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 End of Overeating

The End of Overeating was written based on the personal journey of Dr. David A. Kessler (MD) to understand the obesity epidemic, and treat his own obesity in the process.  Dr. Kessler was the FDA commissioner under presidents George HW Bush and Bill Clinton.  He is known for his efforts to regulate cigarettes, and his involvement in modernizing Nutrition Facts labels on packaged food.  He was also the dean of Yale medical school for six years-- a very accomplished person. 

Dr. Kessler's book focuses on 1) the ability of food with a high palatability/reward value to cause overeating and obesity, 2) the systematic efforts of the food industry to maximize food palatability/reward to increase sales in a competitive market, and 3) what to do about it.  He has not only done a lot of reading on the subject, but has also participated directly in food reward research himself, so he has real credibility.  The End of Overeating is not the usual diet book. 
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Book Review: The Primal Blueprint

Mark Sisson has been a central figure in the evolutionary health community since he began his weblog Mark's Daily Apple in 2006. He and his staff have been posting daily on his blog ever since. He has also written several other books, edited the Optimum Health newsletter, competed as a high-level endurance athlete, and served on the International Triathlon Union as the anti-doping chairman, all of which you can read about on his biography page. Mark is a practice-what-you-preach kind of guy, and if physical appearance means anything, he's on to something.

In 2009, Mark published his long-awaited book The Primal Blueprint. He self-published the book, which has advantages and disadvantages. The big advantage is that you aren't subject to the sometimes onerous demands of publishers, who attempt to maximize sales at Barnes and Noble. The front cover sports a simple picture of Mark, rather than a sunbaked swimsuit model, and the back cover offers no ridiculous claims of instant beauty and fat loss.

The drawback of self-publishing is it's more difficult to break into a wider market. That's why Mark has asked me to publish my review of his book today. He's trying to push it up in the Amazon.com rankings so that it gets a broader exposure. If you've been thinking about buying Mark's book, now is a good time to do it. If you order it from Amazon.com on March 17th, Mark is offering to sweeten the deal with some freebies on his site Mark's Daily Apple. Full disclosure: I'm not getting anything out of this, I'm simply mentioning it because I was reviewing Mark's book anyway and I thought some readers might enjoy it.

The Primal Blueprint is not a weight loss or diet book, it's a lifestyle program with an evolutionary slant. Mark uses the example of historical and contemporary hunter-gatherers as a model, and attempts to apply those lessons to life in the 21st century. He does it in a way that's empowering accessible to nearly everyone. To illustrate his points, he uses the example of an archetypal hunter-gatherer called Grok, and his 21st century mirror image, the Korg family.

The diet section will be familiar to anyone who has read about "paleolithic"-type diets. He advocates eating meats including organs, seafood, eggs, nuts, abundant vegetables, and fruit. He also suggests avoiding grains, legumes, dairy (although he's not very militant about this one), processed food in general, and reducing carbohydrate to less than 150 grams per day. I like his diet suggestions because they focus on real food. Mark is not a drill sergeant. He tries to create a plan that will be sustainable in the long run, by staying positive and allowing for cheats.

We part ways on the issue of carbohydrate. He suggests that eating more than 150 grams of carbohydrate per day leads to fat gain and disease, whereas I feel that position is untenable in light of what we know of non-industrial cultures (including some relatively high-carbohydrate hunter-gatherers). Although carbohydrate restriction (or at least wheat and sugar restriction) does have its place in treating obesity and metabolic dysfunction in modern populations, ultimately I don't think it's necessary for the prevention of those same problems, and it can even be counterproductive in some cases. Mark does acknowledge that refined carbohydrates are the main culprits.

The book's diet section also recommends nutritional supplements, including a multivitamin/mineral, antioxidant supplement, probiotics, protein powder and fish oil. I'm not a big proponent of supplementation. I'm also a bit of a hypocrite because I do take small doses of fish oil (when I haven't had seafood recently), and vitamin D in wintertime. But I can't get behind protein powders and antioxidant supplements.

Mark's suggestions for exercise, sun exposure, sleep and stress management make good sense to me. In a nutshell: do all three, but keep the exercise varied and don't overdo it. As a former high-level endurance athlete, he has a lot of credibility here. He puts everything in a format that's practical, accessible and empowering.

I think The Primal Blueprint is a useful book for a person who wants to maintain or improve her health. Although we disagree on the issue of carbohydrate, the diet and lifestyle advice is solid and will definitely be a vast improvement over what the average person is doing. The Primal Blueprint is not an academic book, nor does it attempt to be. It doesn't contain many references (although it does contain some), and it won't satisfy someone looking for an in-depth discussion of the scientific literature. However, it's perfect for someone who's getting started and needs guidance, or who simply wants a more comprehensive source than reading blog snippets. It would make a great gift for that family member or friend who's been asking how you stay in such good shape.

Paleopathology at the Origins of Agriculture

In April of 1982, archaeologists from around the globe converged on Plattsburgh, New York for a research symposium. Their goal:

...[to use] data from human skeletal analysis and paleopathology [the study of ancient diseases] to measure the impact on human health of the Neolithic Revolution and antecedent changes in prehistoric hunter-gatherer food economies. The symposium developed out of our perception that many widely debated theories about the origins of agriculture had testable but untested implications concerning human health and nutrition and our belief that recent advances in techniques of skeletal analysis, and the recent explosive increase in data available in this field, permitted valid tests of many of these propositions.

In other words, they got together to see what happened to human health as populations adopted agriculture. They were kind enough to publish the data presented at the symposium in the book Paleopathology at the Origins of Agriculture, edited by the erudite Drs. Mark Nathan Cohen and George J. Armelagos. It appears to be out of print, but luckily I have access to an excellent university library.

There are some major limitations to studying human health by looking at bones. The most obvious is that any soft tissue pathology will have been erased by time. Nevertheless, you can learn a lot from a skeleton. Here are the main health indicators discussed in the book:

• Mortality. Archaeologists are able to judge a person's approximate age at death, and if the number of skeletons is large enough, they can paint a rough picture of the life expectancy and infant mortality of a population.
• General growth. Total height, bone thickness, dental crowding, and pelvic and skull shape are all indicators of relative nutrition and health. This is particularly true in a genetically stable population. Pelvic depth is sensitive to nutrition and determines the size of the birth canal in women.
  
• Episodic stress. Bones and teeth carry markers of temporary "stress", most often due to starvation or malnutrition. Enamel hypoplasia, horizontal bands of thinned enamel on the teeth, is probably the most reliable marker. Harris lines, bands of increased density in long bones that may be caused by temporary growth arrest, are another type.
  
• Porotic hyperostosis and cribra orbitalia. These are both skull deformities that are caused by iron deficiency anemia, and are rather creepy to look at. They're typically caused by malnutrition, but can also result from parasites.
  
• Periosteal reactions. These are bone lesions resulting from infections.
• Physical trauma, such as fractures.
• Degenerative bone conditions, such as arthritis.
• Isotopes and trace elements. These can sometimes yield information about the nutritional status, diet composition and diet quality of populations.
  
• Dental pathology. My favorite! This category includes cavities, periodontal disease, missing teeth, abscesses, tooth wear, and excessive dental plaque.

The book presents data from 19 regions of the globe, representing Africa, Asia, the Middle East, Europe, South America, with a particular focus on North America. I'll kick things off with a fairly representative description of health in the upper Paleolithic in the Eastern Mediterranean. The term "Paleolithic" refers to the period from the invention of stone tools by hominids 2.5 million years ago, to the invention of agriculture roughly 10,000 years ago. The upper Paleolithic lasted from about 40,000 to 10,000 years ago. From page 59:

In Upper Paleolithic times nutritional health was excellent. The evidence consists of extremely tall stature from plentiful calories and protein (and some microevolutionary selection?); maximum skull base height from plentiful protein, vitamin D, and sunlight in early childhood; and very good teeth and large pelvic depth from adequate protein and vitamins in later childhood and adolescence...
Adult longevity, at 35 years for males and 30 years for females, implies fair to good general health...
There is no clear evidence for any endemic disease.

The level of skeletal (including cranial and pelvic) development Paleolithic groups exhibited has remained unmatched throughout the history of agriculture. There may be exceptions but the trend is clear. Cranial capacity was 11% higher in the upper Paleolithic. You can see the pelvic data in this table taken from Paleopathology at the Origins of Agriculture.

There's so much information in this book, the best I can do is quote pieces of the editor's summary and add a few remarks of my own. One of the most interesting things I learned from the book is that the diet of many hunter-gatherer groups changed at the end of the upper Paleolithic, foreshadowing the shift to agriculture. From pages 566-568:

During the upper Paleolithic stage, subsistence seems focused on relatively easily available foods of high nutritional value, such as large herd animals and migratory fish. Some plant foods seem to have been eaten, but they appear not to have been quantitatively important in the diet. Storage of foods appears early in many sequences, even during the Paleolithic, apparently to save seasonal surpluses for consumption during seasons of low productivity.

As hunting and gathering economies evolve during the Mesolithic [period of transition between hunting/gathering and agriculture], subsistence is expanded by exploitation of increasing numbers of species and by increasingly heavy exploitation of the more abundant and productive plant species. The inclusion of significant amounts of plant food in prehistoric diets seems to correlate with increased use of food processing tools, apparently to improve their taste and digestibility. As [Dr. Mark Nathan] Cohen suggests, there is an increasing focus through time on a few starchy plants of high productivity and storability. This process of subsistence intensification occurs even in regions where native agriculture never developed. In California, for example, as hunting-gathering populations grew, subsistence changed from an early pattern of reliance on game and varied plant resources to to one with increasing emphasis on collection of a few species of starchy seeds and nuts.

...As [Dr. Cohen] predicts, evolutionary change in prehistoric subsistence has moved in the direction of higher carrying capacity foods, not toward foods of higher-quality nutrition or greater reliability. Early nonagricultural diets appear to have been high in minerals, protein, vitamins, and trace nutrients, but relatively low in starch. In the development toward agriculture there is a growing emphasis on starchy, highly caloric food of high productivity and storability, changes that are not favorable to nutritional quality but that would have acted to increase carrying capacity, as Cohen's theory suggests.

Why am I getting the feeling that these archaeologists have a better grasp of human nutrition than the average medical doctor or nutritionist? They have the Price-esque understanding that comes from comparing the diets and multi-generational health of diverse human populations.

One of the interesting things I learned from the book is that Mesolithic populations, groups that were halfway between farming and hunting-gathering, were generally as healthy as hunter-gatherers:

...it seems clear that seasonal and periodic physiological stress regularly affected most prehistoric hunting-gathering populations, as evidenced by the presence of enamel hypoplasias and Harris lines. What also seems clear is that severe and chronic stress, with high frequency of hypoplasias, infectious disease lesions, pathologies related to iron-deficiency anemia, and high mortality rates, is not characteristic of these early populations. There is no evidence of frequent, severe malnutrition, so the diet must have been adequate in calories and other nutrients most of the time. During the Mesolithic, the proportion of starch in the diet rose, to judge from the increased occurrence of certain dental diseases [with exceptions to be noted later], but not enough to create an impoverished diet... There is a possible slight tendency for Paleolithic people to be healthier and taller than Mesolithic people, but there is no apparent trend toward increasing physiological stress during the mesolithic.

Cultures that adopted intensive agriculture typically showed a marked decline in health indicators. This is particularly true of dental health, which usually became quite poor.

Stress, however, does not seem to have become common and widespread until after the development of high degrees of sedentism, population density, and reliance on intensive agriculture. At this stage in all regions the incidence of physiological stress increases greatly, and average mortality rates increase appreciably. Most of these agricultural populations have high frequencies of porotic hyperostosis and cribra orbitalia, and there is a substantial increase in the number and severity of enamel hypoplasias and pathologies associated with infectious disease. Stature in many populations appears to have been considerably lower than would be expected if genetically-determined maxima had been reached, which suggests that the growth arrests documented by pathologies were causing stunting... Incidence of carbohydrate-related tooth disease increases, apparently because subsistence by this time is characterized by a heavy emphasis on a few starchy food crops.

Infectious disease increased upon agricultural intensification:

Most [studies] conclude that infection was a more common and more serious problem for farmers than for their hunting and gathering forebears; and most suggest that this resulted from some combination of increasing sedentism, larger population aggregates, and the well-established synergism between infection and malnutrition.

There are some apparent exceptions to the trend of declining health with the adoption of intensive agriculture. In my observation, they fall into two general categories. In the first, health improves upon the transition to agriculture because the hunter-gatherer population was unhealthy to begin with. This is due to living in a marginal environment or eating a diet with a high proportion of wild plant seeds. In the second category, the culture adopted rice. Rice is associated with less of a decline in health, and in some cases an increase in overall health, than other grains such as wheat and corn. In chapter 21 of the book Ancient Health: Bioarchaeological Interpretations of the Human Past, Drs. Michelle T Douglas and Michael Pietrusewsky state that "rice appears to be less cariogenic [cavity-promoting] than other grains such as maize [corn]."

One pathology that seems to have decreased with the adoption of agriculture is arthritis. The authors speculate that it may have more to do with strenuous activity than other aspects of the lifestyle such as diet. Another interpretation is that the hunter-gatherers appeared to have a higher arthritis rate because of their longer lifespans:

The arthritis data are also complicated by the fact that the hunter-gatherers discussed commonly displayed higher average ages at death than did the farming populations from the same region. The hunter-gatherers would therefore be expected to display more arthritis as a function of age even if their workloads were comparable [to farmers].

In any case, it appears arthritis is normal for human beings and not a modern degenerative disease.

And the final word:

Taken as a whole, these indicators fairly clearly suggest an overall decline in the quality-- and probably in the length-- of human life associated with the adoption of agriculture.