Saturday, January 5, 2013

The Nutrition Debate #82: A New Dietary Paradigm?

A new dietary paradigm is emerging for a Way of Eating that could avoid, mitigate or ameliorate the devastating impact of Metabolic Syndrome and the Diseases of Civilization with which it is strongly associated. These outcomes affect about half the population that may be genetically predisposed and therefore susceptible. The new paradigm arises from what biologists are learning of the benefits, in terms of longevity and health, associated with Calorie Restriction (CR).

This blog does not, however, advocate for Calorie Restriction per se. It is instead advocating a restricted-calorie Very Low Carbohydrate Ketogenic diet. It closely resembles the concept of “nutritional ketosis,” a phrase that was, I believe, first used by Jeff Volek and Stephen Phinney in their book, “The Art and Science of Low Carbohydrate Living.” It was later further popularized by Jimmy Moore (of “Livin’ La Vida Low-Carb” fame), who recently lost over 50 pounds in 5 months on their program. “Nutritional Ketosis” refers to a low level of ketosis in which the body is “keto adapted” so that it burns ketone bodies instead of glucose as its primary energy source. A low millimolar concentration of ketone bodies can be measured in the blood. To me, the two best aspects of being in mild ketosis are: 1) you have lots of energy and 2) you’re not hungry, so long as you have a supply of body fat to ‘burn’ for energy (and you continue to eschew carbs!).

To quote Dr. Richard L. Veech of the National Institutes of Health: “Doctors are scared of ketosis. They’re always worried about diabetic ketoacidosis. But ketosis is a normal physiologic state. I would argue it is the normal state of man.” This ketosis falls far short, however, of the level of ketone concentration that is required for the anticonvulsive “ketogenic diet” used to treat juvenile epileptics. That “ketogenic diet” is a very high fat diet in use since the 1920s as an effective treatment for childhood epilepsy. It’s still used at places like Johns Hopkins for treatment of drug-resistant forms of childhood epilepsy. It is effective in about 50% of cases. The level of ketosis that I am advocating is much less extreme.

I have inferred and constructed my interpretation of this new dietary paradigm from “The Neuroprotective Properties of Calorie Restriction, The Ketogenic Diet and Ketone Bodies” (see Sect #3 of the full manuscript). I first referred to that manuscript here in The Nutrition Debate #79, “Calorie Restriction and Longevity.” In that column I spoke of the benefits of Calorie Restriction in animal models. In #81, “Calorie Restriction in Humans” here, I describe the concept of “altered pathways of nutrient disposal,” introduced by other authors that I cite, as they affect glucose metabolism. I also discuss some health concerns of CR in humans. But the authors, after discussing the neuroprotective properties of CR, then discuss the ketogenic diet (Sect. 4) and ketone bodies (Sect. 5). This is how and where I came to this new paradigm.

The “ketogenic diet” is also associated with multiple benefits. In the author’s words (Sect. 4), “the neuroprotective effects of the ketogenic diet are not limited to epilepsy;” “The antiepileptic effects of the ketogenic diet have been associated with improvements in cognitive function”; “Similarly, oral intake of a ketogenic medium-chain triglyceride diet improved cognitive function in patients with Alzheimer’s disease.” “Neuroprotective” is how they describe the effect that the ketogenic diet has in reducing the incidence of diseases like Parkinson’s, Alzheimer’s and Huntington’s.

 And here’s the key or “link” to the new paradigm: the authors assert in this paper that the “underlying mechanisms” of the ketogenic diet are “similar to those activated by calorie restriction” (emphasis mine). But does this mean that you have to eat a diet that is so very high in fat as to be anticonvulsive (+/-90% fat content)? Happily, it does not. That’s why, I think, the title and the text of this manuscript includes section (#5) on ketone bodies. What are ketone bodies? They are byproducts of catabolism, i.e., the breakdown of fat molecules (triglycerides). “During conditions of reduced glucose availability, energy is derived from the conversion of fats to ketone bodies,” they explain. Reduced glucose availability!

“Following a day of fasting or exposure to the ketogenic diet, ketone bodies reach low millimolar concentrations in the blood” (my emphasis). “Fasting and the ketogenic diet increase the permeability of the blood-brain barrier to ketones,” so that “ketone bodies cross the blood-brain barrier.” Ketone bodies are good – in fact, they are the ideal – brain food.

The conclusion (Sect. 6) of the article begins: “Calorie restriction and the ketogenic diet share two characteristics: reduced carbohydrate intake and a compensatory rise in ketone bodies.” A further conclusion: “An expanding body of evidence indicates that ketone bodies are indeed neuroprotective, and that the underlying mechanisms are similar to those associated with calorie restriction – specifically at the mitochondrial level.” That is their conclusion, not mine!

Come to think of it though, this “new dietary paradigm” is exactly what I have been advocating consistently throughout this blog. For a quick look at a list of past subjects, open “The Nutrition Debate Index of Columns” in the upper right corner of the blog. It’s listed first under “Favorite Links and Videos.” It’s all there for you in the archives. Check it out.

© Dan Brown 1/5/13

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