Weight training may protect older people's brains from developing dementia by improving memory and protecting areas of the brain associated with Alzheimer's disease , a Brazilian study has found .
The study included 44 participants with mild cognitive impairment. After six months, those who participated in strength training showed improvements in memory and brain structure, while those who did not participate in strength training showed a decline in the assessed parameters.
Weight training has many benefits, including increased strength and muscle mass, reduced body fat, and improved overall well-being and mental health. A recent study conducted by the State University of Campinas (UNICAMP) in São Paulo, Brazil , highlights another key advantage: it helps protect the brains of older adults from dementia. The findings were published in the journal Gerontology .
The study involved 44 participants with mild cognitive impairment, a condition between normal aging and Alzheimer's disease. At this stage, cognitive decline is more severe than expected for age, indicating a higher risk of dementia. The results showed that strength training not only improves memory, but also leads to changes in brain structure.
Effects on brain health
After six months of twice-weekly weight training, participants were protected from atrophy of the hippocampus and precuneus (brain regions associated with Alzheimer's disease), and parameters reflecting neuronal health (white matter integrity) improved.
"We already knew that there are physical improvements. There are cognitive improvements, too, but we wanted to see the impact of weight training on the brains of older adults with mild cognitive impairment. Fortunately, this study shows that weight training is a powerful ally in the fight against dementia, even for those who are already at high risk," says Isadora Ribeiro, a FAPESP doctoral scholarship recipient at the University of Campo Medical School (FCM) and the paper's first author.
The work, carried out within the framework of the Brazilian Institute for Neuroscience and Neurotechnology (BRAINN), a Research, Innovation and Dissemination Center (RIDC) of the São Paulo Research Foundation (FAPESP), Brazil, shows for the first time how white matter integrity changes after weight training in patients with mild cognitive impairment.
"In addition to neuropsychological tests, we performed MRI scans at the beginning and end of the study. These results are very important because they indicate the need to include more physical educators in public health systems at the primary health care level, as increased muscle strength is associated with a reduced risk of dementia. This is a less complex and cheaper treatment that could protect people from serious illnesses," commented Marcio Balthazar, BRAINN researcher and study supervisor.
"For example, new anti-amyloid drugs approved in the United States for the treatment of patients with dementia and mild cognitive impairment cost about $30,000 per year. This is a very high cost. These non-drug measures, as we have shown with weight training, are effective not only in preventing dementia, but also in improving mild cognitive impairment," the researchers added.
Study design and results
Study participants were divided into two groups: half performed resistance training twice a week at a moderate to vigorous intensity with gradually increasing loads; the other half did not perform any exercise during the study and served as the so-called control group.
In analyses conducted at the end of the intervention, volunteers who had weight training performed better on measures of verbal episodic memory, had improved neuronal integrity and were protected from atrophy in areas associated with Alzheimer's disease, while brain parameters in the control group worsened.
"A characteristic of patients with mild cognitive impairment is that they have a reduction in the volume of some brain regions associated with the development of Alzheimer's disease. But in the group that performed strength training, there was no atrophy of the right hippocampus and the precuneus. This result demonstrates the importance of regular strength training, especially for older people," emphasizes Ribeiro.
The researchers believe that longer training sessions could lead to more positive results than what is reported in the study. "All subjects in the bodybuilding group showed improvements in memory and brain anatomy. However, five of them were not clinically diagnosed with mild cognitive impairment at the end of the study, such was their progress. This leads us to imagine that a longer training session, for example lasting three years, could reverse this diagnosis or slow the progression of any type of dementia. This is certainly something to look forward to and something that needs to be studied in the future," Ribeiro believes.
Researchers say weight training may protect the brain from dementia in two ways: by stimulating the production of nerve growth factor , a protein that is essential for the growth, maintenance and survival of neurons , and by promoting systemic anti-inflammation.
"It is well known that any physical exercise, whether it is weight training or aerobic exercise, increases the levels of chemicals involved in brain cell growth. It also mobilizes anti-inflammatory T cells . This is key. After all, the more pro-inflammatory proteins are released in the body, the greater the likelihood of dementia, which accelerates neurodegenerative processes and forms dysfunctional proteins that ultimately kill neurons," explains Balthazar.
To assess these questions, the researchers measured the volunteers' levels of irisin and brain-derived neurotrophic factor (BDNF), two substances whose synthesis is stimulated by muscle contraction and has been implicated in neuroprotection and synaptic plasticity. The results are currently being analyzed.
"This is a continuation of this research, where we will try to better understand the relationship between these factors and changes in brain anatomy. We think that it is a combination of anti-inflammatory and neuroprotective factors that are causing these changes," Ribeiro predicts.