The majority of the public has limited knowledge about dementia and Alzheimer’s disease, with nearly two-thirds believing it’s simply a normal part of aging, a new study has found.

Researchers at Trinity College of Dublin and St. James’s Hospital’s Dementia Services Centre in Ireland analyzed twenty years’ worth of articles on dementia from 15 different countries including France, Israel and the U.K. as part of the study. The results shows that the general public’s understanding of dementia is lacking, with a large majority unsure of when normal age-related memory loss crosses the threshold to dementia.

The most common misconception surrounding dementia and Alzheimer’s was that it’s a normal part of the aging process, researchers said. Many people failed to understand that modifiable risk factors, like smoking and high blood pressure, can influence the disease’s progression.

This lack of understanding from the general public could ultimately lead to those with dementia experiencing stigma, embarrassment and social isolation, researchers said.