Is Alzheimer’s hereditary?

I’m often asked if Alzheimer’s is hereditary. In a nutshell, yes, but this doesn’t mean that if you carry the gene involved that it’s inevitable; far from it.

The main gene involved in Alzheimer’s is the Apolipoprotein E gene, ApoE, for short. There are 3 types - 2, 3 and 4.  We all have a combination of ApoE 3 and 4 - ApoE3/3, ApoE3/4 or ApoE4/4.  The main one concerned in Alzheimer’s is the ApoE4.  For millions of years, we all carried two copies of ApoE4, but about 220,000 years ago, for some reason, it mutated to ApoE3, and then about 80,000 years ago, ApoE3 mutated to ApoE2.  

How did these genes evolve?

The ApoE4 is involved in stimulating an inflammatory response within the body.  Millions of years ago, running around barefoot and the constant risk of abrasions from twigs, brambles, and rocks, there was a high chance of getting infections from these injuries. The body needed a way of protecting itself from this, which required a strong inflammatory response to prevent infection from setting in. In other words, it was a gene required for survival. But these days it is now virtually redundant. We don’t run about barefoot.  The other action this gene has is that it reduces the clearance of amyloid in the brain. Amyloid is laid down in the brain to protect it from the damage caused by inflammation triggered by various toxins in the brain.

Today:

Most people carry two copies of type 3, making them ApoE3/3, giving them an overall lifetime risk of developing Alzheimer’s of 9%, usually starting in the 60s or 70s. 25% of people carry a copy of each type 3 and 4, ApoE3/4, giving them a risk of developing Alzheimer’s of 30% and this starts slightly earlier in the late 50s and 60s.  Only 2% of the population is ApoE4/4, giving them a risk of developing Alzheimer’s of over 50%. Symptoms start much earlier in the 40s and 50s.  Another way of putting it is that they have 10 times the risk of developing Alzheimer’s compared to the general population. It is the gene with the strongest link to Alzheimer’s.  Carriers also have a higher risk of cardiovascular disease due to its link with inflammation and other inflammatory conditions.  

Knowledge is power.

How does it make you feel to find out what genes you carry for Alzheimer’s? Does it fill you with fear, you’d rather not know, bury your head in the sand and accept the inevitable.  Or would it empower you? Knowing what genes you have allows you to make informed and effective choices about your health and life.  Those who are homozygous for ApoE4, that is, have 2 copies of ApoE4,  generally tend to have Type 1 Alzheimer’s, the inflammatory type.  It’s the inflammatory type that responds the best to the Bredesen Protocol, so it’s not all bad news to find that you’re a 4/4 carrier, because these people, if they stick to the Bredesen Protocol, respond the best and notice that they make the most significant improvements in cognition.  However, these lifestyle changes are lifelong, which is the case for everyone concerned with cognitive decline and its prevention. Those who are homozygous to ApoE4 also absorb dietary fat more easily and so need to be cautious in the amount of saturated fat consumed.    

Now that there is a programme that can reduce the risk of Alzheimer’s, the prevalence could be reduced if more of us knew our ApoE status and were willing to take action. Knowing your status before you even start noticing any changes in cognition puts you in the driving seat to take action before it is too late. Prevention is much easier than treating cognitive decline. If you are interested in knowing your genetics, there are several places you can get this done through a blood test. 

Support for ApoE carriers: 

A website providing support for ApoE4 carriers, www.apoe4.info, was set up by a very early participant of the Bredesen Protocol. She was homozygous for ApoE4; that is, she carried two copies of ApoE4. She set up a community for those carrying either one or two copies. It offers support, advice, strategies and current research.  By becoming a member, you have access to forums and podcasts on relevant topics.  

Dr Andrea Haas is passionate about helping people keep their minds sharp and their confidence high, at every stage of their life. With over 30 years as a medical doctor and training in the Bredesen Protocol for prevention and improvement of dementia, she combines medical insight with holistic therapies to create a bespoke journey to lasting cognitive health and improving confidence.

Book a free 20-minute call to find out how she may be able to help you.

Image attribution: 

By Ajpolino - Own work, CC0, https://commons.wikimedia.org/w/index.php?curid=90078263