Dementia Life Expectancy for Older Adults

More than 55 million people worldwide experience dementia, with dementia affecting more females than males. Dementia is the seventh leading cause of death globally, and Alzheimer's disease is the most common form of dementia.

Several other forms of dementia exist. Life expectancy after a dementia diagnosis is affected by the age of diagnosis and the type of dementia. Those diagnosed after the age of 70 or 80 tend to have a shorter life expectancy after diagnosis. There are several steps an individual can take to prolong the quality of life after diagnosis.

This article will discuss the different types of dementia, life expectancy after diagnosis, and factors that affect life expectancy.

How Dementia Affects Older Adults

While some age-related memory changes are expected, dementia is not considered a normal part of aging. Yet age, in and of itself, is the strongest known risk factor for dementia.

This is due to changes in the brains of older adults. About 3% of people ages 70 to 74 are diagnosed with dementia, but that rises to 22% between the ages of 85 and 89, and 33% of those over age 90.

It's common to occasionally forget where you put your keys or the name of the person you just met. What is not normal aging is forgetting the knowledge you once needed regularly to do your job, language, or important memories. Dementia disease symptoms can include:

• Taking longer or needing help to complete basic tasks you always did yourself
• Forgetting the names of people, what objects are called, or what things are used for
• Misplacing your things, or getting lost yourself

Certain lifestyle factors are associated with dementia in older adults, including social isolation and the built environment of the community you live in.

Young-Onset Dementia

There is a subset of dementia called young-onset dementia. In younger individuals, neurodegenerative dementias, such as Alzheimer's disease, are more likely caused by genetics.

Additionally, it is more common that the cause of dementia is reversible in younger populations. Dementia can have metabolic, inflammatory, viral, or toxic causes. Sometimes, these conditions are treatable.

The initial symptoms of young-onset dementia are often more variable than those of late-onset dementia. Symptoms may include challenges with behavior, personality changes, or executive functioning challenges. The initial presentation may look more like a psychiatric illness than dementia. As a result, delays in diagnosis are common.

Risk Factors

While scientists don't entirely understand what causes dementia, they suspect that a combination of changes in the brain from aging, combined with genetic, lifestyle, and environmental factors, play a role. There are several risk factors for dementia.

• Age: Dementia typically occurs in individuals age 65 and older. Age is the strongest risk factor for dementia.
• Family history: Dementia can run in families. If you have an immediate family member with dementia (e.g., a parent or sibling), you may be at a higher risk.
• Race and ethnicity: Black and Hispanic populations have higher rates of dementia than Caucasian individuals.
• Cardiovascular health: Poorly controlled high blood pressure and high cholesterol increase dementia risk.
• Smoking: Smoking increases the risk of dementia.
• Traumatic brain injury: A severe head injury or repeated head injuries can increase dementia risk.

It can take some time for symptoms to develop, too. It is theorized that the brain changes that lead to the symptoms of Alzheimer's begin over a decade before any noticeable symptoms appear.

Life Expectancy for Different Types of Dementia

Life expectancy after diagnosis depends on several factors, including age at diagnosis, the stage of dementia, other health conditions, general health, and the type of dementia.

For example, individuals with cardiovascular disease may be more likely to develop dementia. Their cardiovascular disease may contribute to a shorter life expectancy.

Individuals who receive a late-stage diagnosis may experience difficulties with swallowing or a weakened immune response. They may spend more time in bed, leading to increased frailty. These factors can all lead to a shorter life expectancy.

The type of dementia also plays a role. Those with vascular dementia are at an increased risk of heart disease and stroke. So, someone with this type of dementia may have a shorter life expectancy, regardless of the stage of dementia they are in.

The average life expectancy for several types of dementia is as follows:

• Alzheimer's Disease: Eight to 10 years
• Vascular Dementia: Five years
• Dementia With Lewy Bodies: Six years
• Frontotemporal Dementia: Six to eight years

These are simply averages. Someone with Alzheimer's disease may live beyond 10 years if they are diagnosed at a younger age and in overall good health at diagnosis. However, someone diagnosed with dementia with Lewy bodies may be at an increased fall risk and have a shorter life expectancy.

Factors That Affect Life Expectancy

Taking care of your mental and physical health is essential in early-stage dementia. This means eating healthy, exercising, staying social, focusing on good sleep, and being mindful.

Several factors determine longevity after diagnosis. Being a female, receiving an Alzheimer's disease diagnosis vs. a different type of dementia, younger age at diagnosis, and an earlier stage of dementia all contribute positively to a longer lifespan.

Other factors can negatively affect life expectancy, such as:

• Older age
• Male gender
• Frailty
• Living alone
• Polypharmacy (taking five or more prescription medications)
• Certain dementia subtypes, such as Parkinson-Plus Syndrome (PPS) and dementia due to multiple etiologies (DMA)

Increased age and male gender are the most consistent factors for reduced life expectancy after diagnosis. While these risk factors are non-modifiable, you can still improve your quality of life.

How to Improve Your Quality of Life

Once an individual has been diagnosed with dementia, care recommendations include:

• Providing holistic care that focuses on other health conditions the person may have along with dementia. Those with dementia may experience difficulty caring for themselves and managing their conditions. Addressing an individual's mental health care and social support are essential, too.
• Managing the individual's neuropsychiatric symptoms and recognizing that psychotropic drugs may be ineffective and harmful in those with dementia
• Caring for family members reduces the strain of caregiving and improves the patient's quality of life

The extent to which a person with the disease can maintain their social relationships can also play a significant role. Patients should talk with their doctor or a psychologist for strategies to cope with social situations.

In addition, maintaining household responsibilities for as long as possible can help improve the quality of life and prevent an individual from being chair-bound. In later stages, a patient's needs may change, and caregivers need to know how to care for themselves and their loved ones.

While there is no cure for dementia, maintaining a healthy lifestyle can delay the disease's onset or prevent it from happening in some instances. Once diagnosed, several measures can provide whole-person dementia care.

Keep in mind, though, that many people live with severe disability due to their advancing disease. A 2020 study found that among more than 50,000 people ages 65 and over who were diagnosed with dementia, about 41% died within 10 years. The average survival time was a little over five years for females and four years for males.

Preventing Dementia

Regarding dementia, diagnosis, and onset may be partially preventable with lifestyle modification. A 2022 study examined five healthy lifestyle factors of several thousand men and women aged 65 and older. The five factors included:

• Diet
• Cognitive activities
• Physical activity
• Smoking
• Alcohol consumption

Those with four or five healthy lifestyle factors as opposed to zero or one healthy lifestyle factor had a longer life expectancy and fewer years of life with Alzheimer's disease. Individuals who maintain a healthy lifestyle may have a 60% reduced rate of developing Alzheimer's disease.

A 2020 report on dementia lists 12 preventable risk factors for dementia and estimates that 40% of dementia cases could be prevented if those risk factors are modified. Actions individuals can take to reduce dementia risk include the following:

• Managing hypertension (high blood pressure)
• Reducing hearing loss and using hearing aids as needed
• Reducing exposure to air pollution, including from second-hand smoke
• Preventing head injury
• Quitting smoking
• Maintaining a healthy weight and reducing obesity
• Managing diabetes
• Remaining physically active
• Getting quality sleep

Medications to treat high blood pressure are currently the only known medications that can help prevent dementia.

There have been many studies looking into the use of puzzles and other forms of "mental fitness" to help delay or prevent Alzheimer's disease and dementia. A famous older study of nuns showed that the individuals most curious and engaged mentally in the world had a lower risk of developing Alzheimer's disease and dementia.

Summary

Dementia is a common condition among people 65 and older. While it is more common in older individuals, it is not a part of normal aging.

Dementia cannot be entirely prevented, but several modifiable risk factors and lifestyle factors can delay the onset of dementia. In some instances, lifestyle modifications may prevent dementia from happening. For example, quitting smoking, remaining active, and managing chronic health conditions such as high blood pressure can all reduce dementia risk.

There is no cure for dementia. However, several ways exist to improve your quality of life after a dementia diagnosis. If you are concerned that you are someone you care about may be experiencing dementia, contact your healthcare provider for advice.