Preventing Alzheimer's Disease (November 25, 2014)
Even if you couldn’t find your keys this morning because you accidentally put them in the refrigerator last night, you almost certainly do not have Alzheimer’s disease. Mild impairments in memory, communication and thinking develop in nearly everyone as we age. This is called “cognitive decline” and it is ok. It is not until those impairments develop to the point where you start having difficulty with normal daily function that the term “dementia” applies. When you deliberately place your keys into a tub of margarine and put them in the refrigerator because you think that is where they belong, THAT is dementia, and at that point there has been at least a little brain damage. About half of all cases of dementia are Alzheimer’s disease, which is a form of dementia distinguished by characteristic changes in the brain and an inevitable decline to death. [People with anxiety and depression very often exhibit mental impairments that look like cognitive decline, by the way, and usually that is what is happening in a young healthy person who starts experiencing some of this.]
Last week I encountered the unpleasant fact that Alzheimer’s disease is the sixth leading cause of death in the United States. Alzheimer’s doesn’t kill you directly, but the critical brain functions that it eventually damages (swallowing, walking and coordination, lung expansion and contraction) will finally result in death by some other cause. That “sixth leading cause of death” thing (about a third of people 85+ have Alzheimer’s disease) prompted this week’s article, since I figured that with such a wide prevalence it would benefit us all to become better acquainted with the prevention and management of such a common health problem.
And that didn’t take me too long, thanks to the Mayo Clinic’s blunt statement of what nearly every other website out there is pussyfooting around – that there is no known way to prevent Alzheimer’s disease. WebMD was kind enough to chime in with the further statement that there are no medications that prevent or cure it (there are some medications that may help a little with some symptoms, but they don’t fix anything). So it goes.
However, stopping at that very unsatisfactory answer would have resulted in way too short an article, so we need to look at this a little more closely. And when we do THAT, we see that what “no known intervention” means in practical terms is that there is presently insufficient evidence for the powers that be to hand down The Final Word On Alzheimer’s Prevention. That doesn’t mean that there isn’t a lot of interesting, suggestive and even useful data around.
This point is worth examining more closely, and not just for Alzheimer’s disease. In order for an Official Guideline for treatment or prevention regarding a disorder to be declared from the government or from a professional group, there needs to be a substantial amount of good evidence -- enough so that the likelihood of any future evidence changing that guideline substantially is minimal. That is a pretty high standard. If you are old enough to remember the excitement about beta carotene supplements possibly preventing cancer, you may remember that the evidence was ALMOST at the Guideline point when the final study that was meant to nail it came up empty instead. We were all very sad about that, but there is no arguing with evidence. Or at least there shouldn’t be. So whenever you are researching a disease or disorder, it’s a good idea to first see what the state of the science is on it.
Getting back to Alzheimer’s disease, progressive brain damage is rather a nasty way to go and no one would willingly choose it. Nevertheless, although there are currently about 1500 clinical studies under way examining possible interventions, a thorough evidence-based assessment of this area done in April 2010 by the Agency for Healthcare Research and Quality of the HHS not only failed to find good evidence for any of them, it had trouble even finding quality studies on the subject, [I have a soft spot in my heart for the AHRQ, because their predecessor agency found in one of its first investigations that the only really useful intervention for lower back pain was chiropractic manipulation. As a result, they were hounded out of existence by orthopedic surgeons. Interestingly, that particular finding still stands.] Hence the absence of any official guidelines to date. They did manage to find some consistent associations, which are the following:
So we can say that people who smoke are more likely to get Alzheimer’s disease, but we can’t say that if you quit smoking you will reduce your chances of getting Alzheimer’s disease. This is a fine point, but it’s an important difference that crops up a LOT in medical research and it should not be skipped over when you are considering whether or not to change something about your lifestyle. When the intervention being considered is something like quitting smoking, which would be good for you anyway, whether there’s particular benefit in staving off Alzheimer’s may not matter to you. But if the intervention being considered is starting to drink (because there is some evidence that people who use alcohol moderately have less Alzheimer’s disease) that’s another kettle of fish, because drinking really isn’t good for you and if you’re going to start doing it to prevent dementia (or heart disease) the evidence for it better be a whole lot stronger than it is right now.
With any disorder that is, or may be, affected by lifestyle, there are usually several things you can do or not do that the jury is still out on but that might make a difference. If you have the disorder or are very worried about developing it, you may be tempted to try anything that sounds like it might help. Please start by finding out what helps or doesn’t help FOR SURE before you start branching off into areas with more doubtful efficacy – and if you start doing THAT, give preference to interventions that won’t get you into any trouble even if they don’t do the trick (as in the aforementioned example of quitting smoking).
In the case of Alzheimer’s disease, it’s thought that anything that is beneficial for your blood vessels will also decrease the likelihood of developing Alzheimer’s disease, because it seems that there are people out there with the characteristic brain changes found in Alzheimer’s disease that do not have the disorder. The current speculation on this is that you may need the double whammy of brain damage AND cerebral vascular damage to get the disease -- "speculation" being a key term here.
So we stumble onward into what hopefully is a better informed future -- and in the meantime try to make as healthy choices as possible.
--dr. diane holmes
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