New Research on Young Onset Dementia

You may have seen news articles about a study of young onset dementia published in Nature Neurology.  We discussed younger onset (or familial) Alzheimer's disease (AD) in Beating the Dementia Monster.  We said that, while the cause is much more (perhaps entirely) influenced by genetics than older onset (or sporadic) Alzheimer's, it is often very much affected by lifestyle interventions.  But when I began to read the news articles about it, I got the impression the researchers found most young onset dementias were being caused by lifestyle factors -- smoking, alcohol abuse, sedentary lifestyle, etc.

I went to the journal web site where I could read the abstract without having to purchase the whole article.  After reading the abstract, I figured a couple of things out.  First, as we've noted before, "young" refers to under 65 years of age.  (I didn't always think of that as "young," but I sure do now!)  But also, the article was about all causes of dementia, not just Alzheimer's disease.  So the article addressed dementias that included those from vitamin deficiencies, stroke, etc.  Alzheimer's is conceivably a minority of these dementias in the "young."

I was surprised that the researchers found a correlation with the APOE "risk gene" that we discussed in Beating the Dementia Monster.  This gene is normally associated with old onset Alzheimer's.  And they didn't mention the "deterministic genes" we discussed associated with young onset Alzheimer's.  If you have these genes, you almost certainly will get young onset AD.

The research was conducted by scientists from Maastricht University and the University of Exeter.  They studied 350,000 cases in a European database.  The study found 15 factors associated with the development of young onset dementia, including (with my own comments):

Lower formal education (early learning appears to affect how the brain develops)

Lower socioeconomic status (I believe this correlates with other lifestyle habits, such as smoking, alcohol use, diet, and exercise)

Presence of the fourth variant of the APOE gene (I thought this only went with old onset AD)

Excess alcohol use

No alcohol use (a surprise, but alcohol abstinence may be necessitated by other risk factors)

Social isolation (we have discussed this before)

Hearing loss (this promotes social isolation)

Vitamin D deficiency (they don't mention vitamin B12, which we have discussed before)

High levels of C-reactive protein (a symptom of inflammation in the body which promotes AD)

Reduced hand-grip strength (I'm not sure why this is other than a reflection of physical fitness)

Orthostatic hypotension (a likely heart issue)

Stroke (Obviously)

Diabetes (a well-known correlation with Alzheimer's disease)

Heart disease ("What's good for the heart is good for the brain")

Depression (Possible association with social isolation)

So what is modifiable in this list?  There's not much that's inconsistent with the Dementia Toolkit we provided in Beating the Dementia Monster.  But it surprised me that they did not mention diet or exercise.  Of course, these are highly associated with vitamin deficiencies, heart disease, and diabetes.