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Marcus Richards

Publications and source records attributed to Marcus Richards.

At least 19 recordsLinked to original sources
PubMed2006

A randomised controlled trial investigating the effect of n-3 long-chain polyunsaturated fatty acid supplementation on cognitive and retinal function in cognitively healthy older people: the Older People And n-3 Long-chain polyunsaturated fatty acids (OPAL) study protocol [ISRCTN72331636].

The number of individuals with age-related cognitive impairment is rising dramatically in the UK and globally. There is considerable interest in the general hypothesis that improving the diet of older people may slow the progression of cognitive decline. To date, there has been little attention given to the possible protective role of n-3 long-chain polyunsaturated fatty acids (n-3 LCPs) most commonly found in oily fish, in age-related loss of cognitive function. The main research hypothesis of this study is that an increased dietary intake of n-3 LCPs will have a positive effect on cognitive performance in older people in the UK. To test this hypothesis, a double-blind randomised placebo-controlled trial will be carried out among adults aged 70-79 years in which the intervention arm will receive daily capsules containing n-3 LCP (0.5 g/day docosahexaenoic acid and 0.2 g/day eicosapentaenoic acid) while the placebo arm will receive daily capsules containing olive oil. The main outcome variable assessed at 24 months will be cognitive performance and a second major outcome variable will be retinal function. Retinal function tests are included as the retina is a specifically differentiated neural tissue and therefore represents an accessible window into the functioning of the brain. The overall purpose of this public-health research is to help define a simple and effective dietary intervention aimed at maintaining cognitive and retinal function in later life. This will be the first trial of its kind aiming to slow the decline of cognitive and retinal function in older people by increasing daily dietary intake of n-3 LCPs. The link between cognitive ability, visual function and quality of life among older people suggests that this novel line of research may have considerable public health importance.

Aged↗
PubMed2006

Developmental origins of midlife physical performance: evidence from a British birth cohort.

The authors hypothesized that 1) physical growth, as a marker of the early development of muscle fibers, and 2) advanced childhood motor and cognitive abilities, as markers of central nervous system development, would be positively related to midlife standing balance and chair rising, independently of later life experiences. They tested these hypotheses in a representative British sample of 1,374 men and 1,410 women aged 53 years in 1999 with prospective childhood measures of heights and weights, age at first standing and walking, cognitive ability, and motor coordination. Weight gain before age 7 years was positively related to adult performance in men but not women, independently of later body size, social class, physical activity, and health status. Attainment of motor milestones at the modal age and higher scores on tests of cognitive ability and motor coordination were associated with better performance, independently of other factors. This study is the first to show that childhood growth and development affect midlife performance; prevention of disability and frailty in later life may need to start early.

Adolescent↗
PubMed2005

Childhood cognitive ability and age at menopause: evidence from two cohort studies.

OBJECTIVE: To investigate whether poorer cognitive ability in childhood is associated with an earlier menopause. DESIGN: Two cohorts were included: a nationally representative British birth cohort study of 1,350 women born in March 1946 and followed up to age 54 years, and an Aberdeen cohort study of 3,465 women born in Aberdeen from 1950 to 1956 and followed up to age 44 to 50 years. Both cohorts had prospective information on childhood cognitive ability at age 7 or 8 years. RESULTS: In both cohorts, women with lower cognitive scores in childhood reached menopause earlier than women with higher scores. With follow-up of menopause to 49 years, the hazard ratio (HR) for one standard deviation of the cognitive score was 0.80 (95% CI, 0.72-0.90) in the Aberdeen cohort and 0.84 (95% CI, 0.73-0.97) in the older 1946 birth cohort. The effect was still evident in the 1946 birth cohort with follow-up of menopause to 53 years (HR = 0.87; 95% CI, 0.79-0.95). These ratios were weakly attenuated by adjustment for potential confounding effects of lifetime socioeconomic circumstances, parity, and smoking. CONCLUSIONS: The association between early cognitive ability and timing of menopause only partially reflects common risk factors, although residual confounding remains a possibility. Alternatively, early environmental or genetic programming may explain this association, perhaps through setting lifelong patterns of hormone release or causing transient hormonal changes at sensitive periods of development. These findings have implications for the interpretation of studies investigating an association between age at menopause and adult cognitive function.

Adult↗
PubMed2005

Socioeconomic position across the lifecourse: how does it relate to cognitive function in mid-life?

PURPOSE: To examine the association between socioeconomic position (SEP) over the lifecourse and cognitive function in middle age. Two alternative models were assessed: the "direct effects model" where temporally distinct measures of SEP have only direct effects on adult cognition, and the "indirect effects" model where the effect of early life SEP are mediated through later life measures of SEP. METHODS: Data are from the Whitehall II study (N=10,308 at baseline), a longitudinal cohort study of British civil servants, aged between 46 and 68 years at the time of cognitive testing. Structural equation models were used to compare the fit of direct and indirect effects models, and quantify the effects of different measures of SEP on cognition. Childhood SEP, education, and adult SEP were used to model SEP across the lifecourse. Cognitive function was assessed as a latent construct composed of the following: verbal memory, AH 4-I, Mill Hill, phonemic and semantic fluency. RESULTS: The indirect effects model provided a better fit to the data. Childhood SEP had no direct effect on cognitive function but had a substantial "indirect effect," mediated through education and adult SEP. 78.4% of the effect of education in men and 100% in women was indirect. CONCLUSIONS: Socioeconomic differences in adult cognition are a result of the socioeconomic trajectory of individuals throughout their lifecourse. Early measures of SEP influence cognition indirectly, through their influence on later measures of SEP.

Adult↗
PubMed2005

A life course approach to cognitive reserve: a model for cognitive aging and development?

The concept of reserve in neuroscience maintains that there are aspects of brain structure and function that can buffer the effects of neuropathology such that the greater the reserve, the more severe the pathology must be to cause functional impairment. This article provides a concise overview of structural and functional approaches to reserve and shows how reserve may be conceived as the sum of its lifetime input. In this context, reserve therefore provides an empirical yet general model of cognitive aging and development.

Activities of Daily Living↗
PubMed2004

Alcohol consumption and midlife cognitive change in the British 1946 birth cohort study.

AIMS: Cross-sectional studies suggest that alcohol consumption benefits cognitive function. However, more longitudinal studies are required to confirm that alcohol has an effect on cognitive change and to rule out the possibility that those of higher ability engage in a lifestyle that protects against cognitive decline. METHODS: We investigated the association between self-reported alcohol consumption and change in memory, speed and concentration in midlife, in 903 men and 861 women enrolled in the MRC National Survey of Health and Development (the British 1946 birth cohort). RESULTS: After controlling for educational attainment, occupational social class and general cognitive ability, it was found that alcohol consumption was associated with a slower memory decline from 43 to 53 years in men, but a more rapid decline in visual search speed for the same interval in women. These effects were not explained by a further control for health status (body water weight, smoking, exercise, cardio-respiratory disease and affective state). CONCLUSIONS: Our data suggest that alcohol consumption is associated with a slower memory decline. However, the negative association between alcohol and psychomotor function in women is a potential cause for concern.

Adult↗
PubMed2004

Relation between children's height and outdoor air pollution from coal-burning sources in the British 1946 birth cohort.

OBJECTIVE: Air pollution is associated with a number of health outcomes in childhood. In this study, we investigated whether air pollution is related to children's height. METHODS: The 1946 British birth cohort study recruited 5,362 children born in 1 week in March 1946. Height was measured when the children were aged 2, 4, 6, 7, 11 and 15 years. Data on socio-economic conditions and other characteristics were obtained in interviews. Areas of children's residence were categorised into four groups of air pollution on the basis of published coal-consumption data. RESULTS: After controlling for socio-economic factors, we found that air pollution was associated with children's height at several ages. The association, adjusted for socio-economic factors, was strongest at the age of 7 years, when children in the most polluted areas were 1.2 (95% confidence interval 0.5-1.8) cm shorter than those in the least polluted areas. After the age of 7 years the effect of air pollution diminished and disappeared by the age of 15 years. Further adjustment for birth weight and respiratory illness in childhood did not change this pattern. CONCLUSIONS: Children's height was inversely associated with air pollution, but the magnitude of the effect depended on age. However, the biological mechanisms linking children's growth with air pollution are not evident, and it remains to be confirmed whether the relationship is genuine and causal.

Adolescent↗
PubMed2004

Cognitive ability in childhood and cognitive decline in mid-life: longitudinal birth cohort study.

OBJECTIVE: To examine the association between cognitive ability in childhood and mid-life cognitive decline in the normal population. DESIGN: Longitudinal, population based, birth cohort study. PARTICIPANTS: 2058 men and women born in 1946. MAIN STUDY MEASURES: Ability in childhood measured by AH4 and test of verbal comprehension at age 15 years. Ability in adulthood measured by the national adult reading test (NART) at age 53 years. Outcome measures were decline in memory (word list learning) and speed and concentration (timed visual search) from age 43 to 53 years. RESULTS: Ability in childhood was significantly and negatively associated with decline in memory (beta = 0.09, P = 0.005, for men; 0.10, P < 0.001, for women) and search speed (beta = 0.13, P < 0.001, for men; 0.08, P = 0.01, for women), independent of educational attainment, occupational social class, and a range of health indicators. The adult reading test was also significantly and negatively associated with decline in these outcomes (for memory beta = 0.21, P < 0.001, for men; 0.17, P < 0.001, for women; and for search speed beta = -0.05 for men; 0.10, P = 0.008 for women) independent of educational attainment, social class, and childhood ability. CONCLUSIONS: Ability in childhood can protect against cognitive decline in mid-life and beyond. Results for the adult reading test indicate that the protective effect of ability may also be acquired in adulthood.

Adolescent↗
PubMed2004

Childhood cognitive ability and deaths up until middle age: a post-war birth cohort study.

BACKGROUND: Childhood IQ has been related to mortality in later life in four studies. Cognitive ability may be a mediator between early disadvantage and mortality, a marker of the efficiency of information processing in the central nervous system, or predict entry to safe adult environments or healthy behaviours. We examined mortality in relation to cognitive ability at age 8 years in a birth cohort and investigated these possible reasons. METHODS: Cox's proportional hazards models were used to investigate the effect of early cognitive ability on all-cause mortality in 2057 women and 2192 men born in England, Scotland, and Wales in March 1946 and followed until age 54 years. We tested whether the relationship was accounted for by childhood socioeconomic conditions or serious illness, education, adult socioeconomic conditions, or smoking. RESULTS: Cognitive ability was related to mortality in men but not women. The excess mortality rate in men was concentrated in the bottom quarter of the cognitive score (hazard ratio [HR] for bottom versus top quarter 1.8, 95% CI: 1.0, 3.0) and there was no gradient across the range of ability. Adjustment for childhood socioeconomic conditions and serious illness had a small effect on the HR for deaths between 9 and 54 years while adjustment for education or early adult socioeconomic conditions halved the HR for deaths from age 26 years. Smoking was not a mediator of the effect of early ability on adult mortality. CONCLUSIONS: Greater cumulative exposure to poor lifetime socioeconomic conditions is the most likely explanation for the observed relationship between low cognitive ability in childhood and mortality. This relationship may therefore be elucidated further by studying the causes of lifelong socioeconomic inequalities in health.

Adult↗
PubMed2003

Does active leisure protect cognition? Evidence from a national birth cohort.

Social, physical and intellectual activities are thought to facilitate cognitive performance and slow the rate of age associated cognitive decline, but little is known about this association in younger adulthood. We used multiple regression to test the association between two kinds of activity at 36 years-physical exercise and spare-time activity-and verbal memory at 43 and 53 years in 1919 males and females enrolled in the MRC National Survey of Health and Development (the British 1946 birth cohort). Both kinds of activities were significantly and positively associated with memory performance at 43 years, after controlling for sex, education, occupational social class, IQ at 15 years, and recurrent ill health and significant mental distress. Furthermore, physical exercise at 36 years (but not spare-time activity) was associated with a significantly slower rate of decline in memory from 43 to 53 years, after controlling for the same factors, with evidence that continuing physical exercise after 36 years was important for protection. We conclude that physical exercise and spare-time activity are significantly associated with benefit to memory in midlife, although these two kinds of voluntary activity may exert their effects on cognition via different paths.

Adult↗
PubMed2003

Lifetime antecedents of cognitive reserve.

We used path analysis on data from the British 1946 birth cohort to model lifetime antecedents of cognitive reserve, represented by the NART at 53 years, and compared this model for verbal memory and psychomotor function at this age, cognitive outcomes that are sensitive to age-associated decline. We showed independent paths from childhood cognition, educational attainment and adult occupation to cognitive reserve, with that from childhood cognition the strongest, and that from adult occupation the weakest. A similar pattern was found for the verbal memory and psychomotor outcomes, although the pathways were weaker than those to the NART. The pattern was also mirrored by the paths from paternal occupation to childhood cognition, educational attainment and adult occupation, with that to childhood cognition the strongest, and that to adult occupation the weakest. The direct influence of paternal occupation on cognitive reserve was negligible, and almost entirely mediated by childhood cognitive ability and educational attainment.

Adaptation, Physiological↗
PubMed2003

Cigarette smoking and cognitive decline in midlife: evidence from a prospective birth cohort study.

OBJECTIVES: The authors investigated the effects of cigarette smoking on midlife cognitive performance. METHODS: Multiple regression was used to test the association between cigarette smoking and changes in cognitive test scores among male and female members of the British 1946 birth cohort aged between 43 and 53 years. RESULTS: Smoking was associated with faster declines in verbal memory and with slower visual search speeds. These effects were largely accounted for by individuals who smoked more than 20 cigarettes per day and were independent of sex, socioeconomic status, previous (adolescent) cognitive ability, and a range of health indicators. CONCLUSIONS: The present results show that heavy smoking is associated with cognitive impairment and decline in midlife. Smokers who survive into later life may be at risk of clinically significant cognitive declines.

Adult↗
PubMed2002

Mortality in adults aged 26-54 years related to socioeconomic conditions in childhood and adulthood: post war birth cohort study.

OBJECTIVE: To examine premature mortality in adults in relation to socioeconomic conditions in childhood and adulthood. DESIGN: Nationally representative birth cohort study with prospective information on socioeconomic conditions. SETTING: England, Scotland, and Wales. STUDY MEMBERS: 2132 women and 2322 men born in March 1946 and followed until age 55 years. MAIN OUTCOME MEASURES: Deaths between 26 and 54 years of age notified by the NHS central register. RESULTS: Study members whose father's occupation was manual at age 4, or who lived in the worst housing, or who received the poorest care in childhood had double the death rate during adulthood of those living in the best socioeconomic conditions. All indicators of socioeconomic disadvantage at age 26 years, particularly lack of home ownership, were associated with a higher death rate. Manual origins and poor care in childhood remained associated with mortality even after adjusting for social class in adulthood or home ownership. The hazard ratio was 2.6 (95% confidence interval 1.5 to 4.4) for those living in manual households as children and as adults compared with those living in non-manual households at both life stages. The hazard ratio for those from manual origins who did not own their own home at age 26 years was 4.9 (2.3 to 10.5) compared with those from non-manual origins who were home owners. CONCLUSIONS: Socioeconomic conditions in childhood as well as early adulthood have strongly influenced the survival of British people born in the immediate post war era.

Adult↗
PubMed2002

Mild extrapyramidal signs and functional impairment in ageing.

BACKGROUND: Little is known about the clinical significance of mild extrapyramidal signs (EPS) in elderly individuals. We investigated whether EPS are associated with functional impairment in older people with cognitive decline. METHODS: A sub-group of 105 participants from the EUGERIA Study of Cognitive Ageing without Parkinson's disease or dementia, but with informant evidence of cognitive decline, were followed across three years and underwent neurological examination and assessment of mental health, cognition and functional capacity. RESULTS: 28.6% had at least one EPS (resting tremor, muscular rigidity or akinesia, of which rigidity was the most frequent). EPS presence was significantly associated with functional impairment after controlling for age and cognitive impairment (AAMI), although the association was reduced to borderline significance after further adjustment for depression and psychotropic medication use. There was evidence of colinearity between EPS and depression, possibly suggesting similar underlying mechanisms. CONCLUSIONS: There is an association between mild EPS and functional impairment in older persons with evidence of cognitive decline, but free of dementia or Parkinson's disease.

Activities of Daily Living↗
PubMed2002

The distribution of Mini-Mental State Examination scores in an older UK African-Caribbean population compared to MRC CFA study norms.

OBJECTIVE: to describe normative data for the Mini-Mental State Examination (MMSE) in a UK African-Caribbean population and compare these with norms for white UK-born elders. DESIGN: a comparison of MMSE data from two cross-sectional surveys. METHOD: the MMSE had been administered to a community UK African-Caribbean population and scores were compared to norms from the Medical Research Council Cognitive Function and Ageing Study (CFAS). MMSE data were analysed for 248 African-Caribbean participants aged 55-75 and 5379 CFAS participants aged 65-74, without visual or auditory problems. Distributions of scores were tabulated and error rates for individual items compared. RESULTS: Median MMSE scores were 25 (interquartile range 22-27) for the whole African-Caribbean sample, 24 (22-27) for those aged 65-75 in the African-Caribbean sample, and 27 (25-29) for CFAS. Differences in error rates were specific to particular items: naming the season, serial seven subtraction, phrase repetition, three-stage command, and copying intersecting pentagons. These differences persisted when both samples were restricted to those with statutory duration of education, who were literate and who had worked in non-manual occupations. Normative data are displayed for MMSE scores in both groups. CONCLUSION: different distributions of MMSE scores between UK African-Caribbean and Caucasian groups can be principally explained by cultural bias in certain items. If the MMSE is to be administered to older African-Caribbean people, specific normative data should be referred to or else a culturally modified version of the instrument should be used.

Aged↗
PubMed2002

Surveying older people from minority ethnic groups: an evaluation of a primary care sampling method for UK African-Caribbean elders.

There are substantial logistical difficulties in conducting community surveys of minority ethnic group populations. Primary care lists have been identified as an important potential resource but the representativeness of samples derived through this method has received little evaluation. In a community survey of psychiatric morbidity, African-Caribbean people aged 55-75 were identified by practice staff from registration lists for seven primary care teams in south London. The sensitivity of the process was evaluated by contacting a random sample of people whose ethnicity was not known. Participants aged 65-75 (n = 174) were also compared to a similarly aged group sampled through household enumeration (n = 34) with respect to demographic factors, risk factors for vascular disease, depression and cognitive function. For those with correct addresses, the identified group was estimated to include 72% of the potentially eligible population. Only 8% of contacted people were found not to be eligible in terms of ethnicity. Compared to the household enumeration sample, the primary care sample had marginally higher socio-economic status but was similar with respect to all other measured characteristics. Primary care list sampling with staff-assigned ethnicity therefore appeared highly specific, reasonably sensitive, and did not seem to introduce substantial bias for this population.

Africa↗
PubMed2002

Long-term effects of breast-feeding in a national birth cohort: educational attainment and midlife cognitive function.

OBJECTIVE: A recent meta-analysis showed that breast-feeding confers a 3.2 point increment in cognitive function through adolescence. Little is known, however, about possible longer-term effects of breast-feeding. We investigated the effect of breast-feeding on educational attainment, and on a range of cognitive skills in midlife, in the British 1946 birth cohort. DESIGN: Regression analyses were used to test the association between breast-feeding, likelihood of obtaining advanced educational qualifications by age 26 years, and three cognitive test scores at age 53 years: i.e. reading ability (NART), timed visual search and verbal memory. These associations were then adjusted for social confounding variables and for cognitive ability at age 15 years. SETTING AND SUBJECTS: One thousand seven hundred and thirty-nine male and female participants in the MRC National Survey of Health and Development, also known as the British 1946 birth cohort, distributed throughout England, Wales and Scotland. RESULTS: Breast-feeding was significantly and positively associated with educational attainment, an effect that was independent of early social background, but largely accounted for by cognitive ability at age 15 years. Breast-feeding was significantly and positively associated with the NART at 53 years, an effect that was independent of early social background, educational attainment and adult social class, but, again, largely accounted for by cognitive ability at 15 years. There was no independent effect of breast-feeding on timed visual search or verbal memory at 53 years. CONCLUSION: The benefit of breast-feeding has long-term potential impact across the life course through its influence on childhood cognition and educational attainment.

Adolescent↗