home
RSS
Anemia linked to increased risk of dementia
July 31st, 2013
04:08 PM ET

Anemia linked to increased risk of dementia

There is no single test to determine if someone has dementia. The harsh reality is that at this point, it can only be conclusively diagnosed during an autopsy.

So for now doctors rely on physical exams, lab work and cognitive indicators to diagnose dementia with a high degree of certainty while a patient is still alive.

Anemia may be one sign someone has an increased risk of developing dementia, according to a new study published in Neurology, the medical journal of the American Academy of Neurology.

“I’ve been studying Alzheimer’s for a long time,” says study author Dr. Kristine Yaffe, of the University of California – San Francisco. “In particular, I’m interested in things you can modify: cardiovascular disease, sleep, physical activity. We’ve done a number of studies looking at how different chronic diseases of the body effect aging. We started looking into the issue of anemia... after seeing rudimentary studies that linked it to dementia.”

The basics

Anemia is a condition in which your red blood cells don’t carry enough oxygen to the rest of your body. In most cases, a lack of iron causes anemia.

Having anemia may result in extreme fatigue. Loss of blood is the most common cause, resulting in short- or long-term symptoms, which can range from mild to severe.

“Anemia is common in the elderly and occurs in up to 23% of adults ages 65 and older,” says Yaffe. “The condition has also been linked in studies to an increased risk of early death.”

The study

The study followed approximately 2,500 participants who were in their 70s when the data collection began in 1997. They were initially tested for anemia and cognitive function, and underwent subsequent testing over the next decade.

The researchers found that people who had anemia at the beginning of the study had a 41% higher risk of developing dementia than those who were not anemic. The link remained after considering other factors, such as age, race, sex and education.

“There are several explanations for why anemia may be linked to dementia,” says Yaffe. “For example, anemia may be a marker for poor health in general, or low oxygen levels resulting from anemia may play a role in the connection. Reductions in oxygen to the brain have been shown to reduce memory and thinking abilities and may contribute to damage to neurons.”

“The biggest caution in a study like this is over-interpreting it,” says Dr. David Knopman, a neurology consultant at the Mayo Clinic (who served as the handling editor for the publication of this study). “This study does not – and was not intended to – show a causality between anemia and dementia. All it does is show an association.”

The breakdown

The study’s authors concede that “the mechanisms linking anemia to... dementia are not clearly understood" but discussed four hypotheses that had previously been proposed:

1. Chronic brain hypoxia (not getting enough oxygen) associated with anemia may contribute to risk of dementia. Anemia has been associated with the progression of white matter disease in older adults with high blood pressure.

2. Anemia due to chronic kidney disease may be linked to dementia. Erythropoietin receptors, which regulate red blood cell production, seem to have a protective effect on the brain - at least in animal models. Kidney disease or failure is known to lower erythropoietin levels.

3. Anemia due to deficiency of micronutrients - such as iron and vitamin B12 - may also be associated with cognitive impairment and dementia. Deficiency of iron, because it plays an important role in oxygen transport and storage in the brain, may lead to cerebral hypoxia and cognitive decline.

4. It is also possible that anemia is a marker of poor health. Other studies have demonstrated that dementia is often associated with a range of health-related outcomes, or there may be another latent variable associated with both anemia and dementia that is driving the association.

“If I had to vote, I would vote on the fourth one: a marker of poor health,” says Knopman, “but I ultimately can’t prove that. The one thing that links these non-traditional risk factors may be health behavior. The extent to which people are attentive to their health care, generally, seems like the easiest explanation to me.”

Next, Yaffe hopes to investigate the underlying mechanism linking anemia and dementia.

“I have a feeling it’s probably the oxygen story (the lack of oxygen in the brain),” she says. “It’d be important to find out if you treat anemia, does that reduce your likelihood of developing dementia? Obviously, that’s not ethical, because you’d want to treat everyone. But there’s got to be a back-door way to get at that question.”


soundoff (15 Responses)
  1. Bill Rhoades

    It's important to differentiate between iron deficiency anemia and anemia of inflammation / chronic disease.

    It's not only possible, but quite common to see high iron (elevated ferritin) and anemia occurring at the same time in a substantial percentage of the elderly population.

    Elevated iron has also been associated with Alzheimer's Disease so it would be unwise to imply supplemental iron may be good for anemic/geriatric patients at risk for dementia without first determining whether they are truly iron deficient. Dumping more iron into an already overloaded geriatric body is a recipe for disaster.

    July 31, 2013 at 17:31 | Report abuse | Reply
    • bankrupt due to student loans

      useful. thanks.

      August 1, 2013 at 06:02 | Report abuse |
    • xcbxcbery5436

      Hi man~!~My Life is so lonely .How about you? Recently, I join a serious interracial singles dating site on__ MīxedSinglë. ℂoм___ I just find my true love here, so I I strongly recommend this site . You interracial dating journey is just beginning! Meet singles living in your local area or in countries around the world. The common interest will help make dating easier and more effective. If you are single, have a try.

      August 5, 2013 at 11:51 | Report abuse |
  2. Bill Rhoades

    Getting the iron out: phlebotomy for Alzheimer's disease?

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2732125/

    July 31, 2013 at 17:42 | Report abuse | Reply
  3. lebana

    print for class

    August 1, 2013 at 07:19 | Report abuse | Reply
  4. Organic1

    And in other news, this same link is rumored to cause male pattern baldness.

    August 1, 2013 at 08:25 | Report abuse | Reply
  5. Lesbana

    Yes, however it may be the syrup on the waffles.

    August 1, 2013 at 17:18 | Report abuse | Reply
  6. Anna77

    Dementia and Alzheimer's has been reversed naturally in many people in Europe. This has been shown in 2 studies
    There is no need for a drug for this illness.

    just google "MAL ALZHEIMER"

    August 2, 2013 at 11:03 | Report abuse | Reply
  7. EdL

    Holy Cow! Another study! Thanks, Kristine. I wonder why nobody thought of this before! And now on to your next study?

    August 3, 2013 at 11:49 | Report abuse | Reply
  8. sortedsortof

    If CNN is serious about spreading news, I would think you would take the time to get two or three other opinions on what you write. Right now it just looks like you're being used to spread a single opinion. We have enough of those kind of news outlets.

    August 5, 2013 at 01:44 | Report abuse | Reply
  9. deligoer

    As a person who has experienced anemic episodes through much of my life, and even spent a 'Blue Summer' once, the study is very important to me. I'm hoping it evolves into a 'fix' for dementia that is caused this way before I too am diagnosed. (Yes, that summer they called me Lady Smurf)

    August 5, 2013 at 07:48 | Report abuse | Reply
  10. Gonrodepatricia

    I already knew that...having pernicous anemia due to no B12... I will have a great tendency to suffer neurological problems..and unfortunately that is one. So...B12 for life here I come...!!

    August 14, 2013 at 01:00 | Report abuse | Reply
  11. FGHJFGJHWERQWERQW345345345

    DOES THAT INFORMATION NORMAL.

    VENEZUELAN IRRADIATED FROM SATELITES, MANIPULATION OF HUMANS WITH NEURONAL VOLTAGE.

    CHVIST CHILD TALKIN ABOUT POLITIC, TEHER IS NO CUBANS TO TEACH THEM, TO 7 YEARS OLD.

    DO YUOU HAVE A NANO TRANSMISORS IN A SATELITE CAN YOU MANIPULATE THE TRANSMITION, OR ITS JUST THE VENEZUELANS.

    IRRADIATE THE VOTATION MASHINE OR THE FINGER OF THE VENEZUELANS.

    WHY MUDPGI DENOUNCE A ROB OF A MODEL PERFECTIBLE BANK TO NORTH AMERICA, SPAIN, GENRMANY, BERLUSCONNI, VATICAN, RUSSIA, JOSIKO NODAS, CHINA MINISTER, KIN JON IL, BAN KI MOON.

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    SEND THE DENOUNCE TO FBI INTERPO EUROPOL.

    WHAT THEY SAY, WE CANT TALK TO NANO TECHNOLOGY8.

    WE DID NOT DO A MENTAL TORTURE.

    CASE OF: BRAIN, HIPOTALAMO, ORGANS, FORNIX, DESTRUCTION.

    CAUTERIZATION WITH NANO TECNOLOGY.

    WAIT ISNT IT INFAMOUS, WE HAVE THE PROOBS.

    WE ALL AMERICANS.

    MENTAL VOTE: IN VENEZUELA CITIZENS VOTE MENTALY FOR OBAMA?, THIS IS AN MATHEMATIC ALGORITM.

    MAINFRAMES CALCUL EVERY THINK OBOUT ANY PRESIDENT.
    dddddddddddddddddddddddddddddddddddddddddddddd

    August 19, 2013 at 20:44 | Report abuse | Reply
  12. FGHJFGJHWERQWERQW345345345

    DOES THAT INFORMATION NORMAL.

    VENEZUELAN IRRADIATED FROM SATELITES, MANIPULATION OF HUMANS WITH NEURONAL VOLTAGE.

    CHVIST CHILD TALKIN ABOUT POLITIC, TEHER IS NO CUBANS TO TEACH THEM, TO 7 YEARS OLD.

    DO YUOU HAVE A NANO TRANSMISORS IN A SATELITE CAN YOU MANIPULATE THE TRANSMITION, OR ITS JUST THE VENEZUELANS.

    IRRADIATE THE VOTATION MASHINE OR THE FINGER OF THE VENEZUELANS.

    WHY MUDPGI DENOUNCE A ROB OF A MODEL PERFECTIBLE BANK TO NORTH AMERICA, SPAIN, GENRMANY, BERLUSCONNI, VATICAN, RUSSIA, JOSIKO NODAS, CHINA MINISTER, KIN JON IL, BAN KI MOON.

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    http://www.mudpgi.blog.com

    SEND THE DENOUNCE TO FBI INTERPO EUROPOL.

    WHAT THEY SAY, WE CANT TALK TO NANO TECHNOLOGY8.

    WE DID NOT DO A MENTAL TORTURE.

    CASE OF: BRAIN, HIPOTALAMO, ORGANS, FORNIX, DESTRUCTION.

    CAUTERIZATION WITH NANO TECNOLOGY.

    WAIT ISNT IT INFAMOUS, WE HAVE THE PROOBS.

    WE ALL AMERICANS.

    MENTAL VOTE: IN VENEZUELA CITIZENS VOTE MENTALY FOR OBAMA?, THIS IS AN MATHEMATIC ALGORITM.

    MAINFRAMES CALCUL EVERY THINK OBOUT ANY PRESIDENT.

    August 19, 2013 at 20:45 | Report abuse | Reply
  13. KHS

    Why does CNN not delete such lunatic, senseless comments, while it removes a lot of sensible, non-abusive contributions because of a wrong word or political incorrectness?

    August 4, 2013 at 14:08 | Report abuse | Reply

Post a comment


 

CNN welcomes a lively and courteous discussion as long as you follow the Rules of Conduct set forth in our Terms of Service. Comments are not pre-screened before they post. You agree that anything you post may be used, along with your name and profile picture, in accordance with our Privacy Policy and the license you have granted pursuant to our Terms of Service.

Advertisement
About this blog

Get a behind-the-scenes look at the latest stories from CNN Chief Medical Correspondent, Dr. Sanjay Gupta, Senior Medical Correspondent Elizabeth Cohen and the CNN Medical Unit producers. They'll share news and views on health and medical trends - info that will help you take better care of yourself and the people you love.