It’s time to look at the risk factors for Alzheimer’s disease. As most people know, there is no specific, single cause for Alzheimer’s. Rather, the disorder seems to be what scientist call multifactorial, which just means there are many things that may contribute to it’s development.
Over the years, many possible causes have been researched.
For example, there are some specific gene mutations that are known to increase the likelihood of a person getting Alzheimer’s. Those gene mutations are most often found in well-studied groups of related people and result in familial Alzheimer’s disease, also called early onset Alzheimer’s disease. They account for roughly 10% of Alzheimer’s cases. Only one of these mutations, the one producing the epsilon 4 variety of a cholesterol-transport protein called Apoliporotein E, is likely to be found in the general population, where it could increase the likelihood of you or I having Alzheimer’s. Even then, it is only a risk factor, not an absolute cause, and is most dangerous only if you have inherited the epsilon 4 allele from both of your parents. (In other words, if instead of having one epsilon 4 allele, you have two, the likelihood of developing Alzheimer’s increases dramatically, but is still not guaranteed.) The frequency of the epsilon 4 allele in the general population runs from 12 to 14 percent in the sources I reviewed.
Other Risk Factors
Genes aside, what other risk factors can increase your chances of getting Alzheimer’s?
- Getting older. Though Alzheimer’s is NOT part of normal aging, it is more prevalent in older groups.
- Having a close blood relative (sibling or parent) with Alzheimer’s.
That’s the whole list for well-documented risk factors. Other factors which MAY (or may not) put you at higher risk for developing Alzheimer’s include
- Head trauma, especially multiple instances including loss of consciousness.
- A long history of high blood pressure.
- Being female (though this may simply be a reflection of the fact that women as a group live longer lives than men).
NOT Risk Factors
Some factors once considered possible causes of Alzheimer’s have been thoroughly studied and shown to NOT cause the disorder. These include
While the last two in particular are not good for brain cells, the damage they cause is not related to Alzheimer’s disease.
Nutritional deficiencies are not uncommon in persons with Alzheimer’s, but have never been shown to produce the disorder. In addition, supplements have never been shown to reliably improve the function of Alzheimer’s patients and cannot be shown to prevent the development of the disease.
Great care should be taken with supplements and herbal remedies. More is not necessarily better and it is possible to produce toxic effects if you take too much of almost any vitamin. (With the possible exception of vitamin C, since excess C is flushed from the body when we urinate.)
One herb in particular should be mentioned: Ginkgo biloba. Well-designed studies have shown that it does NOT lower your chance of developing dementia. And ginkgo can be dangerous if taken with blood thinners like Coumadin (warfarin) or with MAOIs (monoamine oxidase inhibitors—a group of antidepressants).
I would like to recommend two very good sources of information, written in understandable language. The first is a newsletter from Boston University. If you follow the link, it will take you to the newsletter. There is an excellent article called, “Reflecting on PAIRS,” that may be encouraging to those of you who are caregivers. The second is from Methodist hospital in Houston. I hope you find these helpful.
Apologies for running late this week. My husband came home yesterday after major surgery, and it’s been a less smooth transition than I’d hoped. But he is doing well now. Until next time…