A team of Brazilian researchers affiliated with the Federal University of São Paulo (UNIFESP) and the University of São Paulo (USP) has shown in recent research that regular exercise, such as resistance training, can prevent Alzheimer’s disease, or at least delay the onset of symptoms, and serves as a simple and inexpensive therapy for sufferers of Alzheimers.
The results of the study were published in the scientific journal Frontiers in Neuroscience.
Resistance training: here are the health benefits
While older people and dementia patients are unlikely to be able to go for long daily runs or perform other high-intensity aerobic exercise, these activities are the focus of most scientific studies on Alzheimer’s disease. The World Health Organization (WHO) recommends resistance training as the best option for training balance, improving posture and preventing falls.
Resistance training involves contracting specific muscles against external resistance and is considered an essential strategy for increasing muscle mass, strength and bone density, and for improving overall body composition, functional capacity and balance. It also helps prevent or mitigate sarcopenia (muscle wasting) by making it easier to perform daily activities.
To observe the neuroprotective effects of this practice, researchers from the Departments of Physiology and Psychobiology of UNIFESP and the Department of Biochemistry of the USP Institute of Chemistry (IQ-USP), conducted experiments on transgenic mice with a mutation responsible for a buildup of beta-amyloid plaques in the brain. The protein builds up in the central nervous system, impairs synaptic connections and damages neurons, all hallmarks of Alzheimer’s disease.
During the study, mice were trained to climb a 110 cm ladder with an 80° slope and 2 cm between rungs. Loads corresponding to 75%, 90% and 100% of their body weight were attached to their tails. The experiment mimicked some types of resistance training undertaken by humans in fitness centers.
At the end of a four-week training period, blood samples were taken to measure plasma levels of corticosterone, the hormone in mice equivalent to cortisol in humans; increased levels in response to stress increase the risk of developing Alzheimer’s.
Levels of the hormone were normal (same as those found in the control group including animals without the mutation) in the resistance-trained mice, and analysis of their brain tissue showed a decrease in the formation of amyloid-beta plaques. .
“This confirms that physical activity can reverse the neuropathological changes that cause the clinical symptoms of the disease,” said Henrique Correia Campos, first author of the paper.
We also observed the animals’ behavior to assess their anxiety in the open field test [che misura l’evitamento dell’area centrale di una scatola, l’area che induce più stress] and we found that resistance exercise reduced hyperlocomotion to levels similar to controls among mice with the Alzheimer’s-associated phenotype,” said Deidiane Elisa Ribeiro, co-author of the paper and researcher at the Neuroscience Laboratory of the University of California. ‘IQ-USP. Restlessness, restlessness, and wandering are frequent early symptoms of Alzheimer’s and other types of dementia.
“Resistance training is increasingly proving to be an effective strategy to avoid the onset of symptoms of sporadic Alzheimer’s [non direttamente causato da una singola mutazione genetica ereditaria], which is multifactorial and may be associated with aging, or to delay its onset in familial Alzheimer’s. The main possible reason for this efficacy is the anti-inflammatory action of resistance exercise,” said Beatriz Monteiro Longo, final author of the article and professor of neurophysiology at UNIFESP.
The animal model study was based on a literature review published on Frontiers in Neuroscience where the same group from UNIFESP collected clinical evidence that the benefits of resistance training include positive effects on cognitive dysfunction, memory impairment and behavioral problems in Alzheimer’s patients, concluding that it may be a cost-effective alternative or a adjuvant therapy.
Researchers from the Federal University of Rio Grande do Norte (UFRN) and the Federal University of Ouro Preto (UFOP) in Brazil also took part in the study. “Alzheimer’s doesn’t just affect the patient. The whole family is affected, especially in low-income families,” said Caroline Vieira Azevedo, first author of the review article and a graduate student at UNIFESP.
“Both articles offer information that can be used to stimulate the creation of public policy. Imagine the cost savings if the onset of symptoms in older patients is deferred for ten years.”
Sarcopenia is the decline in skeletal muscle mass with age, leading to loss of muscle strength (to move objects, shake hands, etc.) and performance (to walk and perform other routine movements effectively). It involves chronic inflammation and is associated with cognitive impairment, heart disease, and respiratory disorders. In short, it affects quality of life, reducing independence and increasing the risk of injury, falls and even death.
Sarcopenia affects 15% of adults over the age of 60 and 46% of those over the age of 80. Sleep disturbances are also common in these age groups. The aging process and sleep disturbances are directly associated with increased inflammation.
The links between these factors were the focus of a study conducted in Brazil by researchers from the Federal University of São Paulo (UNIFESP) and the University of Viçosa (UFV), Minas Gerais, as reported in an article published in the International Journal of Environmental Research and Public Health.
Previous experiments by the group have indicated a correlation between sleep deprivation and muscle wasting in rats. “Our studies in animal models have shown that sleep debt causes muscle atrophy and impairs muscle recovery, in a process closely resembling sarcopenia involving type 2, or ‘fast-twitch’, muscle fibers,” he said. said Helton de Sá Souza, first author of the study and professor in the Department of Physical Education of the UFV.
“Our group also observed poorer sleep in older people with sarcopenia than in older people without this diagnosis.”
Based on this knowledge, the team set out to see if the results for humans would be similar to those for rats and how resistance training could help address the problem by synchronizing biological rhythms, extending the time total sleep, reducing sleep fragmentation, building muscle mass and strength, and assisting immune system activity by reducing inflammation.
In the study, 14 adults with an average age of about 75 and diagnosed with sarcopenia performed a resistance training exercise program three times a week for three months.
The program consisted of eight exercises for large muscle groups alternating upper and lower limbs (chest, back, shoulders, arms – biceps and triceps – and front and back of thighs). It started out at a moderate intensity, building up to 80 percent of max strength over the last eight weeks.
Fourteen other volunteers of the same age group and also diagnosed with sarcopenia attended only weekly meetings with different healthcare professionals to increase their knowledge of recommended lifestyle changes to combat the disease. All 28 participants were supported during the study by physical education professionals, physiotherapists, nutritionists and doctors.
They also underwent a variety of tests, including blood tests to evaluate hormonal, metabolic and inflammatory markers, as well as body composition analyses, physical function assessments and sleep analyses. The results were obtained before the interventions began and after their conclusion so that comparisons could be made.
According to Souza, the main diagnostic marker of age-related sarcopenia is loss of skeletal muscle strength or performance associated with loss of muscle mass. “Muscle loss is inherent in aging, but it becomes a problem in combination with reduced function [debolezza] or performance [agilità, equilibrio, ecc.]”, he has declared. “If one of these parameters [forza o prestazioni] can be improved, then we will be able to reduce sarcopenia.”
In the study, all muscle strength metrics improved in participants undergoing the resistance training program, including hand grip and leg torque measured with a dynamometer.
“We also observed an improvement in objective and subjective sleep quality with the aid of polysomnography and a reduction in inflammation [basata su parametri valutati mediante analisi del sangue]”, said Vânia D’Almeida, last author of the article, professor at the UNIFESP Department of Psychobiology.
“Elderly people with sarcopenia tend to sleep poorly and the study showed that physical training eased their sarcopenia and improved their sleep. This could be due to an increase in two anti-inflammatory cytokines [IL1ra e IL10] associated with muscle metabolism efficiency and possibly with sleep quality,” Souza explained.
More research is needed to clarify how different age and sex groups, with and without sarcopenia, may exhibit specific sleep and muscle responses to potentially anti-inflammatory interventions, such as exercise, the authors conclude.