Half of British adults cannot identify any major risk factors for dementia, according to a study by Alzheimer's Research UK.
The charity investigated 2,361 people and found that only 1% could mention the seven known risks or protective factors for dementia.
The six risk factors are heavy drinking, genetics, smoking, high blood pressure, depression and diabetes.
Physical exercise is a protective factor against the disease.
The study, called Dementia Attitudes Monitor, found that more than half of British adults now know someone with dementia.
But only half acknowledged that dementia is the cause of death, and they found that a fifth mistakenly thinks it's an inevitable part of getting older.
Although one third of dementia is considered to be influenced by factors below our control, only 34% of those surveyed believe it is possible to reduce the risk of dementia, compared to 77% for heart disease and 81% for diabetes.
Hilary Evans, managing director of Alzheimer's Research UK, said that despite growing dementia awareness, there was still much misinformation.
"It's a sad truth that more people are afflicted with dementia than ever before, and half of us now know someone with the condition," she said.
"Despite growing dementia awareness, we need to work harder to improve understanding of the diseases that cause it."
- More than 850,000 people in the UK live with dementia.
- This figure will increase to more than one million by 2025.
- Dementia is an umbrella term for a set of symptoms that affect cognitive function, such as memory loss, confusion and personality change, which become worse over time.
- Alzheimer's disease is the most common cause of dementia, which accounts for approx. two thirds of all cases.
- A person's risk of developing dementia consists of various factors, including age, genetics and lifestyle.
Source: Alzheimer's Research UK
Sue Strachan is 63 years old and lives in Herefordshire. She was diagnosed with vascular dementia in 2014.
"I was not very fit when I was diagnosed with dementia and my doctor advised me to take exercise to try and cope with my condition," she said.
"I wish I had started earlier because good heart health can have such a positive effect on the brain. I can see that society's view of dementia is getting better, but I still experience misconception about the condition – not least that not something that can be done to help. "
Sue ran last year's London Marathon for Alzheimer's Research UK to raise awareness.
The charity said reducing the number of people who believe that dementia is an inevitable part of aging is "key" as "this belief drives other negative attitudes to dementia".
"Our findings show that those who believe dementia are an inevitable part of aging are less likely to see value by seeking a formal diagnosis and are less likely to engage in research projects that can lead to life-changing treatments and in the end. end a cure. "
The study found main groups of people whose understanding of dementia is lower, including those from black, asian and minority ethnic backgrounds and adults under 24 and over 65 years of age.
There is currently no dementia test, but the study showed that if there was a breakthrough in research, 85% would be willing to take a test through their doctor before the symptoms showed.
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