Older adults' memory function is linked to faster movement and better mental health, study suggests
‘Superagers’ – people in their eighties with the memory function of people who are several decades younger – performed well in Timed Up and Go tests that were held as part of a wider study conducted by researchers based in Spain, Germany and Finland.
The full results of the study are published today (14 July) in The Lancet Healthy Longevity journal. Many UK-based physiotherapists will be familiar the Timed Up and Go Test, which is commonly used to assess people’s mobility levels. Researchers who used the test alongside a finger tapping test, which measures fine motor function, found that higher scores were linked to better levels of mobility, agility, and balance among the participants.
This observation was made despite there being no differences in self-reported exercise levels between superagers and typical older adults. As well as being more likely to have greater movement speed than typical older adults, the superagers had lower rates of anxiety and depression, the researchers state.
First author Marta Garo-Pascual, from the Madrid-based Queen Sofia Foundation Alzheimer Centre, said: ‘We are now closer to solving one of the biggest unanswered questions about superagers: whether they are truly resistant to age-related memory decline or they have coping mechanisms that help them overcome this decline better than their peers.
‘Our findings suggest superagers are resistant to these processes, though the precise reasons for this are still unclear. By looking further into links between superageing and movement speed we may be able to gain important insights into the mechanisms behind the preservation of memory function deep into old age.’
While previous research has found differences in brain structure and certain lifestyle factors – such as stronger social connections – among superagers compared with typical older adults, most studies have had small sample sizes and did not track changes over time. As a result, in-depth understanding of demographic, lifestyle, or clinical factors that help to preserve memory function into old age is currently lacking.
By looking further into links between superageing and movement speed we may be able to gain important insights into the mechanisms behind the preservation of memory function deep into old age [Marta Garo-Pascual]Vallecas Project cohort
Ms Garo-Pascual and her colleagues conducted a relatively large analysis of superagers, who were discovered, along with typical older adults, in an ongoing project designed to help identify early indicators of Alzheimer’s disease. The Vallecas Project cohort in Madrid is composed of people aged from 69 to 86 years who do not have a neurological or severe psychiatric disorder. Of the cohort’s 1,213 participants, recruited from 2011 to 2014, 64 superagers and 55 typical older adults, who performed well on several cognitive tasks but did not display superager memory ability, were identified and included in the new study.
Superagers and typical older adults were identified based on their performance in the Free and Cued Selective Reminding Test, which is used to assess people’s memory function. Superagers did at least as well as the average person around 30 years younger with the same education level. older adults performed within a normal range for their age and education. All typical superagers and normal older adults were 79.5 years or older. Most superagers were women (38/64, 59 per cent), as were most typical older adults (35/55, 64 per cent).
Participants received up to six annual follow-up visits, during which demographic and lifestyle factors were recorded. Participants also underwent MRI scans to measure grey matter volume and completed a range of clinical tests. Blood samples were taken to screen for biomarkers for neurodegenerative disease and a key genetic risk factor for Alzheimer’s disease. A machine learning computer model including 89 demographic, lifestyle, and clinical predictors was used to identify factors associated with superagers.
More grey matter
In line with previous studies, MRI scans showed superagers to have more grey matter – tissue vital for normal brain function – in key brain areas involved in memory, and also in a part of the brain involved in movement. Superagers’ overall level of grey matter in key areas also degenerated more slowly over five years than in typical older adults. Using the machine learning computer model, the authors found faster movement speed and better mental health were the factors most often associated with superagers.
In clinical tests to measure levels of anxiety and depression, superagers scored lower than typical older adults. Previous research suggests depression and anxiety can impair performance on memory tests in people of all ages, and are risk factors for developing dementia.
Among other self-reported differences, superagers’ lifestyles in midlife were generally more active, were satisfied with their sleep duration, and were more likely to have a musical background – either taught or amateur – in comparison with typical older adults. Superagers also demonstrated greater independence in their day-to-day living and scored higher in intelligence tests.
As with any observational study, it is not possible to say whether the factors reported have any direct effect on superageing. Despite using 89 variables, the machine learning model was only able to distinguish superagers from typical older adults around 66 per cent of the time, indicating that additional factors – possibly genetic – are linked with superageing.
Further research into overlap between genetic links with superageing and genes associated with fast muscle movements among older people could help to narrow the search.
To access the full version of the article – titled Brain structure and phenotypic profile of superagers compared with age-matched older adults: a longitudinal analysis from the Vallecas Project – clickAuthor: Ian A McMillan