Dementia, or cognitive decline, affects more than 5 million people in the US and more than 35 million people worldwide. Sadly, no effective drugs to inhibit or significantly delay this disease is currently available or expected anytime soon. Many exercise scientists and neuroscientists are frustrated because a simple and potentially effective treatment is available to anyone but ignored by many doctors and health professionals, both in the U.S. and around the world. Writing in the June 2014 issue of the British Journal of Sports Medicine, the researchers lament:
However, despite a large and consistent pool of evidence generated over the past five decades linking exercise to improved cognitive functions in older adults, there is a reluctance among academics, healthcare practitioners and the public alike to embrace exercise as a prevention and treatment strategy for cognitive decline.
Some of the research has concluded that exercise benefits in relation to cognitive decline are “weak” or have “no strong evidence”. The advocates argue that an abundance of current research has shown something else:
Since 2010, we have additional evidence from RCTs (randomised controlled trials) that exercise, both moderate to vigorous intensity aerobic and resistance training, promotes cognitive and brain plasticity and have gained further insight into underlying mechanisms. Notably, the behavioural and mechanistic outcomes converge and support a cohesive picture.
Other studies have concluded that aerobic exercise resulted in increased hippocampal volume in healthy community dwelling older adults. A similar study demonstrated that aerobic exercise also improved the functional connectivity or temporal coherence of brain regions that are functionally related in a network known to decouple with aging. A wide variety of other randomised controlled trials have reached similar conclusions. Many have found that regular exercise improved executive functions, spatial memory and associative memory with concurring functional plasticity and exercise can alter the structure and function of the brain directly.
The researchers contend that the benefits of exercise can exceed that of pharmaceutical approaches. A regular fitness regimen should be a part of healthy aging for everyone, whether they are at risk for dementia or not:
Exercise significantly reduces the key vascular risk factors ( hypertension, diabetes type II, etc.) for Alzheimer’s disease and vascular dementia—the two most common types of dementia.
The researchers caution that waiting for the inevitable research to come in and be 100% certain, definite and conclusive will be too little too late for many:
Of relevance, it is estimated that if the onset and progression of dementia could be delayed by a mere 1 year, there would be nearly 9.2 million fewer cases in 2050. Given that exercise can be promoted at a population level with relatively low risks and costs, we highly recommend that older adults should be encouraged to engage in regular exercise to boost cognitive function as further research is concurrently conducted, rather than wait until all the intricacies of the relationship between exercise and cognition have been resolved.
Lindsay S Nagamatsu, Leon Flicker, Arthur F Kramer, Michelle W Voss, Kirk I Erickson, Chun Liang Hsu, Teresa Liu-Ambrose, “Exercise is medicine, for the body and the brain” The British Journal of Sports Medicine, June 2014
What is dementia? http://www.alz.org/what-is-dementia.asp
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