Alzheimer’s, Dementia, & Cholesterol
Previously, I wrote a pretty extensive blog on cholesterol wellness. In that blog, I discussed what cholesterol is, why we need it, and ways to control it. I also added a 10+ page cholesterol wellness guide that you can download for free.
Today, I’ll be diving in a little bit further and talking about how cholesterol can have an impact on dementia. We’ll talk about what dementia is and how it relates to Alzheimer’s
Disease (AD), what you need to know about cholesterol and fats in relation to dementia, and what you can do to lower your risk.
Hang with me, I have a feeling this one’s going to be pret-ty intense!
What is Dementia?
Dementia is a well-known cognitive concern that many people confuse with AD. Sometimes, individuals use the words interchangeably. They would be incorrect in doing so. Dementia is a set of symptoms without a definitive diagnosis…it’s one stage further then your run of the mill senility. There are well over 100 diseases that fall under the realm of dementia…AD is one of them. While AD is a form of dementia, dementia is not a form of AD.
I think many people often wonder “is Alzheimer’s genetic?” The answer to that would be yes and no. I’ve talked about genes and gene expression in the past. Just because we have a specific gene, that does not mean that gene will be expressed…meaning it will be activated. We carry tons of different genes…some handed down from our parents and some we’ve created on our own through mutation due to environmental aspects (the air we breathe, the food we eat, the lifestyle we live, etc). There’s a reason AD is lovingly called Type 3 Diabetes.
So, while you can be a carrier for AD, that does not mean you’re going to develop AD as you age. And just because you are not a carrier, that doesn’t mean that you can’t develop it through mutated genes.
It’s important to remember that forgetfulness gets the best of us all at some point. If you’re concerned about your forgetfulness, bring you symptoms to the attention of your primary care physician.
Cholesterol and fats as it relates to AD
Hang with me here kids…this is going to get a bit science-y but I’ll do my best to explain it thoroughly.
A lipoprotein is a carrier of lipids. For instance, most of us are familiar with LDL and HDL. Neither of these are actually cholesterol but they are both cholesterol transporters…think little cars that drive the cholesterol to other parts of the body. Apolipoproteins are proteins that bind the cholesterol to the car….they are the seatbelts.
We have several apolipoproteins but we are only going to focus on Apolipoprotein E or ApoE in this blog. ApoE is linked to increased LDL and increased triglycerides (4) (to find out more about the role of LDL and triglycerides in overall cholesterol, read my in-depth blog here). While ApoE the lipoprotein is NOT the same as ApoE4, the gene that has been linked to AD (3).
Let’s be clear though…just because you have a genetic variant of ApoE4 does not mean that you are going to develop AD. Inversely, you can develop AD without the ApoE4 gene due to lifestyle.
For those with the ApoE variant, a high cholesterol diet was shown to increase plaque formation, specifically in the brain, in animal studies (2). High cholesterol intake was also shown to increase the beta amyloid plaques in the brain, in animal studies (2). Beta amyloid plaques are sticky proteins that build up between the nerve cells in the brain and cause damage to those nerve cells.
While cholesterol that we consume cannot actually cross the blood brain barrier (a nifty little tool that allows for blood and other things to pass to the brain but tries to keep out anything that would bring harm), oxidized cholesterol known as oxysterols (aka bad shit that causes hardening of the arteries) can. (2)
This is where the oxysterols come in…they cause more beta amyloid plaques to form.
How do oxysterols form in the body…through oxidative stress. Oxidative stress occurs when we have too many bad things coming in and not enough bad things going out. In other words, our natural detoxifying system in the body can’t keep up with our lifestyles.
You can also consume oxysterols in food. Some foods containing high amounts of oxysterols would be fast food, meat, dairy, and cereals…to name a few. All meat contains oxysterols and the amount increases when the meat is cooked. Oddly, the amount increases greatly when it’s been cooked in the microwave. Oils, butter, milk/yogurt, and eggs all had an increased number of oxysterols when cooked/heated. (1)
So, while the cholesterol that we consume has little impact on the levels of our serum cholesterol, the types of fats/cholesterol we consume and the lifestyle that we lead will have an impact on brain health when it comes to AD and our genes.
Phew…did you get all that (my brain hurts!)??
How to lower your risk
The first thing you should do is to determine if you have the ApoE4 genetic variant. Your physician can test this. Also, if you’ve ever had genetic testing done through 23andme, you have access to your raw data and can determine if you have a form of the gene.
There are 3 forms:
ApoE2, ApoE3, and ApoE4. ApoE2 and ApoE4 are the least common and ApoE3 is the most common (about 70% of the US population). I carry one copy of the ApoE4 and one copy of the ApoE3. This isn’t surprising as my maternal grandfather had AD.
I know that if I am stressed or lead a poor overall lifestyle, it can drive up my cholesterol levels and cause hardening of my arteries. Not to mention all the not-so-fun-stuff that’s happening in the brain. But, if I limit my saturated fat intake and consume a moderate fat diet, I’m A.O.K.
For someone that has a double copy (homozygous) of the ApoE4 gene, you’d likely be better off following a low-fat diet overall.
If you’re not into getting your gene’s tested, all you have to do is eat healthy, don’t smoke, drink alcohol in moderation, and exercise! My previous cholesterol post covers all the nutrition aspects of cholesterol in detail…so read up!
Do you have the ApoE4 genetic variant? What are you doing to protect your brain health? Let me know in the comments.
Brzeska, M., Szymczyk, K., & Szterk, A. (2016). Current Knowledge about Oxysterols: A Review. Journal of Food Science, 81(10). doi:10.1111/1750-3841.13423
Gamba, P., Testa, G., Gargiulo, S., Staurenghi, E., Poli, G., & Leonarduzzi, G. (2015). Oxidized cholesterol as the driving force behind the development of Alzheimer’s disease. Frontiers in Aging Neuroscience, 7, 119. http://doi.org/10.3389/fnagi.2015.00119
Hughes, T. M., Rosano, C., Evans, R. W., & Kuller, L. H. (2013). Brain Cholesterol Metabolism, Oxysterols, and Dementia. Journal of Alzheimer’s Disease : JAD, 33(4), 891–911. http://doi.org/10.3233/JAD-2012-121585
Pollin, T. I., & Quartuccio, M. (2013). What We Know About Diet, Genes, and Dyslipidemia: Is There Potential for Translation? Current Nutrition Reports, 2(4), 236–242. http://doi.org/10.1007/s13668-013-0065-z