SARAH DI LORENZO: Exercise is key to preventing dementia. What you can do now to lower your risk in old age

Dementia is the leading cause of death for Australian females, it makes up 12.2 per cent of female deaths. But dementia is growing significantly and really now a global health concern.

In 2021 it was estimated that 57 million people were living with dementia and 60

of those are in low and middle income countries. Every year 10 million more cases are diagnosed globally.

The future projections are that the number of people living with dementia will be expected to rise significantly and by 2050 there could be 152 million people living with the disease mainly due to increased life expectancy and ageing population.

Here in Australia the number of people living with dementia has doubled since 1954.

Dementia is an umbrella term for a range of neurological conditions that lead to cognitive decline, affecting memory, thinking, behaviour, and the ability to perform everyday activities.

The most common is Alzheimer’s disease making up 60–70 per cent of cases.

The risk factors for developing dementia include age, particularly over 65. Cardiovascular disease and diabetes can also increase the risk of dementia.

Poor diet plus elevated alcohol consumption, sedentary lifestyle and smoking can contribute to dementia. Depression, isolation, air pollution and hearing loss can be factors.

To help prevent dementia there is a lot we can do including minimising or avoiding alcohol, eating a healthy diet and living a healthy lifestyle. Something you can make sure you are doing daily is exercise. Regular physical exercise can significantly lower the risk of developing dementia.

Research indicates that incorporating physical activity into your routine is one of the most effective lifestyle strategies for maintaining brain health and reducing the likelihood of cognitive decline.

I always tell my patients to try and find doing exercise that they love so they can stay motivated and be consistent.

Exercise can stimulate the release of brain-derived neurotrophic factor (BDNF), a protein that supports the growth and survival of neurons. Physical activity also enhances insulin-like growth factor-1 (IGF-1), which promotes cognitive function and all of this helps maintain memory and our ability to learn as we age.

Exercise also reduces the protein accumulation in the body that is considered harmful. Physical activity may decrease the buildup of beta-amyloid plaques and tau proteins in the brain; these are hallmarks of Alzheimer’s disease.

As well this exercise improves our metabolic health, circulation and blood flow.

This increases blood flow to the brain and delivers oxygen and nutrients supporting cognitive function. It also helps lower the risk of high blood pressure, diabetes, and obesity, which are all linked to a higher risk of dementia.

Plus exercise will support brain structure and volume. As we age the brain can shrink and have less volume. Regular exercise will slow this down and prevent loss of volume and shrinkage. The better preserved the brain the better the cognitive performance.

So how much exercise do you need to be doing to make a difference and really lower your risk of dementia?

There is research indicating that just 35 minutes of physical activity per week is associated with a 41 per cent reduction in dementia risk. I suggest to my patients to do around 150 minutes per week of moderate to intense physical activity.

The benefits of exercise are observed even in older adults and those with genetic predispositions to dementia.

To be consistent, find the exercise you love. Some great aerobic exercises include cycling, swimming, power walking and resistance training. A mix of these is great. I have patients who do dance classes, join running clubs, have exercise buddies or equipment at home.

Exercise is not only amazing to reduce the risk of dementia but it also is amazing for us. It can put us in a good mood, improve sleep and help manage stress.

Don’t forget, many forms of exercise are completely free, they don’t have to hurt your hip pocket. Use this important tool to lower your dementia risk but also improve your quality of life.