A recent study supports the notion that an 'ancestral diet' focused around high-starch agricultural foods can cultivate leanness and metabolic health.
John McDougall gave Christopher Gardner a hard time at the McDougall Advanced Study Weekend. Dr. Gardner conducts high-profile randomized controlled trials (RCTs) at Stanford to compare the effectiveness of a variety of diets for weight loss, cardiovascular and metabolic health. The "A to Z Study", in which Atkins, Zone, Ornish, and LEARN diets were pitted against one another for one year, is one of his best-known trials (1).
Dr. McDougall asked a simple question: why haven't these trials evaluated the diet that has sustained the large majority of the world's population for the last several thousand years? This is an agriculturalist or horticulturalist diet based around starchy foods such as grains, tubers, legumes, and plantains, and containing little fat or animal foods. Researchers have studied a number of cultures eating this way, and have usually found them to be lean, with good cardiovascular and metabolic health. Why not devote resources to studying this time-tested ancestral diet? I think it's a fair question.
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Rabu, 01 Oktober 2014
Senin, 08 September 2014
Thoughts on the McDougall Advanced Study Weekend
For those of you who aren't familiar with him, Dr. John McDougall is a doctor and diet/health advocate who recommends a very low fat, high starch, whole food vegan diet to control weight and avoid chronic disease. He's been at it for a long time, and he's a major figure in the "plant-based diet" community (i.e., a diet including little or no animal foods).
Dr. McDougall invited me to participate in his 3-day Advanced Study Weekend retreat in Santa Rosa, CA. My job was to give my talk on insulin and obesity, and participate in a panel discussion/debate with Dr. McDougall in which we sorted through issues related to low-carb, Paleo, and the health implications of eating animal foods. I was glad to receive the invitation, because I don't see myself as a diet partisan, and I believe that my evidence-based information is applicable to a variety of diet styles. I saw the Weekend as an opportunity to extend my thoughts to a new community, challenge myself, and maybe even learn a thing or two. It was particularly interesting to compare and contrast the Advanced Study Weekend with the Ancestral Health Symposium, which is more Paleo- and low-carb-friendly.
General Observations
The attendees were a lot older than AHS attendees. I estimate that most of them were in their 60s, although there were some young people in attendance.
I don't place too much emphasis on peoples' personal appearance at conferences like this. You don't know what a person's background, genetics, or personal struggles may be, you don't know how closely they adhere to the program, and you don't know to what degree a group of people might be self-selected for particular traits*. But I will note that Dr. McDougall, his family, and many of the other starch-based/plant-based diet advocates tended to be extremely lean with low fat and muscle mass. They also tended to have a healthy and energetic appearance and demeanor. As I would expect, decades of exceptionally high starch intake hasn't made them obese or obviously ill.
Read more »
Dr. McDougall invited me to participate in his 3-day Advanced Study Weekend retreat in Santa Rosa, CA. My job was to give my talk on insulin and obesity, and participate in a panel discussion/debate with Dr. McDougall in which we sorted through issues related to low-carb, Paleo, and the health implications of eating animal foods. I was glad to receive the invitation, because I don't see myself as a diet partisan, and I believe that my evidence-based information is applicable to a variety of diet styles. I saw the Weekend as an opportunity to extend my thoughts to a new community, challenge myself, and maybe even learn a thing or two. It was particularly interesting to compare and contrast the Advanced Study Weekend with the Ancestral Health Symposium, which is more Paleo- and low-carb-friendly.
General Observations
The attendees were a lot older than AHS attendees. I estimate that most of them were in their 60s, although there were some young people in attendance.
I don't place too much emphasis on peoples' personal appearance at conferences like this. You don't know what a person's background, genetics, or personal struggles may be, you don't know how closely they adhere to the program, and you don't know to what degree a group of people might be self-selected for particular traits*. But I will note that Dr. McDougall, his family, and many of the other starch-based/plant-based diet advocates tended to be extremely lean with low fat and muscle mass. They also tended to have a healthy and energetic appearance and demeanor. As I would expect, decades of exceptionally high starch intake hasn't made them obese or obviously ill.
Read more »
Jumat, 01 Agustus 2008
Composition of the Hunter-Gatherer Diet
I bumped into a fascinating paper today by Dr. Loren Cordain titled "Plant-Animal Subsistence Ratios and Macronutrient Estimations in Worldwide Hunter-Gatherer Diets." Published in 2000 in the American Journal of Clinical Nutrition, the paper estimates the food sources and macronutrient intakes of historical hunter-gatherers based on data from 229 different groups. Based on the available data, these groups did not suffer from the diseases of civilization. This is typical of hunter-gatherers.
Initial data came from the massive Ethnographic Atlas by Dr. George P. Murdock, and was analyzed further by Cordain and his collaborators. Cordain is a professor at Colorado State University, and a longtime proponent of paleolithic diets for health. He has written extensively about the detrimental effects of grains and other modern foods. Here's his website.
The researchers broke food down into three categories: hunted animal foods, fished animal foods and gathered foods. "Gathered foods" are primarily plants, but include some animal foods as well:
The paper also discusses the nature of the plant foods hunter-gatherers ate. Although they ate a wide variety of plants occasionally, more typically they relied on a small number of staple foods with a high energy density. There's a table in the paper that lists the most commonly eaten plant foods. "Vegetables" are notably underrepresented. The most commonly eaten plant foods are fruit, underground storage organs (tubers, roots, corms, bulbs), nuts and other seeds. Leaves and other low-calorie plant parts were used much less frequently.
The paper also gets into the macronutrient composition of hunter-gatherer diets. He writes that
However, some groups may have eaten more fat than this. Natives on the North American Pacific coast rendered fat from fish, seals, bears and whales, using it liberally in their food. Here's an excerpt from The Northwest Coast by James Swan, who spent three years living among the natives of the Washington coast in the 1850s:
Initial data came from the massive Ethnographic Atlas by Dr. George P. Murdock, and was analyzed further by Cordain and his collaborators. Cordain is a professor at Colorado State University, and a longtime proponent of paleolithic diets for health. He has written extensively about the detrimental effects of grains and other modern foods. Here's his website.
The researchers broke food down into three categories: hunted animal foods, fished animal foods and gathered foods. "Gathered foods" are primarily plants, but include some animal foods as well:
Although in the present analysis we assumed that gathering would only include plant foods, Murdock indicated that gathering activities could also include the collection of small land fauna (insects, invertebrates, small mammals, amphibians, and reptiles); therefore, the compiled data may overestimate the relative contribution of gathered plant foods in the average hunter-gatherer diet.There are a number of striking things about the data once you sum them up. First of all, diet composition varied widely. Many groups were almost totally carnivorous, with 46 getting over 85% of their calories from hunted foods. However, not a single group out of 229 was vegetarian or vegan. No group got less than 15% of their calories from hunted foods, and only 2 of 229 groups ate 76-85% of their calories from gathered foods (don't forget, "gathered foods" also includes small animals). On average, the hunter-gatherer groups analyzed got about 70% of their calories from hunted foods. This makes the case that meat-heavy omnivory is our preferred ecological niche. However, it also shows that we can thrive on a plant-rich diet containing modest amounts of quality animal foods.
The paper also discusses the nature of the plant foods hunter-gatherers ate. Although they ate a wide variety of plants occasionally, more typically they relied on a small number of staple foods with a high energy density. There's a table in the paper that lists the most commonly eaten plant foods. "Vegetables" are notably underrepresented. The most commonly eaten plant foods are fruit, underground storage organs (tubers, roots, corms, bulbs), nuts and other seeds. Leaves and other low-calorie plant parts were used much less frequently.
The paper also gets into the macronutrient composition of hunter-gatherer diets. He writes that
...the most plausible... percentages of total energy from the macronutrients would be 19-35% for protein, 22-40% for carbohydrate, and 28-58% for fat.He derives these numbers from projections based on the average composition of plant foods, and the whole-body composition of representative animal foods (includes organs, marrow, blood etc., which they typically ate).
However, some groups may have eaten more fat than this. Natives on the North American Pacific coast rendered fat from fish, seals, bears and whales, using it liberally in their food. Here's an excerpt from The Northwest Coast by James Swan, who spent three years living among the natives of the Washington coast in the 1850s:
About a month after my return from the treaty, a whale was washed ashore on the beach between Toke's Point and Gray's Harbor and all the Indians about the Bay went to get their share... The Indians were camped near by out of the reach of the tide, and were all very busy on my arrival securing the blubber either to carry home to their lodges or boiling it out on the spot, provided they happened to have bladders or barrels to put the oil in. Those who were trying out [rendering] the blubber cut it into strips about two inches wide, one and a half inches thick, and a foot long. These strips were then thrown into a kettle of boiling water, and as the grease tried out it was skimmed off with clam shells and thrown into a tub to cool and settle. It was then carefully skimmed off again and put into the barrels or bladders for use. After the strips of blubber have been boiled, they are hung up in the smoke to dry and are then eaten. I have tried this sort of food but must confess that, like crow meat, "I didn't hanker arter it".I was very impressed by the paper overall. I think it presents a good, simple model for eating well: eat whole foods that are similar to those that hunter-gatherers would have eaten, including at least 20% of calories from high-quality animal sources. Organs are mandatory, vegetables may not be. Sorry, Grandma.
Sabtu, 26 Juli 2008
The Inuit: Lessons from the Arctic
The Inuit (also called Eskimo) are a group of hunter-gatherer cultures who inhabit the arctic regions of Alaska, Canada and Greenland. They are a true testament to the toughness, adaptability and ingenuity of the human species. Their unique lifestyle has a lot of information to offer us about the boundaries of the human ecological niche. Weston Price was fascinated by their excellent teeth, good nature and overall robust health. Here's an excerpt from Nutrition and Physical Degeneration:"In his primitive state he has provided an example of physical excellence and dental perfection such as has seldom been excelled by any race in the past or present...we are also deeply concerned to know the formula of his nutrition in order that we may learn from it the secrets that will not only aid in the unfortunate modern or so-called civilized races, but will also, if possible, provide means for assisting in their preservation."
The Inuit are cold-hardy hunters whose traditional diet consists of a variety of sea mammals, fish, land mammals and birds. They invented some very sophisticated tools, including the kayak, whose basic design has remained essentially unchanged to this day. Most groups ate virtually no plant food. Their calories came primarily from fat, up to 75%, with almost no calories coming from carbohydrate. Children were breast-fed for about three years, and had solid food in their diet almost from birth. As with most hunter-gatherer groups, they were free from chronic disease while living a traditional lifestyle, even in old age. Here's a quote from Observations on the Western Eskimo and the Country they Inhabit; from Notes taken During two Years [1852-54] at Point Barrow, by Dr. John Simpson:
These people [the Inuit] are robust, muscular and active, inclining rather to spareness [leanness] than corpulence [overweight], presenting a markedly healthy appearance. The expression of the countenance is one of habitual good humor. The physical constitution of both sexes is strong. Extreme longevity is probably not unknown among them; but as they take no heed to number the years as they pass they can form no guess of their own ages.One of the common counterpoints I hear to the idea that high-fat hunter-gatherer diets are healthy, is that exercise protects them from the ravages of fat. The Inuit can help us get to the bottom of this debate. Here's a quote from Cancer, Disease of Civilization (1960, Vilhjalmur Stefansson):
"They are large eaters, some of them, especially the women, eating all the time..." ...during the winter the Barrow women stirred around very little, did little heavy work, and yet "inclined more to be sparse than corpulent" [quotes are the anthropologist Dr. John Murdoch, reproduced by Stefansson].Another argument I sometimes hear is that the Inuit are genetically adapted to their high-fat diet, and the same food would kill a European. This appears not to be the case. The anthropologist and arctic explorer Vilhjalmur Stefansson spent several years living with the Inuit in the early 20th century. He and his fellow Europeans and Americans thrived on the Inuit diet. American doctors were so incredulous that they defied him and a fellow explorer to live on a diet of fatty meat only for one year, under the supervision of the American Medical Association. To the doctors' dismay, they remained healthy, showing no signs of scurvy or any other deficiency (JAMA 1929;93:20–2).
Yet another amazing thing about the Inuit was their social structure. Here's Dr. John Murdoch again (quoted from Cancer, Disease of Civilization):
The women appear to stand on a footing of perfect equality with the men, both in the family and the community. The wife is the constant and trusted companion of the man in everything except the hunt, and her opinion is sought in every bargain or other important undertaking... The affection of parents for their children is extreme, and the children seem to be thoroughly worthy of it. They show hardly a trace of fretfulness or petulance so common among civilized children, and though indulged to an extreme extent are remarkably obedient. Corporal punishment appears to be absolutely unknown, and children are rarely chided or punished in any way.Unfortunately, those days are long gone. Since adopting a modern processed-food diet, the health and social structure of the Inuit has deteriorated dramatically. This had already happened to most groups by Weston Price's time, and is virtually complete today. Here's Price:
In the various groups in the lower Kuskokwim seventy-two individuals who were living exclusively on native foods had in their 2,138 teeth only two teeth or 0.09 per cent that had ever been attacked by tooth decay. In this district eighty-one individuals were studied who had been living in part or in considerable part on modern foods, and of their 2, 254 teeth 394 or 13 per cent had been attacked by dental caries. This represents an increase in dental caries of 144 fold.... When these adult Eskimos exchange their foods for our modern foods..., they often have very extensive tooth decay and suffer severely.... Their plight often becomes tragic since there are no dentists in these districts.Modern Inuit also suffer from very high rates of diabetes and overweight. This has been linked to changes in diet, particularly the use of white flour, sugar and processed oils.
Overall, the unique lifestyle and diet of the Inuit have a lot to teach us. First, that some humans are capable of being healthy eating mostly animal foods. Second, that some humans are able to thrive on a high-fat diet. Third, that humans are capable of living well in extremely harsh and diverse environments. Fourth, that the shift from natural foods to processed foods, rather than changes in macronutrient composition, is the true cause of the diseases of civilization.
Senin, 07 Juli 2008
Cancer in Other Non-Industrialized Cultures
In Cancer, Disease of Civilization (1960), Wilhjalmur Stefansson mentions a few cultures besides the Inuit in which large-scale searches never turned up cancer. Dr. Albert Schweitzer examined over 10,000 traditionally-living natives in Gabon (West Africa) in 1913 and did not find cancer. Later, it became common in the same population as they began "living more and more after the manner of the whites."
In Cancer, its Nature, Cause and Cure (1957), Dr. Alexander Berglas describes the search for cancer among natives in Brazil and Ecuador by Dr. Eugene Payne. He examined approximately 60,000 people over 25 years and found no evidence of cancer.
Sir Robert McCarrison conducted a seven year medical survey among the Hunza, in what is now Northern Pakistan. Among 11,000 people, he did not find a single case of cancer. Their diet consisted of soaked and sprouted grains and beans, fruit, vegetables, grass-fed dairy and a small amount of meat (including organs of course).
In Cancer, its Nature, Cause and Cure (1957), Dr. Alexander Berglas describes the search for cancer among natives in Brazil and Ecuador by Dr. Eugene Payne. He examined approximately 60,000 people over 25 years and found no evidence of cancer.
Sir Robert McCarrison conducted a seven year medical survey among the Hunza, in what is now Northern Pakistan. Among 11,000 people, he did not find a single case of cancer. Their diet consisted of soaked and sprouted grains and beans, fruit, vegetables, grass-fed dairy and a small amount of meat (including organs of course).
Selasa, 17 Juni 2008
Vitamin K2, menatetrenone (MK-4)
Weston Price established the importance of the MK-4 isoform of vitamin K2 (hereafter, K2) with a series of interesting experiments. He showed in chickens that blood levels of calcium and phosphorus depended both on vitamin A and K2, and that the two had synergistic effects on mineral absorption. He also showed that chickens preferred eating butter that was rich in K2 over butter low in K2, even when the investigators couldn't distinguish between them. Young turkeys fed K2-containing butter oil along with cod liver oil (A and D) also grew at a much faster rate than turkeys fed cod liver oil alone.
He hypothesized that vitamin A, vitamin D and vitamin K2 were synergistic and essential for proper growth and subsequent health. He particularly felt that the combination was important for proper mineral absorption and metabolism. He used a combination of high-vitamin cod liver oil and high-vitamin butter oil to heal cavities, reduce oral bacteria counts, and cure numerous other afflictions in his patients. He also showed that the healthy non-industrial groups he studied had a much higher intake of these fat-soluble, animal-derived vitamins than more modern cultures.
Price found an inverse correlation between the levels of K2 in butter and mortality from cardiovascular disease and pneumonia in a number of different regions. A recent study examined the relationship between K2 (MK-4 through 10) consumption and heart attack risk in 4,600 Dutch men. They found a strong inverse association between K2 consumption and heart attack mortality risk. Men with the highest K2 consumption had a whopping 51% lower risk of heart attack mortality and a 26% lower risk of death from all causes compared to men eating the least K2! Their sources of K2 MK-4 were eggs, meats and dairy. They obtained MK-5 through MK-10 from fermented foods and fish. The investigators found no association with K1, the form found in plants.
Perigord, France is the world's capital of foie gras, or fatty goose liver. Good news for the bon vivants: foie gras turns out to be the richest known source of K2. Perigord also has the lowest rate of cardiovascular mortality in France, a country already noted for its low CVD mortality.
Rats fed warfarin, a drug that inhibits K2 recycling, develop arterial calcification. Feeding the rats K2 completely inhibits this effect. Mice lacking matrix Gla protein (MGP), a vitamin K-dependent protein that guards against arterial calcification, develop heavily calcified aortas and die prematurely. So the link between K2 and cardiovascular disease is a very strong one.
Mammals can synthesize K2 MK-4 from K1 to some degree, so dietary K1 and other forms of vitamin K may contribute to K2 MK-4 status.
The synergism Weston Price observed between vitamins A, D and K2 now has a solid mechanism. In a nutshell, vitamins A and D signal the production of some very important proteins, and K2 is required to activate them once they are made. Many of these proteins are involved in mineral metabolism, thus the effects Price saw in his experiments and observations in non-industrialized cultures. For example, osteocalcin is a protein that organizes calcium and phosphorus deposition in the bones and teeth. It's produced by cells in response to vitamins A and D, but requires K2 to perform its function. This suggests that the effects of vitamin D on bone health could be amplified greatly if it were administered along with K2. By itself, K2 is already highly protective against fractures in the elderly. It works out perfectly, since K2 also protects against vitamin D toxicity.
I'm not going to go through all the other data on K2 in detail, but suffice it to say it's very very important. I believe that K2 is a 'missing link' that explains many of our modern ills, just as Weston Price wrote. Here are a few more tidbits to whet your appetite: K2 may affect glucose control and insulin release (1, 2). It's concentrated in the brain, serving an as yet unknown function.
Hunter-gatherers didn't have multivitamins, they had nutrient-dense food. As long as you eat a natural diet containing some vegetables and some animal products, and lay off the processed grains, sugar and vegetable oil, the micronutrients will take care of themselves.
Vitamin K2, MK-4 is only found in animal products. The best sources known are grass-fed butter from cows eating rapidly growing grass, and foie gras. K2 tends to associate with beta-carotene in butter, so the darker the color, the more K2 it contains (also, the better it tastes). Fish eggs, other grass-fed dairy, shellfish, insects and other organ meats are also good sources. Chris Masterjohn compiled a list of food sources in his excellent article on the Weston Price foundation website. I highly recommend reading it if you want more detail. K2 MK-7 is found abundantly in natto, a type of fermented soybean, and it may be partially converted to MK-4.
Finally, you can also buy K2 supplements. The best one is butter oil, the very same stuff Price used to treat his patients. I have used this one personally, and I noticed positive effects on my skin overnight. Thorne research makes a synthetic liquid K2 MK-4 supplement that is easy to dose drop-wise to get natural amounts of it. Other K2 MK-4 supplements are much more concentrated than what you could get from food so I recommend avoiding them. I am generally against supplements, but I've ordered the Thorne product for a little self-experimentation. I want to see if it has the same effect on my skin as the butter oil (update- it does).
He hypothesized that vitamin A, vitamin D and vitamin K2 were synergistic and essential for proper growth and subsequent health. He particularly felt that the combination was important for proper mineral absorption and metabolism. He used a combination of high-vitamin cod liver oil and high-vitamin butter oil to heal cavities, reduce oral bacteria counts, and cure numerous other afflictions in his patients. He also showed that the healthy non-industrial groups he studied had a much higher intake of these fat-soluble, animal-derived vitamins than more modern cultures.
Price found an inverse correlation between the levels of K2 in butter and mortality from cardiovascular disease and pneumonia in a number of different regions. A recent study examined the relationship between K2 (MK-4 through 10) consumption and heart attack risk in 4,600 Dutch men. They found a strong inverse association between K2 consumption and heart attack mortality risk. Men with the highest K2 consumption had a whopping 51% lower risk of heart attack mortality and a 26% lower risk of death from all causes compared to men eating the least K2! Their sources of K2 MK-4 were eggs, meats and dairy. They obtained MK-5 through MK-10 from fermented foods and fish. The investigators found no association with K1, the form found in plants.
Perigord, France is the world's capital of foie gras, or fatty goose liver. Good news for the bon vivants: foie gras turns out to be the richest known source of K2. Perigord also has the lowest rate of cardiovascular mortality in France, a country already noted for its low CVD mortality.
Rats fed warfarin, a drug that inhibits K2 recycling, develop arterial calcification. Feeding the rats K2 completely inhibits this effect. Mice lacking matrix Gla protein (MGP), a vitamin K-dependent protein that guards against arterial calcification, develop heavily calcified aortas and die prematurely. So the link between K2 and cardiovascular disease is a very strong one.
Mammals can synthesize K2 MK-4 from K1 to some degree, so dietary K1 and other forms of vitamin K may contribute to K2 MK-4 status.
The synergism Weston Price observed between vitamins A, D and K2 now has a solid mechanism. In a nutshell, vitamins A and D signal the production of some very important proteins, and K2 is required to activate them once they are made. Many of these proteins are involved in mineral metabolism, thus the effects Price saw in his experiments and observations in non-industrialized cultures. For example, osteocalcin is a protein that organizes calcium and phosphorus deposition in the bones and teeth. It's produced by cells in response to vitamins A and D, but requires K2 to perform its function. This suggests that the effects of vitamin D on bone health could be amplified greatly if it were administered along with K2. By itself, K2 is already highly protective against fractures in the elderly. It works out perfectly, since K2 also protects against vitamin D toxicity.
I'm not going to go through all the other data on K2 in detail, but suffice it to say it's very very important. I believe that K2 is a 'missing link' that explains many of our modern ills, just as Weston Price wrote. Here are a few more tidbits to whet your appetite: K2 may affect glucose control and insulin release (1, 2). It's concentrated in the brain, serving an as yet unknown function.
Hunter-gatherers didn't have multivitamins, they had nutrient-dense food. As long as you eat a natural diet containing some vegetables and some animal products, and lay off the processed grains, sugar and vegetable oil, the micronutrients will take care of themselves.
Vitamin K2, MK-4 is only found in animal products. The best sources known are grass-fed butter from cows eating rapidly growing grass, and foie gras. K2 tends to associate with beta-carotene in butter, so the darker the color, the more K2 it contains (also, the better it tastes). Fish eggs, other grass-fed dairy, shellfish, insects and other organ meats are also good sources. Chris Masterjohn compiled a list of food sources in his excellent article on the Weston Price foundation website. I highly recommend reading it if you want more detail. K2 MK-7 is found abundantly in natto, a type of fermented soybean, and it may be partially converted to MK-4.
Finally, you can also buy K2 supplements. The best one is butter oil, the very same stuff Price used to treat his patients. I have used this one personally, and I noticed positive effects on my skin overnight. Thorne research makes a synthetic liquid K2 MK-4 supplement that is easy to dose drop-wise to get natural amounts of it. Other K2 MK-4 supplements are much more concentrated than what you could get from food so I recommend avoiding them. I am generally against supplements, but I've ordered the Thorne product for a little self-experimentation. I want to see if it has the same effect on my skin as the butter oil (update- it does).
Senin, 16 Juni 2008
Activator X
Activator X, the almost-mythical vitamin discovered and characterized by Weston Price, has been identified! For those of you who are familiar with Weston Price's book 'Nutrition and Physical Degeneration', you know what I'm talking about. For the rest of you, allow me to explain.
Weston Price was a dentist and scientist in the early part of the 20th century. Practicing dentistry in Cleveland, he was amazed at the poor state of his patients' teeth and the suffering it inflicted. At the time, dental health was even worse than it is today, with some children in their teens already being fitted for dentures. Being a religious man, he could not bring himself to believe that 'physical degeneration' was what God intended for mankind. He traveled throughout the world looking for cultures that did not have crooked teeth or dental decay, and that also exhibited general health and well-being. And he found them. A lot of them.
These cultures were all considered 'primitive' at the time, and were not subject to the lifestyles or food choices of the Western world. He documented, numerically and with photographs, the near-absence of dental cavities and crooked teeth in a number of different cultures throughout the world. He showed that like all animals, humans are healthy and robust when occupying the right ecological niche. Price had a deep respect for the nutritional knowledge these cultures curated.
He also documented the result when these same cultures were exposed to Western diets of white flour, sugar and other industrially processed foods: they developed rampant cavities, their children grew with crooked teeth due to narrow dental arches, as well as a number of other strikingly familiar health problems. I think it's worth mentioning that Price's findings were universally corroborated by doctors in contact with the same cultures at the time. They are also corroborated by the archaeological record. Many of his findings were published in respected peer-reviewed journals. 'Nutrition and Physical Degeneration' is required reading for anyone interested in the relationship between nutrition and health.
Naturally, Price wanted to understand what healthy diets had in common besides the absence of white flour and sugar. Having studied cultures as diverse as the carnivorous Inuit, the dairy-eating Masai and agricultural groups in the Andes, he realized that humans are capable of thriving on very diverse foods. However, he did find one thing in common: they all ate some amount of fat-soluble, animal-derived vitamins. Even the near-vegetarian groups ate insects or small animals that were rich in these vitamins. He looked for, but did not find, a single group that was entirely vegetarian and had the teeth and health of the groups he described in 'Nutrition and Physical Degeneration'.
There were three vitamins he found abundantly in the diets of healthy non-industrialized people: A, D, and an unknown substance he called 'activator X'. He considered them all to be synergistic and critical for proper mineral metabolism (tooth and bone formation and maintenance) and general health. He had a chemical test for activator X, but he didn't know its chemical structure and so it remained unidentified. He found activator X most abundantly in grass-fed butter (but not grain fed!), organ meats, shellfish, insects, and fish eggs. Many of these foods were fed preferentially to pregnant or reproductive-age women in the groups he studied.
Price used extracts from grass-fed butter (activator X), in combination with high-vitamin cod liver oil (A and D), to prevent and reverse dental cavities in many of his patients. 'Nutrition and Physical Degeneration' contains X-rays of case studies showing re-calcification of severe cavities using this combination.
After reading his book, I wasn't sure what to make of activator X. If it's so important, why hasn't it been identified in the 60+ years since he described it? I'm happy to say, it finally has. In the summer of 2007, Chris Masterjohn wrote an article for the Weston Price foundation website, in which he identified Weston Price's mystery vitamin: it's vitamin K2, specifically the MK-4 isoform (menatetrenone).
It occurs exactly where Weston Price described it, and research is beginning to find that it's also critical for mineral metabolism, bone and tooth formation and maintenance. Its function is synergistic with vitamins A and D. To illustrate the point, where do A, D and K2 MK-4 all occur together in nature? Eggs and milk, the very foods that are designed to feed a growing animal. This is true from sea urchins to humans, confirming the ubiquitous and critical role of these nutrients. K2 has not yet been recognized as such by the mainstream, but it is every bit as important to health as A and D. The scientific cutting edge is beginning to catch on, however, due to some very tantalizing studies.
In the next post, I'll go into more detail about K2, what the science is telling us and where to get it.
Weston Price was a dentist and scientist in the early part of the 20th century. Practicing dentistry in Cleveland, he was amazed at the poor state of his patients' teeth and the suffering it inflicted. At the time, dental health was even worse than it is today, with some children in their teens already being fitted for dentures. Being a religious man, he could not bring himself to believe that 'physical degeneration' was what God intended for mankind. He traveled throughout the world looking for cultures that did not have crooked teeth or dental decay, and that also exhibited general health and well-being. And he found them. A lot of them.
These cultures were all considered 'primitive' at the time, and were not subject to the lifestyles or food choices of the Western world. He documented, numerically and with photographs, the near-absence of dental cavities and crooked teeth in a number of different cultures throughout the world. He showed that like all animals, humans are healthy and robust when occupying the right ecological niche. Price had a deep respect for the nutritional knowledge these cultures curated.
He also documented the result when these same cultures were exposed to Western diets of white flour, sugar and other industrially processed foods: they developed rampant cavities, their children grew with crooked teeth due to narrow dental arches, as well as a number of other strikingly familiar health problems. I think it's worth mentioning that Price's findings were universally corroborated by doctors in contact with the same cultures at the time. They are also corroborated by the archaeological record. Many of his findings were published in respected peer-reviewed journals. 'Nutrition and Physical Degeneration' is required reading for anyone interested in the relationship between nutrition and health.
Naturally, Price wanted to understand what healthy diets had in common besides the absence of white flour and sugar. Having studied cultures as diverse as the carnivorous Inuit, the dairy-eating Masai and agricultural groups in the Andes, he realized that humans are capable of thriving on very diverse foods. However, he did find one thing in common: they all ate some amount of fat-soluble, animal-derived vitamins. Even the near-vegetarian groups ate insects or small animals that were rich in these vitamins. He looked for, but did not find, a single group that was entirely vegetarian and had the teeth and health of the groups he described in 'Nutrition and Physical Degeneration'.
There were three vitamins he found abundantly in the diets of healthy non-industrialized people: A, D, and an unknown substance he called 'activator X'. He considered them all to be synergistic and critical for proper mineral metabolism (tooth and bone formation and maintenance) and general health. He had a chemical test for activator X, but he didn't know its chemical structure and so it remained unidentified. He found activator X most abundantly in grass-fed butter (but not grain fed!), organ meats, shellfish, insects, and fish eggs. Many of these foods were fed preferentially to pregnant or reproductive-age women in the groups he studied.
Price used extracts from grass-fed butter (activator X), in combination with high-vitamin cod liver oil (A and D), to prevent and reverse dental cavities in many of his patients. 'Nutrition and Physical Degeneration' contains X-rays of case studies showing re-calcification of severe cavities using this combination.
After reading his book, I wasn't sure what to make of activator X. If it's so important, why hasn't it been identified in the 60+ years since he described it? I'm happy to say, it finally has. In the summer of 2007, Chris Masterjohn wrote an article for the Weston Price foundation website, in which he identified Weston Price's mystery vitamin: it's vitamin K2, specifically the MK-4 isoform (menatetrenone).
It occurs exactly where Weston Price described it, and research is beginning to find that it's also critical for mineral metabolism, bone and tooth formation and maintenance. Its function is synergistic with vitamins A and D. To illustrate the point, where do A, D and K2 MK-4 all occur together in nature? Eggs and milk, the very foods that are designed to feed a growing animal. This is true from sea urchins to humans, confirming the ubiquitous and critical role of these nutrients. K2 has not yet been recognized as such by the mainstream, but it is every bit as important to health as A and D. The scientific cutting edge is beginning to catch on, however, due to some very tantalizing studies.
In the next post, I'll go into more detail about K2, what the science is telling us and where to get it.
Kamis, 12 Juni 2008
More Masai
I left out one of the juicier tidbits from the last post because it was getting long. Investigators Kang-Jey Ho et al. wanted an explanation for why the Masai didn't have high serum cholesterol despite their high dietary cholesterol intake (up to 2,000 mg per day-- 6.7 times the US FDA recommended daily allowance).
They took 23 male Masai subjects aged 19 to 24 and divided them into two groups. The first group of 11 was the control group, which received a small amount of radioactive cholesterol in addition to a cholesterol-free diet that I will describe below. The second group of 12 was the experimental group, which they fed 2,000 mg cholesterol per day, a small amount of radioactive cholesterol as a tracer, and the exact same cholesterol-free diet as the control group. For the duration of the 24-week trial, the subjects ate the experimental diet exclusively. Here's what it was (in order of calories, descending):
The really interesting thing is that serum cholesterol increased dramatically in both groups. It went from 125 mg/100 mL to over 170 mg/100 mL, despite a large decrease in the saturated fat they were eating. The change took about two weeks to occur, and remained fairly stable for the remainder of the trial.
Both groups also gained weight. In the first week, they gained an average of 3 pounds each. To be fair, the initial gain was probably most water, which is what happens when a person increases their carbohydrate and salt intake. The investigators freaked out and cut their calorie intake by 400 kcal, only allowing them 3,600 kcal per day. Initially, they were voluntarily consuming 4,000 kcal per day. I find that interesting as well. Something tells me they weren't chugging non-dairy creamer because it was so delicious, but because their confused hormones were telling them to EAT.
Even after putting the subjects on calorie restriction (not letting them eat as much as they wanted, by an average of 400 kcal/day), they continued gaining weight. By the end of the study, the 23 subjects had gained an average of 7.8 lbs per person.
To summarize, this is what the investigators saw when they put 23 unfortunate Masai men on a bottom-rung industrially processed diet: elevated cholesterol, hyperphagia (excessive eating), and weight gain. Sounds familiar, doesn't it?
They took 23 male Masai subjects aged 19 to 24 and divided them into two groups. The first group of 11 was the control group, which received a small amount of radioactive cholesterol in addition to a cholesterol-free diet that I will describe below. The second group of 12 was the experimental group, which they fed 2,000 mg cholesterol per day, a small amount of radioactive cholesterol as a tracer, and the exact same cholesterol-free diet as the control group. For the duration of the 24-week trial, the subjects ate the experimental diet exclusively. Here's what it was (in order of calories, descending):
- Nondairy coffee creamer (made of corn syrup solids and vegetable oil)
- Beans
- Sugar
- Corn
- Corn oil
- A vitamin pill
The really interesting thing is that serum cholesterol increased dramatically in both groups. It went from 125 mg/100 mL to over 170 mg/100 mL, despite a large decrease in the saturated fat they were eating. The change took about two weeks to occur, and remained fairly stable for the remainder of the trial.
Both groups also gained weight. In the first week, they gained an average of 3 pounds each. To be fair, the initial gain was probably most water, which is what happens when a person increases their carbohydrate and salt intake. The investigators freaked out and cut their calorie intake by 400 kcal, only allowing them 3,600 kcal per day. Initially, they were voluntarily consuming 4,000 kcal per day. I find that interesting as well. Something tells me they weren't chugging non-dairy creamer because it was so delicious, but because their confused hormones were telling them to EAT.
Even after putting the subjects on calorie restriction (not letting them eat as much as they wanted, by an average of 400 kcal/day), they continued gaining weight. By the end of the study, the 23 subjects had gained an average of 7.8 lbs per person.
To summarize, this is what the investigators saw when they put 23 unfortunate Masai men on a bottom-rung industrially processed diet: elevated cholesterol, hyperphagia (excessive eating), and weight gain. Sounds familiar, doesn't it?
Rabu, 11 Juni 2008
Masai and Atherosclerosis
I've been digging deeper into the health of the Masai lately. A commenter on Chris's blog pointed me to a 1972 paper showing that the Masai have atherosclerosis, or hardening of the arteries. This interested me so I got my hands on the full text, along with a few others from the same time period. What I found is nothing short of fascinating.
First, some background. Traditional Masai in Kenya and Tanzania are pastoralists, subsisting on fermented cow's milk, meat and blood, as well as traded food in modern times. They rarely eat fresh vegetables. Contrary to popular belief, they are a genetically diverse population, due to the custom of abducting women from neighboring tribes. Many of these tribes are agriculturalists. From Mann et al: "The genetic argument is worthless". This will be important to keep in mind as we interpret the data.
At approximately 14 years old, Masai men are inducted into the warrior class, and are called Muran. For the next 15-20 years, tradition dictates that they eat a diet composed exclusively of cow's milk, meat and blood. Milk is the primary food. Masai cows are not like wimpy American cows, however. Their milk contains almost twice the fat of American cows, more protein, more cholesterol and less lactose. Thus, Muran eat an estimated 3,000 calories per day, 2/3 of which comes from fat. Here is the reference for all this. Milk fat is about 50% saturated. That means the Muran gets 33% of his calories from saturated fat. This population eats more saturated fat than any other I'm aware of.
How's their cholesterol? Remarkably low. Their total serum cholesterol is about half the average American's. I haven't found any studies that broke it down further than total cholesterol. Their blood pressure is also low, and hypertension is rare. Overweight is practically nonexistent. Their electrocardiogram readings show no signs of heart disease. They have exceptionally good endurance, but their grip strength is significantly weaker than Americans of African descent. Two groups undertook autopsies of male Masai to look for artery disease.
The first study, published in 1970, examined 10 males, 7 of which were over 40 years old. They found very little evidence of atherosclerosis, even in individuals over 60. The second study, which is often used as evidence against a high-fat diet, was much more thorough and far more interesting. Mann et al. autopsied 50 Masai men, aged 10 to 65. The single most represented age group was 50-59 years old, at 13 individuals. They found no evidence of myocardial infarction (heart attack) in any of the 50 hearts. What they did find, however, was coronary artery disease. Here's a figure showing the prevalence of "aortic fibrosis", a type of atherosclerotic lesion:
It looks almost binary, doesn't it? What could be causing the dramatic jump in atherosclerosis at age 40? Here's another figure, of total cholesterol (top) and "sudanophilia" (fatty streaks in the arteries, bottom). Note that the Muran period is superimposed (top).
There appears to be a pattern here. Either the Masai men are eating nothing but milk, meat and blood and they're nearly free from atherosclerosis, or they're eating however they please and they have as much atherosclerosis as the average American. There doesn't seem to be much in between.
Here's a quote from the paper that I found interesting:
This may suggest that you can eat a wide variety of foods and be healthy, except industrial grain products (particularly white flour), sugar, industrial vegetable oil and other processed food. The Masai are just one more example of a group that's healthy when eating a traditional diet.
First, some background. Traditional Masai in Kenya and Tanzania are pastoralists, subsisting on fermented cow's milk, meat and blood, as well as traded food in modern times. They rarely eat fresh vegetables. Contrary to popular belief, they are a genetically diverse population, due to the custom of abducting women from neighboring tribes. Many of these tribes are agriculturalists. From Mann et al: "The genetic argument is worthless". This will be important to keep in mind as we interpret the data.
At approximately 14 years old, Masai men are inducted into the warrior class, and are called Muran. For the next 15-20 years, tradition dictates that they eat a diet composed exclusively of cow's milk, meat and blood. Milk is the primary food. Masai cows are not like wimpy American cows, however. Their milk contains almost twice the fat of American cows, more protein, more cholesterol and less lactose. Thus, Muran eat an estimated 3,000 calories per day, 2/3 of which comes from fat. Here is the reference for all this. Milk fat is about 50% saturated. That means the Muran gets 33% of his calories from saturated fat. This population eats more saturated fat than any other I'm aware of.
How's their cholesterol? Remarkably low. Their total serum cholesterol is about half the average American's. I haven't found any studies that broke it down further than total cholesterol. Their blood pressure is also low, and hypertension is rare. Overweight is practically nonexistent. Their electrocardiogram readings show no signs of heart disease. They have exceptionally good endurance, but their grip strength is significantly weaker than Americans of African descent. Two groups undertook autopsies of male Masai to look for artery disease.
The first study, published in 1970, examined 10 males, 7 of which were over 40 years old. They found very little evidence of atherosclerosis, even in individuals over 60. The second study, which is often used as evidence against a high-fat diet, was much more thorough and far more interesting. Mann et al. autopsied 50 Masai men, aged 10 to 65. The single most represented age group was 50-59 years old, at 13 individuals. They found no evidence of myocardial infarction (heart attack) in any of the 50 hearts. What they did find, however, was coronary artery disease. Here's a figure showing the prevalence of "aortic fibrosis", a type of atherosclerotic lesion:
It looks almost binary, doesn't it? What could be causing the dramatic jump in atherosclerosis at age 40? Here's another figure, of total cholesterol (top) and "sudanophilia" (fatty streaks in the arteries, bottom). Note that the Muran period is superimposed (top).
There appears to be a pattern here. Either the Masai men are eating nothing but milk, meat and blood and they're nearly free from atherosclerosis, or they're eating however they please and they have as much atherosclerosis as the average American. There doesn't seem to be much in between.
Here's a quote from the paper that I found interesting:
We believe... that the Muran escapes some noxious dietary agent for a time. Obviously, this is neither animal fat nor cholesterol. The old and the young Masai do have access to such processed staples as flour, sugar, confections and shortenings through the Indian dukas scattered about Masailand. These foods could carry the hypothetical agent."
This may suggest that you can eat a wide variety of foods and be healthy, except industrial grain products (particularly white flour), sugar, industrial vegetable oil and other processed food. The Masai are just one more example of a group that's healthy when eating a traditional diet.
Kamis, 15 Mei 2008
Lessons From the Pima Indians
At 38% and climbing in 2006, the Pima indians (Akimel O'odham) of Arizona have the highest rate of diabetes of any population in the world. They also have staggering rates of obesity (~70%) and hypertension. Things were very different for them before 1539, when the Spanish first made contact. They lived on an agricultural diet of beans, corn and squash, with wild fish, game meat and plants. As with most native people, they were thin and healthy while on their traditional diet.
In 1859, the Pima were restricted to a small fraction of their original land along the Gila river, the Pima Reservation. In 1866, settlers began arriving in the region and diverting the Gila river upstream of the reservation for their own agriculture. In 1869, the river went dry for the first time. 1886 was the last year any water flowed to the Pima Reservation in the Gila river.
The Pima had no way to obtain water, and no way to grow crops. Their once productive subsistence economy ground to a halt. Famine ensued for 40 desperate years. The Pima cut down their extensive mesquite forests to sell for food and water. Eventually, after public outcry, uncle Sam stepped in.
The government provided the Pima with subsidized "food": white flour, sugar, partially hydrogenated lard, and canned goods. They promptly became diabetic and overweight, and have remained that way ever since.
The Pima are poster children for mainstream nutrition researchers in the US for several reasons. First of all, their pre-contact diet was probably fairly low in fat, and researchers love to point out that they now eat more fat (comparable to the average American diet). Another reason is that there's another group of Pima in Mexico who still live on a relatively traditional diet and are much healthier. They are genetically very similar, supporting the idea that it's the lifestyle of the American Pima that's causing their problems. The third reason is that the Mexican Pima exercise more than the Arizona Pima and eat a bit less.
I of course agree with the conclusion that their lifestyle is behind their problems; that's pretty obvious. I think most Pima know it too. If they got their water back, maybe things would be different for them.
However, the focus on macronutrients sometimes obscures the fact that the modern Pima diet is pure crap. It's mostly processed food with a low nutrient density. It also contains the two biggest destroyers of indigenous health: white flour and sugar. There are numerous examples of cultures going from a high-fat diet to a lower-fat "reservation food" diet and suffering the same fate: the Inuit of Alaska, the Maasai and Samburu of Kenya, tribes in the Pacific Northwestern US and Canada, certain Aboriginal groups, and more. What do they all have in common? White flour, sugar and other processed food.
The exercise thing is somewhat questionable as well. True, Mexican Pima exercise 2.5 times more than Arizona Pima, but the Arizona Pima still exercise much more than the average American! Women clock in at 3.1 hours a week, while men come in at a whopping 12.1 hours a week! I am a bike commuter and weight lifter, and even I don't exercise that much. So forgive me if I'm a little skeptical of the idea that they aren't exercising enough to keep the weight off.
The history of the Pima is a heart-wrenching story that has been repeated hundreds, perhaps thousands of times all over the world. Europeans bring in white flour, sugar and other processed food, it destroys a native populations' health, and then researchers either act like they don't understand why it happened, or give unsatisfying explanations for it.
The Pima are canaries in the coal mine, and we can learn a lot from them. Their health problems resemble those of other poor Americans (and wealthier ones also, to a lesser extent). This is because they are both eating similar types of things. The problem is creeping into society at large, however, as we rely more and more on processed wheat, corn, soy and sugar, and less on wholesome food. Obesity in the US has doubled in the past 30 years, and childhood obesity has tripled. Diabetes is following suit. Life expectancy has begun to diminish in some (poor) parts of the country. Meanwhile, our diet is looking increasingly like Pima reservation food. It's time to learn a lesson from their tragedy.
Senin, 17 Maret 2008
Say Hello to the Kuna
For those of you who haven't been reading the comments, we've been having a spirited discussion about the diet and health of hunter-gatherers here. I brought up the Kuna indians in Panama, who are immune to hypertension, live a good long time, do not gain excess weight, and seem to have less cardiovascular disease and cancer than their city-dwelling cousins.
I was hungry for more information about the Kuna lifestyle, so over the last few days, I've dug up every paper I could find on them. The first paper describing their lack of hypertension was published in 1944 and I don't have access to the full text. In 1997, a series of studies began, headed by Dr. Norman Hollenberg at Harvard. He confirmed the blood pressure findings, and collected data on their diet, lifestyle and kidney function. Here's a summary:
The Kuna are half hunter-gatherers, half agricultural. They cultivate plantains, corn, cocoa, yucca, kidney beans, and several types of fruit. They trade for sugar, salt, some processed cocoa and miscellaneous other foods. They drink 40+ oz of hot cacao/cocoa per day, some locally produced and some imported. A little-known secret: the Kuna eat an average of 3 oz of donut a week. They also fish and hunt regularly.
In the first recent study, published in 1997, the Kuna diet is described as 29% lower in fat than the average US diet (56 g/day), 23% lower in protein (12.2 g), 60% higher in cholesterol, and higher in sodium and fiber. The study doesn't specifically mention this, but the reader is left to infer that 65% of their calories come from carbohydrate. This would be from plantains, corn, yucca, sugar and beans. The fat in their diet comes almost exclusively from coconut, cocoa and fish: mostly saturated and omega-3 fats.
In the next study, the picture is slightly different. Their staple stew, tule masi, is described as being 38% fat by calories (from coconut and fish), exceeding the American average. In the final study in 2006, Hollenberg's group used a more precise method of accounting for diet composition than was used in previous attempts. The paper doesn't report macronutrients as a percentage of calories however.
I was able to find some clues about their diet composition. First of all, they report the meat consumption of the Kuna at approximately 60 oz per week, mostly from fish. That's 8.6 oz per day, identical to the American average.
By putting together the pieces from the later studies, a new picture emerges: a diet high in fish and moderate in protein, moderate in unprocessed fat (especially saturated and omega-3), and moderately high in mostly unprocessed carbohydrate.
Here's my interpretation. The Kuna are healthier than their city-dwelling cousins for a number of reasons. They have a very favorable omega3:6 ratio due to seafood, wild game and relatively saturated vegetable fats. Their carbohydrate foods are mostly unprocessed and mostly from non-grain sources. They also live an outdoor life full of sunshine (vitamin D) and exercise. The chocolate may also contribute to their health, as it contains high levels of potentially protective polyphenols. They're healthier than industrialized people because they live more naturally.
Another lesson to be learned from the Kuna and other exceptionally healthy indigenous peoples is that the human body can tolerate a large amount of carbohydrate under the right conditions.
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