People over 40 in England will be given advice on dementia as part of their free NHS health check.
Guidance on how to reduce the risk of dementia will be given to patients at GP surgeries and through community health programmes.
Public Health England (PHE) said up to one-third of dementia cases could be improved through lifestyle choices.
But its says 28% of people have no awareness of risk factors and only 2% know what they can do to reduce them.
The planned roll-out follows a small pilot conducted by PHE, with the help of Alzheimer's Research UK and the Alzheimer's Society, which led to both charities calling for it to become mandatory.
What is the NHS England over 40s health check?
- Recommended every five years for those aged 40 to 74
- Tests include height, weight, blood, and blood pressure
- Takes 20 to 30 minutes
The current health check in England focuses on reducing the risk of cardiovascular disease.
But the public body says the advice for dementia is much the same, adding: "What's good for the heart is good for the brain."
Maintaining a social life, keeping mentally and physically active, and stopping smoking are all recommended by healthcare professionals as ways of reducing the risk.
More than 14 million people - 91% of those eligible - have been offered an NHS health check over the past five years, but fewer than 50% - or seven million - have had one.
Duncan Selbie, chief executive of PHE, said the check "could add years to your life".
Minister for Public Health, Steve Brine, added: "Early detection and prevention are vital to the health of our nation and our programmes in this area are among the most ambitious in the world.
"Our aim is to keep everyone as healthy as possible, for as long as possible."
Dementia schemes around the UK
A survey by British Social Attitudes showed 52% of adults in the UK named dementia as one of their top three health worries.
The NHS in Wales does not offer the checks, but has a separate scheme called "add to your life" - which targets groups at risk of disease, rather than by age.
It did launch a new dementia strategy earlier this year, however, focusing on early diagnosis at GP level.
Scotland also has a national dementia strategy focusing on early diagnosis and offering all patients diagnosed with the condition a minimum of a year of "high-quality post-diagnostic support."
PHE estimates more than 850,000 people are living with dementia across the UK.