Memory Research News in Aging

Daily crosswords linked to sharper brain in later life

  • A very large online study has found that doing word puzzles regularly protects against age-related cognitive decline.

Data from more than 17,000 healthy people aged 50 and over has revealed that the more regularly participants engaged with word puzzles, the better they performed on tasks assessing attention, reasoning and memory.

Study participants took part in online cognitive tests, as well as being asked how frequently they did word puzzles such as crosswords. There was a direct relationship between the frequency of word puzzle use and the speed and accuracy of performance on nine cognitive tasks.

The effect was considerable. For example, on test measures of grammatical reasoning speed and short-term memory accuracy, performing word puzzles was associated with brain function equivalent to ten years younger than participants’ chronological age.

The next question is whether you can improve brain function by engaging in puzzles.

The study used participants in the PROTECT online platform, run by the University of Exeter and Kings College London. Currently, more than 22,000 healthy people aged between 50 and 96 are registered in the study. PROTECT is a 10 year study with participants being followed up annually to enable a better understanding of cognitive trajectories in this age range.

https://www.eurekalert.org/pub_releases/2017-07/uoe-dcl071417.php

Reference: 

The Relationship Between the Frequency of Word Puzzle Use and Cognitive Function in a Large Sample of Adults Aged 50 to 96 Years, was presented at the Alzheimer's Association International Conference (AAIC) 2017 on July 17.

How risky is surgery for older adults' cognitive function?

Several studies suggest that post-operative cognitive decline in older adults is due to several factors:

  • the stress of hospitalization, if unexpected
  • brain inflammation caused by an immune response from the brain’s microglia
  • post-operative delirium.

It also seems that higher levels of cognitive function, higher levels of engagement in certain cognitive activities, and better cerebrovascular health, all protect against such decline.

Unplanned hospitalizations accelerate cognitive decline in older adults

Data from the Rush Memory and Aging Project has found that emergency and urgent hospitalizations are associated with an increased rate of cognitive decline in older adults.

Non-elective hospitalizations were associated with an approximately 60% acceleration in the rate of cognitive decline from before hospitalization. Elective hospitalizations, however, were not associated with acceleration in the rate of decline at all.

Of the 930 participants (average age 81), 613 were hospitalized at least once over an average of almost five years of observation. Of those who were hospitalized, 260 (28%) had at least one elective hospital admission, and 553 (60%) had at least one non-elective hospital admission. These groups included 200 participants (22%) who had both types of hospitalizations.

The data was presented at the Alzheimer's Association International Conference in London on July 17.

https://www.eurekalert.org/pub_releases/2017-07/rumc-hac071717.php

Inflammation triggered by brain's own immune cells behind post-surgical decline

There is growing evidence that inflammation might be responsible for the cognitive decline seen in many older adults after surgery. Now a mouse study provides evidence that brain inflammation and cognitive decline following surgery are triggered by the brain's microglia.

When mice had their microglia temporarily depleted before surgery, they didn’t show any cognitive decline several days after surgery. They also had much lower levels of inflammatory molecules in the hippocampus. Controls — those not receiving the experimental drug to deplete microglia to around 5% of normal levels — did typically show a drop in cognitive performance.

Microglia levels returned to normal within two days after the treatment was stopped, and there was no sign of any impairment in surgical wound healing as a result of the intervention.

https://www.eurekalert.org/pub_releases/2017-04/uoc--cda040517.php

Delirium in older patients after surgery linked to long-term cognitive decline

A 3-year study looking at short-term and long-term cognitive decline in older patients following a surgery found that those who experienced delirium after the surgery showed significantly greater decline than those who didn’t suffer such post-surgical confusion.

The study involved 560 patients (70+), of whom 134 experienced delirium. Both groups showed a significant cognitive decline at one month, followed by a return to their previous level of cognitive function at two months and then a gradual decline for the next 34 months. However, the rate of decline over the three year follow-up was not significant for those who hadn’t experienced delirium.

Those who suffered delirium also had significantly lower cognitive function before surgery.

The odd finding that even the delirium group recovered their cognitive function at two months, before once again declining, suggests that something about the delirium triggers a cascade of events which leads to progressive, long-lasting effects.

http://www.eurekalert.org/pub_releases/2016-07/hsif-dio071416.php

Who’s more likely to develop delirium after surgery?

Delirium after surgery can lead to long-term cognitive decline in older adults — but not always. So what makes the difference?

A preliminary study involving 126 older adults suggests the answer lies in their cognitive function before surgery. Their global cognition score explained the most variation, with other significant factors including: IQCODE score, cognitive independent activities of daily living impairment, living alone, cerebrovascular disease, Charlson comorbidity index score, and exhaustion level. Taken together, these factors explained 32% of the variation in people’s outcome.

Delirium, an acute state of confusion, is a common condition affecting up to 50% of hospitalized older adults.

https://www.eurekalert.org/pub_releases/2017-03/hsif-plc031417.php

Certain leisure activities may reduce post-surgical delirium among older adults

A study of 142 older adults who underwent elective surgery found that greater participation in cognitive activities was linked with a lower incidence and lower severity of delirium.

Nearly a third of the patients (average age 71) developed post-operative delirium. Those who did had participated in fewer leisure activities before surgery compared with people who didn't experience delirium.

Out of all the activities, reading books, using email, and playing computer games reduced the risk of delirium. Playing computer games and singing were the only two activities that predicted lower severity of delirium.

The protection afforded was dose-dependent, with each additional leisure activity reducing post-operative delirium by 8%.

http://www.eurekalert.org/pub_releases/2016-06/ags-cla062116.php

http://www.eurekalert.org/pub_releases/2016-06/w-crm062216.php

Reference: 

[4304] Feng X, Valdearcos M, Uchida Y, Lutrin D, Maze M, Koliwad SK. Microglia mediate postoperative hippocampal inflammation and cognitive decline in mice. JCI Insight [Internet]. 2017 ;2(7). Available from: https://insight.jci.org/articles/view/91229

[4222] Inouye SK, Marcantonio ER, Kosar CM, Tommet D, Schmitt EM, Travison TG, Saczynski JS, Ngo LH, Alsop DC, Jones RN. The short-term and long-term relationship between delirium and cognitive trajectory in older surgical patients. Alzheimer's & Dementia: The Journal of the Alzheimer's Association [Internet]. 2016 ;12(7):766 - 775. Available from: http://www.alzheimersanddementia.com/article/S1552-5260(16)30183-2/abstract

[4248] Devore EE, Fong TG, Marcantonio ER, Schmitt EM, Travison TG, Jones RN, Inouye SK. Prediction of Long-term Cognitive Decline Following Postoperative Delirium in Older Adults. The Journals of Gerontology: Series A [Internet]. Submitted . Available from: https://academic.oup.com/biomedgerontology/article-abstract/doi/10.1093/gerona/glx030/3065586/Prediction-of-Long-term-Cognitive-Decline

[4223] Tow A, Holtzer R, Wang C, Sharan A, Kim SJin, Gladstein A, Blum Y, Verghese J. Cognitive Reserve and Postoperative Delirium in Older Adults. Journal of the American Geriatrics Society [Internet]. 2016 ;64(6):1341 - 1346. Available from: http://onlinelibrary.wiley.com/doi/10.1111/jgs.14130/abstract

Greater muscle strength = better cognitive function

  • While handgrip strength has been linked to dementia risk in the elderly, a new study indicates that less impaired or fragile older adults need upper and lower body strength tests — but that these, too, are correlated with cognitive function.

A Finnish study involving 338 older adults (average age 66) has found that greater muscle strength is associated with better cognitive function.

Muscle strength was measured utilising handgrip strength, three lower body exercises such as leg extension, leg flexion and leg press and two upper body exercises such as chest press and seated row.

Handgrip strength, easy to measure, has been widely used as a measure of muscle strength, and has been associated with dementia risk among the very old. However, in this study, handgrip strength on its own showed no association with cognitive function. But both upper body strength and lower body strength were independently associated with cognitive function.

It may be that handgrip strength is only useful for older, more cognitively impaired adults.

These are gender-specific associations — muscle strength was significantly greater in men, but there was no difference in cognitive performance between men and women.

The finding is supported by previous research that found a link between walking speed and cognition in older adults, and by a 2015 study that found a striking correlation between leg power and cognition.

This 10-year British study involved 324 older female twins (average age 55). Both the degree of cognitive decline over the ten year period, and the amount of gray matter, was significantly correlated with high muscle fitness (measured by leg extension muscle power). The correlation was greater than for any other lifestyle factor tested

https://www.eurekalert.org/pub_releases/2017-06/uoef-gms062617.php

Reference: 

[4275] Pentikäinen H, Savonen K, Komulainen P, Kiviniemi V, Paajanen T, Kivipelto M, Soininen H, Rauramaa R. Muscle strength and cognition in ageing men and women: The DR's EXTRA study. European Geriatric Medicine [Internet]. 2017 ;8(3):275 - 277. Available from: http://www.sciencedirect.com/science/article/pii/S1878764917300712

[4076] Steves CJ, Mehta MM, Jackson SHD, Spector TD. Kicking Back Cognitive Ageing: Leg Power Predicts Cognitive Ageing after Ten Years in Older Female Twins. Gerontology [Internet]. 2015 . Available from: http://www.karger.com/?doi=10.1159/000441029

Rapid blood pressure drops in middle age linked to dementia in old age

  • A large study indicates that an inclination to dizziness on standing up is associated with a greater risk of developing cognitive impairment and dementia decades later.

Data from over 11,500 participants in the Atherosclerosis Risk in Communities (ARIC) cohort has found evidence that orthostatic hypotension in middle age may increase the risk of cognitive impairment and dementia 20 years later.

Orthostatic hypotension is the name for the experience of dizziness or light-headedness on standing up. Previous research has suggested an association between orthostatic hypotension and cognitive decline in older adults.

In this study, participants aged 45-64 were tested for orthostatic hypotension in 1987. Those with it (703, around 6%) were 40% more likely to develop dementia in the next 20 years. They also had some 15% more cognitive decline.

Orthostatic hypotension was defined as a drop of 20 mmHg or more in systolic blood pressure or 10 mmHg or more in diastolic blood pressure, when the individual stood up after 20 minutes lying down.

More work is needed to understand the reason for the association.

https://www.eurekalert.org/pub_releases/2017-03/jhub-rbp030817.php

Rawlings, Andreea. 2017. Orthostatic Hypotension is Associated with 20-year Cognitive Decline and Incident Dementia: The Atherosclerosis Risk in Communities (ARIC) Study. Presented March 10 at the American Heart Association's EPI|LIFESTYLE 2017 Scientific Sessions in Portland, Oregon.

Both aerobic exercise & strength training improves older brains

  • A review of research has confirmed the benefits of at least moderate exercise to fight age-related cognitive decline, with different benefits for aerobic exercise and strength training.

A review of 39 studies investigating the effect of exercise on cognition in older adults (50+) confirms that physical exercise does indeed improve cognitive function in the over 50s, regardless of their cognitive status. Aerobic exercise, resistance training, multicomponent training and tai chi, all had significant effects. However, exercise sessions needed to be at least 45  minutes and moderate intensity. Because aerobic exercise and resistance training had different effects (aerobic exercise helped overall cognition, while resistance training was particularly beneficial for executive function and working memory), it’s recommended that an exercise program include both.

https://medicalxpress.com/news/2017-04-aerobic-resistance-combo-boost-brain.html

Reference: 

[4272] Northey JMichael, Cherbuin N, Pumpa KLouise, Smee DJane, Rattray B. Exercise interventions for cognitive function in adults older than 50: a systematic review with meta-analysis. Br J Sports Med [Internet]. 2017 :bjsports - 2016-096587. Available from: http://bjsm.bmj.com/content/early/2017/03/30/bjsports-2016-096587