Before we answer that question (“Do you want to know if you will develop Alzheimer’s?), let me remind readers that Alzheimer’s is only one type of dementia. However, around 60-80% of all dementias are Alzheimer’s. Other dementias include vascular dementia, Lewy Body dementia, Parkinson’s dementia, Huntington’s dementia, Korsakoff’s syndrome dementia (from alcohol abuse), and dementia secondary to chronic traumatic encephalopathy (repeated traumas ala professional football players).
Most of these dementia develop from vascular abnormalities or vascular damage in the brain or from specific illnesses that produce abnormal proteins that clog the neurons in the brain. Alzheimer’s disease has been described as due to the brain’s inability to remove beta amyloid plaques. These plaques block the neurons, disrupting transmissions. A person has a thought, but the neurons cannot transmit that thought to the proper connections – so the thought becomes stranded, lost in isolation.
But here is a new key. Recent research suggests that Alzheimer’s Disease might be better explained as a developmental abnormality from childhood. That’s right. Not just a problem in older adults. Instead, a problem in younger children that leads to the memories difficulties in older age. These studies show that the brain of children, those who later develop Alzheimer’s, have distinctly different sizes of the different parts of the brain. Those parts, like the hippocampus, are associated with memory and focus,
There is also one specific gene, known as APOE, that is linked to these early development difficulties in the brain and later development of Alzheimer’s. Recent researchers now assert that 60% of Alzheimer’s cases may be caused directly by this one gene. This gene, APOE, directs the brain to produce a certain protein that carries cholesterol and other fats, which are good for the brain, through the brain’s blood vessels, while also helping to ferry beta amyloid out of the brain.
There are three types of the APOE gene, including variants e2, e3, and e4. Each person gets one variant of APOE from each parent. If you have one, or especially two e4 variants, then you are significantly more likely to develop brain structure abnormalities in childhood and later Alzheimer’s as an older adult. This relationship is independent of a person’s gender, ancestry, family income, and level of education. In short, its ability to predict Alzheimer’s, or at least 60% of Alzheimer’s, is pretty accurate with APOE e4 genes.
So, would you want to know if you have a high chance of developing this type of Alzheimer’s? Researchers can take blood, or even saliva, to sequence your DNA. Sites on the Internet offer this option for determining if you have the e4 variant of the APOE gene, but unless you already have Alzheimer’s, insurance will not cover it. You would have to pay for it yourself. Many people are beginning to utilize these gene tests to clarify their ancestry. But, at this point in your life, would you want to know if you are at high risk or low risk for Alzheimer’s?
Well, there’s one early indication from childhood that can give you a hint. Children with abnormal brain function typically have poor memory, poor attention, and poor communication skills. Think back to your own early childhood years. How was your memory? How was your level of concentration and focus? If you had problems in both areas (and not just one of the areas), then you may very well have a high chance of developing Alzheimer’s.
There is one disclaimer. If you experienced those same problems in childhood, and if you were born with a specific development disorder, autism, ADHD, or fetal alcohol syndrome, your brain’s abnormality is likely independent of the APOE gene. In those situations, your chances of developing Alzheimer’s are no higher than the general public. By age 65, one in nine people will have dementia; and by age 85, one in three people will have dementia.
Back to our question: at this point in your life, would you want to know? I would not. I have no desire to have my blood testing for the APOE gene. Why, as a physician, would I be so resistant? Because I would be depressed to learn my fate. I would rather go through life, cope as well as possible, and learn my diagnosis as late as possible. Again why? Because there is not much that medicine can offer to stop the progression of Alzheimer’s.
Think back to the movie “Still Alice.” Julianne Moore’s character developed memory difficulties; they determined that she had the worse type of dementia – early onset dementia – and her future was sealed. The doctors could not treat it. Today doctors prescribe Aricept and Namenda. Doctors encourage regular exercise and daily increased mental activity. Doctors also encourage a better diet with less sugar. Most doctors also encourage reduced sleeping pills, reduced benzodiazepines, and better sleep for greater physiologic repair in the brain. But doctors acknowledge the limits of these suggestions.
In closing, most researchers believe that this disease and the APOE gene variant needs to be discovered early in childhood and that any successful treatment needs to be initiated for the child, not for the older adult. So, we are faced with a disease that is overlooked in childhood, that is discovered decades too late, and that medicine offers little effective treatment. But you do have one option: Do you want to know if your odds of developing Alzheimer’s are high or low? Do you want to know if you have those APOE e4 genes?
You may decide to be tested. I will not … (although there are a few politicians I would love to test!)
I will stick to exercise, physical and mental, plus a healthy diet …
And I will pray for luck with no serious memory loss …
Now where was I? …