Dementia is a collection of symptoms that are caused by disorders of the brain. It’s not one specific disease. It can affect thinking, behaviours and the ability to perform everyday tasks. Dementia is currently the second leading cause of death in Australia, contributing to 5.4% of all deaths in males and 10.6% of all deaths in females.
There were an estimated 436,366 people living with dementia in Australia in 2018, with the numbers expected to rise to 589,807 by 2028. This translates to costs of >15 billion$ in 2018.
With no known cure for dementia, preventative strategies provide the best options for tackling dementia in the community. 2 major reports released in 2017 reviewed literature on potentially modifiable risk factors for dementia and highlighted the strengths and weaknesses in the available data. while no single intervention is useful in delaying or preventing dementia, there is optimism that intensive risk factor reduction mid-life (45-65) has the potential to delay or prevent a substantial number of cases.
Lifestyle and Activity
Observational evidence supports an inverse association between various components of a healthy lifestyle (eg, social interaction, education and mental activities, physical exercise) and the incidence of dementia.
Physical exercise has synergistic benefits as part of a more comprehensive risk factor reduction strategy.
Various cognitive interventions including memory training, the use of external memory cues, and organisational aids have shown positive short-term effects on cognition in healthy older adults.
Education and Cognitive Reserve:
Higher levels of education have been associated with a reduced risk of dementia. Advanced education is believed to represent a higher cognitive reserve that decreases the impact of Dementia on cognitive function, rather than providing a protective effect.
Trails such as the FINGER trial tested a multidomain intervention that included diet, exercise, cognitive training, and vascular risk monitoring in 1260 at-risk elderly adults. Compared with controls who were given general health advice, individuals who were randomly assigned to the intervention showed greater improvements in neuropsychological test battery scores at two years. Long term impacts on rates of dementia and cognitive decline are yet to be determined
Vascular Risk factor Modification
It appear that the incidence of all-cause dementia, and especially vascular dementia, is declining in high-income countries over the past several decades, based on population based data. This trend has occurred as the prevalence of many vascular risk factors such as Hypertension, diabetes and inactivity have decreased over time. These population based studies offer optimism that reduction for these vascular risk factors is worthwhile not only for heart health but also for brain health.
Interventions with unproven benefit
Omega 3 fatty acids: Longitudinal cohort studies have shown an association between higher fish oil consumption and reduced risk of dementia, cognitive decline, and/or accumulation of white matter abnormalities on brain MRI.
Mediterranean Diet: These diets are typically high in fruits, vegetables, whole grains, beans, nuts, and seeds and include olive oil as an important source of fat. There are typically low to moderate amounts of fish, poultry, and dairy products, and there is little red meat. Observational studies using dietary questionnaires to assess and quantify adherence to the diet in different population cohorts have found that patients who were most adherent to the diet had a lower incidence of mild cognitive impairment and AD and slower rates of cognitive decline compared with those who did not follow this diet.
Alcohol: While there is some evidence that light to moderate alcohol use may be protective, this is largely based on observational studies and the findings have been inconsistent.
Antioxidant Vitamins: Although autopsy studies have shown that oxidative stress may be important in the pathogenesis of Alzheimer disease (AD) and other forms of dementia, Trials to date have failed to confirm a benefit. This includes vitamin E, Vitamin C, Beta carotene and selenium.
Vitamin B6, B12 and folate- low levels of these vitamins have been associated with impaired cognition and dementia but there is no evidence that supplementation prevents dementia.
Vitamin D- Vitamin D deficiency has been associated with dementia but the effect is very small and uncertain Multivitamins, statin- No current role has been attributed to either of these agents.
Flavonoids- Diets with higher intake of flavonoids- blueberries, strawberries have been associated with slower rate of cognitive decline due to proposed antioxidant and anti-inflammatory actions.
Hormone therapy, NSIAD therapy and Gingko Bilbos- have had multiple trails which have proven the inefficacy.
Further information and ways of managing and reducing risks can be found on : https://yourbrainmatters.org.au/your-brain-matters. This site provides information about simple changes that can be made to lifestyle that can impact cognition.
Information on dementia: https://www.dementia.org.au