Sunday, April 27, 2008

Book Review: Blood Sugar 101

I just finished reading "Blood Sugar 101" by Jenny Ruhl. It's a quick read, and very informative. Ruhl is a diabetic who has taken treatment into her own hands, using the scientific literature and her blood glucose monitor to understand blood sugar control and its relationship to health. The book challenges some commonly held ideas about diabetes, such as the notion that diabetics always deteriorate.

She begins by explaining in detail how blood glucose is controlled by the body. The pancreas releases basal amounts of insulin to make glucose available to tissues between meals. It also releases insulin in response to carbohydrate intake (primarily) in two bursts, phase I and phase II. Phase I is a rapid response that causes tissues to absorb most of the glucose from a meal, and is released in proportion to the amount of carbohydrate in preceding meals. Phase II cleans up what's left.

In a person with a healthy pancreas, insulin secretion will keep blood glucose under about 130 mg/dL even under a heavy carbohydrate load. The implications of this are really interesting. Namely, that blood glucose levels will not be very different between a person who eats little carbohydrate, and one who eats a lot, as long as the latter has a burly pancreas and insulin-sensitive tissues.

Most Americans don't have such good control however, hence the usefulness of low-carbohydrate diets. This begs the question of why we lose blood sugar control. Insulin resistance seems like a good candidate, maybe preceded by
leptin resistance. As you may have noticed, I'm starting to think the carbohydrate per se is not the primary insult. It's probably something else about the diet or lifestyle that causes carbohydrate insensitivity. Grain lectins are a good candidate in my opinion, as well as inactivity.

Diabetics can have blood glucose up to 500 mg/dL, that remains elevated long after it would have returned to baseline in a healthy person. Ruhl asserts that elevated blood sugar is toxic, and causes not only diabetic complications but perhaps also cancer and heart disease.


Heart attack incidence is strongly associated with A1C level, which is a rough measure of average blood sugar over the past couple of months. It makes sense, although most of the data she cites is correlative. They might have seen the same relationship if they had compared heart attack risk to fasting insulin level or insulin resistance. It's difficult to nail down blood sugar as the causative agent. More information from animal studies would have been helpful.


Probably the most important thing I took from the book is that the first thing to deteriorate is glucose tolerance, or the ability to pack post-meal glucose into the tissues. It's often a result of insulin resistance, although autoimmune processes seem to be a factor for some people.
Doctors often use fasting glucose to diagnose diabetes and pre-diabetes, but typically you are far gone by the time your fasting glucose is elevated!

I like that she advocates a low-carbohydrate diet for diabetics, and lambasts the ADA for its continued support of high-carbohydrate diets.

Overall, a good book. I recommend it!

8 comments:

Nick said...

Stephan,
I just read Michael Eades' book, Protein Power, thanks to your recommendation on the side bar. Loved it! Very helpful. These two books are probably very similar. Thanks

Stephan said...

Hi Nick,

Glad you liked it! I agree with all of Eades' big points. There's quite a bit of information in Jenny Ruhl's book that's not in Protein Power though. Some of it's nitty-gritty blood glucose stuff. She also discusses all the major diabetes drugs in depth.

Peter said...

Hi Stephan,

I browse her blog and you can see her in action on Dr Bernstein's forum (she stopped posting for quite a while after a little VERY surprising unpleasantness, it's a supportive place, a while ago). I would expect her book to be good but there are aspects of her outlook I find very amusing. From various posts she appears to dislike being LC and is only pushed there by her pancreas. She is also adamant that LC is not the answer to the ills of modern civilisation. Perhaps not, but it side steps a lot of the metabolic ones!


Snippet from here

"I recently got an email from someone complaining about her 80 year old father's refusal to do anything about his diabetes. I also have gotten mail about 90 year olds who insist on eating too much carbohydrate. I find these reports extremely comforting. You better believe that if I make it to 80 I'm going to eat whatever I please"

I wouldn't like to consider what she thinks about an elective LC eater! Hee hee, each to their own. If I'm lucky enough getting to 80 on the diet I eat now, I'm not going off to binge on candy!

Peter

Stephan said...

Peter,

Interesting. I'm beginning to think there's some insult that makes people carbohydrate-intolerant, after which carb restriction is the only way to sidestep their metabolic problems, as you said. It seems to me that a lot of things point to grains and sugar as the culprits. It always seems to come back to Weston Price... What do you think about this idea?

Well if I make it to 80 and I need an indulgence, I think I'll get some drugs instead.

Peter said...

Hi Stephan,

I keep kicking the ideas you put forward around in my head. It's very difficult to unravel the knot. A great deal of it will really come down to genetics. There will probably be a Normal distribution to the consequences of all sorts of metabolic pertubations that we're playing with nowadays. The other thing that keeps coming back to me is the neurological control of pancreatic and hepatic function. There is a massive nerve supply to these organs and there are a number of snippets that suggest that glucose intolerance may be a brain problem rather than a simple peripheral problem...

I've also got a paper on brown adipose tissue ablated mice which is quite interesting, looking at what appears to be a simple inability to burn calories for heat as rodents normally do, leading to diabetes without gluten or fructose getting a look in.... Keep meaning to post about it but you know how it goes!

I've a lot of time for Weston Price's work. Also Stefansson. The later gives a more long term account of daily life and there were clearly illnesses and medicine men before acculturation. All very thought provoking

Peter

Stephan said...

Peter,

Thanks for the ideas. I'm interested in the neurological control of pancreatic/hepatic function. Are you going to post on that someday?

I'll look forward to your post on BAT in mice. One of the links that seems to keep popping up is PGC-1alpha. It's activated by fasting in the liver and it also plays a role in adaptive thermogenesis in BAT. I didn't mention this in my last post, but one of the papers I was using to learn about liver function explored the adaptive functions of SIRT1 and PGC-1alpha in fasting liver. Don't know if this is relevant but I thought I'd throw it out there.

I'm planning on reading Stefansson soon, and I'm really looking forward to it. Right now I'm reading about Indians of the Pacific NW coast of the US. I have quantitative info about how they spent their day on various activities, what foods they ate and more. By all accounts, they did get sick but not from chronic non-infectious illness like we do. That's despite rampant alcoholism at the time most of these accounts are from.

Peter said...

Hi Stephan,

I've Stefansson's Cancer:Disease of Civilisation as a pdf. I can email you a copy of you would like it

Peter

Stephan said...
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