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: ????