The Link Between Alzheimer's Disease and Genes (Alzheimer's & APOE4 Gene) - Are You Also at Risk?

We all have a little fear of memory loss as we age, don't we? Especially if someone in your family has had a disease like Alzheimer 's, the question 'Will I get it too?' may be on the back of your mind. How do our genes actually affect this? Recent research suggests that there is a stronger link between a specific gene called APOE4 and Alzheimer's disease than previously thought. So today, let's talk about this, whether it affects you, and what we can do about it.

What exactly is this gene called APOE4?

Simply put, APOE is a gene in our body. Its main job is to transport fats , such as cholesterol, between our cells (lipid transport). Think of the cells in our body as little houses. These houses need fats to function, to build them, and to produce energy. The APOE gene is like a 'delivery service' that brings these fats into and out of the cells. If this job doesn't work properly, problems can arise, especially in brain cells.

Does everyone have this APOE gene?

Yes, we all have this APOE gene in our bodies. But it's not the same. It's like how, even in the same 'delivery service', some employees are very smart, some are average, and some are a little lazy. There are three main types. Let's see what the differences are.

What does the new study say?

We used to think that APOE4 was just a 'risk factor' for Alzheimer's. That is, having it doesn't mean you'll develop the disease, but it does mean that the chance is higher.

But this new study suggests that having two copies of the APOE4 gene isn't just a risk factor, it could be a genetic form of Alzheimer's disease itself. That means people with both genes are at a much higher risk of developing the disease. And symptoms can start at a relatively young age.

We usually know that the genes that cause Alzheimer's disease are `(APP)`, `(PSEN1)` and `(PSEN2)`. They are very rare. But this study has brought the APOE4 gene closer to them. They have found that 95% of people with two copies of APOE4 have abnormally high levels of `(beta amyloid)`, a harmful protein associated with Alzheimer's disease, in the brain by the age of 65.

Does having the APOE4 gene mean you will definitely develop Alzheimer's?

No. It's not 100% guaranteed. But the risk is very high. It's like driving a car too fast and having an accident increases your chances of having an accident. It won't happen, but it increases your chances. About 2% of the population has both copies of the APOE4 gene. Between 15% and 25% have one copy.

Can I test to see if I have this gene?

Yes, there are genetic tests for this. But this is not a test that is usually prescribed by your doctor and can be easily done in a hospital. This is not very common in Sri Lanka. Even in foreign countries, it is rarely covered by insurance.

These tests can be paid for through private institutions. Whether or not you choose to have this done is entirely your personal decision. If several members of your family have Alzheimer's disease, you may want to talk to a doctor and come to a decision about this.

Despite the risk, what can we do to prevent the disease?

Here's the important part. We can't change our genes. But we can fight the risk that comes with them. Although we can't reverse the disease once it's fully developed, our lifestyle can delay or prevent it from occurring.

1. Let's start with nutrition.

Studies have repeatedly shown that a plant-predominant diet can reduce the risk of Alzheimer's by about 50%. That means a diet high in vegetables, fruits, legumes, nuts, and whole grains . The Mediterranean diet is also beneficial.

2. Exercise is not just about walking.

Exercise is another powerful tool for reducing risk. But just walking in the garden isn't enough. It's the kind of exercise that makes you sweat and feels physically tiring that really works on your brain. Strength training, like weightlifting , is especially important. One study showed that people with pre-dementia who did leg-strengthening exercises reduced their risk of developing the disease by 40%.

3. Exercise your brain too

Mental exercise is as essential as physical exercise. This strengthens the connections between the cells called neurons in the brain.

• Learn something new (a language, a musical instrument).
• Solve puzzles, Sudoku, etc.
• Go deep into a hobby you love.
• Face new challenges.

What everyone should know about genes, even if they don't know it

That means that all of us in our 30s, 40s, and 50s need to think about our brain health right now.

Talk to your doctor and learn about your cholesterol levels, blood pressure, and HbA1c test values, which indicate your diabetes status. Controlling these is one of the biggest investments you can make in protecting your brain.