Less than half of people over 40 years old have taken a free health check that can reduce the risk of developing dementia, according to NHS England.
Approximately 15 million people have the right to undergo a 20-minute estimate that shows for heart problems, kidney disease and type 2 diabetes over the past five years.
Dementia and Alzheimer's disease remained the leading cause of death in England and Wales in 2017, representing nearly 13% of all registered deaths, according to the Office of National Statistics.
Someone who has a stroke or has diabetes or heart disease is about twice as likely to develop vascular dementia, according to the Alzheimer's Association.
"The beginning of the new year is precisely the right time to commit to taking a simple, free and potentially life-saving step towards a healthier life," said Alister Barnes, the national clinical director of dementia in England.
Anyone between the ages of 40 and 74 with no pre-existing health conditions automatically responds to the check every five years. It is part of England's goal of improving the early diagnosis of dementia.
Laura Phips, head of communications in the Alzheimer's UK study, says: "There is good evidence that good for the heart is also good for the brain, but while 77% of people believe they can reduce the risk of heart disease, only 34 % of people know they can reduce the risk of dementia.
"Research shows that the middle of life is a crucial time to take action that will help maintain a healthy brain in later life. With dementia now the leading cause of death in the UK, we must encourage everyone to take positive steps to maintain good brain health throughout life and at an older age. "
Jamie Vaol, who heads the public health program in England, said: "The NHS Health Check examines the main causes of premature death and ill health, but more importantly, it supports people to take action to reduce the risk of preventative conditions such as are dementia and heart disease. "
NHS England said the national goal of providing at least two-thirds of people living with dementia had been diagnosed and treated had been met in the past two years.