A combination of exercise, controlling blood pressure and some form of brain training may reduce mental decline in old age and reduce the risk of Alzheimer's-type dementia, US experts have concluded.
A new report released by the National Academies of Sciences, Engineering, and Medicine states there is "encouraging" evidence, although inconclusive, to support these three interventions for brain health.
"The evidence is strong enough to suggest the public should at least have access to these results to help inform their decisions about how they can invest their time and resources to maintain brain health with ageing," Alan Leshner, chair of the committee and CEO emeritus of the American Association for the Advancement of Science, said.
Additional research is needed to understand and analyse their effectiveness, the reported noted.
An earlier systematic review published in 2010 by the Agency for Healthcare Research and Quality (AHRQ) had concluded that there was insufficient evidence to make recommendations about any interventions to prevent cognitive decline and dementia.
Since then, the understanding of dementia has advanced.
Based on all the available evidence, the NASEM report concluded that three classes of interventions were supported by "encouraging but inconclusive" evidence.
These interventions are:
* Cognitive training: includes programs aimed at enhancing reasoning and problem solving, memory, and speed of processing - to delay or slow age-related cognitive decline. May or may not be computer-based.
* Blood pressure management for people with hypertension: particularly during midlife - generally ages 35 to 65 years - to delay, and slow clinical Alzheimer's-type dementia.
* Increased physical activity: to delay or slow age-related cognitive decline.
Maree McCabe, Alzheimer's Australia chief executive officer, says managing vascular health is critical for brain health.
"We know what's good for your heart is good for your brain and having a healthy vascular system certainly reduces the risk of vascular dementia," Ms McCabe.
Exercise and keeping the brain active - learning new things and remaining engaged in enjoyable activities - are all part of the risk reduction program that Alzheimer's Australia runs called Your Brain Matters.
Ms McCabe says there is also evidence that has shown that exercise can increase the volume of the hippocampus, the part of the brain where Alzheimer's disease starts.
"If you've got more volume in that area then people if they get Alzheimer's disease will be slower to show clinical symptoms because there is more volume that the disease has got to get through," Ms McCabe told AAP.
Ms McCabe says the evidence is there and people should not wait to implement these simple lifestyle measures.
"If we could just reduce the incidence of dementia by just five per cent per year we would reduce the number of people who get it by 24 per cent and that would save the economy $120 billion dollars by 2056, not to mention ensure people have much happier and healthier lifestyles," she said.
