Book Review: Your Personal Paleo Code

Chris Kresser has been a major figure in the ancestral health community for some time now.  It's funny to recall that I was actually one of his first readers, back in the early days of his blog when it was called The Healthy Skeptic and the audience was small.  Chris's readership rapidly eclipsed mine, and now he's in high demand for his ability to convey ideas clearly and offer practical solutions to important health concerns.

He recently published a book titled Your Personal Paleo Code, which also happens to be a New York Times bestseller.  The primary goal of the book is to help you develop a diet and lifestyle that support health and well-being by starting from a generally healthy template and personalizing it to your needs.  Let's have a look.

Introduction

Kresser opens with the poignant story of his own health problems, which began with an infectious illness in Indonesia and several courses of antibiotic therapy.  After years of struggling with the resulting symptoms, trying a variety of diets, and finally accepting his condition, he was unexpectedly able to recover his health by adopting a personalized Paleo-like diet that included bone broth and fermented foods.

Why Paleo?

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Mindless Eating

You think you're in control of your eating behavior-- but you aren't

In 2005, Brian Wansink's research group published a remarkable study that demonstrates the powerful unconscious influence of the food environment on our consumption (1). 

Volunteers were invited to a test kitchen to eat bowls of tomato soup for lunch.  Each person was given a bowl containing 18 ounces of soup-- but there was a catch.  Half the volunteers were given custom-made soup bowls that partially refilled as they ate, such that the soup level dropped more slowly.

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Book Review: Salt, Sugar, Fat

Michael Moss is a Pulitzer prize-winning journalist who has made a career writing about the US food system.  In his latest book, Salt, Sugar, Fat: How the Food Giants Hooked Us, he attempts to explain how the processed food industry has been so successful at increasing its control over US "stomach share".  Although the book doesn't focus on the obesity epidemic, the relevance is obvious.  Salt, Sugar, Fat is required reading for anyone who wants to understand why obesity is becoming more common in the US and throughout the world.

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Book Review: "The Human Diet: Its Origins and Evolution"

I recently read this book after discovering it on another health site. It's a compilation of chapters written by several researchers in the fields of comparative biology, paleontology, archaeology and zoology. It's sometimes used as a textbook.

I've learned some interesting things, but overall it was pretty disappointing. The format is disjointed, with no logical flow between chapters. I also would not call it comprehensive, which is one of the things I look for in a textbook. Here are some of the interesting points:

• Humans in industrial societies are the only mammals to commonly develop hypertension, and are the only free-living primates to become overweight.
  
• The adoption of grains as a primary source of calories correlated with a major decrease in stature, decrease in oral health, decrease in bone density, and other problems. This is true for wheat, rice, corn and other grains.
• Cranial capacity has also declined 11% since the late paleolithic, correlating with a decrease in the consumption of animal foods and an increase in grains.
• According to carbon isotope ratios of teeth, corn did not play a major role in the diet of native Americans until 800 AD. Over 15% of the teeth of post-corn South American cultures showed tooth decay, compared with less than 5% for pre-corn cultures (many of which were already agricultural, just not eating corn).
  
• Childhood mortality seems to be similar among hunter-gatherers and non-industrial agriculturists and pastoralists.
  
• Women may have played a key role in food procurement through foraging. This is illustrated by a group of modern hunter-gatherers called the Hadza. While men most often hunt, which supplies important nutrients intermittently, women provide a steady stream of calories by foraging for tubers.
• We have probably been eating starchy tubers for between 1.5 and 2 million years, which precedes our species. Around that time, digging tools, (controversial) evidence of controlled fire and changes in digestive anatomy all point to use of tubers and cooked food in general. Tubers make sense because they are a source of calories that is much more easily exploited than wild grains in most places.
• Our trajectory as a species has been to consume a diet with more calories per unit fiber. As compared to chimps, who eat leaves and fruit all day and thus eat a lot of fiber to get enough calories, our species and its recent ancestors ate a diet much lower in fiber.
  
• Homo sapiens has always eaten meat.
  

The downside is that some chapters have a distinct low-fat slant. One chapter attempted to determine the optimal diet for humans by comparing ours to the diets of wild chimps and other primates. Of course, we eat more fat than a chimp, but I don't think that gets us anywhere. Especially since one of our closest relatives, the neanderthal, was practically a carnivore.
They consider the diet composition of modern hunter-gatherers that eat low-fat diets, but don't include data on others with high-fat diets like the Inuit.

There's some good information in the book, if you're willing to dig through a lot of esoteric data on the isotope ratios of extinct hominids and that sort of thing.

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!