APOE: Is This Gene Linked To Alzheimer’s?

Written by Lewis Cuthbertson, PhD | Last updated:

After age, the ApoE gene is the single greatest risk factor for late-onset Alzheimer’s disease. Read on to find out more and what you can do to identify whether you’re at an increased risk of Alzheimer’s and what you can do to lower your risk.

What is APOE?

The ApoE gene codes for the ApoE protein. The main functions of this protein are transporting cholesterol in the bloodstream, repairing injury and clearing a protein called beta-amyloid in the brain.

Due to how important these functions are for overall health, this gene has been the target of considerable research. As a result, scientists discovered that after age, this gene is the single most important risk factor for late-onset Alzheimer’s disease, as well as a contributing factor for cardiovascular disease.

APOE Variants

The three most common ApoE genetic variants are ApoE e2, ApoE e3, and ApoE e4. Every individual carries two of these variants, which can constitute either two of the same variant e.g. e3/e3 or a combination e.g. e3/e4.

ApoE e3 is the most common genetic variant of this gene found in 79% of people, followed by the e4 (14%) and e2 (7%) variants.

Each variant of this gene produces an ApoE protein which functions differently, and the combination of variants you carry has an impact on your health.

Is Alzheimer’s Genetic?

If you google ApoE then the first thing you’ll likely come across are links to pages about Alzheimer’s. As mentioned earlier we now know that the variants of the ApoE gene you carry are the largest genetic factor in determining your risk of late-onset Alzheimer’s disease.

The exact mechanism behind this link isn’t clear yet. Clumps of a protein called beta-amyloid are often found in the brain of those with Alzheimer’s, and these clumps are thought to disrupt signaling in the brain leading to the symptoms of Alzheimer’s.

ApoE is involved in the removal of beta-amyloid in the brain, so if your ApoE gene is lower functioning and less beta-amyloid is being removed from your brain, you are more likely to have a buildup of these clumps and go on to develop Alzheimer’s.

The genetic variant of this gene linked to an increased risk of the disease is the e4 variant which is thought to be lower functioning. Carrying just one copy of the ApoE e4 variant may increase your risk of developing Alzheimer’s by 2 to 3 times. Worse yet, carrying two copies of this variant can increase your risk by as much as 12 times.

On the other hand, carrying just one of the rare e2 variants has been linked to an up to 40% reduction in risk of Alzheimer’s. The most common variant e3 doesn’t represent either an increased or decreased risk of Alzheimer’s.

Even if you carry one or two e4 genetic variants it’s not all doom and gloom though. Alzheimer’s risk isn’t entirely determined by our genetics, it’s actually a combination of our genes, lifestyle and environment.

In fact, if you do happen to identify that you’re at an increased risk of Alzheimer’s genetically, there are specific lifestyle and environment changes you can make to optimize your genetic health and lower your risk.

Is there an ApoE test?

When it comes to the ApoE gene 23andMe and SelfDecode are great examples of services that you can use to identify which variant(s) you carry and whether you’re at an increased risk of Alzheimer’s or other health conditions.

Whilst knowing whether you are at an increased risk of a disease based upon your genetics can be scary, finding out early that you are more predisposed to a condition can help you to make lifestyle adjustments to lower your risk. This may actually put you at a lower overall risk of developing Alzheimer’s than someone who carries a favorable ApoE variant but does not optimize their health.

If you’re interested in not only identifying whether you are at risk, but also how you can counteract a poorly functioning ApoE variant, consider SelfDecode’s dedicated ApoE Genetic Report. This report not only identifies which gene variants you carry, but also provides you with personalized recommendations based on your genotype, for example they provide ways to decrease amyloid levels in the brain if you happen to carry an e4 variant.


The ApoE gene influences many aspects of your health, and has been found to be the greatest genetic factor when it comes to your risk of developing late-onset Alzheimer’s disease. As a result of this, it’s particularly important that you learn as early as possible which gene variants you carry so that you can take action to counteract your risk of developing the disease.

Genetic health services can assist you by helping to identify your ApoE genotype and SelfDecode in particular also offer personalized diet, lifestyle and supplement recommendations to optimize the function of your ApoE gene even if you carry a poorly functioning genetic variant.


About the Author

Lewis Cuthbertson

Lewis completed his PhD in Molecular Microbiology at Northumbria University (UK).Lewis spent several years researching the biodiversity of bacterial communities in the Arctic and Antarctic, whilst also performing research for a DNA sequencing service, where he was involved in several health based microbiome studies. This gave him an insight into how the highly diverse and invisible to the naked eye portion of human health, can potentially impact an individual’s quality of life, driving his desire to help others understand their own complex health needs through the most current scientific research.


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