- Regular exercise is a known modifiable risk factor for dementia.
- A new study suggests that weight training may help protect the brains of older adults from dementia.
- The benefits of weight training were also observed in those already showing signs of mild cognitive impairment.
As of 2021, researchers estimate that about
Past studies show there are a number of modifiable lifestyle factors that may help reduce a person’s risk of developing dementia, such as regular exercise both earlier in life and at an older age.
“Dementia affects millions of people worldwide and has a major impact not only on individuals, but also on families and Healthcare systems,” Isadora Ribeiro, PhD, a São Paulo Research Foundation (FAPESP) doctoral fellowship recipient at the School of Medical Sciences (FCM) at the State University of Campinas (UNICAMP) in Brazil told Medical News Today.
“Since there is still no cure [for dementia], finding ways to delay or prevent its onset — especially through accessible, non-pharmacological strategies — is essential to improve quality of life in aging.”
— Isadora Ribeiro, PhD
Ribeiro is the first author of a new study recently published in the journal GeroScience reports that weight training may help protect the brains of older adults from dementia, including those already showing signs of mild cognitive impairment.
For this study, researchers recruited 44 adults ages 55 or older with a diagnosis of mild cognitive impairment.
Study participants were divided into two groups. The weight training group participated in a resistance exercise program with moderate to high intensity sessions twice a week, with progressive loads, meaning weight or sets were increased as participants’ muscles strengthened. The control group did not exercise for the duration of the study.
“We chose to study resistance training because its primary goal is to increase muscle strength, which is especially important in older adults,” Ribeiro explained.
At the study’s conclusion, Ribeiro and her team found that after six months, participants in the weight training group showed improvement in
Conversely, the control group’s participants showed signs of worsening brain parameters.
“This is an interesting finding because it suggests that weight training may not only help to increase cognition, but also prevent the development of atrophy in regions related to Alzheimer’s disease — potentially delaying progression or even preventing the onset of dementia,” Ribeiro details.
How exercise changes the brain“The fact that we observed changes in white matter integrity indicates that resistance training may directly affect the anatomical structure of neurons, which is essential for efficient communication between brain regions, supporting memory, attention, and overall cognitive function.”
— Isadora Ribeiro, PhD
Scientists also discovered that five participants in the weight training group no longer had a diagnosis of mild cognitive impairment when they reached the end of the study.
“This suggests that weight training may alter the clinical trajectory of individuals with mild cognitive impairment, shifting them from an increased risk of dementia to preserved cognition by the end of the study,” Ribeiro said.
“Even in a small sample, the fact that several participants showed improved cognitive health after the intervention is a hopeful indication of the potential protective effects of this type of exercise,” she said.
“Weight training can reduce inflammation, improve insulin sensitivity, and increase levels of neurotrophic factors like BDNF (brain-derived neurotrophic factor), which support the growth and survival of neurons. It also improves cardiovascular health and cerebral blood flow, all of which are important for maintaining brain function. These physiological changes contribute to reducing key risk factors for dementia, such as obesity, cardiovascular disease, and diabetes. Additionally, physical exercise stimulates the release of
irisin , a hormone associated with neuroprotection and improved brain plasticity.”
— Isadora Ribeiro, PhD
“We plan to explore the molecular mechanisms behind these effects, including
MNT had the opportunity to speak with Gary Small, MD, chair of psychiatry at Hackensack University Medical Center in New Jersey and author of numerous books on cognitive health and aging, including the New York Times best seller The Memory Bible, about this study.
“These findings are consistent with previous research in animals and humans showing that strength training improves cognitive abilities,” Small commented. “Most of the previous studies demonstrating the brain health benefits of physical activity have focused on aerobic exercise, and that body of research has been compelling that regular physical exercise increases the volume of brain regions controlling memory and thinking.”
“The present study demonstrates similar benefits from strength training. Moreover, it is never too late to begin a strength training program — older adults often experience tremendous benefits. In addition to improved stamina and energy, strength training helps older adults in their everyday tasks and may diminish risks of
injuries due to falls .”
— Gary Small, MD
“Further research detailing the amount, cadence, and form of physical exercise that slows, stabilizes, or even reverses age-related cognitive decline will inform the public on how best to keep their bodies and brains functioning well throughout a long life,” Small added.
MNT also talked to David Cutler, MD, a board certified family medicine physician at Providence Saint John’s Health Center in Santa Monica, CA, about this research.
Cutler said he did not find the study’s findings surprising because doctors always recommend patients engage in exercise to help prevent cognitive decline.
“I hadn’t seen any studies specifically looking at resistance training, but that wasn’t a surprise, that it was reinforcing that the things that patients are doing in terms of resistance exercises are most likely helpful,” he continued.
“Anytime people engage in any activity, whether it’s exercise, dietary, supplements, or medications, we want to make sure the benefits exceed the risks. And exercise training, especially for older people, can entail some risk. So these exercises need to be guided by someone to make sure patients don’t incur injuries when they’re doing them,” he underscored.
“I think we want to see (this study) in larger numbers, in both men and women, in people with other medical conditions, to make sure that we’re not putting people at risk when they’re undergoing these types of exercise regimens,” Cutler added.
