Is Alzheimer’s Type 3 Diabetes?By MARK BITTMAN
We all need insulin: in non-diabetics, it's released to help cells take in the blood sugar (glucose) they need for energy. But the cells can hold only so much; excess sugar is first stored as glycogen, and - when there's enough of that - as fat. (Blood sugar doesn't come only from sugar, but from carbohydrates of all kinds; easily digested carbohydrates flood the bloodstream with sugar.) Insulin not only keeps the blood vessels that supply the brain healthy, it also encourages the brain's neurons to absorb glucose, and allows those neurons to change and become stronger. Low insulin levels in the brain mean reduced brain function.
Mark Bittman, I love your work and your important advocacy to changes in the American diet and American factory food production. But I think you're sliding into theory-induced blindness here: You credit all the data that fits your view and ignore all the data that doesn't.
It may well be that Type-2 diabetes, insulin resistance, and metabolic syndrome wind up creating an Alzheimer's end state. If so, that's important - and alarming. But lots of causal pathways could wind up at the same end state.
A large percentage of people with Alzheimer's disease are or were physically fit and lean. Particularly in the past, the average sufferer would have looked like the average American, who was thinner and had a more plant-based diet 50 or 100 years ago.
For what it's worth, my disciplined, fit grandfather whose weight never fluctuated and who walked every day died of Alzheimer's, while my aunt (by marriage), a tiny vegetarian, died of early-onset Alzheimer's at age 55.
El Jefe Boston, MA
This is a disturbingly credulous puff piece about a fringe idea with precious little scientific support. A lone paper published in a fourth-tier journal and a couple of propaganda items from the same researcher comprise the totality of evidence cited in support of over-reaching statements such as, "the studies are increasingly persuasive," and "increasing numbers of researchers have taken to calling it Type 3 diabetes." Not a single expert researcher in the field is consulted for a critical assessment of this idea, and Mr. Bittman as a food columnist clearly lacks the scientific expertise to render these judgments himself. Beyond simply presenting a distorted view of the current scientific understanding of Alzheimer's disease, this kind of uncritical cheerleading masquerading as scientific journalism is highly irresponsible as it promotes a facile but misleading view of the disease to the families of loved ones afflicted with Alzheimer's. Hundreds if not thousands of physicians will now need to explain to the families of Alzheimer's victims who come bearing clippings of Mr. Bittman's article why carbohydrates didn't actually cause their disease and why insulin isn't going to cure them.
Richard Bozeman, MT
There are so far a dozen comments about some very fit and diet obsessed relative who wound up with Alzheimer's. Fortunately science cannot take such stories seriously, because they are anecdotal and provide no evidence of correlation or non-correlation. Compare that with Bittman's assertion (true) that diabetes 2 and Alzheimer's have risen together in a lock-step fashion. That is a real correlation, not causal , but of scientific interest. It also suggests an environmental link. The view that Alzheimer's is just bad (genetic?) luck and beyond our control may be comforting, but is very difficult to reconcile with the data that we have so far. Feel free to be skeptical, but you need real data to have anything worthwhile to share. That is what the scientists are trying to gather now.
Very good explanation and scientifically grounded -- except for the bit about processed meats. Carbohydrates drive blood sugar, which drives insulin, which leads to metabolic syndrome, diabetes, possibly Alzheimers and probably some cancers. Foods generally thought of as healthy, such as "whole grain" muffins and sugary fruits -- are in fact be bad for us because they drive blood sugar. Processed meats may present some risks (though study evidence has not been clear at all) but we at least know they do not drive blood sugar and insulin. In other words, there is probably enough evidence to indict the hot dog bun (even a "multi-grain" bun) -- but not the hot dog at this point. Anyway, for a writer who is trying to persuade people to give up meat, this piece was fair and brave to write. Thank you. Our society needs to realize that we are being poisoned on an epidemic scale by our excessive intake of refined carbohydrates.