The research found that those with a high genetic risk of developing dementia who lead a healthy lifestyle lowered the risk by 32 percent, compared to those with an unhealthy lifestyle.
Findings discovered that participants with a high genetic risk and leading an “unfavourable” lifestyle tripled the risk of developing dementia, compared to those with a low genetic risk and a “favourable” lifestyle.
The study was undertaken by the University of Exeter, based in the United Kingdom, and collaborated with researchers from the University of South Australia (UniSA), the University of Michigan and the University of Oxford.
Director of UniSA’s Australian Centre for Precision Health, Professor Elina Hyppönen, was a senior collaborator for the research and advised on genetic and statistical aspects of the study.
“Our results clearly show that in the context of dementia risk, it is possible to notably reduce the inherited risk by our own actions,” explains Dr Hyppönen.
“Indeed, 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.”
The study involved 196,383 adults of European ancestry aged 60 and older, and researchers were able to identify 1,769 cases of dementia over a follow-up period of eight years.
The team then grouped the participants into three categories of genetic risk for dementia; high risk, intermediate risk or low risk.
Genetic risk of an individual was assessed off of previously published data that identified risk factors for Alzheimer’s disease.
Research Fellow in Neuroepidemiology from the University of Exeter Medical School, Dr Elżbieta Kuźma, says, “This is the first study to analyse the extent to which you may offset your genetic risk of dementia by living a healthy lifestyle.
“Our findings are exciting as they show we can take action to try to counteract our genetic risk for dementia. Sticking to a healthy lifestyle was associated with a reduced risk of dementia, regardless of the genetic risk.”
Researchers assessed lifestyle as either favourable, intermediate or unfavourable and placed participants into one of the three categories based on their diet, physical activity, smoking and alcohol consumption.
No smoking, regular physical activity, a healthy diet and moderate alcohol consumption was considered healthy behaviour and lifestyle by the researchers.
Across all genetic risk groups (high risk, intermediate risk, or low risk), a healthy lifestyle lowered the risk of developing dementia.
Associate Professor at the University of Exeter Medical School and a Fellow at the Alan Turing Institute, Dr David Llewellyn, says, “This research delivers a really important message that undermines a fatalistic view of dementia.
“Some people believe it’s inevitable they’ll develop dementia because of their genetics. However, it appears that you may be able to substantially reduce your dementia risk by living a healthy lifestyle.”
The study was partly funded by Australia’s National Health and Medical Research Council (NHMRC), and Professor Hyppönen anticipates further UniSA and NHMRC involvement in future related research.
Professor Hyppönen says, “This study suggests 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.
“We will be working further to establish pathways and drivers of dementia risk.
“What I find particularly exciting with these new studies is that we will be using hypothesis-free, large-scale data driven approaches, which are not limited by the current scientific understanding, and which therefore will have the potential to suggest new solutions and help to identify new ways to prevent dementia.”
The findings were published in The Journal of the American Medical Association (JAMA) and presented at the Alzheimer’s Association International Conference 2019 in Los Angeles.