Lifestyle choices may help combat genetic risk of dementia: Study

The major international study, which involved researchers from the University of South Australia, analysed data from 196,383 adults and identified 1769 cases of dementia over a follow-up period of eight years.
 
To assess genetic risk, the researchers looked at previously published data and identified all known genetic risk factors for Alzheimer’s disease. Each genetic risk factor was weighted according to the strength of its association with Alzheimer’s disease, which the team used to group participants into those with high, intermediate and low genetic risk for dementia.
 
Professor Dimity Pond, a GP with a special interest in dementia and aged care, pointed out that exercise, diet and smoking cessation are already discussed in the RACGP’s Guidelines for preventive activities in general practice as recommendations for early intervention and prevention for dementia.
 
However, she added that the results are ‘interesting’ and told newsGP similar trials should be performed within general practice, particularly focused on how to provide lifestyle advice in the most effective way possible.
 
‘To me it is a no brainer that we should give this diet, exercise and smoking advice, as well as the advice about alcohol consumption mentioned in the study,’ she said.
 
‘There is almost no cost to this advice and even though not all our patients will take it up, it is worthwhile to [try and] prevent dementia, which is a progressive terminal disease lasting 10 years or so and costing many hundreds of thousands of dollars in health and social care costs.’
 
Professor Pond said the study’s findings were comparable to previous research related to statin use and non-fatal heart attack and stroke – namely that one case of dementia would be prevented for each 121 individuals per 10 years with high genetic risk who improved their lifestyle from unfavourable to favourable.
 
‘It is interesting to reflect on the number needed to treat in this analysis. At the moment genetic risk is too difficult to identify in Australia, except in a research setting,’ she said.
 
‘However, if it were possible, then we could compare 121 individuals successfully given dietary, exercise and smoking cessation advice to prevent one case of dementia in 10 years, with the US Preventive Services Task Force (USPSTF) finding that we need to treat 217 with a statin to prevent a non-fatal heart attack, or 313 to prevent a non-fatal stroke, over four to five years.’
 
To assess lifestyle, researchers grouped participants into favourable, intermediate and unfavourable categories based on their self-reported diet, physical activity, smoking and alcohol consumption. The researchers considered no current smoking, regular physical activity, healthy diet and moderate alcohol consumption as healthy behaviours.
 
The team found that living a healthy lifestyle is associated with a reduced dementia risk across all genetic risk groups. The most at risk were participants with high genetic risk and an unfavourable lifestyle, who were almost three times more likely to develop dementia than those with a low genetic risk and favourable lifestyle.
 
Professor Elina Hyppönen, Director of UniSA’s Australian Centre for Precision Health said the study’s results suggest that much of dementia is ‘preventable’.
 
‘There is a saying, that “what is good for your heart, is good for your brain”, and these results very much support that notion,’ she said.
 
‘In the context of dementia risk, it is possible to notably reduce the inherited risk by our own actions.
 
‘I was delighted to see the lifestyle choices which appear to work against dementia are those which we know to also be beneficial for reducing the risks of other chronic diseases, including cardiovascular disease and cancer.’
 
Further research using ‘hypothesis-free, large-scale data driven approaches’ will be conducted to establish pathways and drivers of dementia risk, potentially leading to new solutions and ways to prevent dementia.

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