Exercise and the prevention of Alzheimer’s disease

 

New research suggests that exercise can play an important role in helping to prevent the development of Alzheimer’s disease.

Words: Helen HawkesExercise and Alzheimers

 

Most Australians have been touched by dementia, whether personally or through the experience of family or friends. And this situation is showing no signs of diminishing.

In fact, according to Alzheimer’s Australia, the number of dementia cases is expected to almost triple by 2050, reaching around 900,000 in this country and more than 100 million worldwide1.

It’s a scary thought, but the good news is that there may be something you can do to minimise your risk of developing the illness as you age. “There is a strong and growing body of evidence showing that physical exercise can reduce the risk of Alzheimer’s disease and other dementias,” says Dr Chris Hatherly, National General Manager of Research at Alzheimer’s Australia.

In a paper published by Alzheimer’s Australia in 20132, researchers Dr Maree Farrow and Dr Kathryn Ellis found that physical activity enhances brain plasticity and the growth and survival of brain cells. Additional brain imaging studies have shown that people who undertake regular, moderate-intensity physical activity – compared with those who are inactive – have increased brain volume in regions that are important for memory, learning and concentration3. People who exercise also have increased connectivity between brain regions and better cognitive function.

Drs Farrow and Ellis explain that the health of blood vessels in the brain is vital for brain function. “Diabetes, high blood pressure, high cholesterol and obesity can damage blood vessels and lead to vascular disease in the brain – a major cause of dementia,” they explain. “Physical activity reduces the risk of these conditions, helps to keep blood vessels healthy and supports the growth of new small blood vessels.”

Supporting their findings, a UK study released in 2014 estimated that physical inactivity accounted for 21.8 percent of the risk of developing Alzheimer’s4.

“Nothing, unfortunately, can guarantee prevention of dementia at this stage,” says Dr Hatherly. “However, we do know that if we could get just 5 percent of Australians who currently do no or very little physical activity to engage in regular exercise, the number of cases of dementia in the future would reduce dramatically – as many as 100,000 fewer cases over the next 36 years.”

And the benefits of physical activity may also extend to those who already have dementia, adds Dr Hatherly. “Evidence is beginning to suggest that regular activity might slow the progression of Alzheimer’s disease and other dementias,” he explains.

“And it can certainly help to manage or prevent other physical and mental health conditions that often co-occur with dementia.”

Exercises for brain health

So, what sort of physical activity should you do and how often? Both Dr Farrow and Dr Ellis say it is not currently possible to provide a formula that is optimal for brain health. However, in a study published in 2013, researchers found that 150 minutes of moderate exercise a week can significantly improve memory performance after just 12 weeks5.

Aerobic or endurance exercises, such as walking, jogging, swimming or cycling, have been shown to improve blood flow and cognitive function. Strength training, on the other hand, can be beneficial in preventing and managing type 2 diabetes, which has been linked with an increased risk of dementia6.

Personal trainer Jane Kilkenny, Director of Melbourne-based Fitness Energy, says age is no barrier either, with research showing that starting an exercise regimen later in life can still alter the size of the prefrontal and hippocampal brain areas, which may lead to a reduction in memory impairments7.

“Just make sure you check with your doctor before undertaking any new exercise regimen,” says Kilkenny, “and seek the advice of an accredited fitness professional to provide you with the right advice and exercise program.”

Minimise risk

Keep these things* in mind to lessen your chances of developing Alzheimer’s disease.

  •   Heart disease and mid-life hypertension increase the risk of Alzheimer’s disease and vascular dementia.

  • Smoking has also been identified as a risk factor.

  • Type 2 diabetes increases the risk of developing Alzheimer’s disease by 39 percent (some studies suggest this figure could be even higher). This risk can be reduced by careful management of diabetes and with medications that maintain blood glucose levels within a healthy range.

  • High cholesterol in mid and late life can increase the risk of Alzheimer’s disease. Cholesterol-lowering drugs may help
  • Moderate to severe head injury increases the risk of developing Alzheimer’s disease and other dementias – a risk that is further increased if the head injury resulted in loss of consciousness.

1 fightdementia.org.au/about-dementia-and-memory-loss/statistics 2 Dr Maree Farrow and Dr Kathryn Ellis, ‘Physical Activity for Brain Health and Fighting Dementia,’ September 2013 3 Biochimica et Biophysica Acta (BBA), ‘The influence of exercise on brain aging and dementia,’ 2012 4 The Lancet Neurology, ‘Potential for primary prevention of Alzheimer’s disease: an analysis of population-based data,’ August 2014 5 Journal of Alzheimer’s Disease, ‘Semantic memory functional MRI and cognitive function after exercise intervention in mild cognitive impairment,’ 2013 6 yourbrainmatters.org.au/brain_health/evidence/diabetes 7 Archives of Medical Research, ‘Physical Activity, Brain Plasticity and Alzheimer’s Disease,’ 2012 *Source: Alzheimer’s Australia fightdementia.org.au

Information provided in this article is not medical advice and you should consult with your healthcare practitioner. Australian Unity accepts no responsibility for the accuracy of any of the opinions, advice, representations or information contained in this publication. Readers should rely on their own advice and enquiries in making decisions affecting their own health, wellbeing or interest.