How to prevent dementia!


It is a very scary beast that is becoming more and more common in Australia due to our ageing population and lifestyle factors. Having had family members, family members of close friends and many patients with dementia, I have intimate knowledge of the devastating effects of this condition on our loved ones. And is terrifying to know that it may also one day afflict oneself. Currently, there are few treatments for dementia and those available merely slow the progression or manage the behavioural and psychological symptoms. There is currently no cure for dementia. We can, however, reduce our risk of developing dementia and this week the World Health Organisation (WHO) released their guidelines for risk reduction of cognitive decline and dementia.

What is dementia?

Dementia is actually not a disease in of itself. Rather, it describes a common group of symptoms that can be caused by different brain disorders and diseases. It causes long-term, usually gradual but may be rapid, declines in a person’s ability to think and remember that affects their daily functioning. While many people are know about the memory issues in dementia, other symptoms that are common in dementia are emotional disturbance, language difficulties, confusion, decreased motivation and physical decline. Dementia is not a normal part of ageing but it occurs more commonly with increasing age.

The most common type of dementia is called Alzheimer’s disease, accounting for half to two thirds of cases. Other common types of dementia include:

  • Vascular dementia: related to strokes, often multiple mini-strokes, and poor blood supply to the brain

  • Lewy body dementia: where abnormal deposits of a protein in the brain form ‘Lewy bodies’ and has physical symptoms similar to Parkinson’s disease

  • Frontotemporal dementia: a type of dementia that affects the front part of the brain and causes personality and social behavioural changes, and language difficulties, and typically has a younger onset between ages 45 and 65

How common is dementia in Australia?


Dementia is the second leading cause of death in Australia. It is the leading cause of death in Australian women, overtaking heart disease in 2016 and is the third leading cause of death in men. In 2019, there are an estimated 441,115 living with dementia in Australia. There are estimated 250 new dementia diagnoses every day with 1 in 10 people over 65 living with dementia and 3 in 10 people over 85 living with dementia. Almost 1.5 million Australians are estimated to be involved in the care of someone living with dementia. Dementia accounts for 52% of all residents living in residential aged care facilities and dementia is estimated to cost Australia more than $15 BILLION in 2018. Statistics from Dementia Australia.

So what are risk factors for developing dementia and how can I reduce MY risk of developing dementia?

There are several risk factors for dementia that are unmodifiable or cannot be reduced. These include age and family history. Age is in fact the strongest risk factor for cognitive decline. If I knew how to ameliorate this risk factor, I would be rich beyond my wildest dreams. However, it is important to understand that dementia is not an inevitable or even normal consequence of getting older. There are known modifiable risk factors, that is, those we can change and these are what the WHO Guidelines aim to address. It will come as no surprise to many that the key ways to prevent dementia are core to living a healthy life and what I bang on about to my patients all the time - don’t smoke, don’t drink in excess, move and eat healthy. They also discuss the role (or lack there of) for supplements, brain training activity and hearing assessments. I have summarised below the risk factors for dementia and what you can do to reduce your own risk. As always, this is general advice and you should discuss your own circumstances with your own GP.

Physical inactivity.

Physical inactivity is associated with an increased risk of developing dementia and it has been observed that those who are more active are less likely to develop cognitive decline. This benefit is most obvious at the highest level of physical exercise, which I am happy to hear - shout out to all my fellow endurance athletes - exercise is good, m’kay! The benefits of exercise are likely attributable to direct beneficial effects on the brain as well as indirect effects of improved cardiovascular health by reduced blood pressure, improved cholesterol and blood sugar levels. Summarising the body of evidence, the WHO Guideline Development Group concluded that there was low to moderate quality evidence that physical activity has a small but beneficial effect on cognition. This cognitive benefit was also seen in adults with mild cognitive impairment, albeit lower quality evidence. The benefits were mostly seen with aerobic exercise, that is, ‘cardio’ as opposed to resistance exercise which is more weights based. The guidelines strongly recommend exercise for all healthy adults and supports exercise for those with cognitive decline as well.

WHO Global recommendations on physical activity

Australia’s Physical Activity and Sedentary Behaviour Guidelines and the Australian 24-Hour Movement Guidelines

Tobacco use.

You would have to be intentionally living under a rock if you claim to be unaware that smoking causes cancer. But amongst the myriad of other nasties that are linked to smoking, is the association with, you guessed it - dementia and cognitive decline. Although there are no trials specifically looking at smoking cessation interventions compared with no intervention for reducing the risk of dementia, the body of evidence of the harms of smoking is so large that any intervention that will reduce smoking is likely to be more beneficial than harmful. Basically, smoking is terrible for you. Please see your doctor for interventions to help you stop smoking if you are a smoker.


Unhealthy diet.

Another no brainer - a healthy diet is good for you & an unhealthy diet is bad for you. We know that healthy diets can reduce prevent many of the medical conditions that are linked to higher risks of dementia, including diabetes and hypertension. Animal studies also suggest that dietary factors can directly cause brain changes that lead to the development of dementia. The Mediterranean diet is the most extensively studied diet and evidence indicates that following the Mediterranean diet closely is associated with a decreased risk of mild cognitive impairment and Alzheimer’s disease. Unfortunately, a half-assed approach does not seem to be helpful with those only partially adherent to the Mediterranean diet not seeing any benefits. Foods that are likely or thought to be protective against dementia are fish, fruit, vegetables, nuts, olives oil and, this might be exciting for some, maybe even coffee.

Unfortunately, what we hear about healthy diets is usually faddish and focused solely on weight loss as an end point. This is not helped by the fact nutritional studies are notoriously difficult to control for all the differences in individuals to be able to identify what particular aspect of the diet is responsible for which outcome. Nor is it helped by sensationalist and inaccurate media reporting of research (I hope to write a post on understanding science in the near future). Currently, most nutritional data comes from observational studies where groups of people are monitored for various outcomes. However, when researchers try to demonstrate these findings in trials the results are more inconsistent. What we do know is that it is a good idea to eat lots of vegetables, some lean protein and little saturated fats and nutrient supplementation does not come close to the benefits of consuming these nutrients through your diet. A healthy diet needs to be a lifestyle not a short-term drastic and unsustainable modification to achieve a particular end point. I know from personal experience that no matter how good you perceive your diet to be, you are still likely to benefit from input from an Australian Accredited Practicing Dietician.

Find an Accredited Practicing Dietician

WHO recommendations on healthy diet

Information the Mediterranean diet from my college and from the ABC

The DASH (dietary approaches to stop hypertension) diet is another diet with evidence associating it with better cognition as well as other beneficial health outcomes

Alcohol excess.

I have previously posted about the risks of alcohol with regards to cancer. Excessive alcohol consumption is a known risk factor for dementia and the evidence for this is strong. The recommendations for alcohol consumption are here. If you or others are concerned about your levels of drinking please see your GP. If you are not worried about your levels of drinking, signs that you SHOULD be worried include, needing to drink more than usual to get drunk, drinking when you wake up in the morning, regularly consuming alcohol on your own or trying to hide your alcohol consumption from others, worsening relationships with friends or family or always staying out late and encouraging friends to keep drinking when they’ve said that they want to go home.

Reduce your risk: new national guidelines for alcohol consumption

Information on Alcohol Support Services

Social isolation.

Social engagement is associated with well-being through out life while social disengagement is a risk factor for cognitive impairment and dementia. Lower social participation, less frequent social contact and loneliness are associated with higher rates of dementia. It is unclear if interventions to improve social engagement reduce the risk of dementia. Furthermore, it is possible that the social disengagement itself is a sign of early dementia rather than it being a cause. However, the WHO found that because social participation and social support are strongly connected to good health and well-being through out life that social inclusion should be supported for all people. If you are feeling lonely and disconnected please reach out to your GP as this can be a symptom of depression which can be treated.

Black Dog Institute - Loneliness

Crisis numbers and other mental health resources

Cognitive inactivity.

Before dementia there is a period of cognitive decline. It is theorised that those with more cognitive reserve, that is, the ability to cope with or compensate for brain damage, have more protection against cognitive decline. It is further theorised that activities that aim to increase cognitive reserve may be protective against dementia; think sudokus or those brain training apps. Unfortunately, the data is very limited and the quality of evidence is poor. It does appear as though cognitive training can have small positive cognitive effects but there is not enough data to recommend these activities to reduce the risk of dementia. However, the harms are likely low other than the frustration at a failed sudoko so brain train away.


Obesity is defined as a body mass index over 30 and has been associated with cognitive impairment. Obesity is also associated with other medical conditions that place people at risk of dementia including hypertension, high cholesterol and diabetes. Now this is not to say we all need to be Victoria Secret’s model skinny. Indeed, there is some evidence that being overweight (BMI 25-30) in older age may be protective and the link been excess weight and cognitive decline has only been demonstrated for obese and not overweight individuals. Thus the WHO recommends weight loss in mid life for those who are obese. The good news is that the above interventions of physical exercise and diet to improve dementia risk typically can also lead to modest reductions in weight.

Calculate your BMI

Medical conditions.

Some medical conditions place individuals at higher risk of dementia. These include hypertension (high blood pressure), diabetes, high cholesterol, depression. In these instances the evidence is mostly observational and one directional. That is, studies that observe populations over time find that those with these conditions are more likely to develop cognitive impairment and dementia. However, it is very difficult to carry out trials to actually scientifically prove whether treating these conditions leads to reduced rates of cognitive impairment and dementia due to the difficulties in carrying out a large scale intervention over the long time it takes for dementia to develop. There are some studies underway but currently there is a lack of evidence to say that treating these condition does prevent dementia. However, there are other proven benefits and limited adverse outcomes in treating these conditions and well known complications of NOT treating these conditions that the WHO strongly recommends treating these conditions especially in mid life for improved health outcomes. Hopefully in the future it can be proven that it also reduces dementia.


To date, there is no evidence that supplementation with multi-complex vitamins, polyunsaturated fatty acids, vitamin B or vitamin E has any beneficial effects on cognitive function and in particular high dose vitamin E supplementation results in undesired that outweigh any benefit and were specifically recommended AGAINST by the WHO. As always, nutrients are most beneficial when consumed as part of your diet rather than added in.

In summary, to reduce your risk not only of dementia but many other disease and have better well-being:

  • don’t smoke

  • drink only a little

  • MOVE

  • eat well

  • be social

To that end I am about to hop on a plane to Qld for the weekend for Tough Mudder Qld - lots of fun in the mud. I hope to have posts on each of these individual aspects coming soon. Hae a great weekend!


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