Dementia predominantly affects individuals over the age of 65. However, young-onset dementia, which occurs in those under 65, is relatively rare. A recent study, published in JAMA Neurology in December 2023, has uncovered 15 factors that may increase the risk of young-onset dementia.
Let’s explore their findings and importantly, how you can lower your risk.
Are early dementia and young-onset dementia synonymous?
No. Early dementia is considered an initial stage of dementia, encompassing mild cognitive impairment and mild dementia. It can occur in individuals aged 50, 65, or even 88.
Young-onset dementia, however, is defined by the age at which the diagnosis is made. It is characterized by the onset of symptoms and diagnosis before the age of 65.
What has previous research revealed?
Earlier studies, including one focusing on Swedish men, have identified various risk factors for young-onset dementia. These include high blood pressure, stroke, depression, alcohol use disorder, vitamin D deficiency, drug use disorder, and overall cognitive function.
Insights from the new study
The recent study involved a team from the Netherlands and the UK analyzing data from the UK Biobank. This biobank tracks about half a million UK residents, aged 37 to 73 at the time of their enrollment between 2006 and 2010. Most participants were white (89%), with the rest categorized as “other.” Women made up a slight majority (54%).
Excluding individuals over 65 or those already diagnosed with dementia at the study’s start, the researchers focused on 356,052 participants. Over approximately a decade, 485 developed young-onset dementia. The study aimed to identify potential risk factors by comparing those who developed the condition to those who did not.
What were the identified risk factors for young-onset dementia?
The study categorized the risk factors into various groups:
Eight factors believed to cause dementia directly or indirectly:
- Genetics: Specifically, having two apolipoprotein E (APOE) ε4 alleles, linked to Alzheimer’s disease due to inefficient amyloid clearance in the brain.
- Alcohol use disorder (AUD): Associated with damage to various brain regions, leading to impaired executive function and memory.
- Social isolation: A significant risk factor, possibly due to reduced brain engagement and social interactions.
- Vitamin D deficiency: Linked to increased viral infections, which may raise dementia risk.
- Poor hearing: Increases dementia risk, potentially due to reduced brain stimulation. Hearing aids can mitigate this risk.
- History of stroke: Directly damages the brain, potentially leading to vascular dementia.
- Heart disease: A major stroke risk factor, which can then lead to vascular dementia.
- Diabetes in men: Linked to ministrokes and subsequent vascular dementia.
Two factors that diminish cognitive reserve:
- Lower education levels: May impact performance on cognitive tests used for dementia diagnosis.
- Lower socioeconomic status: Possibly related to lower-quality education.
Are all these factors definitive risks?
Not necessarily. Some might be reverse causation, appearing as risk factors due to early dementia symptoms.
- Lower handgrip strength: Indicates frailty, often linked with dementia.
- Abstaining from alcohol: Could be a response to early memory loss.
- Depression: May arise from memory issues or dementia-related concerns.
Other risk factors could be both a cause and an effect of dementia:
- High C-reactive protein: Indicates inflammation.
- Orthostatic hypotension: Could cause or result from certain dementia types.
How to prevent young-onset dementia?
To reduce the risk of developing dementia before 65, consider these steps:
- Avoid excessive alcohol consumption.
- Engage in regular social activities.
- Ensure adequate vitamin D intake, through sunlight exposure or supplements if necessary.
- Maintain good hearing, using aids if needed.
- Exercise regularly, eat healthily, maintain a healthy weight, and work with your doctor to manage risks of strokes, heart disease, and diabetes.