The theory that Alzheimer's dementia is in part caused by metabolic syndrome is fairly well known in the paleoblogosphere and literature. I touch upon it now more for the sake of completeness than to try to explore anything new and mind-blowing - at least for the first part of the series. Also, I always learn a bit more about neurobiology when I dig a little into these subjects. As much as I love and appreciate my several regular readers, much of this blog is a selfish endeavor.
Today, though, I'll start with one of my favorite secondary sources: Good Calories, Bad Calories: Fats, Carbs, and the Controversial Science of Diet and Health (Vintage) by Gary Taubes. He has a whole chapter on dementia, cancer, and aging - pages 204-225 if you are following along in the hard copy - which I bought directly after seeing Mr. Taubes interviewed on the Colbert Report back in 2007. If it weren't for watching that interview, I might have tried counting calories or something really silly rather than consulting a paleolithic-friendly nutritionist in order to lose the last of the baby weight at the beginning of this year, and then none of this would have happened. So thank you, Stephan Colbert. I just put a big hunk of pastured butter to melt into my local-grown vegetable soup (simmered with grassfed cow marrow bones), and I owe it all to you.
Here's the theory. Hypertension, atherosclerosis, smoking, and apo E4 increase the risk of cardiovascular disease, vascular dementia (obviously - vascular dementia is generally thought to be caused my multiple and increasing stepwise vascular insults to the brain, like little strokes or clots) and Alzheimer's dementia (which is associated with excess tau and amyloid protein build-up in the brain, like a fish tank that never gets cleaned). Folks with type 2 diabetes have twice the risk of developing Alzheimer's, and diabetics on insulin therapy have four times the risk.
There's a protein called insulin-degrading enzyme that does just what you might expect. It clears out insulin in the brain. It also clears out excess amyloid (at least in test tubes), so one can imagine if it were super-busy with the insulin, amyloid might get left cluttering up the joint. Unlucky mice with no insulin-degrading enzyme get dementia, and elderly people get increased amyloid in their cerebral spinal fluid when insulin is injected into their veins.
The obvious conclusion is that once wants low insulin levels so that your insulin-degrading enzyme can keep itself busy with the pesky amyloid, leaving none to form plaques. One way to achieve that is a low carbohydrate diet. Even the high-carbohydrate Kitavans, though, had exceedingly low fasting insulin levels (1), so a paleolithic-style diet will seem to do the trick if you don't have metabolic syndrome to begin with, whether low or high carb. If you have a bit of high blood pressure and some tub about the waist, you might want to skip the squash and go straight for the meat and butter. But forget the refined carbohydrates. They do not love your brain.
Is Alzheimer's disease increasing? Yes, absolutely. Wouldn't it be nice if we could do something about it? The National Institutes of Health convened a panel earlier this year, who determined there is no reliable way to prevent Alzheimer's. I can see myself at the back of the room, frantically waving my hand. "The Kitavans have no dementia!" I would say. Would there be raised eyebrows? Puzzlement? A security team called to escort me off the premises?
Evolutionary medicine can sometimes be very lonely.
Today's Vegetable Soup
1 small blue potato
1/2 winter squash, peeled and seeded
1 beet, peeled
3 pieces of celery
2 tbs pastured butter (maybe three?)
Glop of olive oil
2 marrow bones from grassfed cow
celtic salt, dulse, basil, garlic, pepper, seasoned salt (or whatever) to taste
Chop veggies and cover with filtered water in large pot, add marrow bones (roast first for best flavor, but no biggie if you don't). Add spices, oil. Bring to boil and simmer for 30-45 minutes or so. Remove bones, making sure the good stuff has dissolved into the soup. Remove from heat for a bit. Blend to pleasing chunkiness with stick blender. Return to heat, melt in butter. Cool somewhat. Eat.
Servings: Three? Calories: ???? Nutrient Ratios: ????
Well, if you cannot prevent, at least there are ways you can accelerate it! One is been a hypothyroid receiving a conventional treatment.ReplyDelete
Hypothyroid pacients using synthetic T4 only drugs consistently have higher levels of free/total T4 and lower levels of free T3 than euthyroids (Pubmed 20693806, 18285588, 16982586 and 16416346 for some examples).
Higher total and free T4 levels are associated with increased risk of dementia and Alzheimer’s (Pubmed 17870208, 17136019, 17132968, 16636121).
Finally, hypothyroids taking thyroid medications progressed more rapidly to a diagnose of Alzheimer’s dementia than hypothyroids not taking thyroid medications (Pubmed 19666883). In this last one they don’t tell, but I presume that thyroid medications were T4 only drugs.
Given my 40 years of a high-carb, and therefore highly insuligenic diet, I wonder how much damage I had been doing to my nervous system, and if I was on the road towards dementia/Alzheimer's disease. I also wonder if the past few years of lower-carb primal have helped reverse any damage that had been done. I certainly feel much better, with steady energy levels throughout the day and no more brain fog like I used to get daily (usually in the afternoon, but it could strike anytime of day).ReplyDelete
What a coincidence, we made some soup with left over goat bones, cauliflower leaves/stems, and a big red tomato for dinner tonight. It was a great accompaniment to lamb-shoulder steak and bison burgers.
I'd love to believe that a low-carb diet (and low insulin levels) would prevent Alzheimers. I'm very skeptical at this point.ReplyDelete
See "Insulin resistance is associated with the pathology of Alzheimer disease [in Japan]," in Neurology, vol. 75, August 31, 2010, pages 764-770
Despite the hopeful title, after reading the article and reviewing the abstracts of references 33-35, I seriously question whether Alzheimers is even associated with diabetes, at least in non-Japanese populations.
I'll blog about it when I have time.
I saw some of those studies - saw a differential in many between men and women, too. My plan is to look at them more closely over the next several days to see if we can sort out some truth. However, Dr. Lindeberg did some very careful screening for dementia in Kitava, and also asked people if they knew of anyone who had died, to their recollection, who had symptoms of dementia, and no one could remember anyone. It was a large enough population that there should have been some dementia. So somewhere between the lifestyle and genetics and diet of the kitavans and our western lifestyle is a cause. Gary Taubes thinks it is refined carbs - he quotes a few studies, some mouse models, and some test tubes. Anyway, well see what the other studies say! I'm also interested in the link between osteoporosis and dementia.ReplyDelete
Mario - thanks for the links! I have to say that there is a bit of a disconnect between the subtleties of the different hypothyroidism disorders and the one size fits all sort of treatment. It really is on my list of things to do to look into more.ReplyDelete
I look forward to anything you write on hypothyroidism!ReplyDelete
I can't seem to find any reference as to which Colbert episode Taubes was on. Would you happen to know? I've never seen that interview and I'd love to!ReplyDelete
pK - I looked for it to link to this post but couldn't find it. There was a later interview in 2009, I believe, but I definitely bought GCBC right when it came out after seeing it on Colbert (there is a slight chance it was The Daily Show, but I couldn't find the interview there either).ReplyDelete