Category Archives: Paleo Theory

Once Again, There Is No “Paleo Diet”

David Despain, reports on “The Evolution of Human Nutrition” meeting of December, 2012.  Example:

Want to eat a diet that mimics that of our Paleolithic ancestors? It might be a little more complicated than what the popular books say.

The fact is, there was never one Paleo Diet; it’s more likely there were hundreds of them and that they were continually changing and broadening over evolutionary time.

That was the overarching message of an impressive lineup of experts on ancient human diets at a symposium entitled “The Evolution of Human Nutrition” organized by the Center of Academic Research and Training in Anthropogeny (CARTA) at UC San Diego on December 7, 2012.

Read the rest.  David has embedded some videos made at the symposium.

Steve Sailer on the Paleo Diet

In addition to an iconic picture of Raquel Welch, Steve Sailer at VDare has posted an article on the paleo diet.  It’s mostly about whether the Paleolithic analogy is pertinent to modern times.  An excerpt to pique your interest:

A big reason there’s so much confusion on this topic is that we aren’t supposed to think about genetic differences between people based on their ancestry. So, a couple of decades ago Tooby and Cosmides came up with the idea that everybody’s ancestors 50,000 years ago were paleolithic hunter-gatherers, and thus we’ve all inherited the exact same human nature. But, of course, humans have continued to evolve over the last 50,00 years, often in radically different environments.

Thus, we see major differences based on ancestry: Italians and Jews suffer less from binge drinking than Scandinavians because their ancestors had alcohol many generations earlier. In the Olympics, high altitude-adapted Ethiopians make better distance runners than sprinters, while West Africans and their diaspora make better sprinters than distance runners.

That doesn’t mean that everything is racially determined, just that it will probably be worth your while to think about what your ancestors were like and what worked for them. If, say, you have a lot of alcoholics in your family tree or it’s a stereotype about your ethnicity, be careful with the booze. Probably none of your ancestors evolved successful adaptations for hitting the crack pipe without it hurting them much, so avoid cocaine altogether.

Read the rest.

Git’R Done: Efficient Exercise For Those Who Don’t Enjoy It

“Wanna arm wrestle?”

I hate exercising.

I’d rather watch TV, play Parcheesi, play my mandolin, bowl, go to a movie, sleep, blog, surf the ‘net, work on my next book, fish, visit with my wife and kids, practice shooting, work on new recipes, or even go to work.

But….

I want the health benefits of exercise.

Loren Cordain, a godfather of the modern paleo diet movement, characterizes the physical activity pattern of hunter-gatherers thusly: “periods of intense exertion generally alternated with days of rest and relaxation.”  Nevertheless, “the amount of physical activity performed by an average hunter-gatherer would have been about four times greater that that of a sedentary office worker….”

Eaton and Eaton suggest than ancient hunter-gatherers burned 490 calories a day in physical activity, which would require about an hour of modern exercise.

For much of this year I’ve been experimenting with various exercise programs that may yield the health benefits with minimal time commitment.  Like 60 minutes a week.  Not the 150 minutes recommended by some public health authorities.  In case you’re interested, here are some links that outline the programs:

If you’re tempted to try any of these programs, get your personal physician’s blessing first.  I’d love to hear about your experience with them.

Steve Parker, M.D.

PS: Cordain quotes are from The Paleo Diet (2002).

Paleo Pioneer S. Boyd Eaton’s Personal Lifestyle

African Savanna

African Savanna

Dr. Eaton (M.D.) spoke at the last Ancestral Health Symposium about his own diet and exercise program.  He’s 74-years-old and has been following his paleo lifestyle for 30 years.  In this video, Dr. Eaton looks quite fit and is obviously mentally sharp.

He talks about a “weak form” of the paleo diet that would include relatively small amounts of whole grains (e.g., shredded wheat) and dairy (e.g., skim milk).  He doesn’t proscribe beans.  He limits saturated fat, but enjoys red wine.

Dr. Eaton also discusses a “strong form” diet that would cut out the dairy, grains, and probably alcohol.  This is for those with certain diseases of modern civilization, such as high blood pressure, coronary artery disease, metabolic syndrome, adverse blood lipids, etc.  He didn’t mention diabetes specifically, but I bet he would include it in the list.

He has an impressive daily exercise program that probably takes at least an hour, with weight training on machines plus an aerobics (stationary bike and swimming).

Dr. Eaton supplments with a multivitamin/multimineral (showed a picture of Centrum), EPA/DHA, and fiber (especially soluble fiber).

The video is only 20 minutes long and well worth a look.

Steve Parker, M.D.

h/t Melissa McEwen. (Melissa has the impression the Eaton partakes of whole grains and dairy.  I didn’t hear that in the video but may have missed it.)

 

A Default Position on the Omega-6/Omega-3 Debate

ASBMB Today has a well-written balanced article on the omega-6/omega-3 fatty acid ratio debate written by Rajendrani Mukhopadhyay.  A fair amount of it is understandable to non-science majors.  The main question is whether the high consumption of omega-6 fatty acids in Western societies is unhealthy.

It’s estimated that throughout most of human evolution, our dietary omega-6/omega-3 ration has been around 3:1 or 2:1.  Today, it’s about 15:1, thanks to a large increase in omega-6 consumption.  Are our bodies adapted for the lower ratio?  A hard-core paleo diet like Dr. Cordain’s aims for that lower ratio.

Both sides of the debate agree that we would probably be better off eating more omega-3 fatty acids, as found in cold-water fatty fish.

I’m an omega-6/omega-3 ratio agnostic at this point.  I’ve never studied it in depth, so I have no strong opinion either way.

Here are a couple excerpts from the article to pique your interest:

No one is disputing that we’re eating more omega-6 than our predecessors did. Over the past 100 years, consumption of linoleic acid [an omga-6] has increased dramatically in the U.S., mainly through the use of soybean oil. Soybean oil intake has gone up from being 1 percent of calories in the American diet to as much as 10 percent, according to Hibbeln. Lands, Salem and others contend that the rise, driven by the processed food and agriculture industries, has happened without anyone knowing its effects. “If I were now to try to get permission to change 10 percent of the calories in the U.S. diet, I would need a very large body of data unequivocally proving that it was safe,” says Hibbeln. “No such body of data exists for soybean oil. But it’s in our diet. We’re the experiment. It’s been a very large, uncontrolled intervention.”

Experts like Harris and Willett say this increase has been to our benefit. “We have seen a massive decline in cardiovascular disease mortality and huge increase in life expectancy,” says Willett. “Not all the benefit is due to the increase in linoleic acid, but almost certainly much of it is. It was not an absolute disaster.” But the lipid biochemists counter that it’s not just cardiovascular disease at stake. They say diabetes, obesity and even psychiatric disorders are some outcomes of a diet heavy on omega-6s.

I’ve never before heard anybody credit linoleic acid with a major role in our  “huge increase in life expectancy” over the last century.  I doubt that’s the case.  I vote more in favor of better sewage systems, cleaner water, better hygiene, antibiotics, or improvements in surgery and medical care.

Evolutionary biologist Theodosius Dobzhansky said, “Nothing in biology makes sense except in the light of evolution.”  If that’s true, the default position is that lower amounts of omega-6 fatty acid are better than our current high consumption.  It’s up to the high-consumption proponents to prove otherwise.

Steve Parker, M.D.

h/t David Despain

PS: Dobzhansky was a Christian, by the way.

PPS: A Twitter reader (@pronutritionist) suggested that the modern Western dietary omega-6/omega=3 ratio is 9.6, not 15:1, citing Amer J Clin Nutr.  My source for 15:1 is Journal of Nutrition and Metabolism, vol. 2012, article ID 539426, doi 10.1155/2912/539426, by E. Patterson et al. I admit it’s not a great reference. Cordain’s 2002 book, The Paleo Diet, says 10:1.  Maybe it is closer to 10:1.  I’m sure there’s lots of inter-person variability.

How Long Have Our Ancestors Been Cooking With Fire?

“We mastered fire with the invention of matches, silly!”

Earlier this month I mentioned that biological anthropologist Richard Wrangham estimates hominins tamed fire and started cooking with it 1.8 million years ago.

A recent article at Slate reviews the debate among anthropologists.  Some respected authorities date our mastery of fire from 12,000 to 400,000 years ago.

I don’t know the answer, but I’d wager it was much earlier than 12,000 years ago.

—Steve

What Exactly Is the Paleo Diet?

Pure paleo

Let’s be realistic: There’s no way to eat a Stone Age diet these days unless you live off the land, hunting, fishing, and gathering from what’s naturally available in the wild.  Few can do that, although it’s not impossible.  I’m going to specify my version of the paleo diet because I’m starting a paleo diet trial soon—a first for me.

How long has man had fire?  Biological anthropologist Richard Wrangham estimates hominins tamed fire and started cooking with it 1.8 million years ago.  So I’m cooking my paleo foods if I wish.

As with my beloved Mediterranean diet, definitions of the paleo diet vary.  The following guidelines are influenced by my review of blogs or websites by Loren Cordain, Julianne Taylor, Robb Wolf, and Kurt Harris.  The first three are closely affiliated with each other, so expect lots of overlap.  It’s simplest to define paleo by what’s not allowed.

What’s NOT Paleo?

Industrial vegetable oils (e.g., soybean, corn,safflower), legumes, dairy, refined sugars, grains, alcohol, and high salt consumption.

What Is Paleo? 

The focus is on minimally processed, in-season, locally available foods.  Many favor pastured, grass-fed beef, free-range chickens, “organic,” and the like.  I guess that’s fine if you can afford it; I choose to spend my money elsewhere.

Proteins

Meat, fish/seafood, eggs, poultry, and wild game.  Most paleo proponents favor lean meats over fatty ones; it’s debatable. Undoubtedly, our domesticated feedlot animals are fattier than wild game, generally.  Processed meats such as bacon would not be pure paleo, but many paleo advocates allow it.

Nuts and Seeds

Favor those with the best omega-6/omega-3 ratio (2 or 3:1), such as walnuts, almonds, macadamia, and cashews.  Modern humans eat way more omega-6 fatty acids compared to ancient hunter-gatherers.

Fruits and Vegetables

It’s probably best to favor those with lower glycemic index.  Examples are berries, melons, cauliflower, tomatoes, onions, and broccoli.  Most modern fruits and veggies  have been bred for large size and good looks.  Ancient fruits and veggies were smaller and had much more fiber per serving.

Tubers, Roots, Bulbs

These are OK per Cordain, and I agree.  Examples include potatoes, cassava, taro root, onions.  Some paleo proponents exclude potatoes.

Oils

Cordain favors oils such as canola, flax, olive. Others mention avocado oil.  Aim for a good omega-6/omega-3 ratio.  Lard is probably OK although obviously processed.

Herbs and Spices

Many of our favorites should be OK.  Wolf says balsamic vinegar is allowed, although processed, like all vinegars.  Vinegar is “natural,” as you might have noticed if you ever walked through an apple orchard with rotting fruit on the ground; you can smell the vinegar.

Condiments

Undecided.  Note that you can make mayonnaise from olive oil and egg yolk.

Miscellaneous

Olives?  They’re processed, but I’m inclined to keep them in the mix.  Coffee?  Not paleo, but I ain’t givin’ it up.  Consider limiting nuts to one ounce daily since most of them are high in omega-6 fatty acids.  Fresh foods are more purely paleo than canned or frozen, but I’ll not exclude canned and frozen.  Limit fruit?  Probably: in most environments, they’re available only seasonally.  Diet sodas?  Clearly not paleo, but I enjoy one now and then and don’t see any drawbacks to low consumption.

Steve Parker, M.D.

Update October 8, 2012

I learned today that my version of paleo, by coincidence, is similar to the Hartwigs’s Whole30 plan.  But they allow clarified butter or ghee, green beans, and snow peas.  I include potatoes, but Whole30 doesn’t.

Notable Quotes From Kuipers’ “Multidisciplinary Reconstruction of Palaeolithic Nutrition”

Australian Aborigine in Swamp Darwin

I scored of copy of “A multidisciplinary reconstruction of Palaeolithic nutrition that holds promise for the prevention and treatment of diseases of civilisation” by RS Kuipers, JCA Joordens, and FAJ Muskiet. I’m not going to review it here. I’m just assembling some interesting “facts” for my files, so this could be boring. You won’t offend me much if you stop reading now.

This paper is from the University Medical Center Groningen and Human Origins Group (Faculty of Archaeology, Leiden University), both in The Netherlands. It’s 23 pages long, not counting the 450 references.

I’ll following the spelling conventions of the paper’s publisher.

Introduction

“…our genome has remained basically unchanged since the beginning of the Palaeolithic era.”

“Since the onset of the Agricultural Revolution, some 10 thousand years ago, and notably in the last 200 years following the start of the Industrial Revolution, humans have markedly changed their dietary habits. Consequently, it has been advocated that the current pandemic of diseases of civilization results in part from the mismatch between the current diet and our Palaeolithic genome.”

These are some of the diseases that may result from the mismatch of our Palaeolithic genome and modern lifestyle (including diet): type 2 diabetes, high blood pressure, osteoporosis, fertility problems (polycystic ovary syndrome), pregnancy complications (pre-eclampsia, gestational diabetes), some cancers (colon, breast, prostate), heart disease (such as coronary artery disease), major and postpartum depression, autism, schizophrenia, some neurodegenerative diseases (Parkinsons disease, Alzheimer’s disease). [Sorry, Dr. Cordain – no mention of acne. And I wonder about dental and eye problems.]

Evolutionary Medicine

“Many, if not all, diseases can become explained [sic] by both proximate and ultimate explanations. The science searching for the late explanations has become known as ‘evolutionary medicine.’ Unfortunately, modern medicine deals mostly with proximate explanations, while ultimate explanations seem more prudent targets for long-time disease prevention.”

The term “evolutionary medicine” was coined by Randolph M. Nesse and George C. Williams in the early 1990s. It’s also called Darwinian medicine.

“…about 20% of modern hunter-gatherers reach at least the age of 60 years.”

After the transition to the Agricultural Revolution about 10,000 years ago, life expectancy fell from about 40 years to about 20 years. This is astounding news to me, assuming it’s accurate.  (Remember that for most of human existence, infant and child mortality has been very high. If an infant dies at 6 months old and an adult dies at 40 years, average life expectancy for the two would be about 20 years.)

Average life expectancy among modern hunter-gatherers is about 40 years—same as it was for students of the Harvard College class born in 1880.

Life expectancy in the Neolithic era was stable until the late 18th century, rarely exceeding 25 years in civilized nations.  At that point, life expectancy started to improve dramatically thanks to sanitation, water and food hygiene, immunizations, and quarantine practices. (Thomas Jefferson was the third president of the U.S.  His wife Martha had six children but only two survived to adulthood.)

The earliest species in the genus Homo appeared about  two million years ago.   Homo sapiens appeared about 200,000 years ago in south or east Africa. Several different hominin lines co-existed with modern humans.

The current world population of humans may be derived for only 1000 or so individuals that survived a decimating event.

The ability to store fat is one of the things that differentiate us from other primates.

Hunting and Our Ancient Diet

The composition of the early human diet is still hotly debated.

Lotta work to snag one of these

In modern hunter-gatherers, only about 30% of diet energy is derived from hunting, with the rest coming from gathering plant food and aquatic animals.

In contrast to the arid, hot, iconic savanna, “…the combined evidence strongly suggests that early hominins frequented the land-water ecosystem and thus lived there.” If rainfall and other conditions allowed, there would be wooded grasslands.

“…the proportion of the human gut dominated by the small intestine (>56%) suggests adaptation to a diet that is highly digestible, indicating a closer structural analogy with carnivores than to [animals that eat leaves and fruit].”

“The data of combined studies of early hominins and the more recent hominins suggest a gradual increase in dietary animal protein, a part of which may derive from aquatic resources. In the more recent human ancestors, a substantial part of the dietary protein was irrefutably derived from marine resources, and this habit was only abandoned in some cases after the introduction of agriculture at the onset of the Neolithic.”

Sea levels have risen over the past 17,000 years, up to 150 meters.

“In conclusion, there is ample archeological evidence for a shift from the consumption of plant towards animal foods.”

“For a long time period in hominin evolution, hominins derived large amounts of energy from (terrestrial and aquatic) animal fat and protein. This habit became reversed only by the onset of the Neolithic Revolution in the Middle East starting about 10,000 years ago.”

“The Homo genus has been on earth for at least 2.4 million years and for over 99% of this period has lived as hunter-gatherers.”

“We conclude that gathering plays, and most likely always played, the major role in food procurement of humans. Although hunting doubtlessly leaves the most prominent signature in the archaeological record, gathering of vegetables and the collection of animal, notably aquatic, resources (regardless of whether their collection is considered as either hunting or gathering), seems much easier compared with hunting on the hot and arid savanna. We suggest that it seems fair to consider these types of foods as an important part of the human diet, unless proven otherwise. Conversely, while hunting might have played a much more important role at higher latitudes, dietary resources in these ecosystems are rich in n-3-fatty acids (for example, fatty fish and large aquatic mammals), while the hominin invasion of these biomes occurred only after the development of more developed hunting skills.”

Even though traditional Maasai showed extensive atherosclerosis with fibrous changes and lipid infiltration, they had very few complicated arterial lesions and rarely had clinical cardiovascular disease events.

The Agricultural and Industrial Revolutions

“Contrary to earlier belief, the advent of agriculture coincided with an overall decline in nutrition and general health, but at the same time provided an evolutionary advantage since it increased birth rates and thereby promoted net population growth.”  [Both supporting references are from CS Larsen.]

Good news for birth rates

With the advent of the Industrial Revolution, nutritional quality and general health declined even more rapidly.

“Among the many dietary and lifestyle changes are: a grossly decreased n-3:n-6 fatty acid ratio, the combined high intakes of saturated fatty acids and carbohydrates, the introduction of industrially produced trans-fatty acids, reduced intakes of n-3 and n-6 long-chain polyunsaturated fatty acids, reduced exposure to sunlight, low intakes of vitamins D and K, disbalanced anti-oxidant status and high intakes of carbohydrates with high glycaemic indices and loads, such as sucrose and industrially produced high-fructose maize syrup.”  [Aren’t we eating more n-6 fatty acids, not less?]

Potential Benefits of a Palaeolithic Diet

The authors conclude with a review of the few medical scientific studies of Palaeolithic diets in modern humans. These are the ones by Frassetto, Osterdahl, Jönsson, and Lindeberg. I’ve already reviewed those here.  They missed O’Dea and Kerin’s study.

My Overall Impressions

This article seems very well researched.  It lays out a logical framework for the discipline of evolutionary medicine and should spur further clinical research.  It’s well worth a read if you have more than a passing interest in paleo lifestyle theory.

Bear in mind I’m not a paleontologist, anthropologist, paleo-anthropologist, or archeologist.  So caveat lector.

Steve Parker, M.D.  (B.S. degree in zoology)

Reference: Kuipers,RS; Joordens, JCA; and Muskiet, FAJ. A multidisciplinary reconstitution of Palaeolithic nutrition that holds promise for the prevention and treatment of diseases of civilization. Nutrition Research Reviews, 25 (2012): 96-129.  doi: 10.1017/S0954422412000017

PS: The Paleolithic diet is also called paleo, ancestral, hunter-gatherer, Stone Age,  Old Stone Age, and caveman diet.

Are Dense Acellular Carbohydrates the Primary Cause of Obesity?

That’s a proposal in a recent scientific article, from which I quote:

The present hypothesis suggests that in parallel with the bacterial effects of sugars on dental and periodontal health, acellular flours, sugars, and processed foods produce an inflammatory microbiota via the upper gastrointestinal tract, with fat able to effect a “double hit” by increasing systemic absorption of lipopolysaccharide. This model is consistent with a broad spectrum of reported dietary phenomena. A diet of grain-free whole foods with carbohydrate from cellular tubers, leaves, and fruits may produce a gastrointestinal microbiota consistent with our evolutionary condition, potentially explaining the exceptional macronutrient-independent metabolic health of non-Westernized populations, and the apparent efficacy of the modern “Paleolithic” diet on satiety and metabolism.

You can read the whole shebang free online.

Steve Parker, M.D.

Bacteria in Petri dish

Reference:  Spreadbury, Ian.  Comparison with ancestral diets suggests dense acellular carbohydrates promote an inflammatory microbiota, and may be the primary dietary cause of leptin resistance and obesity.Diabetes Metab Syndr Obes. 2012; 5: 175–189. Published online 2012 July 6. doi:  10.2147/DMSO.S33473 PMCID: PMC3402009

 

Do Cordain, Wolf, Konner, and Eaton Have It All Wrong?

The Face of Iconoclasm

In case you missed it, here’s a link to the recent Scientific American article arguing that the paleo diet is vegetarian.  I’ll read it when I have time.

—Steve