Dementia is a debilitating disease, and Australia’s second biggest killer. While there is currently no cure, there are treatments to help improve the symptoms, but the best strategy is to try and prevent it from developing altogether.
The American Heart Association has identified seven cardiovascular and brain health factors, known as Life’s Simple 7:
While Life’s Simple 7 have been linked to lowering the risk of dementia overall, it has not been investigated whether this applies to people with high genetic risks. A 30-year study following over 11,000 people with mixed genetic risk scores (based on the APOE gene variant) from both European and African ancestries aims to provide some answers.
The average starting age was 54 years, with participants divided into eight different groups based on genetic risk scores. At the end of the study, 18% of people with European ancestry developed dementia, compared to 23% of people with African ancestry. This implies there may be a genetic risk factor linked to the risk of developing dementia.
For people with European ancestry, people with the highest scores in the lifestyle factors had the lowest risk of dementia, including the group with the highest genetic risk. Those with intermediate to high scores in healthy lifestyle factors had an associated 30-40% lower risk of dementia. For every lifestyle factor that was adhered to from the Life’s Simple 7, the risk of developing dementia decreased by 9%.
“These healthy habits in the Life’s Simple 7 have been linked to a lower risk of dementia overall, but it is uncertain whether the same applies to people with a high genetic risk,” says author Dr Adrienne Tin of the University of Mississippi Medical Centre (US). “The good news is that even for people who are at the highest genetic risk, living by this same healthier lifestyle means they are likely to have a lower risk of dementia.”
For people with African ancestry, the intermediate and high categories were associated with a 6-17% lower risk of dementia. Of those participants, 40% had at least one copy of the APOE gene variant, which is associated with Alzheimer’s disease, compared to 27.9% of people with European ancestry. A limitation of this study was the smaller number of participants with African ancestry, and that many of these participants were recruited from one location.
“Larger sample sizes from diverse populations are needed to get more reliable estimates of the effects of these modifiable health factors on dementia risk within different genetic risk groups and ancestral backgrounds,” Tin says.
This study has been published in Neurology, the medical journal of the American Academy of Neurology. For more information about dementia, visit dementia.org.au (Australia) and BrainandLife.org (worldwide).
Qamariya Nasrullah holds a PhD in evolutionary development from Monash University and an Honours degree in palaeontology from Flinders University.
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