The quest for the “fountain of eternal youth” has moved from ancient maps to modern laboratories. We have all wondered at some point what determines how long we will live. As we explored in our previous article on whether a long life can be inherited, the answer is not simple: it is a complex dance between our habits, our environment, and, of course, our DNA.
However, in recent months we have noticed growing concern in our community. Many of you constantly ask us about a very specific protagonist in this molecular dance: the APOE gene.
What are APOE genes and why are they so important?
The APOE gene provides instructions for making a fundamental protein: apolipoprotein E. This protein is responsible for packaging cholesterol and other fats to transport them through the bloodstream. It is essential in removing lipoproteins from the plasma and is directly involved in the maintenance and function of neurons.
Although we all have this gene, we do not all have the same version. There are primarily three APOE variants (alleles):
- E2: The least common, often associated with a protective effect.
- E3: The most frequent in the general population (neutral).
- E4: The variant that causes the most concern and the one most of your questions revolve around.
Despite the APOE gene being the main genetic factor contributing to Alzheimer’s disease (and the most studied), its development has a clear polygenic influence. This means its onset does not depend on a single gene, but on the interaction of various genes involved in different biological processes, such as the production and accumulation of beta-amyloid proteins, neuronal synapses, or lipid metabolism in the brain.
Genetic research has allowed us to advance our understanding of how these various genes contribute to the development of Alzheimer’s, opening new possibilities for more precise diagnoses and personalised treatments in the future.
APOE Gene and Alzheimer’s
It is impossible to talk about longevity without addressing cognitive health. The primary concern for our users when taking an APOE genetic test for Alzheimer’s risk is understanding what it means to have one variant or another.
There is a solid scientific correlation between the APOE4 allele (or E4 variant) and a higher risk of developing late-onset Alzheimer’s. But how does the APOE gene influence Alzheimer’s disease? It is believed that the E4 variant is less efficient at clearing beta-amyloid deposits (plaques) in the brain, a key characteristic of the disease.
Here we break down the most common scenarios you ask us about:
1. The risk of Alzheimer’s: APOE3/E4 and APOE4/E4 We inherit one copy of the gene from each parent.
- If you have an APOE3/E3 combination, you have the most common genotype in the population and your risk is the population average.
- If you are a carrier of one E4 copy (heterozygous, APOE3/E4 genotype), the risk of Alzheimer’s increases slightly.
- Having two APOE4 copies in homozygosis (APOE4/E4) raises the risk further, but it is crucial to remember one thing: risk is not destiny.
2. The multifaceted roles of APOE in Alzheimer’s disease The APOE protein in Alzheimer’s is not just about amyloid plaques. It also influences brain inflammation and glucose metabolism. Therefore, understanding your APOE genotype and its possible relationship with Alzheimer’s is just one piece of the puzzle. There are people with the E4 variant who reach 90 years of age with a sharp mind, and people without it who develop dementia.
Should I have a DNA test for Alzheimer’s?
This is a very personal decision. The revelation of an APOE genotype for Alzheimer’s risk can be impactful, but it is also a powerful prevention tool. If an APOE Alzheimer’s test indicates that you have the E4 variant, it is not a sentence; it is a call to action.
Active Prevention: Your lifestyle rules If you discover you have a genetic predisposition, you can counteract that risk. Science proves that what is good for the heart is good for the brain:
- Regular physical exercise: Improves cerebral blood flow.
- MIND or Mediterranean diet: Reduces inflammation.
- Quality sleep: This is the brain’s cleaning system.
- Cognitive challenge: Learning new things creates cognitive reserve.
Knowing if you have the APOE4 allele associated with Alzheimer’s or protective variants gives you a strategic advantage. The relationship between genetics and longevity is not set in stone.
The tellmeGen DNA test will help you understand that it is one more step towards personalised and preventive medicine, allowing you to take charge of your future health today within your family lineage.