I recently wrote about a study that showed people who get skin cancer
have a significantly lower risk of developing Alzheimer’s disease (AD).
But this effect isn’t just skin-deep.
Two new studies add to the growing evidence that getting any type of cancer reduces the risk of developing AD. Not just skin cancer.
In the first study, researchers looked at data for more than 1 million residents living in Northern Italy. They found that patients with AD had a 50 percent lower risk of developing cancer than those without AD. And the connection worked the other way around, too. Cancer patients had a 35 percent lower risk of developing AD. This inverse relationship persisted in nearly every subgroup the researchers examined.
In the second study, researchers from the Mayo Clinic looked at nearly 3.5 million patients 65 years and older. All the patients took part in the Veterans Administration Health Care System between 1996 and 2011. And at the study’s outset, none of the patients had cancer or AD.
During the follow-up period, 22 percent of the patients came down with 14 different types of cancer. And 2 percent were diagnosed with AD.
Researchers linked most types of cancer with a decreased risk of developing AD. This decrease in risk ranged from 9 percent to 51 percent. And certain cancers appeared to “protect” patients against AD more than other cancers.
For example, researchers linked cancers of the liver, pancreas, esophagus, lung, kidney, stomach, and head and neck with the greatest drops in AD risk. Myeloma, leukemia, and lymphoma also appeared to reduce AD risk.
So why does getting cancer seem to protect you against Alzheimer’s?
We don’t really know. But the Mayo Clinic researchers think that the cancer treatment itself might play a part.
In fact, all the patients in the study who got cancer did receive treatment. And we know that brain cells affected by AD do try to divide. Some researchers have even called AD a “cancer of the brain.”
Plus, cancer treatments like chemotherapy prevent cancer cells (and non-cancer cells) from dividing. So, this may even affect brain cells.
However, this dividing-cell theory does not fully explain the decreases in AD risk. Clearly, something more is going on.
For example, remember last month I wrote about the strong association between non-melanoma skin cancer and lower AD risk?
These skin cancer patients generally do not get systemic chemotherapy. They simply have their tumors removed from the skin with local treatment. Yet they still seem to gain some protection against AD. So this dividing-cell theory cannot explain the entire story.
At this point, these kinds of complex studies improve our understanding of the human brain. However, no one is suggesting that getting cancer, or undergoing cancer treatment, is any kind of realistic approach to dealing with Alzheimer’s disease.
Indeed, the researchers at the Mayo Clinic cautioned against using cancer treatments to treat AD. Furthermore, not all cancer treatments reach the brain. And those that do can cause long-lasting debilitating problems, such as “chemo-brain.”
I’d like to see more research exploring the promising benefits of natural AD treatments, such as berberine.
In the February 2012 issue of my Insiders’ Cures newsletter, I told subscribers about this natural powerhouse that nearly slipped through the cracks. Subscribers to my newsletter get free access to all my archives, including this important report on berberine. If you are not yet a subscriber, now is the perfect time to get started.
Sources:
1. “Inverse occurrence of cancer and Alzheimer disease,” Neurology; published online before print, July 10, 2013
2. Alzheimer’s Association International Conference, July 15, 2013