Resistance exercise, such as bodybuilding, can prevent or at least delay the onset of symptoms related to Alzheimer's, serving as an easily accessible therapy for patients with the disease. This discovery was published by scientists from the Federal University of São Paulo (Unifesp) and the University of São Paulo (USP) in the journal Frontiers in Neuroscience.
Although the elderly and patients with dementia may have difficulty engaging in high-intensity aerobic exercise, such as running, these activities have been the focus of most scientific research on Alzheimer's. The World Health Organization (WHO), however, suggests resistance exercise as the best option to maintain balance and posture, preventing falls.
Characterized by contractions of specific muscles against external resistance, resistance exercise is a key strategy for increasing muscle mass, strength and bone density, as well as improving body composition, functional capacity and balance. It also helps to avoid or reduce the sarcopenia (muscle weakness), facilitating daily activities.
experiments with mice
To study the neuroprotective effects of this practice, researchers from the departments of Physiology and Psychobiology at Unifesp and Biochemistry at IQ-USP (Institute of Chemistry at the University of São Paulo) carried out experiments with transgenic mice carrying a mutation that causes accumulation of beta-plaques. amyloid in the brain. These proteins accumulate in the central nervous system, impair the transmission of synapses and cause damage to neurons, being considered hallmarks of Alzheimer's disease.
During the study, funded by FAPESP, the animals were trained to climb a 110 cm high ladder, with an 80º inclination and steps spaced every 2 cm. A progressive load of 75%, 90% and 100% of the mice's weight was attached to their tails. This exercise simulates what can be done on gym equipment for this purpose.
After four weeks of training, blood samples from the mice were collected and the levels of corticosterone (hormone equivalent to human cortisol, whose increase is related to stress and, consequently, to a higher risk of developing Alzheimer's) were measured. The analyzes indicated that the level of this hormone in the trained animals was normalized, equaling that of the control group, composed of healthy mice (without the mutation). Brain analysis also showed a reduction in the formation of beta-amyloid plaques.
“These results confirm that physical activity can reverse the neuropathological changes responsible for the clinical symptoms of the disease”, says Henrique Correia Campos, co-author of the study. The scientists also observed the behavior of mice in relation to anxiety and found that resistance exercise reduced hyperlocomotion in animals with the phenotype associated with Alzheimer's, matching the control group.
“Resisted physical exercise is increasingly showing itself as an effective strategy to prevent the onset of sporadic Alzheimer's symptoms, which is multifactorial and may be related to aging, or to delay them in cases of the familial form of the disease”, highlights Beatriz Monteiro Longo, professor of neurophysiology at Unifesp and coordinator of the work. “The main possible explanation for this is its anti-inflammatory action.”
Minimize the deficit in cognitive functions
The animal model study was based on a research review published by the same group from Unifesp in Frontiers in Neuroscience, which provides clinical evidence that resistance physical exercises are really beneficial to minimize the deficit in cognitive and behavioral functions caused by Alzheimer's and can be proposed as an accessible alternative therapy.
“In addition to affecting the patient, Alzheimer's disease also impacts the entire family, especially if it is low-income”, comments Caroline Vieira Azevedo, author of the review article. “The two works provide information that can be used to stimulate the creation of public policies, such as the reduction of expenses by delaying the appearance of symptoms in elderly patients by ten years.” Researchers from UFRN (Federal University of Rio Grande do Norte) and Ufop (Federal University of Ouro Preto) also participated in the investigation.