APOE4 and What it Means for Dementia and Dementia Prevention

In today’s post, 23andme tests for APOE4, a genetic variant in 20% of the population that is linked to dementia and potentially treatable with over the counter supplements.

I was driving in the fall of 2024, listening to an interview with Dr. Richard Isaacson, the man who started the Alzheimer’s Prevention Clinic.⚭ 

Richard is a neurologist who works in preventative brain heath. He has two skills that I admire: 

1. The ability to clearly explain complex topics. 

2. He’s funny! 

The entire podcast is a good listen, but if you don’t have time right now, let me just tell you about one thing, the thing he said that made me immediately want to pull over and login to 23andme.

APOE4

There is a gene we all have called APOE (Ape-O-E). You get one copy of APOE from each parent and it comes in a few variants. One variant is called APOE4, and it is the single highest genetic risk factor for Alzheimers Disease.⚭

20% of people have one copy of APOE4. 2-5% of people have two copies, one from each parent. The more APOE4, the higher the chance of developing dementia.⚭

If you have done 23andme, you have already tested for this genetic marker and can, RIGHT NOW, know if you have it. (I don’t know about other genetic testing companies, but my guess is they tested for it as well.)

Do I even want to know? The evidence is that people with APOE4 start developing predementia in midlife, one to two decades before anything could be officially diagnosed. The evidence also suggests that the greatest protection against cognitive decline and neurodegeneration in APOE4 carriers can be achieved by increasing Omega 3 levels early in life, several years before the onset of AD dementia.

I wanted to know. I checked, and I don’t carry APOE4. But if you do, and you find out, there may be something you can do.

APOE4 and Fish Oil / Omega 3s

IAlthough it’s not fully understood why APOE4 correlates with dementia, a new study suggests that the highest level of protection against AD dementia for people with the APOE4 is Fish Oil supplements, taken early in life, several years before any signs of dementia. 

What’s odd is that the Fish Oil supplements didn’t work the same on all patients with AD. Only those with APOE4 showed improved brain scans.⚭

Testing for APOE4

So eating more oily fish may only help if you have APOE4. For the curious, check out 23andme. I’m sure there are many other genetic testing resources out there, but 23andme is the one that I have any experience with.

If you already have a 23andme account, here are the steps: Login to 23andMe, type “Late-Onset Alzheimer's Disease” into the search bar, and hit ENTER.

The report will look like this:

The results will tell you if you have zero, one, or two of the APOE4 genes. Only 2% of the population has two of these markers. We hope you don’t, but if you do, my feeling is that it’s better to know now and start working on prevention.

Fingers crossed that you are not 1 in 50.

If you are, we’re here for you, B.

Want to keep reading? Check out the links below.

Brain image scans of patients taking fish oil vs. placebo over 3 years.