Dementia Medical Myths 1 -3

 Medical myths: All about dementia written by Tim Newman on September 21, 2020 — Fact checked by Zia Sherrell, MPH

In our Medical Myths series, we approach medical misinformation head-on. Using expert insight and peer-reviewed research to wrestle fact from fiction, MNT brings clarity to the myth-riddled world of health journalism.

Dementia is not a normal part of aging.

Today, an estimated 5.8 million people aged 65 years or older in the United States have dementia.

Due to the fact that the average lifespan of people in the U.S. has increased over recent decades, some experts project that by 2050, the number of older adults with dementia could reach 13.8 million.

Figures of this stature spark justifiable fear, and, as we have found in previous Medical Myths articles, fear tends to breed misconceptions.

In this article, we aim to dispel 11 of these myths.

1. Dementia is inevitable with age

This statement is not true. Dementia is not a normal part of aging. According to a report that the Alzheimer’s Association published, Alzheimer’s disease, which is the most common form of dementia, affects 3% of people aged 65–74 years in the U.S. As a result of the risk increasing as we age, 17% of people aged 75–84 years and 32% of people aged 85 years and older have a dementia diagnosis.

2. Dementia and Alzheimer’s disease are the same things

This is not quite correct. Alzheimer’s is a type of dementia, accounting for 60–80% of all dementia cases. Other types of dementia include frontotemporal dementia (FTD), vascular dementia, mixed dementia, and Lewy body dementia.

The National Institute on Aging defines dementia as “the loss of cognitive functioning — thinking, remembering, and reasoning — and behavioural abilities to such an extent that it interferes with a person’s daily life and activities.”

Although dementias share certain characteristics, each type has a distinct underlying pathology. Alzheimer’s disease is associated with a buildup of so-called plaques and tangles in the brain. These structures interfere with brain cells, eventually killing them. In contrast, brain cell death in vascular dementia occurs due to a lack of oxygen, which can result from a stroke, for instance.

3. A family member has dementia, so I will get it

A common myth is that dementia is purely genetic. In other words, if a person’s family member has a dementia diagnosis, they are guaranteed to develop dementia later in life. This is not true.

Although there is a genetic component to some forms of dementia, the majority of cases do not have a strong genetic link. As we learned above, rather than genetic factors, the most significant risk factor for dementia is age. However, if a parent or grandparent developed Alzheimer’s when they were younger than 65 years, the chance of it passing on genetically is higher.

Early-onset Alzheimer’s is relatively uncommon, though. It occurs in about 5.5% of all Alzheimer’s cases.

As the majority of dementia cases are Alzheimer’s disease, this means that most dementia cases are not hereditary. But if a parent or grandparent develops the condition, it does not mean that children or grandchildren are guaranteed to develop it.