Question: What can you do to prevent dementia-related illness?

Dementia isn’t a single disease, but rather a range of conditions that cause a loss of mental functioning that gets worse over time.

There are many different forms, but the most common dementia is Alzheimer’s disease. There are big overlaps in symptoms between each type.

Commonly, dementia can result in memory loss and confusion, reduced skills in planning, reasoning, language and communication, as well as personality and behaviour changes.

Almost one in 10 Australians aged over 65 have dementia, but by 85, it’s one in three.

So it’s not surprising there’s great interest in knowing what can be done to ward off this illness.

The good news is there’s “quite a lot of research” showing there are things you can do that can make a difference in reducing your risk of dementia — and it comes down to your lifestyle, says Dr Maree Farrow, a cognitive neuroscientist with the University of Tasmania’s Wicking Dementia Research and Education Centre.

“For any individual, we can’t say how much doing these things will lower your risk, because we don’t know what other factors [like genes] are influencing them as an individual,” Dr Farrow said.

“But evidence suggests about 30 per cent of dementia cases could be prevented if we addressed all the lifestyle risk factors we’re aware of.”

A ‘brain healthy’ lifestyle

There are five key things Dr Farrow suggests you do to keep your brain functioning as well as possible as you age:

1) Stay mentally active – do things that make you think and learn

“We know from lots of research that people who do more stimulating activities throughout their life have better brain function and a lower chance of developing dementia,” Dr Farrow says.

While there has been much emphasis on crosswords and sudoku puzzles to boost your brain, other activities you could do include taking up a second language, pursuing a course of study, reading widely or learning a musical instrument.

No-one’s certain which activities work best.

“There’s no reason you should sit down and do a crossword every day if you hate crosswords,” Dr Farrow says.

“Choose something else you’re going to enjoy. And if you’ve been doing crosswords for 30 years and are really good at them, it’s not going to be as stimulating for your brain as trying something you’ve not done before.

“The research suggests it’s challenging the brain so it’s learning something new or different that’s important.”

Unfortunately there’s no evidence computerised brain training prevents dementia, although it may help healthy older people get some minor improvements in cognitive abilities.

2) Stay socially active – maintain a network of friends and acquaintances

No-one’s quite sure why, but staying socially connected with large networks of friends, seems to be good for your brain.

“We believe it’s probably because social activity is another kind of mental activity. By engaging with other people, you are exercising your brain,” Dr Farrow says.

“You have to think about what you’re saying and understand what they’re saying. You have to understand facial expressions and body language. Lots of different parts of your brain are working.”

Combining your mental and social activities, say by getting together with others for a weekly game of bridge is ideal.

3) Stay physically active – increase your heart and breathing rate

Over the past five to 10 years, the evidence has grown that you need to keep your body active as well as your mind, if you want a healthy brain.

It’s partly because exercise helps keep your blood vessels in good shape, Dr Farrow says.

“The blood vessels in your brain are absolutely vital, and the healthier we can keep those, the better off we’ll be. But studies also show physical activity helps with growing new brain cells and new connections between brain cells. It also boosts the levels of some chemicals in the brain that help keep brain cells healthy.”

Most of the research has been into the effects of aerobic exercise, the exercise that gets your heart and breathing rate up.

But you don’t have to join a gym or structured exercise class. Just 30 minutes a day of moderate intensity aerobic exercise like brisk walking is enough to have a significant impact.

But exercising longer, or more vigorously, is probably better still.

4) Eat well – have a healthy balanced diet

While there’s a huge amount of interest in how eating certain foods will keep your brain young, it’s the area supported by the least hard evidence, Dr Farrow says.

So far what’s clear is there’s no magic food that’s going to keep your brain healthy; it’s about having a healthy balanced diet overall.

While some research suggests eating foods like oily fish, which are high in omega-3 fats, is important, Dr Farrow says the evidence is mixed.

Likewise, the jury is still out on the importance of antioxidants.

“What does come out as being mostly positive is the research on fruit and vegetables. They’re the foods most rich in antioxidants,” Dr Farrow says.

The best advice is to eat a healthy balanced diet, taking particular care to make sure you eat enough fruit and vegetables.”

And if you drink alcohol, have no more than two standard drinks on any one day. (A standard drink is one that contains 10 grams of alcohol and the volume will vary with the alcohol strength of the drink.)

Not smoking is also protective.

5) Keep your key health numbers healthy

It’s important to keep your blood pressure, cholesterol and blood sugar levels in the healthy range.

The brain might be only 2 per cent of our body weight, but it uses 20 per cent of our blood supply. So there’s a high demand on our blood vessels to supply the brain with the oxygen and nutrients it needs.

“If your blood vessels in your body are unhealthy, they’ll be unhealthy in your brain as well,” Dr Farrow says.

That means your brain cells get damaged and die and this affects your thinking ability.

“In fact, some people have vascular dementia that is primarily due to this type of cell damage. It’s due to things like high blood pressure or high cholesterol and not treating them effectively. Over time, this damages brain cells more and more,” Dr Farrow says.

Studies have shown that people who have high blood pressure and take medication that brings it back to normal, reduce their risk of dementia.

While there is lesser evidence of an effect for treating cholesterol and high blood sugar, it’s nonetheless recommended for your brain as much as the rest of your body.

Start early

It’s worth knowing too that the disease process that causes dementia starts decades before, says Professor Kaarin Anstey, director of Australian National University’s Centre for Research on Ageing, Health and Wellbeing.

So the earlier you start a healthy lifestyle, the stronger its protective effects will be.

Arguably, the best time to establish healthy habits is in childhood. But it’s never too late to make a difference.

Even people who have dementia already, who start exercising see improvements in their function.

Want to learn more about preventing dementia?

If you can allocate two hours flexibly each week, you might like to take part in a free five-week online course being run through the University of Tasmania. You can enrol in the until May 19 and at the end, there is an opportunity to undertake an assessment of your individual risk. So far more than 12,000 people have enrolled from all over the world. It covers the latest evidence on all the major risk factors and is suitable for people from all backgrounds. There are no exams or assignments.

This post originally appeared on ABC News.