BMJ Psychiatry: Relationship between afternoon napping and cognitive function in the ageing Chinese population

Cai, H., et al 2021| Relationship between afternoon napping and cognitive function in the ageing Chinese population|General Psychiatry|34|e100361| doi: 10.1136/gpsych-2020-100361

Research that looked at the potential relationship between having a nap in the afternoon and cognitive function in older people, reports an association between resting after lunch and improved cognitive function. Chinese researchers identified an association between demography, napping, napping frequency, physical diseases, and cognition in their sample of more than 2200 Chinese participants aged 60 or over at the study’s outset.

The authors add that n addition to reducing sleepiness, mid-day naps offer a variety of benefits such as memory consolidation, preparation for subsequent learning, executive functioning enhancement and a boost to emotional stability, but these effects were not observed in all cases.

Abstract

Background Several studies have shown that afternoon napping promotes cognitive function in the elderly; on the other hand, some studies have shown opposite results. This current study further examined the relationship between afternoon napping and cognitive function in the ageing Chinese population.

Methods A total of 2214 elderly were included (napping group: n=1534; non-napping group: n= equal to 680). They all received cognitive evaluations by the Beijing version of the Montreal Cognitive Assessment, the Mini-Mental State Examination, and the Chinese version of the Neuropsychological Test Battery. Among all the subjects, 739 elderly volunteered to take blood lipid tests.

Results Significant differences in cognitive function and blood lipids were observed between the napping and the non-napping groups. Afternoon napping was associated with better cognitive function including orientation, language, and memory in the present study. Subjects with the habit of afternoon napping also showed a higher level of triglyceride than the non-napping subjects.

Conclusion The results demonstrated that afternoon napping was related to better cognitive function in the Chinese ageing population.

Full paper from BMJ Psychiatry

In the news:

Science Daily Afternoon napping linked to better mental agility

Staying fit and mentally active linked with reduced dementia risk

Researchers in Sweden have found that women who exercise and stay cognitively active during midlife have a reduced risk of dementia in older age | Neurology | via Alzheimer’s Research UK

In 1968, Swedish researchers began studying a group of 800 women in midlife, between the ages of 38 and 54, and measured the amount of time they spent doing cognitively stimulating activities, including reading books and writing. The team also recorded how much physical activity the women did including walking, and intense training like swimming.

The team followed the volunteers until 2012 to see if they went onto develop dementia. They found that those who were more engaged in physical activity and spent more time doing cognitive tasks had a lower risk of developing the condition.

Abstract
Objective:  To investigate whether cognitive and physical activities in midlife are associated with reduced risk of dementia and dementia subtypes in women followed for 44 years.

Methods:  A population-based sample of 800 women aged 38–54 years (mean age 47 years) was followed from 1968 to 2012. Cognitive (artistic, intellectual, manual, religious, and club) and physical activity were assessed at baseline. During follow-up, dementia, Alzheimer disease, vascular dementia, mixed dementia, and dementia with cerebrovascular disease were diagnosed according to established criteria based on information from neuropsychiatric examinations, informant interviews, hospital records, and registry data. Cox regression models were used with adjustment for age, education, socioeconomic status, hypertension, body mass index, cigarette smoking, diabetes mellitus, angina pectoris, stress, and major depression.

Results:  We found that cognitive activity in midlife was associated with a reduced risk of total dementia and Alzheimer disease during follow-up. Physical activity in midlife was associated with a reduced risk of mixed dementia and dementia with cerebrovascular disease. The results were similar after excluding those who developed dementia before 1990, except that physical activity was then also associated with reduced risk of total dementia.

Conclusion: Our findings suggests that midlife cognitive and physical activities are independently associated with reduced risk of dementia and dementia subtypes. The results indicate that these midlife activities may have a role in preserving cognitive health in old age.

Full story at Alzheimer’s Research UK

Full reference: Najar, J. et al. | Cognitive and physical activity and dementia. A 44-year longitudinal population study of women | Neurology | First published February 20, 2019

 

Living in greener neighbourhoods is associated with slower cognitive decline

Study shows a relation between neighbourhood green space and mental capacity after following 6,500 people in the UK for 10 years | Environmental Health Perspectives | via ScienceDaily

Contact with greenspace is known to have beneficial effects for mental health. A new study by the Barcelona Institute for Global Health suggests that it may also play a positive role against cognitive decline in elderly. In particular, this research published in Environmental Health Perspectives shows that the loss in cognitive functions expected as part of the ageing process is slightly slower in people who live in greener neighbourhoods.

Researchers performed a 10 years follow-up of 6,500 people aged 45 to 68 from the Whitehall II cohort in the UK. At three different timepoints during the course of the study, participants completed a battery of cognitive tests that assessed their verbal and mathematical reasoning, verbal fluency and short-term memory, as well as the decline in these functions. Neighbourhood greenspace for each participant was estimated using satellite images.

The data revealed that the decline in the cognitive score after the 10-years follow up was 4.6% smaller in participants living in greener neighbourhoods.

There is evidence that the risk for dementia and cognitive decline can be affected by exposure to urban-related environmental hazards (such as air pollution and noise) and lifestyle (such as stress and sedentary behavior). In contrast, living near green spaces has been proposed to increase physical activity and social support, reduce stress, and mitigate exposure to air pollution and noise.

Full story at ScienceDaily

Full reference: Carmen de Keijzer et al. | Residential Surrounding Greenness and Cognitive Decline: A 10-Year Follow-up of the Whitehall II Cohort | Environmental Health Perspectives | 126 (7) | July 2018

Longitudinal changes in global and domain specific cognitive function in the very-old

Stephan B C M, Muniz-Terrera G (et al) | Longitudinal changes in global and domain specificcognitive function in the very-old: findings from the Newcastle 85+ Study | International Journal of Geriatric Psychiatry |  33(2) February 2018

Many older people maintain high levels of cognitive function, or only mild impairment, well into their nineties. Using findings from the Newcastle 85+ study, this article reports that older people, with no or only mild impairment, experience very little cognitive decline between the ages of 85 and 90.  This group of successful cognitive agers may provide insight for identifying predictors of cognitive integrity in later life.

Full document available here

 

What keeps you sharp?

The majority of people expect their memory to worsen in their 50s and that there are preventive measures that can maintain or improve cognition. This report outlines the findings of a survey of more than 3,000 people aged between 40 and 98 years old on memory and cognitive skills | Heriot-Watt University | April 2018

The results from the “What Keeps You Sharp?” survey reveals the majority of those asked believe lifestyle and genetics are equally important contributors to the changes they might experience. Almost nine out of 10 people are of the opinion that there are things they can do to maintain or improve their thinking skills; however, when asked if they knew what those things were, less than six in 10 were sure.

Image source: http://www1.hw.ac.uk

More than 3000 people aged between 40 to 98 years-old responded to the study from across the UK. The report is intended to be used by members of the public, older peoples’ groups and charities, and as a reference for GPs and other health professionals. It links some of the beliefs the public have about the topic to what other research in the area suggests, and directs people to resources so they can follow-up to get more information.

Full report: What keeps you sharp? A National survey about what people in the UK think about their thinking skills!

When do problems with memory and decision-making affect older adults’ ability to drive?

Study finds lower levels of cognitive function were linked to a higher risk of motor vehicle crashes | Journal of the American Geriatrics Society | via ScienceDaily

A team of researchers designed a study to learn more about cognitive health and older drivers’ crash risks. The study focused on links between levels of cognitive function and crash risk among older drivers without dementia. They also assessed the link between changes in cognitive function over time and later risks of crashes.

Researchers followed 2,615 participants for an average of 6.7 years, and looked at motor vehicle crashes involving participants. For older licensed drivers without dementia, lower levels of cognitive function were linked to a higher risk of motor vehicle crashes. Depression also was linked to a higher risk for crashes in older licensed drivers without dementia.

The researchers noted that, unfortunately, there is not yet a widely accepted specific clinical exam, procedure, or lab test that can evaluate driving and crash risk related to cognitive function. The researchers concluded that older drivers with lower levels of cognitive function were somewhat more likely to be involved in a crash.

Full story at ScienceDaily

Full reference: Fraade-Blanar, L.A. et al. |  Cognitive Decline and Older Driver Crash Risk. Journal of the American Geriatrics Society | published online 17 April 2018

When does cognitive decline begin?

Karr, J. E. et al. | When does cognitive decline begin? A systematic review of change point studies on accelerated decline in cognitive and neurological outcomes preceding mild cognitive impairment, dementia, and death |  Psychology and Aging |  Vol 33 (2), 195-218

Abstract:

Older adults who ultimately develop dementia experience accelerated cognitive decline long before diagnosis. A similar acceleration in cognitive decline occurs in the years before death as well.

To evaluate preclinical and terminal cognitive decline, past researchers have incorporated change points in their analyses of longitudinal data, identifying point estimates of how many years prior to diagnosis or death that decline begins to accelerate.

The current systematic review aimed to summarize the published literature on preclinical and terminal change points in relation to mild cognitive impairment (MCI), dementia, and death, identifying the order in which cognitive and neurological outcomes decline and factors that modify the onset and rate of decline.

A systematic search protocol yielded 35 studies, describing 16 longitudinal cohorts, modeling change points for cognitive and neurological outcomes preceding MCI, dementia, or death.

Change points for cognitive abilities ranged from 3–7 years prior to MCI diagnosis, 1–11 years prior to dementia diagnosis, and 3–15 years before death. No sequence of decline was observed preceding MCI or death, but the following sequence was tentatively accepted for Alzheimer’s disease: verbal memory, visuospatial ability, executive functions and fluency, and last, verbal IQ.

Some of the modifiers of the onset and rate of decline examined by previous researchers included gender, education, genetics, neuropathology, and personality. Change point analyses evidence accelerated decline preceding MCI, dementia, and death, but moderators of the onset and rate of decline remain ambiguous due to between-study modeling differences, and coordinated analyses may improve comparability across future studies.

Full detail at American Psychological Association

Cognitive decline: Does where you live and how well you sleep matter?

Hunter, J. C. et al. | Neighborhoods, sleep quality, and cognitive decline: Does where you live and how well you sleep matter? | Alzheimer’s and Dementia | April 2018 | Volume 14, Issue 4 | Pages 454–461

New study finds sleep quality and socioeconomic status were associated with cognitive decline.

Introduction
We evaluated the association between neighborhood socioeconomic status (NSES) and sleep quality on cognitive decline in the Health and Retirement Study.

Methods
Health and Retirement Study participants (n = 8090), aged 65+ with DNA and multiple biennial cognitive observations (abbreviated Telephone Interview for Cognitive Status), were included. Participants were grouped into quartiles of NSES and sleep quality scores. We adjusted for apolipoprotein E ε4, demographic, and cardiovascular risk factors. Random effects modeling evaluated cognitive change over time.

Results
NSES and sleep were significantly associated with cognitive decline, and there was a significant interaction between them (P = .02). Significant differences between high/low NSES and high/low sleep quality (P < .0001) were found.

Discussion
Sleep and NSES were associated with cognitive decline; the association between sleep and cognition appeared stronger among those with low NSES. The association between low NSES, poor sleep quality, and cognitive decline was roughly equivalent to the association between apolipoprotein E ε4 and cognitive decline.

Full article available here

Poor fitness linked to weaker brain fibre, higher dementia risk

New research supports the hypothesis that improving people’s fitness may improve their brain health and slow down the aging process | Journal of Alzheimer’s Disease | via ScienceDaily

A new study has provided more evidence to suggest that exercise improves brain health and could be a lifesaving ingredient that prevents Alzheimer’s disease. Published in the Journal of Alzheimer’s Disease, the study suggests that the lower the fitness level, the faster the deterioration of vital nerve fibres in the brain.

This deterioration results in cognitive decline, including memory issues characteristic of dementia patients.

The research focused on a type of brain tissue called white matter, which is composed of millions of bundles of nerve fibres used by neurons to communicate across the brain.

Older patients at high risk to develop Alzheimer’s disease and who had early signs of memory loss, or mild cognitive impairment (MCI) were enrolled. The researchers determined that lower fitness levels were associated with weaker white matter, which in turn correlated with lower brain function.

Further detail at ScienceDaily

Full reference: Ding, K. et al. | Cardiorespiratory Fitness and White Matter Neuronal Fiber Integrity in Mild Cognitive Impairment | Journal of Alzheimer’s Disease, Vol 61 (2): 729 – 739

Psychosocial interventions for people with dementia

New research finds good evidence to suggest that multi-component exercise with sufficient intensity improves global physical and cognitive functions and activities of daily living skills for people with dementia | Aging & Mental Health

Objectives: Over the last 10 years there has been a multitude of studies of psychosocial interventions for people with dementia. However, clinical services face a dilemma about which intervention should be introduced into clinical practice because of the inconsistency in some of the findings between different studies and the differences in the study qualities and trustworthiness of evidence. There was a need to provide a comprehensive summary of the best evidence to illustrate what works.

Methods: A review of the systematic reviews of psychosocial interventions in dementia published between January 2010 and February 2016 was conducted.

Results: Twenty-two reviews (8 physical, 7 cognitive, 1 physical/cognitive and 6 other psychosocial interventions) with a total of 197 unique studies met the inclusion criteria. Both medium to longer-term multi-component exercise of moderate to high intensity, and, group cognitive stimulation consistently show benefits. There is not sufficient evidence to determine whether psychological or social interventions might improve either mood or behaviour due to the heterogeneity of the studies and interventions included in the reviews.

Conclusion: There is good evidence that multi-component exercise with sufficient intensity improves global physical and cognitive functions and activities of daily living skills. There is also good evidence that group-based cognitive stimulation improves cognitive functions, social interaction and quality of life. This synthesis also highlights the potential importance of group activities to improve social integration for people with dementia. Future research should investigate longer-term specific outcomes, consider the severity and types of dementia, and investigate mechanisms of change.

Full reference: McDermott, O et al. | Psychosocial interventions for people with dementia: a synthesis of systematic reviews |Aging & Mental Health | Published online 17 Jan 2018

View the full article here