young-onset dementia (YOD)

Major Study Links 15 Factors to Early Dementia Risk
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Low socioeconomic status, social isolation, hearing impairment,
stroke, diabetes, heart disease, and depression were all associated
with a higher risk of YOD.

Vitamin D deficiency and high levels of the C-reactive protein
(produced by the liver in response to inflammation) also meant a
higher risk, as did having two of the ApoE4 e4 gene variants (a
genetic scenario already linked to Alzheimer's disease).

The researchers described the relationship between alcohol and YOD as
"complex".

While alcohol abuse led to an increased risk, moderate to heavy
drinking correlated with a reduced risk - possibly because people in
this second group are usually healthier in general (bear in mind that
those who abstain from alcohol often do so on medical grounds).

Higher levels of formal education and lower physical frailty (measured
through higher handgrip strength) were also associated with a lower
YOD risk. This all helps to fill in some of the knowledge gaps around
YOD.

https://www.sciencealert.com/major-study-links-15-factors-to-early-dementia-risk