New research into dementia risk factors suggests preventative measures should be specific to each individual.
The study says controlling blood pressure, and having a healthier lifestyle before middle age, could reduce the risk of developing dementia in later life.
They looked at risk factors including age, sex, history of cardiovascular disease, diabetes and blood pressure.
The researchers found differing vascular risk factors for dementia among various age groups.
High blood pressure and diabetes were the most important indicators at the age of 55, while cardiovascular disease was identified as the main risk for 65-year-olds.
For respondents aged 70 and 75, a previous stroke or diabetes were among the potential predictors for loss of cognitive function. These risks were also common to 80-year-olds, who had uncontrolled blood pressure.
Professor Emer McGrath, from the College of Medicine at NUI Galway, led the study and said predicting future risk can help reduce it.
The findings show people who had diabetes at the age of 55 were four times more likely to go on to develop dementia than those who did not have diabetes at that age.
Those with heart disease at age 65 were nearly twice as likely to later develop dementia, while people with a stroke at age 70 were over three times more likely to develop the condition.
Prof McGrath said the findings suggest preventative measures need to be tailored for each individual.
It is thought this would be more effective than a 'one-size-fits-all' approach to dementia risk prediction.
She pointed out that early interventions could significantly reduce the chance of developing cognitive issues in later life.
The Alzheimer Association of Ireland has said 64,000 people are living with dementia in Ireland.
It is estimated that the number of people with the condition will more than double in the next 25 years.