Early Onset Dementia: Signs, Causes, and Risk Reduction
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Dementia symptoms like memory and/or emotional disturbances, agitation, and decreased cognitive functioning, most commonly exhibited in those diagnosed with Alzheimer’s, are not exclusive to the golden years. Early or young-onset dementia is diagnosed when a person is 65 or younger experiences memory loss and other cognitive difficulties associated with Alzheimer’s disease. Early onset dementia—which can occur in a person’s 40s and 50s—is believed to occur in up to 5 percent of the 5 million Americans currently living with Alzheimer’s.

Experts have yet to pinpoint the reason younger adults experience early onset dementia. However, they have narrowed down a few possible causes.

1. Head Trauma

“We can see dementia following a head injury,” says James Giordano, Ph.D. professor of Neurology and Biochemistry and Chief, Neuroethics Studies Program, Pellegrino Center for Clinical Bioethics at Georgetown University Medical Center. Chronic traumatic encephalopathy (CTE) is a degenerative brain disease often occurring in those with a history of repetitive brain injuries (football players, boxers, military veterans, etc.) and can cause dementia-like symptoms in those much younger than 65. Concussions and Alzheimer’s disease also share a surprising link. “Early-onset dementia can also occur in an individual with vascular problems. The same inflammatory causes of clogging or hardening of the arteries can negatively affect the brain.”

2. Genetics

But Giordano says your DNA is likely the biggest culprit and contributor to a diagnosis of early-onset dementia. “There is a very strong genetic component to early-onset dementia,” he explains. “A few genes that directly cause Alzheimer’s disease have been identified and those who inherit them from their parents can develop symptoms as early as in their 30s.” This is called familial early-onset dementia.

3. Inflammation

Early-onset dementia can occur in those without a family history and genetic risk of the condition. In those instances, Giordano says inflammation is believed to be what triggers changes in the brain resulting in the diagnosis of early onset dementia.

“A high level of inflammation in the body can cause diabetes and/or heart disease, among other things,” he explains. “That same type of inflammation is now believed to induce actions in the brain that lead to dementia symptoms.” Learning how to keep an anti-inflammatory diet may help to guard against general inflammation in the body.

Exposure to toxins like aluminum and lead has also been examined as a possible—albeit less likely—risk of triggering the inflammatory state that leads to dementia-inducing changes in the brain.

4. Weight

A new study with 1.3 million participants in the U.S. and Europe published in the Alzheimer's & Dementia journal says those with a high body mass index (BMI) are more likely to develop dementia than those with a normal weight.

"The BMI-dementia association observed in longitudinal population studies, such as ours, is actually attributable to two processes," said lead author of the study, Professor Mika Kivimäki (UCL Institute of Epidemiology & Health). "One is an adverse effect of excess body fat on dementia risk. The other is weight loss due to preclinical dementia. For this reason, people who develop dementia may have a higher-than-average body mass index some 20 years before dementia onset, but close to overt dementia have a lower BMI than those who remain healthy. The new study confirms both the adverse effect of obesity as well as weight loss caused by metabolic changes during the pre-dementia stage."

Giordano says he’s not surprised by the new study’s findings. If your scales readout is inching upward due to visceral, or belly, fat, Giordano says you could have an even higher risk for early onset dementia than those who carry excess weight all over their body. “Apple shapes can be a bit more dangerous because that visceral fat is white fat, which triggers a cascade of chemicals in the body that can increase glucose sensitivity and ultimately inflammation.” It can be beneficial to look into a diet plan that can help guard against dementia to help maintain a healthy weight and optimal brain health.

The younger a person is, the more likely genetics (familial history) are the cause of early-onset dementia. Alzheimer's disease, vascular disease, FTD, and Dementia with Lewy bodies are other common causes of dementia in younger people.

Signs of Early Onset Dementia

It is important to recognize the signs of early-onset dementia. Even though we don’t have a cure or treatment for dementia, having a diagnosis can help families plan for the future and address quality of life issues. These are some of the signs of the mental decline associated with early-onset dementia.

  • Memory problems (especially short-term) and difficulty learning and retaining new information
  • Asking the same information over and over again
  • Trouble solving problems like keeping up with paying bills, cooking, or following directions
  • Losing track of the day or time of year
  • Trouble with depth perception or other visual problems
  • Getting lost or wandering
  • Increasingly poor judgment which can compromise safety
  • Changes in mood and personality

Diagnosing Early Onset Dementia

Giordano says that regardless of a person’s age, early diagnosis of any cognitive changes is important to finding the most appropriate intervention that may help slow the progression of the disease because, “You can’t reverse memory loss or other neurological changes, but you may be able to slow down any new loss or changes.”

He says diagnosing early onset dementia can be tricky because many patients—or their loved ones—may justify symptoms like memory loss to stress and/or a hectic lifestyle and “As a result, they don’t speak to their doctor to have a diagnostic evaluation that may lead to interventions.”

Evaluation of the diagnosis includes pencil and paper tests administered by a clinician. The results may indicate loss of cognitive function at an early stage. “Blood tests to detect the presence of inflammatory markers and also tests that determine if the person has a strong genetic risk of early onset dementia and an MRI screening are also commonly used to diagnose the condition,” says Giordano.

Reducing Your Risk of Early Onset Dementia

“A healthy lifestyle that includes a well-balanced diet and daily exercise promotes a healthy weight that then counters a body’s inflammatory response and reduces the risk of non-familial, early-onset dementia,” he explains. Your brain is less likely to be subjected to negative changes that occur when the body is battling inflammation.

Other lifestyle changes may or may not prevent or even reduce someone’s risk, but having a foundation of both physical and mental health may mitigate the symptoms of the disease or slow the progression. These are some of the health-related conditions associated with Alzheimer's disease and other dementias:

  • Risks associated with cardiovascular disease like high blood pressure, diabetes, and high cholesterol also increase the risk of Alzheimer’s disease. The message here is to control cardiovascular disease to reduce your risk of many heart-related conditions along with Alzheimer’s disease.
  • Physical exercise increases blood oxygen flow to the brain and improves mood.
  • Heart-healthy eating may protect the brain. This includes limiting the intake of sugar and saturated fats and making sure to eat plenty of fruits, vegetables, and whole grains. Avoid processed foods.
  • Several studies show that maintaining social connections and engaging in stimulating activities may lower the risk of cognitive decline.

Managing Early Onset Dementia

An early-onset dementia diagnosis can be devastating for families and their loved ones. However, there are concrete steps to take to manage someone’s health and well being. Without a cure or viable treatment, focus on the positive changes you can make to help someone cope with this challenging disease.


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About the Author(s)

For over two decades, Gina Roberts-Grey has pored over studies and interviewed leading health experts on topics ranging from healthy aging, caregiving and longevity. Having been an active caregiver to her grandparents who lived into their 90’s, Gina is passionate about supporting caregivers through their journeys. Her work has been featured in publications like Woman’s Day, AARP, Oprah, Neurology Now and many more.

Amanda Lambert is the owner and president of Lambert Care Management, LLC which provides care management for older and disabled adults. She is the co-author of Choose Your Place: Rethinking Home as You Age (November 2020) and of Aging with Care: Your Guide to Hiring and Managing Caregivers at Home (Rowman and Littlefield, 2018). She has worked for over 20 years in the senior-related industry including mental health, marketing and guardianship. She has a passion for topics related to health, wellness and resilience as we age.

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