Alzheimer’s is a medical diagnosis with which we continue to struggle, despite the commitment of brilliant researchers, the prevalence of well-funded studies, and the steady progress of knowledge on the disease.
This is more than an academic question, as a huge segment of society is moving toward 65 years old, the age when this disease becomes more common. But here’s a big surprise: .*
That’s good news, even if we are not sure why. Some good humor has replaced some dark humor, I suppose.
We have yet to find out what really causes Alzheimer’s. We know a lot about the pathology, the cell physiology, and the genetics, but “the why” remains elusive.
Looking back 30 years to my medical training, we were then talking about Alzheimer’s as an aluminum storage disease. Researchers were concerned about deodorants and soda cans. None of this went anywhere, although a few people lost weight and smelled badly.
As the medical field’s testing got better, we were able to look at the anatomy of nerve cells in the brain. Alzheimer’s patients have very abnormal anatomy. Nerve cells get tangled up in knots and there are protein deposits (neurofibrillary tangles and amyloid plaques). The other prominent finding is a lack of nerve cells. The brain is measurably smaller. Something is killing nerve cells.
The latest theory is that a protein vital to nerve cell support, growth, and repair (the Tau protein) is deformed and kills the nerve cell. So now the killer has been identified, but of course the next question is, “Why it is deformed?”
There is no straightforward answer. There are about 20 genes that are involved in various ways with this process. We find that 60% to 70% of Alzheimer’s patients show some genetic flaw in the process, which we believe is part of the problem. There is a big step between 20 odd genes and a protein deformity, so there is plenty of work left to do.
Stepping back from the microscope, it is said that to protect the brain, you must protect the heart. I don’t know that this has anything to do with Tau protein, but health characteristics that keep you from having heart attacks also reduce the risk of Alzheimer’s. Specifically, having normal or well-controlled blood pressure, normal body weight, avoiding smoking, and treating high cholesterol and high blood sugar (diabetes) all reduce Alzheimer’s risk. Exercise also tends to keep both your heart and brain out of trouble.
Mental exercise is also protective. The higher the level of education, the lower the rate of dementia. Continued learning also is protective. We know that adult learning increases the connections between nerves. Essentially, the more cognitive connections you have, the more you can lose, yet still feel relatively normal.
Recently an unexpected study was released showing a 24% drop in the rate of dementia. This is exciting and wonderful news, but the medical world is still scratching its collective head. We are looking for something that has changed significantly in the last few years among senior citizens, or soon-to-be seniors. I would love to say we exercise more, weigh less, and spend our spare time learning Mandarin. But, I’m afraid it isn’t so. Smoking, at least, is steadily decreasing.
So the news is good, albeit perplexing. At least if you follow the theory that if you protect your brain, you protect your heart, you are likely to live long enough to see Alzheimer’s figured out.
*The study referenced in this blog post was published in JAMA Internal Medicine
Photo courtesy of the artists of Unsplash.
Donald Bucklin, MD (Dr. B) is a Regional Medical Director for U.S. HealthWorks and has been practicing clinical occupational medicine for more than 25 years. Dr. B. works in our Scottsdale, Arizona, clinic.