Despite new drugs, reducing modifiable risk factors is key to prevention and slowing disease progression

Dementia broadly encompasses a variety of conditions characterised by gradual brain function impairment. Prevalence increases with age, and the Australian Institute of Health and Welfare estimated over 400 000 people living with dementia in 2022, expecting the number to more than double by 2058.

Dementia has now overtaken coronary heart disease as the leading cause of disease burden in the older population.

Dr Marita Long, a GP working with Dementia Training Australia (DTA), says dementia is a major public health issue. The Medical Journal of Australia published a Dementia Prevention Action Plan in 2021 that calls for better resourcing to equip primary care to take leadership in this space. They also call for dementia risk reduction research to be translated into practice.

Dr Long is frustrated by the lack of dementia education in both undergraduate and post graduate medical training courses. “We should be preparing our workforce and supporting GPs to better support people living with dementia,” she says.

“We know there’s no cure for dementia,” Dr Long says. “Sure, there’s some promising work on the horizon with drugs such as lecanemab, but they’re just for Alzheimer’s disease, and at the moment they’re only demonstrating a similar effect to the cholinesterase inhibitors which we already have, that are relatively cheap and easy to administer.”

She says it’s important not to over-hype impending monoclonal antibodies: “They’re very expensive, they are difficult to administer, not without some significant side effects and will be for a select population only. They’re certainly not going to help people in low or middle income countries. And research to date would suggest they are not as effective for women,” she says, adding that they do show “some long awaited promise.”

Dr Long has been campaigning to get dementia on the women’s health agenda, noting that it’s the leading cause of both death and disability for women in Australia.

Women are twice as likely to be diagnosed with dementia than men in Australia — and they are diagnosed later and have a faster trajectory than their male counterparts.

“It may in part be because we’re diagnosing women so much later than men that the drugs are less effective,” she proposes, but she also points out that dementia studies take a very binary approach to studying males and females equally, without acknowledging the role of reproductive hormones and other heterogeneities within the female cohort.

“Perhaps factors like parity, birth complications, exposure to contraceptive hormones or MHT—or lack there-of—may influence the development of dementia. From my understanding, the studies to date are not really pulling out that info,” she says, noting that women also tend to be underrepresented in clinical trials.

“Really, at this stage prevention is the key for dementia. Whether someone has normal age-related cognitive changes, mild cognitive impairment or dementia, we should be looking at optimising brain health,” Dr Long says.

She says modifying risk factors is key to slowing down the progression of disease, regardless of what stage someone is at.

She notes that there is overlap with preventative measures for other diseases that are more firmly in the public eye. She comments that although the overall number of people living with dementia is increasing due to our ageing population, we are seeing a proportionate decline in countries like Australia. “That’s probably because we are addressing cancer, stroke and cardiovascular disease prevention and there’s a lot of overlap in the modifiable risk factors for dementia.”

Risk factors for dementia

The list below includes potentially modifiable risk factors.
Dr Long notes that not all these risk factors will be easy or practical for all patients to modify, so when she discusses them with a patient, she frames the conversation as ‘these are your protective factors, and these are things that could be better, what do you think is modifiable for you and what do you want me to help with?’

High Blood Pressure
High Cholesterol
Smoking
Diabetes
Poor Diet – especially low fish intake
High Alcohol Consumption
Physical Inactivity
Low Levels of Cognitive Engagement
Depression
Social Isolation/Low Social Engagement
High BMI
Stroke
Atrial Fibrillation
Insomnia
Traumatic Brain Injury (repeated head injuries, falls risk)
Hearing Loss
Air Pollution
(Reference: Anstey et al., 2022)

“This is where the CogDrisk is a fantastic evidenced based tool that can be fairly easily utilised in primary care,” says Dr Long, referring to a dementia risk factor assessment tool developed by Professor Kaarin Anstey and her team at UNSW/NeuRA. (Access the tool here: https://cogdrisk.neura.edu.au/)

Validated for use in patients over the age of 18, the CogDrisk provides a neat summary of which modifiable risk factors are currently favourable, and which could perhaps be optimised. For patients over the age of 40, it also provides a numerical risk of developing dementia at age 65.
Professor Anstey explains that it can’t provide a numerical risk for patients under 40 as the content is highly evidence-based and we simply don’t have the evidence yet for these risk factors at a younger age.

Dr Long cautions “we should be very wary when we talk about risk reduction and prevention, that we don’t blame the individuals. I prefer to use the term lifestyle ‘factors,’ not choices, as there can be significant barriers for some people to access the healthiest lifestyle options.”

She likes to use the CogDrisk results as a starting point for a conversation about brain health with the patient, to assess areas they think they could and would like to change.

Although it’s never too early to improve dementia risk, Professor Anstey says “addressing the risk factors in middle age is really important. Once we’ve already noticed cognitive changes, things have progressed quite significantly.”

Both experts recognise that it may sometimes be difficult for doctors to raise future brain health with their patients, due to both time constraints and a perceived lack of urgency by both patients and doctors. Dr Long reminds us that the 45-49 year old health check is an excellent time to bring this up, as are appointments related to menopause.

Professor Anstey also recommends discussing a patient’s own risk factors when they mention their ageing parents may be developing cognitive problems.

There are a couple of limitations to using CogDrisk in general practice. “It does take 20 minutes, so it’s not something you can sit in a consultation and do,” says Professor Anstey.

She recommends encouraging patients to complete it at home, or in the waiting room before their appointment, and bring the results. Dr Long notes that it may be possible to have the practice nurse work through the questionnaire with the patient if extra support is needed.

Patients from a non-English speaking background or with low health literacy may require assistance.
Professor Anstey says there are updates in the works for the CogDrisk. “We’re adding in a few more questions,” she says, noting plans to include questions about hearing loss and make it more user friendly on mobile platforms.

They are also in the process of validating a Chinese language version, and are looking at developing more options for people with lower health literacy.

When it comes to actual diagnosis of dementia, using the right tools is again important. Professor Anstey says that the mini mental (MMSE) may be very useful at a population level for research, “but one-on-one for GPs, there are better options out there.”

Dr Long agrees. She says the MMSE is one of the least sensitive cognitive assessment tools, with highly educated patients often scoring well and appearing ‘normal’ despite having cognitive changes, while patients with low levels of education or with a first language other than English may score poorly despite normal cognition.

In general practice, she prefers to use the GP-COG (https://gpcog.com.au/) as part of a thorough assessment for any cognitive issues alongside an informant history. If a GP is worried about a potential diagnosis of dementia and doesn’t feel confident to make a diagnosis then referring to a memory clinic, a geriatrician, old age psychiatrist or a neurologist is an option.

Dr Long would love to see more GPs upskill in the areas of dementia prevention, diagnosis and treatment. She and the GP clinical education team at Dementia Training Australia (https://dta.com.au/) have developed a variety of workshops for the primary care setting. Her team has shown that attending DTA’s three-hour workshop improves both knowledge and attitudes, independently of each other, and subsequently also confidence.

“Someone with a worry about their cognition, or a relative worried about someone’s cognition, the first person they come to is the GP.” Dr Long is confident that her GP colleagues can make a real difference in this space. “In terms of prevention, especially, as GPs, we do that really well.”
“We all know that prevention is better than cure, but when there really isn’t a cure then the prevention is…it’s everything.”