Physical activity lowers dementia risk

Each year in Ireland 4,000 people develop dementia; that's 11 people every day according to The Alzheimer's Society of Ireland. And this number is on the rise. Currently there are 55,000 people with dementia in Ireland, the most common type being Alzheimer's disease, but this number is expected to reach 113,000 by 2036.

The biggest risk factor for developing dementia is something that can't be prevented - getting older. But the good news is there are things you can do to reduce your risk. And 1 of these things is to stay physically active.

UK dementia charity The Alzheimer's Society suggests that being active for at least 30 minutes, 5 times a week can help prevent dementia. The aim is to be active enough to get slightly out of breath and raise your heart rate. And it's never too late to start - regular physical exercise such as walking, cycling, swimming or dancing reduces the risk of developing dementia in middle-aged or older adults, the charity claims.

Another US charity, the Alzheimer's Research & Prevention Foundation, even claims that being physically active can also slow further deterioration in people who have already started to develop brain function problems. And as well as moderate-intensity exercise such as walking or swimming, the charity recommends 2 to 3 sessions a week where you work on developing your muscle strength, along with balance and co-ordination exercises such as yoga, tai chi or exercises using balance balls.

Dementia prevention research

But how exactly does being physically active benefit your brain? The Alzheimer's Research & Prevention Foundation suggests that exercise protects against Alzheimer's disease by stimulating the brain's ability to maintain old connections as well as make new ones.

A new study sheds further light on the role of exercise in dementia prevention. Carried out by researchers at Goethe University in Frankfurt, the study - published in the journal Translational Psychiatry - examined the effects of regular exercise on brain metabolism and memory, and involved 60 participants aged between 65 and 85.

Some of the participants followed an aerobic training programme by working out on exercise bikes for 30 minutes, 3 times a week for 12 weeks, while others did nothing. Before the exercise programme started, all the participants had their fitness levels and cognitive performance assessed. They also had scans to determine their brain metabolism and structure. Then after the 12-week period was over they were examined again to find out if - and to what extent - exercise might have an effect on both physical fitness and brain metabolism.

The scientists were expecting the exercise programme to have an influence on the participants' brain metabolism, but this time they believe they discovered how. Normally in cases of Alzheimer's disease there is an increased loss of nerve cells in the brain. This is accompanied by a rise in the concentration of a substance in the brain called choline, which has been described as a marker of neurodegeneration.

After 12 weeks, those who completed the exercise programme were found to have stable cerebral choline concentrations, but those who didn't exercise showed increased choline levels.

The exercise group also enjoyed improved physical fitness. So the researchers concluded that regular physical exercise not only boosts fitness but also has a protective effect on the brain.

If you're thinking of starting an exercise programme, always consult your doctor beforehand if you're new to exercise, haven't been very active lately, or if you have a medical condition.