Here are two evils — Alzheimer’s disease and cancer. Which would you choose? Of course, neither. I recently read something that said if you have Alzheimer’s you’re not likely to get cancer and vice versa, if you get cancer, you’re not likely to get Alzheimer’s. So that got me researching — is Alzheimer’s disease protection for cancer?

In December 2009, Neurology published a report by Dr. Catherine M. Roe of Washington University School of Medicine in St. Louis which stated that understanding the link between Alzheimer’s disease and cancer may lead to possible treatments.

Roe and her team studied 3,020 people aged 65 and older. They were followed for an average of five years to see if they developed dementia and an average of eight years for cancer. Here is how the study started:

• 164 (5.4%) had Alzheimer’s disease
• 522 (17.3%) had cancer

Here is what they found:

For people who had Alzheimer’s disease at the outset, the risk of future cancer was reduced by 69 percent compared to those who did not have Alzheimer’s disease when the study started.

For white people who had cancer when the study started, their risk of developing Alzheimer’s disease was reduced by 43 percent compared to people who did not have cancer at the start of the study.

This effect, however, did not apply to minority populations. In fact, the opposite effect was observed in minority populations — those who started out with cancer at the beginning of the study were more likely to develop Alzheimer’s disease. However, the sample size of minorities starting off with cancer (29 individuals) was too small for the result to be considered significant.

Overall, the results of this study support previous findings that cancer and brain degenerative diseases such as Parkinson’s and Alzheimer’s disease may share common molecular underpinnings. However, Roe noted in an email to Reuters Health, “Since we found no associations between vascular dementia and cancer, we don’t think that cancer is linked to dementia generally.”

Vascular dementia, the second most common form of dementia after Alzheimer’s disease, is caused by clogged blood vessels and other conditions affecting the blood supply to the brain. Based on the current study, only the degenerative form of dementia, and not the form caused by lack of blood to the brain, appears to be somehow protective against cancer.

To read the full article, click here.

How is dementia different from Alzheimer’s disease? According to ezinearticles.com author Molly Shomer, she says that the term dementia seems to be preferred over Alzheimer’s disease possibly because of the less frightening connotation and that many are using the word interchangeably, but that is not correct. Dementia and Alzheimer’s are different.

Shomer says dementia is a symptom, just as pain is a symptom for something causing the pain. According to the National Institute of Neurological Disorders and Stroke, memory loss by itself does not mean you have dementia. People with dementia have serious problems with two or more brain functions, such as memory and language. Many different diseases can cause dementia, including Alzheimer’s disease and stroke. Drugs are available to treat some of these diseases. For a list of other dementias from the Fischer Center for Alzheimer’s Foundation, click here.

So the actual cause of dementia could be one of a myriad of things where cognitive abilities have been impaired. With dementia, it could simply be a temporary thing if the cause is treated. On the other hand, Alzheimer’s is an actual disease and the disease causes dementia. Many different diseases can cause dementia, including Alzheimer’s disease and stroke. Drugs are available to treat some of these diseases.

What we know about Alzheimer’s disease today, according to the Alzheimer’s Association, is that:

1. Alzheimer’s is a progressive and fatal brain disease.
2. Alzheimer’s is the most common form of dementia.
3. Alzheimer’s has no current cure.

In our next post next week, we will specifically look at how Alzheimer’s disease is defined. In the meantime, challenge your brain to something new as was discussed here.