Here is at first the letter that started the
discussion, sent by Nicolai Worm on Feb 12,
Purdue News http://news.uns.purdue.edu/html4ever/020204.Watkins.paleo.html
Cave men diets offer insights to today's health
problems, study shows
WEST LAFAYETTE, Ind. Eat meat. That's the dietary advice given by a team of scientists
who examined the dietary role of fat in a study that combined nutritional analysis with
anthropologic research about the diets of ancient hunter-gatherer societies. But there's a
catch: To be as healthy as a cave man you have to eat certain kinds of fish, wild game
such as venison, or grass-fed meat such as beef.
The research was conducted by Bruce
Watkins, professor and university faculty scholar at Purdue University and director of the
Center for Enhancing Foods to Protect Health, and anthropologist Loren Cordain, professor of health
and exercise science at Colorado State University and author of "The Paleo diet"
(John Wiley & Sons, 2002). Watkins and Cordain conducted detailed chemical analysis of
the meats people ate 10,000 years ago and compared those results to the most common meat
people eat today.
They found that wild game,
such as venison or elk meat, as well as grass-fed beef, contain a mixture of fats that are
actually healthy for you, and, the researchers say, lower cholesterol and reduce other
chronic disease risk.
Recent studies have indicated that a healthy diet should contain a
balance of essential fats. The two types of most concern are omega-6 and omega-3, and both are essential for proper nutrition.
Omega-3 fat, which is often found in high levels in certain fish, has been shown to reduce
the risk of cardiovascular disease, but too much omega-3 can increase the risk of stroke.
Omega-6 fat also is an essential fat, but too much omega-6 in the diet can contribute to
inflammatory responses associated with of chronic disease.
According to Watkins, the analysis done at Purdue found that wild elk, deer
and antelope from the Rocky Mountains region have greater amounts of omega-3 fatty acids
and a lower and therefore healthier ratio of omega-6 to omega-3 fatty acids in
muscle meats, compared to grain-fed beef. "Both grass-fed steers and the wild
ruminants have a ratio of omega-6 to omega-3 fatty acids slightly above two in meat. In
other words, two parts omega-6 to one part omega-3," Watkins says. "That ratio
is much lower than the ratios of 5-to-1 to 13-to-1 reported in previous studies for
grain-fed steers." Watkins says the low fat ratio of wild ruminants and grass-fed
beef is good news for people who need to reduce their cholesterol. "The fatty acid
ratio in wild ruminants is consistent with the recent American Heart Association
recommendation to increase the consumption of
omega-3 fatty acids found in certain fish in order to reduce the risk of cardiovascular
disease," he says.
The results of the study were published in the January issue of
European Journal of Clinical Nutrition. The
research was funded by the National Science Foundation, the Purdue University Office of
Research Programs and the Pope & Young Club, a national conservation organization.
Analyzing the foods that people ate 10,000 years ago is not a flight of scientific
esoterica. The researchers say this finding has important implications for what we eat
today. Although 10,000 years ago predates all modern civilizations, it is a small blip in
the evolutionary timeline of humans. Some nutritionists believe that by studying what
people ate in the Paleolithic Era, also known as the Old Stone Age, they can determine the
proper mix of foods for modern man.
Cordain says anthropological nutritionists such as
himself have studied the few isolated hunter-gatherer societies such as the Nanamiut of
Alaska, the Aborigines of Australia and the !Kung of Africa that remained into the 20th
century and found that modern maladies, such as heart disease, high cholesterol, obesity
and diabetes, are rare in these populations. "Over
the past several decades, numerous studies have found that indigenous
populations have low serum cholesterol and
triglyceride levels," Cordain says. This is despite the fact that their diets aren't
going to reap praise from many modern nutritionists. "Previous studies by myself and
colleagues had found that nearly all 97 percent of the world's hunter-gatherer
societies would have exceeded recommended guidelines for fat," Cordain says.
says although this may be surprising to many people, it fits exactly with what research is
showing about the importance of specific types of fat in the diet. "Current research
is showing that, with the decline of fat in the diet, the amount of fat isn't as important
as the relative amounts, or ratio, of specific fats in your diet. It's a qualitative
issue, not a quantitative issue," he says. "By eating more of the good fat you
can lower your cholesterol and reduce your risk of cardiovascular disease." This
balance of fats has changed dramatically in the past century, he adds. "Generally,
our modern diets, especially in the past 100 years, have changed to where we're consuming
excess amounts of omega-6 fat. Omega-6 is found in high levels in many of the oil seed
crops that we consume," Watkins says. "It's also found in the meat of the
livestock that eat these grains, as this
Watkins adds that this research suggests new ways for potential
diversification in agricultural production. "Our study points out that there are
opportunities for ranchers and
producers to develop niche markets for grass-fed beef that fit consumer interest in beef
products that deliver special nutrients," Watkins says. "There may also be
branding opportunities for products like the Laura's Lean Beef Products."
Writer: Steve Tally, (765) 494-9809; firstname.lastname@example.org
Sources: Bruce Watkins, (765) 494-5802; email@example.com
Loren Cordain, (970) 491-7436; firstname.lastname@example.org
Fatty acid analysis of wild ruminant tissues: evolutionary implications for reducing diet-related
chronic disease L. Cordain, Colorado State University, Bruce Watkins, Purdue
University, M. Kehler, CSU, L. Rogers, Purdue, Y Li, Purdue
Hypotheses: Consumption of wild ruminant fat represented the primary lipid source
for pre-agricultural humans. Hence, the lipid composition of these animals' tissues may
provide insight into dietary requirements that offer protection from chronic disease in
Method: We examined the lipid composition of muscle, brain and subcutaneous adipose
tissue (AT) from 17 elk (Cervus elaphus), 15 mule deer (Odocoileus hermionus), and 17
antelope (Antilicapra americana), and contrasted them to wild African ruminants and
pasture and grain-fed cattle.
Results: Muscle fatty acid (FA) was
similar among North American species with polyunsaturated fatty acids/saturated acids
(P/S) values from 0.80 to 1.09 and n-6/n-3 FA from 2.32 to 2.60. Marrow FA was similar
among North American species with high levels (59.3 percent to 67.0 percent) of
monounsaturated FA; a low P/S (0.24<0.33), and an n-6/n-3 of 2.24<2.88. Brain had
the lowest n-6/n-3 (1.20<1.29), the highest concentration of 22:6
n-3 (elk, 8.90 percent; deer, 9.62 percent; antelope, 9.25 percent) and a P/S of 0.69. AT
had the lowest P/S (0.05<0.09) and n-6/n-3 (2.25<2.96). Conjugated linoleic acid
(CLA) isomers were found in marrow of antelope (1.5 percent), elk (1.0 percent) and deer
(1.0 percent), in AT (deer, 0.3 percent; antelope, 0.3 percent) in muscle (antelope, 0.4
percent; elk, trace) but not in brain.
Conclusions: Literature comparisons showed tissue lipids of North American and
African ruminants were similar to pasture-fed cattle, but dissimilar to grain-fed cattle.
The lipid composition of wild ruminant tissues may serve as a model for dietary lipid
recommendations in treating and preventing chronic disease.
The Cordain Camp support the Lipid Hypothesis
100% so they are not exactly allies. Cordain mistakenly thinks that the fats in wild game
animals was primarily made up of MUFAs and PUFAs and very little SFAs. While its true that
the muscle meats of wild game animals are non-marbled, it is not true that this was the
only part of the animal that was eaten. He is also wrong in saying that the fatty acid
profiles of wild ruminant animals can be affected by their diets; only the monogastric
animals show this. The omega-3/6 ratio in ruminant animals stays pretty constant, no
matter what they eat.
If you check out Cordain's book THE PALEO diet, you will quickly see all of the
politically correct gobbeldygook about saturated fats and cholesterol clogging arteries
and causing heart disease. Since Cordain cannot divorce himself from this view, he MUST
come up with an explanation to rationalize the reality that hunter/gatherer peoples ate
lots of animals foods, but
suffered from little heart disease. His explanation, though, is off the mark. While
Cordain is certainly correct about our ancestors being meat-eaters, he is wrong about the
quantity and type of fat they ate on a daily basis. You may want to check out two articles
co-authored by Mary Enig on this: "Guts and Grease: The diet of Native
Americans" and "Caveman Cuisine"
Both are posted at http://www.westonaprice.org
in the "Traditional diets" section.
All the best,
Dear group: Eskimos are indeed an interesting group to look at. Weston Price visited
there and because he told them to stay on their health maintaining high fat diet they told
him how they prevented the disease the white man called scurvy. Everytime they killed an
animal they removed the adrenal gland and cut a slice for every man, woman and child in
the village and ate it raw. (Eskimo means eater of raw meat and, as Uffe
knows, I picked
up the nick name Puckick working in Alaska during college). It is now known the
adrenal gland has the highest concentration of vitamin C in the body. Outsiders went
there, were kindly offered the raw adrenal slice, refused, and got scurvy toward the end
of the long winter. For many years the medical staff of a hospital in Edmonton, Alberta,
Canada, rotated through a hospital that served Eskimos north of the Artic
1955 the Eskimos remained free of diseases of physical degeneration. In 1955 the DEW line
went into effect, involving the building of radar installations and airfields to detect
Russina Nukes. The Eskimos gave up their hunting and gathering life
style, moved to civilization, and became the labor force. Overnight they switched from an all fresh food
raw diet to a diet of 100% processed foods. In a short time of 15 years women were getting
gall bladder disease, children crooked teeth and acne, and men heart attacks and diabetes,
all conditions formerly absent. The doctors wrote this up in a fairly major nutrition
journal with the title, "When the Eskimo Comes to Town." Don't ask for the
reference as it is buried away in old files in a locker and it is too cold here (North
Idaho) to go looking for it. Maybe when it warms up.
The anthropoligist Stephenson spend
many winters living in the North where he ate the Eskimo high fat diet. He returned to New
York and gave some lectures about his adventures and observations. Physicians couldn't
believe how he remained healthy on the high fat diet and challenged him. As he had about a
year's writing to do he volunteered to live under observation in a hospital 24 hours a day
and eat the same diet for 12 months and be tested, etc. He stayed perfectly healthy as did
all of his lab tests, much to the disbelief of the fat theory believing physicians
Paul Dudley White, founder of the speciality of
cardiology, wrote about 3
books for the public. He graduated medical school in 1910 and had read about the early and
few descriptions of myocardial infarctions in Europe. He was looking for similar cases and
found his first in 1921. He was asked one time what he thought about the cholesterol
theory. He answered he didn't believe it because it was not consistent with the history of
the disease. He said they didn't ask him anymore. The history of the disease he was
referring to was that the very first MI confirmed with an autopsy was in England published
in 1878 by Adam Hammer. That occurred near the end of a century in which tens of thousands
of autopsies were perfomed in Europe during the explosion of pathologic examinations that
led to naming most of our serious diseases. In a part of Austria everyone who died was
autopsied by royal decree. During this same time period American pioneers were eating
animals, cooking with lard, and bread spread with lard was a popular
food. Guess what? No
heart attacks until after 1900 and the MI was not coded as a separate cause of death until
1950 and by that time it was the most common cause of death. When I was writing one of my
books I wrote the National Center for Health Statistics asking the
question. I got a phone
call back with that response. I have been curious about one aspect of the fat
were taught in medical school that we are omnivors, able to eat all
foods. We have the
biochemistry to process carbs, proteins, and fats. Then suddently we are not able to
process a list of high fat natural foods our ancestors ate throughout history with no
evidence of harm. Shame on the cholesterol mafia.
There may have been very few recorded cases of
MI prior to the nineteen thirties. But John Hunter in 1793 described people with the
symptoms of angina. In the mid-nineteenth centery. Virchow and Rokitansky had both
identified atherosclerotic plaques (with cholesterol in them). I don't know if the plaques
were thought to be the cause of death. In 1911 Osler described the typical victim of heart
disease as (sic) Iron grey in complexion, a man who looks as though his engine is stuck at
William Harvey, who 'discovered' how the
CV system works, described the victim of heart disease as a man of stormy and agitated
personality. He is thought to have died of a heart attack in 1628. In short, heart
disease wasn't common, but it did exist. (I read, and lost, an article in which the
arteries of Egyptian mummies were analysed, and showed signs of atherosclerotic
As correctly suggested by Stephen, that mob
continue to disregard many facts on what constituted a typical diet of
It is now claimed that for instance Australian Aborigines ate very low-fat diet, based on
a typical analysis of marsupial meat and "known" fact that fish were a large
part of their diet. This of course is total rubbish. I belive the web site cited by
Stephen also contains Mary's article on what really was eaten by them, written
based on the research of Weston Price. Furthermore, these days a lot is being written on
how bad was the Eskimo diet (apart from good effect of fish oils in that type of diet),
recent epidemiological studies have described effects of what has happened to these people
after introduction to "our" foods. I have an article given to me by Barry Groves
(written in early 50's) in which the author is amazed how healthy these people
before adoption of "healthy diet", considering how little carbs they had and
their limited Vit C supply. Funny how until only recently Canadian government shot their
dogs and prevented them from living their natural lifestyle, in return for some paid work
and supermarkets. The same, in principle, goes for Australian natives. These days both of
these peoples are obese and are sicker than their dogs, which somehow managed to stay
closer to their natural diet.
In the hands of the nutritional "spin-doctors," all accurate food history and
anthrolpology are routinely tossed into the garbage in favor of politically-correct ideas.
Often, for example, it is typical for modern investigators to disregard or overlook insect
consumption when assessing
traditional diets. Insects are typically loaded with fat, including the grubs that
were/are a feature of Aboriginal diets.
Dear Chee Energy I think you are referring to Vilhalmur Stefansson's comments
after his first expedition to the Arctic where he was impressed by the complete absence of
cancer in Eskimos. My recollection is that he later wrote a book entitled
A Disease of Civilization?. Albert Schweitzer similarly noted the absence
of cancer in African natives on his initial visit to the Congo but its gradual emergence
as natives " lived more and more after the manner of the whites" and adopted
their diets and stressful lifestyles.
The first notation of such relationships was by Sir Robert McCarrison, a very alert and
perceptive physician who had been assigned by the British Army to establish a hospital and
health care delivery system for Hunza natives in the Kashmir around 100 years
He traced family records, conducted detailed interviews, performed careful
physical examinations, and kept meticulous records for almost a decade and was astounded
by the magnificent physical and mental status of the very elderly. diet was
important but after reviewing all the information he had gathered, McCarrison concluded
that the unusual longevity and extraordinarily good health of the Hunzas, well into the
eighth and ninth decades, was due to the absence of the stresses of contemporary
civilization, noting: ". . . and they are far removed from the refinements of
civilization. Certain of these races are of magnificent physique, preserving until
late in life, the character of their youth; they are unusually fertile and
endowed with nervous systems of notable stability. . . Cancer is
Thanks for your response. I am aware of the
extensive contributions of McCarrison. I have not heard anyone mention another
nutrition-disease pioneer, British epidemiologist T.L.Cleave, who found that
primitive people with adequate nutritional food supplies remained free of degenerative
diseases until the entry of modern foods (he called the villains "refined
carbohydrates"). From the entry of the refined carbs to the first observed cases
of heart attacks, high blood pressure, diabetes, etc. took 20 to 30 years which
obscured the connection, but he found no exceptions to the pattern in hundreds of
areas regardless of other changes going on.
Another pioneer was a Brit named Trowell who
went to work in Kenya in 1930 and noted an absence of degen. diseases. He worked there 30
years and during that time the same diseases began to occur. When he returned to England
he did a small study on about 15 people with hypertension and got about 12 of them off of
meds. by having them switch to an all fresh food diet. His simple working hypothesis
was the reversal of sodium and potassium levels in fresh versus processed foods, but this
applied to all of the other minerals as well and at that time there was no way for him to
The general message from this is that a
variety of diets kept people in primitive cultures free of degenerative diseases and
at least 16 cultures had very high saturated fat diets. Of course, all the food was fresh,
with whole grains, full levels of minerals, high levels
of antioxidants plus B vitamins to prevent homocysteine problems, and
adequate folate levels to prevent neural tube defects and fragile X syndrome (both
linked to low folate levels). Missing were refined carbohydrates, oils containing trans
fats (before margarine}, refined sugar, canned and frozed foods, in fact, no foods in
containers at all.
British physicians recorded the same findings
when they surveyed the Bantu population in 1930 to see what diseases they were going to
encounter in a new medical school about to open. Once again, no HBP, no evidence of
coronary artery disease, diabetes, and strokes, all conditions it is easy to check for in
the bush with only a blood pressure cuff, physical exam, EKG, and dipstick urine test
I saw the same pattern when I treated
Ecuadorian Indians in in an Indian hospital in Cuenca, Ecuador, for a year (1965-6)
9000 feet up in the Andes.There were 320,000 Indians in the province and only one facility
to provide medical care for them. Considered to be lower than animals by the city folk
"Spanish" they lived in the countryside with no running water, no electricity,
and didn't even cover their waste. They were entirely self sufficient for food and
clothing. The only income was selling a few vegetables in the open markets for
pennies with which they purchased batteries for transister radios so they could listen to
an Indian radio station.
Generally there were only about 40
patients in the hospital, almost all with trauma, burns, and complications related to
severe shock with previous obstetrical complications trying to deliver in the
countryside. No degenerative diseases ever seen, and very little cancer. Only one
appendicitis case seen in one year. The young people grew up to have 32 straight,
decay-free teeth and no acne. City kids hung out at the soda fountain and had crooked
teeth, tooth decay, and were getting acne. I didn't appreciate what I was seeing until
about a decade later.
Perhaps we should have a contest to see
who has the highest cholesterol level. Mine is 330. Can anyone of you skeptics
top that? My level was 260 in the 1960s at a that time we were told normal was up to 300.
I began to give up on the cholesterol theory in 1977 when I had dinner with Linus Pauling.
I asked him if he wasn't taking a risk in eating his thick steak. He told me he believed
if the body was well nourished with every thing it needed to function optimally
then cholesterol would take care of itself and we didn't need to worry about
it. By the way, he lived to 93.
After a lengthy debate with Loren Cordain, I have been unable to have him
see the obvious: cave men sought out fat first and threw away lean muscle meat. A major
flaw in the numbers Cordain presented is the amount of food one has to eat to fulfil his
paleolithic prescription: 2.665 kg for 2200 kcal. With 77 kg and physically active I
cannot eat more that about 1.2-1.5 kg/d during one whole day. For an active stone-ager
eating 3000 kcal the only solution to fulfilling energy needs (lacking high-density grains
etc) would be to eat substantially more fats. It would be interesting to hear if any of
you can down 2.5-3 kilos of food during one day, and how in the heck could an athlete
cover all needs with 15-20% fat (as suggested by Khalsa to be optimal), eating lots of
veggies and fruits, and covering energy needs as high as 4000-5000 kcal/day?
Dag and Everyone: Cordain has been backed into a corner
several times on this issue, most notably by Mary Enig and Sally Fallon a few years back
when they engaged him in an online debate in the Paleodiet mailing list. He could never
answer their objections, so Sally and Mary eventually dropped it.
You should know that several years ago, Cordain's estimates of actual fat intake by paleo
peoples was much LOWER than his estimates today. After the debate with Enig and
revised his numbers, but he STILL will not admit that the increase included any
significant amounts of saturated fat! And his definition of "rabbit starvation"
is a far cry from what Stefansson described among the Northern Canadian Indians and Inuit
back in his book The Fat of the Land. Cordain, politically correct as ever, claims that the sickness and
wasting that occurs when large amounts of lean animal protein are eaten occurs because the
body has hit a "protein ceiling." REAL rabbit starvation,
however, as defined by
Stefansson happened when Inuit and/or Indians would not get enough animal fat to go along
with their catches of lean meat, which were not preferred by these
Dear Stephen and all It is
fascinating to speculate about the diet of man in prehistoric time.
However, knowing how
difficult it is to get reliable information about the diet of individuals living
it seems a little absurd to guess what kind of food people ate 10,000 or more years
in particular which kind of fatty acids. And even if we knew, so what? Can we deduct
anything about the influence of this diet on these peoples health, of which we know even
less? Isn't it a subject much better suitable for a cosy after-dinner
chat, than for
creating scientific hypotheses? However, if you consider his recent papers good I would
certainly like to read them.
The paper by Glew et al is a good example of
another unfalsifiable hypothesis.
Best wishes - and beware of electronic microorganisms!
Uffe: It really is not speculation about what
people ate thousands of years ago as
prehisotric remains and tooth analysis can reveal what the diet was. As far
as health impacts, I think it is relevant: all you need to do is look at
modern-day peoples who are, for all intents and purposes, the equivalents of
our Ice Age ancestors. The field of nutritional anthropology is not as murky
as some think.
A colleague brought the book (see below) to my
attention with great seriousness. I suggest it be handled as follows:
The Okinawa Program: How the World's
Longest-Lived People Achieve Everlasting Health--and How You Can Too -- by Bradley J.
Willcox, et al.
One of the major findings in this book was that Okinawans
consumed very little saturated fat (meaning fat containing saturated fatty acid [SFA]),
and this was supposed to be a major benefit. The main oil used in cooking was said
to be canola oil. Since canola oil is a recent invention, becoming common only in
the last 20 years in Canada and the USA, it could hardly have been a benefit to Okinawans
who are now very old.
My co-workers at the University of the Sciences in Philadelphia, Mignon S. Adams and
David C. Geliebter, spent a month in Okinawa recently, with special attention on
They did not see any canola oil in use. The common oils were peanut (16%
SFA), soybean (15% SFA), rapeseed (1% SFA) and lard (44% SFA). Data are mostly
from Mary C. Enig, Know Your Fats, Bethesda Press, 2000.
The Okinawans also eat significant amounts of pork and moderate amounts of
both of which contain considerable SFAs. This was confirmed by Stephen C. Byrnes,
who lives in Honolulu, HI, and has friends raised in Okinawa. They ate
and vegetables, but pork and lard ...have always been the mainstay of this peoples
diet. Sally Fallon and Mary C. Enig quoted an Okinawan professor who wrote
that the Okinawan diet was greasy and good.
The glycemic index table was incomplete, missing all the good foods that have very
low glycemic indices that diabetics can eat, such as nuts, cheese, fats,
oils, and meat.
Diabetics have been punished for decades by being handed tables such as this where
they might assume that foods not included should not be eaten.
Nuts, in particular,
despite their carbohydrate content, have very low glycemic indices, and high nut
consumption is strongly associated with longer lifespan (Hu FB et al., British Medical J.
These authors seems to have had a hidden agenda. This book is certainly
Joel M. Kauffman Has anyone additional suggestions?
The Stoneage diet" by Walter Voegtlin is
a good reference work. But whether you can get a copy now may be problematic as it was
published in the USA in 1975. In m y opinion, the 30% fat allowed in the Zone is much too
low. It should be over 80%. In my opinion, The Zone is trying to be all things to all
people - to be politically correct. It is heading in the low-carb direction, but playing
safe by not going too high on fats. This is not healthy for anyone.
The amount of protein we need is
approximately one gram per kilogram of lean body weight - whatever our evolutionary
background. The only other macronurient necessary is to provide energy.
You should use carbs as an
energy source as do the Japanese - if you have their evolutionary background, or you use
fats as an energy source as should the northern Eurasians with an evolution through 2.5
million yearss of Ice Ages and a carnivorous background. Under no circumstances should the
two protocols be mixed. For
those of us whose ancestry is northern Eurasian, the best source of energy is fat --
the more saturated the better as energy density is dependent on hydrogen saturation. This
leaves carbohydrates in the position of being merely condiments -- something to make the
meal more tasty. Carbs should not
be thought of as a major energy source for anyone whose evoltionary ancestry is northern
Eurasian. It is the carb/fat combination that is at the root of the current health
problems in these areas. But
that is what The Zone does. The
problem with a lot of the dietary advice given today is based on trying to correct a diet
that is wrong to start off with. For example, it might be prodent to eat antioxidants with
today's diet. But if you didn't eat anything that oxydised, you wouldn't need the
I agree with your assessment of the "Zone diet" (but I doubt Barry
Sears would ;)). I still think the protocol outlined by Allan and Lutz in "Life
Without Bread" is the way to go for most people. I've had a lot of clinical success
with lower-carb, higher fat diets. If people are having problems, it is usually due to
some digestive defect like hypochlorhydria which is easily corrected with some HCL
capsules. Anyway, on Voegtelin's
"Stone Age diet," the book is virtually impossible to find, but you can find an
excerpt of the section comparing the digestive system of a human with that of a dog and a
sheep at http://www.paleodiet.com/comparison.html.
The chart shows that our physiology is closer
to a carnivore than a herbivore.
More thoughts about the hunter-gatherer diet,
based on the paper by Cordain et al, sent to me by Stephen (attached). The aim of the
paper is to explain that although our ancestors ate much meat they did not get
cardiovascular disease, as expected (?). To cite Cordain:
consumption in Western diets is frequently associated with increased risk for CVD
mortality. As far as I know there is little evidence if any that meat causes
atherosclerosis or CHD (Jerome may perhaps correct me). The two references that Cordain
uses to back up his allegation are at least invalid. One of them, by Hu et al (Am J Clin
Nutr 1999;70:1001-8) effectively disproved that read meat is associated with CHD (RR 1.09;
0.91-1.30), although Hu try to say otherwise by making ratios of red meat and chickens and other statistical
humbug. The other is a 25-years follow-up of Seven Countries. Anyone who has read how
Seven Countries was structured and has studied the data in depth cannot take that project
seriously (See my book for details). Of relevance here: Do you really think that an
analysis of the diet of a day or a few days reflect what these people have eaten the rest
of the 25 years? And these food analyses were performed on statistical subsets
of the populations only. Nothing was written about the size of these subsets although the
dietary data are the most important part of that study. After having read most of Ancel
Keys scientific papers I am confident that these subsets were very
small. Note also that the analyses were group comparisons, not individual ones as in the
many recent, large and contradictive cohort studies.
Cordain et al argue that our ancestors ate
much animal food but had little CVD. Their main argument is analyses of the diet of
present-day hunter-gatherer societies, where the average amount of animal food is 65% and
the average amount of plant food is 35%. They find it curious considering that CVD is rare
among these people.
As Stephen also pointed out, their paper seems to be an ad hoc modification
of the current concept they were saved from high cholesterol and CVD because wild
animals fat has less fat than domesticated animals and the wild fat has relatively
more MUFA. Whether this is true, I dont know. But to use the average consumption of
animal and plant food as a measure is grossly misleading. According to table 1 the amount
of animal food in 13 present hunter-gatherer populations varied between 26 and 99 per
cent, and the plant food between 1 and 67 per cent! As all of these populations have
little CVD according to Cordain et al. the only valid conclusion from such figures is that
it is highly unlikely that the diet has any importance for the development of
et al also ignore some ugly facts, the African tribes who live almost
exclusively on camels' or zebu cows milk (which is very fat!) but in spite of that
have very low cholesterol, smooth arteries and very little CVD. Cordain et al also ignore
the finding by Malhotra that southern Indians had seven times more CHD and died much
younger than people from the north although the latter ate 19 times more fat, mainly of
the animal variety. And those of you who have read my book know that this is only the top
of the iceberg.
As Uffe points out, the Seven Countries study
was a sham. In fact, in the follow up book there was a lot of evidence that increased fat
and protein consumption coupled with decreased carbohydrates was positive for disease
reduction (Cancer and Heart Disease). Even though the authors reported the information and
they even were forced to conclude that the changes in diet seem to benefit many
populations, they still finished by stating that there could be an epidemic of Heart
Disease in these countries in the years to come. This after more than 15 years of
follow-up from the original study!!
I found it interesting that the follow-up
was/is ignored by the folks who still use the first study to implicate fat in heart
disease. In the first book one can even find a few paragraphs that sugar
was implicated in heart disease, but the Authors' dismiss this quickly. Why? It must
be the classic issue that Keys was trying to prove a theory, and not observe and
report objectively. This was probably the beginning of the problem we are in
today. This is also about the same time funding for the NIH and the Heart Institute
Dear all, Re: The seven countries study, I
included a little section on the Seven Countries Study in my book. Sorry if it is bit
long, but I though it may amuse you all.
The Seven Countries Study
But what of the supportive data? Surely it
must be based on something? Of course it is, and what it is mainly based on is Ancel Keys
and his seven countries study - possibly the single most important piece of research in
the development of the saturated fat hypothesis. This study proved that the
more saturated fat consumed in a country, the greater the rate of CHD. Or did it?
If you chose, in the mid-nineteen fifties, to
study the seven countries that Ancel Keys looked at.
Then you could find an almost perfect correlation between saturated fat intake and
However, if Ancel Keys had chosen to
Then he would have discovered the exact
opposite. Namely, the more cholesterol/saturated fat consumed, the less
CHD. Indeed, if
you were to have chosen any other seven countries in the world, apart from the ones Ancel
Keys chose, you would get a different set of results. How Ancel Keys came to choose his
seven countries will probably never be known unless he makes a deathbed
As a piece of scientific research, the possibility that Ancel Keys introduced bias
is so great that were this study to be proposed today it would be
thrown out by any decent research committee. (Imagined conversation)
I would like to carry out research into the correlation between heart disease
and saturated fat/cholesterol consumption in different countries.
Member of research council: Very good how will you select the
Ancel Keys: I have already selected them.
Member of research council: How did you make the selection?
Ancel Keys: I just thought they seemed like good countries.
Chairman of research council: Jolly good, carry
Ancel Keys: Thanks.
I can just imagine what would happen if
I suggested a study on another seven countries, specifically designed to disprove the diet-heart
hypothesis, having first chosen my seven countries, for my own reasons, I would be laughed
out of court, and so I should be.
you think that I am joking about this, then read on, because I am deadly serious.
Recently, Henry Blackburn, a doctor who worked closely with Ancel Keys, and became a
personal friend, wrote a history of the Seven Countries Study. What does Dr Blackburn have
to say about the lack of randomisation?
study has been criticized for the method in which populations were selected for the
and the way that the population (ecologic) correlations, with limited numbers of
were carried out. These days, the configuration of populations for such internal and
international comparisons is strengthened by the random selection of greater numbers of
units. But the Seven Countries Study was state-of-the-art for its time, and the concept
ahead of its time. Henry Blackburn M.D. Division of Epidemiology. University of
its all right. Everyone admits that there was no randomisation in the seven
countries study, but this doesnt matter because it was state-of-the-art for
its time. No it wasnt, people were carrying out randomised clinical trials at
the turn of the twentieth century, and the first population study known of was done in
1666, in London, to discover the cause of an outbreak of cholera, a mere two hundred and
ninety years before. Ahead of its time?
revealing perhaps is a short tale about the motivation for Ancel Keys and his Seven
1954, the fledgling World Health Organization called its first Expert Committee on the
Pathogenesis of Atherosclerosis to consider the burgeoning epidemic of coronary disease
and heart attacks. Several medical leaders of the time were assembled in
Dudley White of Boston, Gunnar Björk of Stockholm, Noboru Kimura of Japan, George
Pickering of Oxford, Ancel Keys of Minnesota, and others. As reported by
discussion was lively, tending to tangents and tirades.
Keys was in good form -- outspoken, quick, typically blunt. When, at this critical
conference, he posed with such assurance his dietary hypothesis of coronary heart disease,
he was ill-prepared for the indignant reaction of some.
George Pickering, recently named Knight of the Realm by Queen Elizabeth, interrupted Keys'
peroration. He put it something along these lines: 'Tell us, Professor Keys, if you would
be so kind, what is the single best piece of evidence you can cite in support of your
thesis about diet and coronary heart disease?'
ordinarily quick on the draw, was taken aback. Rarely, of course, is there ever a 'single
best piece of evidence' supporting any theory. Theory is developed from a body of evidence
and varied sources. This is particularly true in regard to the many facets of lifestyle
that relate to disease. It is the totality and congruity of evidence that leads to a
theory -- and to inference of causation.
fell headlong into the trap. He proceeded to cite a piece of evidence. Sir George and the
assembled peers were easily able to diminish this single piece of evidence, and did so.
And by then it was too late to recover -- for Keys to summon the total evidence in a
constructive, convincing argument.
theory is that Keys was so stung by this event that he left the Geneva meeting intent on
gathering the definitive evidence to establish or refute the diet-Heart
Theory. Out of
this singular, moving, personal experience -- so my theory goes -- came the
motivation, and eventually, the implementation of the Seven Countries
As Dr Blackburn
reveals, point one: Ancel Keys was already certain that a high
animal fat diet was the cause of heart disease before he organised the seven
countries study. More worryingly, Ancel Keys was so stung by an attack on him by Sir
George Pickering that he vowed to go out and prove him wrong! Now thats a good
motivation for an objective, scientific clinical trial. Any chance that a man aiming for
revenge could be tempted towards bias?
this whole trial should be consigned to the dustbin. The results themselves cannot be
argued with. They are what they are. But in reality all that this study proved was that if
you carefully choose seven countries where you already know the rates of CHD, and the
level of saturated fat consumption, then you can demonstrate a close association between
saturated fat consumption and CHD. That association, in those countries, has now broken
down, and it never clearly existed for any other seven countries in the world.
Finally, there was no association between CHD and saturated fat intake within the
countries he chose to study. In Greece, the level of saturated fat consumption was
virtually the same in all regions studied, yet the rate of CHD varied by a factor of
seven. If it were not for the risk of libel, I would state what I really think of the
seven countries study.