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| My mom hanging out my sister's new puppy. Summer, 2014 |
My mom has Alzheimer's disease.
If your life has been touched by Alzheimer's disease, you know the pain, frustration, anger and exhaustion of witnessing a person deteriorate from the inside out. For those who are part of the immediate circle of care, it feels impossible to find balance. Balance between caring for your loved one and hanging on to your own life while fearing that this is going to one day happen to you. In some ways I am lucky. I am experiencing this from several states away and the responsibility rests with my sister. My sister and mom live in the same city. I am not able to alleviate the day-to-day grind, but am able to offer my sister some emotional support.
How many people have Alzheimer's disease?
According to the National Institute of Aging and the Alzheimer's Association (both accessed on September 5, 2014), more than 5 million people in the United States have Alzheimer's disease. Approximately 200,000 of those with Alzheimer's are are less than 65 years old. Women are twice as likely as men to have this disease. Women, lucky us, also are more likely to be the primary care giver of someone with Alzheimer's.
What is Alzheimer's disease?
The brain is a complex organ that communicates through a network of specialized cells. Neurons are specialized cells that send messages throughout the body. Neurons respond to stimuli received from the environment, package up messages that tell other cells what is gong on, and transmit or relay these messages to other responder (effector) cells through nerve impulses. Nerve impulses deliver these messages to the responder (effector) cells. The responder (effector) cells then act in response to the message. It is an understatement to say neurons play an important role in the communication network within the brain. Alzheimer's is a progressive and degenerative disease in which neurons deteriorate. As neurons and brain tissue die, the way the brain functions permanently changes (interactive tour of the brain). This impacts things like memory and speech.
It remains unclear why some people develop Alzheimer's disease, why exactly neurons deteriorate, or precisely how the disease develops in the first place. What is known is that people with Alzheimer's disease have a significant build-up of beta-amyloid protein in between neurons. This can be thought of like the build-up of plaque in the arteries but in the brain. This blocks neurons from communicating with each other. It is normal for people without Alzheimer's also to have some beta-amyloid protein in the brain, however, most people are able to clear out (remove) these proteins from the brain so it is not a problem. People with Alzheimer's disease have a problem with tau proteins within neurons. Tau proteins are a normal part of neurons and are needed for neurons to function. However, people with Alzheimer's disease have tau proteins that do not work right. Instead of performing their job, they accumulate inside the cell which impairs the ability of the neuron to function properly.
The following websites provide more detailed explanations of Alzheimer's disease, information about signs and symptoms, how the disease is diagnosed, how it is treated and managed:
What is being done about Alzheimer's disease?
As of September 5, 2014, over 1000 clinical studies focused on Alzheimer's disease research have been registered at Clinical Trials.gov (Alzheimers disease). This is a voluntary registry of clinical research. Investigators report the title, an abstract, funding source(s), status (if they are recruiting participants, completed the research, reporting results), where the study is centered, and more. Alzheimer's research focuses on understanding the way the disease works, how it progresses, identifying genetic risk factors if they exist, finding biomarkers to help identify people at risk or in earliest stages of the disease, and finding ways to prevent and and treat Alzheimer's disease.
I am interested in the role of nutrition with regard to Alzheimer's disease. There are a number of ways that this is being investigated. One aspect of research in this area focuses on overall nutritional status and disease. It is common for Alzheimer's patients to become malnourished because they forget to eat, lose interest in eating, or their perception of taste and texture has changed and so nothing tastes or feels good. One question that has been and continues to be studied is whether or not well-nourished Alzheimer's participants perform better than those who are not well-nourished. Another aspect with regard to nutrition that I find particularly interesting and that is the impetuous for this blog post is whether or not a deficiency of a specific nutrient, like vitamin D, influences one's risk for developing Alzheimer's disease.
Why focus on vitamin D?
Vitamin D is needed for bone health, calcium metabolism, cell signaling, and gene expression. We make vitamin D in the skin in response to UV light. There are several factors that influence our effectiveness in synthesizing vitamin D.
- Lighter skin tones require about 10 - 15 minutes of sun exposure and darker skin tones need more sun exposure (increase from 15 minutes)
- Sunscreen (anything at or above SPF 8 will block UV rays to reduce vitamin D synthesis)
- Smog, fog, cloud cover
- Clothing
- Latitude - more northern regions have less access than southern regions
- Time of year
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| Coronado Beach, Summer 2014 Sun, sand, and water. And sunblock. Lots of sunblock for this red-head. |
- Regions of the brain that are important for memory contain lots of VDRs indicating that they use vitamin D. This is of interest with dementia in general because memory is impaired, and specifically with Alzheimer's disease.
- Our ability to make vitamin D decreases with age, especially after the age 70. Also, vitamin D deficiency among older adults is quite common.
- Remember neurons? The cells that interpret stimuli and send out messages to other cells telling them what is going on so that they can respond? The cells that die in people with Alzheimer's? Neurons appear to need vitamin D for development, survival, and function.
- Some research is going on now with neuronal tissue to try to figure out if vitamin D can prevent or reduce beta-amyloid accumulation.
The bullets above provide an overview of some of the rationale about why vitamin D deficiency may contribute to an increased risk of developing all-cause dementia and Alzheimer's disease.
Can vitamin D prevent Alzheimer's disease?
A total of 1,658 elderly adults all of whom were mobile, free of all-cause dementia and cardiovascular disease were selected for this study. The participants agreed to participate and signed informed consent. The researchers took initial blood samples to assess each participant's initial vitamin D status at the start of the study period. They then retested participants an average of 5.6 years later.
They classified vitamin D status into three categories:
- Severely deficient (</= 25 nmol/L vitamin D)
- Deficient (25 - < 50 nmol/L vitamin D)
- Adequate (>/= 50 nmol/L vitamin D)
The researchers analyzed blood and incidence of all-cause dementia and Alzheimer's status. They also took into consideration other potential factors that could impact their final results, such as season of year, other diseases like diabetes and hypertension, education, depression, etc.
The authors concluded that their data suggests there is an association between vitamin D status and the risk of developing dementia of any kind and Alzheimer's disease. An association is not the same thing as cause and effect and the authors of this study never said it was.The authors of the study said that their research indicates that there is a relationship between low vitamin D status and dementia.
Observational studies are those in which specific outcomes are measured but no treatment or intervention occurs. Researchers watch and measure predetermined outcomes at specific intervals over a defined period of time. They do not treat or intervene. Observational studies are very useful and help identify health trends and relationships. Observational studies never prove cause and effect.
What concerns me is the amount of media coverage that this one study received. Here is a list of just a few of the countless stories based on this one research study that found an association, not cause and effect.
For the record, I do not endorse or recommend anything within the above links. It is just a list of the top 5 hits that came up when I searched.
Reference:
Littlejohns TJ, Henley WE, Lang IA, et al. Vitamin D and the risk of dementia and Alzheimer disease. Neurology. 2014 Sep 2;83(10):920-8. doi: 10.1212/WNL.0000000000000755. Epub 2014 Aug 6.
How do I find out if my vitamin D status is okay?
Discuss vitamin D with your healthcare provider. It is measured in a simple blood test and this has become much more routine than it used to be. If you have concerns or are interested in learning about your vitamin D status, talk to your doctor or other primary healthcare professional. I cannot stress this enough, it is important to know what your status is before going out and starting to self-supplement. Just right is what you want. In other words, please do not super-size your vitamins and minerals.
- 30-50 nmol/L (12-20 ng/mL): inadequate
- >/= 50 nmol/L (>/= 20 ng/mL): adequate
- > 125 nmol/L (> 50 ng/mL): adverse (negative) health effects. Only use this amount if prescribed by physician and follow all directions.
Final comments
A great deal of questions remain regarding the role of vitamin D, dementia, and Alzheimer's. This is an active and ongoing field of research and it will be interesting to see what emerges in the years to come. This is where we are at with vitamin D at this time:
- Vitamin D deficiency has NOT been proven to cause Alzheimer's disease
- Evidence suggests vitamin D deficiency may increase the risk of Alzheimer's disease.
Oh yeah, and Alzheimer's disease sucks.
#alzheimer'ssucks
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