Genome-wide scans are a likely source to establish genetic contributions. The role of vascular factors in cognitive ageing is increasingly studied and understood. The same applies to diet, biomarkers such as inflammation and lifestyle factors such as exercise. There are marked advances in brain imaging, affording better in vivo studies of brain correlates of cognitive changes. There is growing appreciation that factors affecting general bodily ageing also influence cognitive functions in old age.

Dementia risk is associated with loneliness and having fewer close relationships in later life. The underlying mechanisms remain to be elucidated, but efforts to enhance older peoples' relationship quality may be relevant to dementia risk.

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Background: Vitamin B-12 and folate are micronutrients essential for normal embryogenesis. Vitamin B-12 insufficiency in pregnancy is high in certain parts of the world, such as India, and although this has been linked to low birth weight (LBW) in these populations, the relation between vitamin B-12 and birth weight (BW) elsewhere is unknown. Objectives: We performed a systematic review to assess 1) the worldwide prevalence of vitamin B-12 insufficiency in pregnancy and 2) its association with BW. Design: A search of 5 electronic databases was performed to identify eligible articles. Random-effects meta-analysis was conducted according to geographic regions and pregnancy trimesters for the prevalence subreview and by categorical measures of BW. Results: A total of 57 and 23 articles were included for the prevalence and BW subreviews, respectively. The pooled estimates of vitamin B-12 insufficiency were 21%, 19%, and 29% in the first, second, and third trimesters, respectively, with high rates for the Indian subcontinent and the Eastern Mediterranean. The large heterogeneity between studies was partially addressed by creating a standardized score for each study (mean vitamin B-12 insufficiency O cutoff value), which internally corrected for geographic region, trimester, and assay type. Twelve of the 13 longitudinal studies included showed a decrease in mean or median vitamin B-12 across trimesters. Pooled analysis showed nonsignificantly lower maternal vitamin B-12 concentrations in LBW than in normal-BW infants and higher odds of LBW with lower vitamin B-12 values (adjusted OR: 1.70; 95% CI: 1.16, 2.50), but studies from India largely contributed to the latter. Conclusions: Our review indicates that vitamin B-12 insufficiency during pregnancy is common even in nonvegetarian populations and that concentrations of vitamin B-12 decrease from the first to the third trimester. There is no consistent association between vitamin B-12 insufficiency and LBW. However, given the long-term risks of LBW, this observation warrants further cohort studies and randomized controlled trials.Am J Clin Nutr 2016;103:1232-51.

Social isolation and loneliness show different associations with changes in evaluative and hedonic well-being over time.

Objective: To investigate the influence of social network characteristics on subjective well-being over 6 years in a population sample of older adults. Method: A total of 4,116 participants in the English Longitudinal Study of Aging provided baseline data on social network characteristics and potential confounding factors, and complete follow-up data on 2 measures of subjective well-being. Results: Social network size and network contact frequency were positively and independently associated with future life satisfaction and quality of life after controlling for confounding factors, including demographic characteristics, socioeconomic factors, and long-standing illness. In contrast, social network diversity was not independently related to future subjective well-being. Conclusion: Different aspects of people’s social networks may help sustain levels of subjective well-being in older age. The role of close relationships and frequent contact in later life may be particularly important. These results highlight the need for examining different aspects of social networks for promoting well-being of older people.

Background: Having a network of close relationships may reduce the risk of developing dementia. However, social exchange theory suggests that social interaction entails both rewards and costs. The effects of quality of close social relationships in later life on the risk of developing dementia are not well understood.Objective: To investigate the effects of positive and negative experiences of social support within key relationships (spouse or partner, children, other immediate family, and friends) on the risk of developing dementia in later life.Methods: We analyzed 10-year follow up data (2003/4 to 2012/13) in a cohort of 10,055 dementia free (at baseline) core participants aged 50 years and over from the English Longitudinal Study of Ageing (ELSA). Incidence of dementia was identified from participant or informant reported physician diagnosed dementia or overall score of informant-completed IQCODE questionnaire. Effects of positive and negative experiences of social support measured at baseline on risk of developing dementia were investigated using proportional hazards regression accommodating interval censoring of time-to-dementia.Results: There were 340 (3.4%) incident dementia cases during the follow-up. Positive social support from children significantly reduced the risk of dementia (hazard ratio, HR = 0.83, p = 0.042, 95% CI: 0.69 to 0.99). Negative support from other immediate family (HR = 1.26, p = 0.011, CI: 1.05 to 1.50); combined negative scores from spouse and children (HR = 1.23, p = 0.046, CI: 1.004 to 1.51); spouse, children, and other family (HR = 1.27, p = 0.021, CI = 1.04 to 1.56); other family & friends (HR = 1.25, p = 0.033, CI: 1.02 to 1.55); and the overall negative scores (HR = 1.31, p = 0.019, CI: 1.05 to 1.64) all were significantly associated with increased risk of dementia.Conclusion: Positive social support from children is associated with reduced risk of developing dementia whereas experiences of negative social support from children and other immediate family increase the risk. Further research is needed to better understand the causal mechanisms that drive these associations.

Objectives To prospectively investigate the impact of transitions in informal caregiving on emotional wellbeing over two years in a large population study of older people. Methods Information on provision of unpaid care in 2004/5 and 2006/7 was available for 6571 participants in the English Longitudinal Study of Ageing. Three wellbeing domains were also assessed on each occasion: Life satisfaction (measured with the Satisfaction With Life Scale); Quality of life (assessed with the CASP-19 scale); and depression symptoms (measured using the Centers for Epidemiologic Studies Depression Scale). Multivariable analyses of the impact on wellbeing of two-year caregiving transitions (caregiving entry and caregiving exit, or continued caring) were conducted separately for spousal/child carers and carers of other family/non-relatives. Results Compared to non-caregiving, entry into spousal/child caregiving was associated with decline in quality of life (B = −1.60, p < .01) whereas entry into caregiving involving other kin relations increased life satisfaction (B = 1.02, p < .01) and lowered depression symptoms (B = −0.26, p < .05). Contrary to expectations, caregiving exit was related to increased depression in both spousal/child (B = 0.44, p < .01) and non-spousal/child (B = 0.25, p < .05) carers. Continued spousal/child caregiving was also related to decline in quality of life (B = −1.24, p < .05). Other associations were suggestive but non-significant. Conclusion The emotional impact of different caregiving transitions in later life differs across kin relationships; notably, spousal and child carers’ wellbeing was consistently compromised at every stage of their caregiving career over the two-year study period.