There’s a growing body of evidence that links muscle makeup to cognitive function, particularly in that it may be key to prolonging brain health as you age.
Scientists believe that even a moderate amount of resistance training – which sees specific muscles contract when worked against an external force – can offset cognitive decline and delay the symptoms of age-related dementia and Alzheimer’s disease.
The latest study from scientists at the Federal University of São Paulo (UNIFESP) and the University of São Paulo (USP) has shown how resistance training not only staves off the type of Alzheimer’s disease most associated with aging, but has trickle-down benefits like maintaining bone density and preventing muscle atrophy.
“Resistance exercise is increasingly proving an effective strategy to avoid the appearance of symptoms of sporadic Alzheimer’s,” said Beatriz Monteiro Longo, last author of the study and a professor of neurophysiology at UNIFESP. “The main possible reason for this effectiveness is the anti-inflammatory action of resistance exercise.”
Sporadic Alzheimer’s is not caused by an inherited gene mutation but is instead associated with aging, and is also the most common form of the disease.
The anti-inflammatory effect of resistance training is well known. As is the link between inflammation and cognitive decline, particularly among older adults.
To demonstrate the benefits of resistance training in this study, scientists attached various weights to healthy mice and those with a mutation that made them predisposed to a build-up of beta-amyloid plaques in the brain.
After four weeks of training, the mice with cognitive mutations that had the heaviest weights attached while undergoing physical activity were found to have normal levels of corticosterone – the same as the healthy animals – and fewer beta-amyloid plaques in their brain tissue.
Corticosterone is the mouse equivalent of the cortisol hormone found in humans. Elevated levels in response to stress increase the risk of developing Alzheimer’s and has been shown to have negative impacts on overall cognitive function in middle age.
“This confirms that physical activity can reverse neuropathological alterations that cause clinical symptoms of the disease,” said Henrique Correia Campos, first author of the study.
The researchers also noted a difference in how the animals navigated stressful environments, with the 'biggest lifters' showing less agitation, restlessness and wandering behaviors – common early symptoms of Alzheimer’s.
Weight training may be a better option for those with limited mobility, such as those with other conditions that put high-intensity exercise out of reach and with dementia symptoms that make it difficult to perform complex coordinated physical activities. It’s adaptable to fitness and strength levels, and studies show even a little resistance has big benefits.
What’s more, resistance training is an inexpensive therapy that’s accessible to most people, regardless of access to medical intervention.
“Alzheimer’s doesn’t only affect the patient. The entire family is affected, especially in low-income households," said Caroline Vieira Azevedo, a graduate student at UNIFESP. “Imagine the cost savings if the appearance of symptoms in older patients is deferred by 10 years.”