Saturday, April 24, 2010

Book Review: The CR Way (2008)

Book Review: The CR Way, by Paul McGlothin and Meredith Averill (2008).

Just some quick notes to myself that I thought I might share.

I checked the book out of the public library to skim the recipes.

I just skimmed the theory section. It's mostly a "how-to" book so the theory is pretty minimal, though well-written. The general viewpoint expressed is consistent with the free-radical theory of aging. So it covers the importance of maintaining low and stable glucose levels. However some recent research indicates it is healthier to have some fluctuation in blood glucose levels. (A cite? ... Somewhere in the stacks and stacks of papers around my place....)

The book also talks about advanced glycation end-products, or AGEs. The idea is that in much of the body aging processes are associated with the formation of AGEs in the tissues. Just as a free-radical perspective is important and is frequently debated on longevity research email lists, so to are AGEs. In the case of AGEs it is more about whether dietary AGEs impact only the gastro-intestinal tract or the body generally.

In the larger context, going back to the early 1980s, there is the debate (of sorts) between the views of Denham Harmon and others arguing for the relative importance of the free-radical theory of aging and the views of Roy Walford and others arguing for lesser relative importance of the free-radical theory. The back-and-forth on this rages on to this day. Perhaps there is an element of irony about this book in that the early supporters of caloric restriction (CR) included Roy Walford, and yet many of the practitioners of CR wound up incorporating many of the elements of the free radical theory of aging.

Briefly stating my own position, in the 1980s I tended to view Walford's position as potentially more productive for research. In the 1990s I grew more and more skeptical of either has having much relevance for human longevity, for reasons most often intelligently put forth by researchers following the work of Aubrey de Grey, or of the Gavrilov's. (Basically, large long-lived mammals such as ourselves have more systems of compensation and repair than worms, drosophila, or even mice. And much of the research in the last ten years has more and more been indicating the limited usefulness of earlier approaches to understanding aging processes for us.)

On to the recipes then.

On the whole I was pleasantly surprised that I already follow much of the general guidelines on which foods to eat. Lots of onions, celery, cabbage (Bok Choy), bell peppers, and so on. I made a list of some new ideas (or reminders) to spice up my usual recipes -- turnips, cardamon, rosemary, walnuts, sweet potatoes, mung beans, ginger, and lentils. (Though I have never seemed to be able to eat much in the way of spinach or mushrooms.)

Within CR there has been a long debate over low and high protein versions. Some recent research suggests that protein-restriction may be critical for CR effects to occur in shorter-lived organisms. In skimming the book I did not see this issue addressed, however the recipes seem to all be vegetarian, and only limited eggs and apparently no cheese. The indications in research are that to achieve the life-extension benefits seen in some mouse strains the CR has to be very severe, with consequences to bone density and libido and other effects discussed on the CR email list over the decades. The people on the lists who argue for inclusion of protein often do so suggesting the protein goes a long way in reducing many of the downsides of CR. (Myself, I have always tended more slightly toward the Paleo-Diet preferring at least some meat or easily-digested high-protein in at least a third of my meals. As a kind of caveat, I have not been on anything resembling a CR diet for some twenty years.)

The book almost provides no coverage of the potential drawbacks to CR. This is a serious flaw, and yet an adequate discussion of those drawbacks would take many more pages than this book allows. There has been a tendency in publishing about CR to strongly emphasize to the reader that they should consult their doctors before embarking on CR, but perhaps including a list of some of the major potential drawbacks would make that more of a possibility of actually happening. (Bone loss, minimal libido, constantly thinking about food, feeling cold (thyroid function), and so on.)

Finally, there appears to be a mistake (or typo?) about the calculation of calories that may be quite serious. I have blocked it off below because I ~do~ hope it isn't true and that I'm just experiencing a kind of mind-glitch. Could someone please check this and comment?

Richard Harper

The CR Way book in the standard Savory Barley recipe says
there are four ounces of barley per serving and that the total calories per serving is only 130.

This does not sound correct to me since grains are roughly the same amount in terms of weight and calories, and a single slice of bread is around 110 calories and a pound of bread has around 15 slices. (I just checked the label on the Health-Nut loaf in my freezer.) In other words an ounce of wheat bread is about 100 calories.

Converting the four ounces of barley into grams --
Four ounces equals 113 grams.

The calories per grams per the web --
184 grams of barley equals 651 calories.

Computing the calories per ounce for barley then --
113g/184g x 651calories per 4 ounces = 400 calories per 4 ounces, or 100 calories per ounce. (Same as wheat. Sounds right.)

If this is true, then the amount of calories per serving of Savory Barley needs to be kicked up from 130 to about 430. Since the Savory Barley is a stock recipe incorporated into at least some of the other recipes, this is (if correct) a very serious error. I suspect the author may have somehow confused dry and prepared weights?

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