Some people have genes that put them more at risk of the condition but this research shows that everyone can lower the risk by leading a healthy lifestyle.
The study, led by researchers at the University of Exeter, was revealed at the Alzheimer’s Association International Conference.
They collected data over eight years from almost 196,383 adults of European ancestry aged 60 and over in the UK. The participants were asked about their lifestyles and their DNA was tested to see who carried the genes that mean they are more at risk of developing Alzheimer’s.
They found that among the people who had the genes, only about 11 in every 1,000 with healthier lifestyles developed the condition, compared to 18 in every 1,000 with unhealthy lifestyles.
They looked at four key factors that were previously associated with reducing dementia risk: getting enough exercise, not smoking, eating from multiple food groups with little processed meat and lots of fruit and fish, and drinking one or fewer standard alcoholic drinks a day for women and two or fewer for men.
Everyone was then given a score to show how healthy their lifestyle is and the participants were tracked for eight years.
Joint lead author Dr Elżbieta Kuźma, at the University of Exeter Medical School, said: ‘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 that we can take action to try to offset our genetic risk for dementia. Sticking to a healthy lifestyle was associated with a reduced risk of dementia, regardless of the genetic risk.’
The study was led by the University of Exeter in collaboration with researchers from the University of Michigan, the University of Oxford, and the University of South Australia.
There are some limitations as some cases of dementia could have been missed – the researches relied on hospital inpatient records and death certificates – but they say the research is promising.
Developing dementia in your 60s is also at the younger end of old age but the researchers plan to continue following the group as they get older.