Recent research sheds new light on the risk factors for developing dementia before the age of 65. While dementia is typically associated with individuals aged 65 and older, young-onset dementia, which occurs in those younger than 65, remains relatively rare. A groundbreaking study published in December 2023 in JAMA Neurology has pinpointed 15 key factors associated with an increased risk of young-onset dementia. Here, we’ll explore these findings and discuss actionable steps you can take to mitigate your risk.

Distinguishing Early Dementia from Young-Onset Dementia

Early dementia refers to the initial stages of dementia, including mild cognitive impairment and mild dementia, and can occur at any age, from 50 to 88. In contrast, young-onset dementia is specifically defined by the age of diagnosis—before 65.

Insights from Previous Research

A previous Swedish study identified several risk factors for young-onset dementia, including high blood pressure, stroke, depression, alcohol use disorder, vitamin D deficiency, drug use disorder, and overall cognitive function.

Key Findings from the Recent Study

The new study, conducted by research teams in the Netherlands and the United Kingdom, utilized data from the UK Biobank. This biobank includes approximately 500,000 individuals in the UK, aged 37 to 73, who joined between 2006 and 2010. Of the participants, 89% identified as white, and 11% were categorized as “other,” with slightly more than half being women. Participants aged 65 or older and those with pre-existing dementia were excluded, leaving 356,052 individuals for analysis. Over the course of about a decade, 485 participants developed young-onset dementia. The researchers compared those who developed young-onset dementia with those who did not, identifying various risk factors.

Identified Risk Factors for Young-Onset Dementia

Eight Known or Suspected Causes of Dementia:

1. Genetics: Carrying two apolipoprotein E (APOE) ε4 alleles significantly increases the risk of Alzheimer’s disease. This genetic variant impairs the brain’s ability to clear amyloid, leading to plaque formation and subsequent neurodegeneration.
2. Alcohol Use Disorder (AUD): AUD is linked to damage in several brain regions, including the frontal lobes, impacting executive functions and working memory. Coupled with poor nutrition, AUD can also harm brain areas crucial for memory formation.
3. Social Isolation: Social interactions are crucial for brain health. Reduced social engagement may contribute to cognitive decline due to decreased brain stimulation.
4. Vitamin D Deficiency: Insufficient vitamin D can lead to increased susceptibility to viral infections, some of which may heighten dementia risk.
5. Hearing Loss: Poor hearing is associated with a higher dementia risk, likely due to decreased brain stimulation and social interaction. Hearing aids can help mitigate this risk.
6. Previous Stroke: Strokes cause direct brain damage, increasing the likelihood of developing vascular dementia.
7. Heart Disease: Heart disease is a major risk factor for strokes, which can subsequently lead to vascular dementia.
8. Diabetes in Men: Diabetes can contribute to dementia through various mechanisms, including ministrokes, which are more common in middle-aged men than women.

Two Factors Affecting Cognitive Reserve:

1. Lower Formal Education: Limited education may affect familiarity with cognitive tests used in diagnosing dementia, potentially leading to earlier detection of symptoms.
2. Lower Socioeconomic Status: This factor may be associated with lower-quality education and reduced cognitive reserve.

Ambiguities in Risk Factors

Not all identified factors are clear-cut. Some factors might be indicative rather than causative. For example:

• Lower Handgrip Strength: Often associated with frailty and dementia, but it may not directly cause dementia.
• No Alcohol Use: Some individuals may stop drinking due to early symptoms of memory loss, reflecting the “healthy drinker effect.”
• Depression: May arise as a response to memory issues or dementia-related worries.
• High C-Reactive Protein: Indicates inflammation, which might be both a risk factor and a consequence of developing dementia.
• Orthostatic Hypotension: An abnormal drop in blood pressure upon standing, which can lead to brain damage but may also result from certain types of dementia.

Preventive Measures for Young-Onset Dementia

To reduce the risk of developing dementia before age 65, consider these five strategies:

1. Moderate Alcohol Consumption: Avoid excessive drinking to minimize brain damage and other related risks.
2. Social Engagement: Regularly seek opportunities for social interaction to stimulate cognitive health.
3. Vitamin D: Ensure adequate vitamin D intake through sunlight exposure or supplements, especially in northern climates. Consult your doctor before starting any new supplements.
4. Hearing Health: Address hearing loss promptly and use hearing aids if necessary to maintain brain stimulation and social interaction.
5. Healthy Lifestyle: Engage in regular physical exercise, maintain a balanced diet, and work with your healthcare provider to manage risks related to strokes, heart disease, and diabetes.

By understanding these risk factors and implementing preventive measures, you can take proactive steps to protect your cognitive health and potentially reduce the likelihood of young-onset dementia.

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