Summary: Regular exercise can help reduce episodic memory decline in older adults.
Source: university of pittsburgh
We all know that exercise is good for us, but that still leaves a lot of questions. How much exercise? Who benefits more? And when in our lives?
New research led by psychologists at the University of Pittsburgh pools data from dozens of studies to answer these questions, showing that older adults can prevent the decline of a certain type of memory by exercising regularly.
“Everyone always asks, ‘How much should I exercise? What is the bare minimum to see an improvement?’ said lead author Sarah Aghjayan, Ph.D. in Clinical and Biological Health Psychology. student at the Kenneth P. Dietrich School of Arts and Sciences. “Based on our study, it appears that exercising about three times a week for at least four months is what you need to reap the episodic memory benefits.”
Episodic memory is the type that deals with events that happened to you in the past. It is also one of the first to decline with age. “Usually I like to talk about the first time he got behind the wheel of a car,” Aghjayan said. “So you remember where you were, how old you were, who was in the passenger seat explaining things to you, that feeling of excitement.”
Heart-pumping exercise has shown promise in boosting brain health, and experiments in mice show it improves memory, but studies looking at the same link in humans have been conflicting.
Seeking clarity in the murky waters of the scientific literature, the team painstakingly analyzed 1,279 studies, eventually narrowing them down to just 36 that met specific criteria. They then used specialized software and not a few Excel spreadsheets to transform the data information into a form where the different studies could be directly compared.
That work paid off when they found that pooling those 36 studies was enough to show that for older adults, exercise can benefit their memory.
The team, including Aghjayan’s adviser, Kirk Erickson, in the Department of Psychology and other researchers from Pitt, Carnegie Mellon University and the University of Iowa, published their results in the journal. Communications Medicine on February 17.
Previous analyzes looking at connections between exercise and memory didn’t find one, but Aghjayan and his team took several extra steps to give themselves the best chance of finding a link, if one existed. They limited their search to particular groups and age brackets, as well as a specific type of rigorous experimental setup. Another key was specifically targeting episodic memory, which is supported by a part of the brain known to benefit from exercise.
“When we combine and merge all of this data, it allows us to screen nearly 3,000 participants,” Aghjayan said. “Each individual study is very important – they all contribute to science in significant ways.” However, individual studies may fail to find patterns that actually exist due to a lack of resources to run a large enough experiment. Individual studies failed to find a link between exercise and memory; it was necessary to look at the entire body of research to focus on the pattern.
With that much larger group of participants, the team was able to show a link between exercise and episodic memory, but they were also able to start answering more specific questions about who benefits and how.
“We found that there were greater improvements in memory among 55-68 year olds compared to 69-85 year olds, so intervening earlier is better,” Aghjayan said. The team also found the greatest effects of exercise in those who had not yet experienced any cognitive decline, and in studies in which participants exercised consistently several times a week.
There are still questions to be answered. The team’s analysis couldn’t answer how exercise intensity affects memory benefits, and there is much to learn about the mechanism behind the link. But the public health implications are clear: Exercise is an affordable way older adults can stave off memory decline, benefiting themselves, their caregivers and the health care system, Aghjayan said.
“You just need a good pair of walking shoes, and you can go out and move your body.”
Co-authors on the papers include Kirk Erickson, Chaeryon Kang, Xueping Zhou, Chelsea Stillman, Shannon Donofry, Thomas W Kamarck, Anna L Marsland, and Scott H Fraundorf of the University of Pittsburgh, Themistokles Bournias of Carnegie Mellon University, and Michelle Voss of the University of Iowa.
About this exercise, research news on memory and aging
Author: press office
Source: university of pittsburgh
Contact: Press Office – University of Pittsburgh
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original research: Open access.
“Aerobic exercise improves episodic memory in late adulthood: a systematic review and meta-analysis.” by Sarah Aghjayan et al. Communications Medicine
Summary
See also
Aerobic exercise improves episodic memory in late adulthood: a systematic review and meta-analysis.
Background
Aerobic exercise remains one of the most promising approaches for improving cognitive function in late adulthood, but its potential positive effects on episodic memory remain poorly understood and a subject of intense debate. Previous meta-analyses reported minimal improvements in episodic memory after aerobic exercise, but were limited by restrictive inclusion criteria and infrequent examination of exercise parameters.
Methods
We conducted a meta-analysis of randomized controlled trials to determine whether aerobic exercise influences episodic memory in late adulthood (SUBWAY= 70.82 years) and examine possible moderators. Thirty-six studies met the inclusion criteria and represent data from 2750 participants.
Results
Here we show that aerobic exercise interventions are effective in improving episodic memory (Hedges’gram= 0.28; P= 0.002). Subgroup analyzes revealed a moderating effect of age (P= 0.027), with a significant effect for studies with a mean age between 55-68 but not 69-85. Mixed-effects analyzes demonstrated a positive effect on episodic memory between studies with a high percentage of women (65–100%), participants with normal cognition, studies reporting intensity, studies with a non-physical activity control group aerobic or non-contact and studies prescribing >3900 total minutes of activity (range 540-8190 min).
Conclusions
Aerobic exercise positively influences episodic memory among adults ≥55 years without dementia, with greater effects observed across various samples and intervention characteristics; the clearest moderator is age. These results could have far-reaching clinical and public health relevance, highlighting aerobic exercise as an accessible non-pharmaceutical intervention to improve episodic memory in late adulthood.
