Sao Paulo: Regular physical exercise, such as resistance training, can help to prevent Alzheimer's disease or postpone the onset of symptoms, and it is a simple and inexpensive therapy for Alzheimer's patients.
This is the conclusion of a paper published in Frontiers in Neuroscience by Brazilian researchers from the Federal University of S. Paulo (UNIFESP) and the University of S. Paulo (USP).
Although most Alzheimer's patients and older individuals are unlikely to be able to conduct long daily runs or other high-intensity aerobic workouts, these activities are the subject of most scientific investigations on the disease. Resistance exercise is recommended by the World Health Organisation (WHO) as the greatest way to train balance, improve posture, and reduce falls.
Resistance training involves contracting particular muscles against external resistance and is seen as a vital technique for increasing muscle mass, strength, and bone density, as well as improving overall body composition, functional ability, and balance. It also aids in the prevention or treatment of sarcopenia (muscle atrophy), making daily chores simpler to complete.
To observe the neuroprotective effects of this practice, researchers in UNIFESP's Departments of Physiology and Psychobiology, and the Department of Biochemistry at USP's Institute of Chemistry (IQ-USP), conducted experiments involving transgenic mice with a mutation responsible for a buildup of beta-amyloid plaques in the brain. The protein accumulates in the central nervous system, impairs synaptic connections and damages neurons, all of which are features of Alzheimer's disease.
At the end of a four-week period of training, blood samples were taken to measure plasma levels of corticosterone, the hormone in mice equivalent to cortisol in humans; rising levels in response to stress heighten the risk of developing Alzheimer's. Levels of the hormone were normal (equal to those found in the control group comprising animals without the mutation) in the exercise-trained mice, and analysis of their brain tissue showed a decrease in formation of beta-amyloid plaques.
"This confirms that physical activity can reverse neuropathological alterations that cause clinical symptoms of the disease," said Henrique Correia Campos, first author of the article.
"We also observed the animals' behavior to assess their anxiety in the open field test [which measures avoidance of the central area of a box, the most stress-inducing area] and found that resistance exercise reduced hyperlocomotion to similar levels to the controls among mice with the phenotype associated with Alzheimer's," said Deidiane Elisa Ribeiro, co-first author of the article and a researcher at IQ-USP's Neuroscience Laboratory. Agitation, restlessness and wandering are frequent early symptoms of Alzheimer's and other types of dementia.
"Resistance exercise is increasingly proving an effective strategy to avoid the appearance of symptoms of sporadic Alzheimer's [not directly caused by a single inherited genetic mutation], which is multifactorial and may be associated with aging, or to delay their emergence in familial Alzheimer's. The main possible reason for this effectiveness is the anti-inflammatory action of resistance exercise," said Beatriz Monteiro Longo, last author of the article and a professor of neurophysiology at UNIFESP.
The animal model study was based on a review of the literature published in Frontiers in Neuroscience, where the same group at UNIFESP compiled clinical evidence that the benefits of resistance exercise include positive effects on cognitive dysfunction, memory deficit and behavioral issues in Alzheimer's patients, concluding that it can be an affordable alternative or 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 only affect the patient. The entire family is affected, especially in low-income households," 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 policies. Imagine the cost savings if the appearance of symptoms in older patients is deferred by ten years." (ANI)
