHWAYS FROM COGNITIVE CAPITAL TO HEALTH

Cognition as a biomarker

Cognition may mark underlying physiological processesthat regulate health:

• central nervous system• autonomic nervous system• endocrine axes (growth, thyroid, HPA, HPG)• oxidative biochemistry• immune function• genetic pleiotropy

British 1946 birth cohort: cumulative male death rate 9 to 54 years for the highest and lowest quarters of the cognitive score at age 8 years.

0.88

0.9

0.92

0.94

0.96

0.98

1

108 144 180 216 252 288 324 360 396 432 468 504 540 576 612 648

Age in years (and months since birth)

Prop

ortio

n al

ive

9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54

Highest quartile

Lowest quartile

Kuh, Richards, Hardy, Butterworth & Wadsworth Int J Epidemiol 2004; 33: 408-413

Cognitive ability tests____________________________________________________

1946 cohort 1970 cohort____________________________________________________

Non-Verbal intelligence Non-verbal (BAS)Verbal intelligence - Recall of digitsVocabulary - MatricesPronunciation Verbal (BAS)Arithmetic - Word definitions

- Word similarities___________________________________________________________

LIFESTYLE:

HEALTH-RELATED BEHAVIOURS

Ever smoked cigarettes___________________________________________________________

1946 cohort (36 y) 1970 cohort (30 y) (63.8%) (55.4%)

___________________________________________________________

Unadjusted 0.83 (0.76, 0.92) p < 0.001 -----

Gender 0.84 (0.76, 0.92) p < 0.001 0.92 (0.88, 0.96)

Parental SC 0.86 (0.77, 0.95) p = 0.003 0.93 (0.89, 0.97)

Own education 1.07 (0.95, 1.22) p = 0.26 1.08 (1.03, 1.14)

Adult SC 0.90 (0.80, 1.00) p = 0.05 1.01 (0.96, 1.06)

Adult earnings 0.80 (0.72, 0.88) p < 0.001 0.93 (0.88, 0.98)

All 1.09 (0.96, 1.24) p = 0.19 1.08 (1.02, 1.15)

____________________________________________________________

Batty D, Deary I, Schoon I, Gale C. In press: Journal of Epidemiology and Community Health

Quit smoking cigarettes___________________________________________________________

1946 cohort (36 y) 1970 cohort (30 y) (33.4%) (34.2%)

___________________________________________________________

Unadjusted 1.31 (1.16, 1.48) p < 0.001 -----

Gender 1.31 (1.16, 1.48) p < 0.001 1.25 (1.18, 1.34)

Parental SC 1.29 (1.13, 1.47) p < 0.001 1.18 (1.10, 1.26)

Own education 1.13 (0.97, 1.32) p = 0.11 1.10 (1.02, 1.18)

Adult SC 1.22 (1.06, 1.40) p = 0.005 1.15 (1.07, 1.23)

Adult earnings 1.30 (1.15, 1.48) p < 0.001 1.16 (1.07, 1.25)

All 1.11 (0.95, 1.31) p = 0.19 1.02 (0.93, 1.11)

____________________________________________________________

Batty D, Deary I, Schoon I, Gale C. In press: Journal of Epidemiology and Community Health

1946 cohort: odds of being CAGE positive at 53 yearsper point increase in childhood cognition at 8 years

Odds = 1.04 (1.01 – 1.07) p = 0.02

Adjusting for:

• Gender• SES origin and early adversity (father’s social class, mother’s education, parental

divorce, suboptimal maternal management and poor material home conditions) • Highest educational qualifications by 26 years)• Adult SES (social class and household income)• Adult stressors (unemployment and economic hardship)• Adult health behaviours (exercise and smoking)

Hatch, Jones, Kuh, Hardy, Wadsworth & Richards Soc Sci Med 2007; 64: 2285-2296

Ever CAGE positive (men)___________________________________________________________

1946 cohort (43 y) 1970 cohort (30 y) (13.7%) (20.4%)

___________________________________________________________

Unadjusted 0.99 (0.84, 1.18) p = 0.93 -----

Parental SC 1.00 (0.83, 1.21) p = 0.98 1.13 (1.04, 1.24)

Own education 1.03 (0.82, 1.29) p = 0.79 1.13 (1.04, 1.24)

Adult SC 1.00 (0.82, 1.22) p = 0.99 1.18 (1.07, 1.30)

Adult earnings 0.99 (0.82, 1.19) p = 0.90 1.15 (1.03, 1.26)

Has children 0.99 (0.83, 1.18) p = 0.92 1.11 (1.02, 1.22)

All 1.03 (0.81, 1.30) p = 0.82 1.16 (1.04, 1.28)

____________________________________________________________

Batty D, Deary I, Schoon I, Gale C. In press: American Journal of Public Health

Ever CAGE positive (women)___________________________________________________________

1946 cohort (43 y) 1970 cohort (30 y) (9.3%) (8.1%)

___________________________________________________________

Unadjusted 1.43 (1.06, 1.94) p = 0.02 1.44 (1.24, 1.67)

Parental SC 1.37 (0.99, 1.91) p = 0.06 1.42 (1.22, 1.65)

Own education 1.09 (0.74, 1.62) p = 0.67 1.46 (1.24, 1.71)

Adult SC 1.24 (0.89, 1.74) p = 0.20 1.35 (1.16, 1.59)

Adult earnings 1.16 (0.84, 1.59) p = 0.37 1.44 (1.24, 1.67)

Has children 1.41 (1.04, 1.91) p = 0.03 1.36 (1.18, 1.58)

All 1.02 (0.68, 1.53) p = 0.92 1.38 (1.17, 1.64)

____________________________________________________________

Batty D, Deary I, Schoon I, Gale C. In press: American Journal of Public Health

Any physical exercise___________________________________________________________

1946 cohort (36 y) 1970 cohort (30 y) (65.4%)

___________________________________________________________

Unadjusted 1.40 (1.28, 1.54) p < 0.001 1.21 (1.14, 1.27)

Gender 1.42 (1.29, 1.56) p < 0.001 1.20 (1.14, 1.27)

Parental SC 1.35 (1.22, 1.49) p < 0.001 1.16 (1.10, 1.23)

Own education 1.23 (1.09, 1.39) p = 0.001 1.06 (1.00, 1.12)

Adult SC 1.26 (1.13, 1.40) p < 0.001 1.15 (1.09, 1.22)

Adult earnings 1.30 (1.18, 1.43) p < 0.001 1.16 (1.09, 1.24)

All 1.19 (1.05, 1.35) p = 0.006 1.02 (0.94, 1.09)

____________________________________________________________

Batty D, Deary I, Schoon I, Gale C. Pediatrics 2007 (www.pediatrics.org)

Intense physical exercise___________________________________________________________

1946 cohort (53 y) 1970 cohort (30 y) (37%)

___________________________________________________________

Unadjusted 1.80 (1.60, 2.02) p < 0.001 1.35 (1.29, 1.41)

Gender 1.81 (1.61, 2.04) p < 0.001 1.30 (1.24, 1.36)

Parental SC 1.71 (1.51, 1.94) p < 0.001 1.31 (1.25, 1.37)

Own education 1.43 (1.23, 1.65) p < 0.001 1.25 (1.19, 1.31)

Adult SC 1.60 (1.40, 1.82) p < 0.001 1.22 (1.16, 1.28)

Adult earnings 1.69 (1.50, 1.90) p < 0.001 1.20 (1.14, 1.27)

All 1.39 (1.19, 1.62) p < 0.001 1.15 (1.08, 1.22)

____________________________________________________________

Batty D, Deary I, Schoon I, Gale C. Pediatrics 2007 (www.pediatrics.org)

Healthy food choice at 53 years (1946 cohort)

_________________________________________________

Unadjusted 1.53 (1.35, 1.73) p < 0.001

Gender 1.52 (1.35, 1.72) p < 0.001

Parental SC 1.46 (1.28, 1.66) p < 0.001

Own education 1.14 (0.98, 1.34) p = 0.09

Adult SC 1.44 (1.25, 1.65) p < 0.001

Adult earnings 1.57 (1.38, 1.78) p < 0.001

All 1.14 (0.97, 1.34) p = 0.11

_________________________________________________

Based on forthcoming work in collaboration with the MRC Human Nutrition

Research Centre, Elsie Widdowson Laboratories, Cambridge

Healthy food choice representing 1. frequency of breakfast, 2. type of milk,3. type of bread, 4. proportion of energy derived from fat, and 5. number ofdaily portions of fruit and vegetables (odds of > median total score)

Odds of being a vegetarian at 30 years (1970 cohort)

_______________________

Unadjusted 1.38 (1.24, 1.53)

Gender 1.42 (1.28, 1.59)

Parental SC 1.35 (1.21, 1.51)

Own education 1.16 (1.03, 1.30)

Adult SC 1.29 (1.15, 1.45)

All 1.20 (1.06, 1.36)

_______________________

Gale C, Deary I, Schoon I, Batty D. British Medical Journal 2007;334:245.

Health behaviours: summary

• Childhood IQ is mainly protective of harmful health- related behaviours, although it appears to be associated with increased risk of potential alcohol abuse

• These effects were often explained by educational attainment or adult SES, although there were independent effects of IQ on on risk of alcohol abuse and being a vegetarian in the 1970 and on likelihood of undertaking physical exercise in both cohorts

• There were few obvious cohort effects, although positive associations between IQ and potential alcohol abuse appeared to be stronger in the 1958 cohort

CHRONIC PHYSICAL DISEASE

Hypertension (self reported)___________________________________________________________

1946 cohort (36 y) 1970 cohort (30 y) (3.1%) (7.7%)

___________________________________________________________

Unadjusted 0.75 (0.59, 0.95) p = 0.02 -----

Gender 0.74 (0.58, 0.95) p = 0.02 0.90 (0.83, 0.98)

Parental SC 0.75 (0.57, 0.97) p = 0.03 0.92 (0.84, 0.99)

Own education 0.69 (0.51, 0.95) p = 0.02 0.93 (0.85, 1.01)

Adult SC 0.77 (0.58, 1.02) p = 0.07 0.91 (0.83, 0.99)

Adult earnings 0.78 (0.61, 1.01) p = 0.06 0.89 (0.80, 0.98)

All 0.70 (0.51, 0.98) p = 0.04 0.94 (0.84, 1.06)

____________________________________________________________

Batty D, Deary I, Schoon I, Gale C. In press: Journal of Epidemiology and Community Health

Obesity (BMI > 30 kg/m2 : WHO)___________________________________________________________

1946 cohort (36 y) 1970 cohort (30 y) (5.6%) (11.3%)

___________________________________________________________

Unadjusted 0.73 (0.61, 0.88) p = 0.001 -----

Gender 0.73 (0.61, 0.88) p = 0.001 0.84 (0.79, 0.91)

Parental SC 0.78 (0.94, 0.95) p = 0.02 0.89 (0.83, 0.96)

Own education 0.79 (0.62, 1.00) p = 0.05 0.93 (0.86, 1.00)

Adult SC 0.78 (0.63, 0.97) p = 0.02 0.88 (0.81, 0.95)

Adult earnings 0.76 (0.63, 0.92) p = 0.005 0.86 (0.79, 0.94)

All 0.82 (0.64, 1.05) p = 0.12 0.97 (0.88, 1.07)

____________________________________________________________

Batty D, Deary I, Schoon I, Gale C. In press: Journal of Epidemiology and Community Health

Metabolic syndrome at 53 years (1946 cohort)

_________________________________________________

Unadjusted 0.82 (0.72, 0.94) p = 0.004

Gender 0.82 (0.72, 0.94) p = 0.004

Parental SC 0.86 (0.74, 0.99) p = 0.04

Own education 0.96 (0.80, 1.14) p = 0.64

Adult SC 0.85 (0.73, 1.00) p = 0.04

Adult earnings 0.79 (0.69, 0.91) p = 0.001

All 0.98 (0.82, 1.18) p = 0.84

_________________________________________________

Metabolic syndrome identified in the 1946 cohort by Claudia Langenberg(American Journal of Public Health 2006; 96: 2216-2221)

National Cholesterol Education Program Adult Treatment Panel III (ATPIII) definition (21.9%)

TIMING OF THE NATURAL MENOPAUSE

• Mediation: Cognition may mediate early circumstances that influence reproductive ageing

• Social causation: Education and cognition determine health behaviours (e.g. smoking) that trigger early menopause

• Cognition as a biomarker: oestrogen facilitates neural growth, prevents neuronal damage and death, and increases cerebral blood flow

Survivor functions for age at menopause by cognitive ability score at age 8 years

0.00

0.25

0.50

0.75

1.00

34 36 38 40 42 44 46 48 50 52 54 56 58

Age (years)

Lowest third Highest third

Pro

po

r tio

n p

r e/p

eri

men

op

ausa

l

Richards et al. Neurology 1999; Kuh et al. Menopause 2005

Effect of one standard deviation change in cognitive ability at 8 years on age at menopause

Hazard Ratio (95%CI)

Unadjusted 0.89 (0.82,0.96)

Adjusted for been breastfed 0.88 (0.81,0.96)

Adjusted for father’s social class 0.91 (0.83,0.99)

Adjusted for parental divorce (by 15) 0.89 (0.82,0.96)

Adjusted for parity 0.88 (0.80,0.95)

Adjusted for smoking 0.91 (0.83,0.99)

Fully adjusted 0.90 (0.82,0.98)

Kuh et al. Menopause 2005; 12: 475-82

COX PROPORTIONAL HAZARDS FORCOGNITION AND AGE AT MENOPAUSE

___________________________________________________________

Age of test Hazard ratio (95% CI) p value

___________________________________________________________

8 years 0.73 (0.62 - 0.86) <0.001

11 years 0.78 (0.67 - 0.91) 0.002

15 years 0.80 (0.67 - 0.94) 0.007

26 years 0.85 (0.72 - 1.00) 0.048

__________________________________________________________________

Chronic physical disease: summary

• Childhood IQ is associated with reduced risk of chronic physical disease

• As with health behaviours, this was mostly explained by educational attainment or adult SES, although there is an independent inverse association between IQ and risk of early natural menopause, possibly reflecting early programming of the reproductive hormonal axis

• There were few obvious cohort effects, although associations between IQ and self-reported hypertension appeared to be stronger in the 1946 cohort

MENTAL HEALTH

1946 cohort: total GHQ-28 score at 53 yearsper point increase in childhood cognition at 8 years

Regression coefficient (men) = -0.04 (-0.22, -0.15) p = 0.70Regression coefficient (women) = -0.29 (-0.52, -0.06) p = 0.01

Adjusting for:

• SES origin and early adversity (father’s social class, mother’s education, parental divorce, suboptimal maternal management

and poor material home conditions) • Highest educational qualifications by 26 years)• Adult SES (social class and household income)• Adult stressors (unemployment and economic hardship)• Adult health behaviours (exercise and smoking)

Hatch, Jones, Kuh, Hardy, Wadsworth & Richards Soc Sci Med 2007; 64: 2285-2296

LITERACY, COGNITIVE RESERVE,AND COGNITIVE DECLINE

Father’s occupation

Cognitive abilityat 8 years

Education by 26 years

Own occupationat 43 years

literacyat 53 years

0.33 0.18

0.50

0.05

0.07

0.47

0.60

0.24

0.14

1946 cohort 1958 cohort

Father’s occupation

Cognitive abilityat 7 years

Education by 23 years

Own occupationat 33 years

literacyat 43 years

0.31

0.54

0.43

0.01

0.08

0.11

0.21

0.21

0.41

Richards, Power & Sacker (In press: J Epidemiol Community Health)

Priorability

Age

Cognitive decline (1946 cohort)

Richards M, Shipley B, Fuhrer F & Wadsworth MBritish Medical Journal 2005; 328: 552-554

Age specific prevalence of Alzheimer’s disease

0

5

10

15

20

25

30

0 65 70 75 80 85 90

Age (years)

Prevalence (%)

Clinical expressionof disease

Other influences ondisease expression:PersonalityHealth service delivery and uptakeCultural norms

BRAIN LESIONS

INFLUENCING FACTORS

Genes

Early social and material environment

Educational and occupational attainment

Physical health

Health behaviours and lifestyle

PREMORBIDBRAIN SIZE COGNITIVEAND FUNCTION ABILITY

(RESERVE)

Richards M & Deary I. A life course approach to cognitive reserve: a model for cognitive aging and development? Annals of Neurology 2005; 58: 617-620

But what about wisdom?

• The development of expertise

• The development of contextualisation

• Relativism of values and priorities

• Recognition and management of uncertainty