Scientists have identified a form of exercise that can help prevent Alzheimer’s disease.
The new study carried out on mice led to the findings that regular resistance training can help prevent or at least delay the onset of symptoms for the age-related neurological condition. It could also lead to affordable therapies for people at risk of the disease.
Although dementia patients are unlikely to go on long daily runs or perform other high-intensity aerobic exercises, researchers, including those form the Federal University of São Paulo in Brazil, said these activities happen to be the focus of most scientific studies on Alzheimer’s.
On the other hand, strength training, which comprises contraction of specific muscles against an external resistance, is seen as the best option to train balance, improve posture and prevent falls.
It has been shown to increase muscle mass, strength and bone density, as well as improve overall balance and muscle loss.
In the new study, published recently in the journal Frontiers in Neuroscience, scientists assessed the ability of resistance training to protect the nervous system.
They conducted experiments involving genetically modified mice carrying a mutation responsible for a buildup of beta-amyloid plaques in the brain – a key hallmark of Alzheimer’s disease. The protein accumulates in the body’s central nervous system, damaging nerves and impairing the connections between them, all of which are features of Alzheimer’s disease.
In the research, scientists trained mice to climb a 110cm ladder with a slope of 80 degrees and 2cm between rungs. Loads corresponding to 75 per cent, 90 per cent and 100 per cent of the mice’s body weight were attached to their tails – mimicking the kinds of resistance training undertaken by humans at gyms.
After four weeks of training this way, blood samples were taken from the mice to measure plasma levels of corticosterone – the mice equivalent of the stress hormone cortisol in humans.
Rising levels of cortisol in response to stress have previously been found to heighten the risk of developing Alzheimer’s.The hormone’s levels were found to be normal in the exercise-trained mice. Analysis of their brain tissue also showed a decrease in the formation of beta-amyloid plaques.
“This confirms that physical activity can reverse neuropathological alterations that cause clinical symptoms of the disease,” study co-author Henrique Correia Campos said in a statement.
The anxiety levels of the mice were also gauged using a test that measures their avoidance of the most stress-inducing area of their box. Scientists found that resistance exercise reduced anxiety-induced hyper movement among mice genetically prone to an Alzheimer’s-like state.
“Resistance exercise is increasingly proving an effective strategy to avoid the appearance of symptoms of sporadic Alzheimer’s, which is multifactorial and may be associated with aging, or to delay their emergence in familial Alzheimer’s,” said Beatriz Monteiro Longo, another author of the study.
Researchers suspect the main possible reason for this effect could be the anti-inflammatory action of resistance exercise. The findings can be used to create cost-effective public policies to reduce the prevalence of Alzheimer’s disease.