Category Archives: Paleo Theory

Is the Paleo Diet Truly Low-Carb After All?

Lifextension argues that very case in a recent blog post. If the paleo diet is low carb, then it’s going to be heavily animal-based. According to Lifextension:

Diachronic and comparative analysis of the skeletal data of human hunters and cultivators from across the globe has revealed that – prior to the onset of agriculture – carbohydrates must have comprised only a rare and occasional component of ancestral eating patterns. Furthermore, the impact of the introduction of carbohydrates to human diets was almost immediate in its deterioration of human health and biology.

However, paradoxically, many proponents of a ‘Paleo’ (i.e.: pre-agricultural) diet have promoted the use of tubers and other starches as – not only benign – but necessary health foods to consume for the correction of metabolic and endocrine disorders. Potatoes, rice, and other oxymoronically-labelled ‘safe’ starches, are being promoted in spite of the fact that they are exclusively Neolithic foods. Consequently, it is the conflation of starches, safe, and ancestral that I now wish to address, and hopefully correct.

Lifextension concludes:

The intake of plant foods by hominids was most plausibly and conceivably minimal. This is due to their limited, seasonal availability; the physiological ceiling on fibre and toxin intake; the biological evolution of early Homo physiology; along with the technological, spatial and temporal limitations of obligatory pre-consumption preparations. Consequently, evolutionary arguments for the consumption of what are quite blatantly Neolithic foods are rendered paradoxical and absurd. Starches are neither ‘Paleo’; nor does our evolutionary biology sanction them as ‘safe’.

Lifextension neither pulls punches nor takes prisoners. This could get interesting.

Read the rest.

Seminal Article by Loren Cordain, Ph.D.

I have little to say about it. Just wanted it in my database:

The Nutritional Characteristics of a Contemporary Diet Based Upon Paleolithic Food Groupsin Journal of the American Neutraceutical Association,  2002; 5:15-24.

The title of that journal doesn’t fill me with confidence, but it is what it is. Many of the ideas in the article are likely in his popular books.

Anthropologist Debunks the Paleolithic Diet

paleo diet, paleolithic diet, caveman diet

Not Dr. Warinner

Christina Warinner has a new TEDx talk on the paleo diet.  Dr. Warinner has a Ph.D. in anthropology from Harvard, so I’ll call her an anthropologist. The written TEDx intro mentions she is a paleontologist, and she mentions “archeologist” in her talk.  Anyway, I’m sure she’s very bright and put much thought into her presentation.  She spoke at my old stomping grounds, the University of Oklahoma in Norman.

Click to view video.

Dr. Warinner is probably addressing the smarter half of the general population, who holds the idea, at least superficially, that the paleo diet is meat-based.  (The dumber half of the public isn’t watching TEDx videos.)  Dr. Warinner doesn’t define “meat-based.”  Is half the plate filled with meat, fish, or eggs?  75% of the plate?  Half of total calories?

I’m not familiar with all the popular modern versions of the paleo diet.  Perhaps some are in fact meat-centric, whatever that means.  But the ones I’m more familiar with, like Dr. Cordain’s and mine, prominently feature vegetables, fruits, and nuts.  You could easily fashion a plant-based paleo diet, filling 80 or even 90% of your plate with plants.  (A vegan paleo diet isn’t realistic.  Cultures not eating animals would die out from B12 deficiency.)

I’d swear I heard Dr. Warinner say “we’re not adapted to eat meat.”  Surely she mis-spoke.

She mostly debunks popular misconceptions of the paleo diet.  Most of us deeply familiar with the paleo diet would have little to disagree with her about.

Here are some of Dr. Warinner’s major points:

  • It’s nearly impossible for most of us to eat a true Paleolithic diet.  Selective breeding has altered nearly all our foods to the point of unrecognizability by cavemen.  Examples are bananas, broccoli, carrots, and tomatoes.
  • There is no single paleo diet.  It depends on regional geographic variations in rainfall, latitude, temperature, etc.  Local populations ate what was available, in season, and often migrated seasonally to find food.

Dr. Warinner suggests we all incorporate three concepts from the paleo diet:

  1. Eat a great variety of foods.
  2. For the highest nutrient content, eat fresh food when ripe, in season.
  3. Eat whole foods.

Steve Parker, M.D.

PS: Miki Ben-Dor, a Ph.D. candidate, had many more objections to Dr. Warinner’s speech.  Paul Jaminet made a few comments about it, too (see middle of his post, after the comments on Marlene Zuk’s PaleoFantasy).  Wendy Schwartz weighs in, too. Angelo Coppola does a good job countering most of Dr. Warriner’s criticisms.

My Critique of the Joslin Critique of the Paleo Diet

paleo diet, Paleolithic diet, hunter-gatherer diet

Huaorani hunter in Ecuador

The Joslin Diabetes Blog yesterday reviewed the paleo diet as applied to both diabetes and the general public.  They weren’t very favorably impressed with it.  But in view of Joslin’s great reputation, we need to give serious consideration to their ideas.  (I don’t know who wrote the review other than “Joslin Communications.”)

These are the main criticisms:

  • diets omitting grains and dairy are deficient in calcium and possibly B vitamins
  • you could eat too much total and saturated fat, leading to insulin resistance (whether type 1 or 2 diabetes) and heart disease
  • it’s not very practical, partly because it goes against the grain of modern Western cultures
  • it may be expensive (citing the cost of meat, and I’d mention fresh fruit and vegetables, too)

Their conclusion:

There are certainly better diets out there, but if you are going to follow this one, do yourself a favor, take a calcium supplement and meet with a registered dietitian who is also a certified diabetes educator  to make sure it is nutritionally complete, isn’t raising your lipids and doesn’t cause you any low blood glucose incidences.

Expense and Practicality

These take a back seat to the health issues in my view.  Diabetes itself is expensive and impractical.  Expense and practicality are highly variable, idiosyncratic matters to be pondered and decided by the individual.  If there are real health benefits to the paleo diet, many folks will find work-arounds for any expense and impracticality.  If the paleo diet  allows use of fewer drugs and helps avoid medical complications, you save money in health care costs that you can put into food.  Not to mention quality of life issues (but I just did).

Calcium and B Vitamin Deficiencies

This is the first I’ve heard of possible B vitamin deficiencies on the paleo diet.  Perhaps I’m not as well-read as I thought.  I’ll keep my eyes open for confirmation.

The potential calcium deficiency, I’ve heard of before.  I’m still open-minded on it.  I am starting to wonder if we need as much dietary calcium as the experts tell us.  The main question is whether inadequate calcium intake causes osteoporosis, the bone-thinning condition linked to broken hips and wrists in old ladies.  This is a major problem for Western societies.  Nature hasn’t exerted much selection pressure against osteoporosis because we don’t see most of the fractures until after age 70.  I wouldn’t be surprised if we eventually find that life-long exercise and adequate vitamin D levels are much more important that calcium consumption.

With regards to calcium supplementation, you’ll find several recent scientific references questioning it.  For example, see this, and this, and this, and this, and this.  If you bother to click through and read the articles, you may well conclude there’s no good evidence for calcium supplementation for the general population.  If you’re not going to supplement, would high intake from foods be even more important?  Maybe so, maybe not.  I’m don’t know.

If you check, most of the professional osteoporosis organizations are going to recommend calcium supplements for postmenopausal women, unless dietary calcium intake is fairly high.

If I were a women wanting to avoid osteoporosis, I’d do regular life-long exercise that stressed my bones (weight-bearing and resistance training) and be sure I had adequate vitamin D levels.  And men, you’re not immune to osteoporosis, just less likely to suffer from it.

Insulin Resistance

Insulin resistance from a relatively high-fat diet is theoretically possible.  In reality, it’s not common.  I’ve read plenty of low-carb high-fat diet research reports in people with type 2 diabetes.  Insulin levels and blood glucose levels go down, on average.  That’s not what you’d see with new insulin resistance.  One caveat, however, is that these are nearly all short-term studies, 6-12 weeks long.

If you have diabetes and develop insulin resistance on a high-fat diet, you will see higher blood sugar levels and the need for higher insulin drug doses.  Watch for that if you try the paleo diet.

Are High Total and Saturated Fat Bad?

Regarding relatively high consumption of total and saturated fat as a cause of heart or other vascular disease: I don’t believe that any more.  Click to see why.  If you worry about that issue, choose meats that are leaner (lower in fat) and eat smaller portions.  You could also look at your protein foods—beef, chicken, fish, eggs, offal, etc.—and choose items lower in total and saturated fat.  Consult a dietitian or online resource.  Protein deficiency is rarely, if ever, a problem on paleo diets.

In Conclusion

I think the paleo diet has more healthful potential than realized by the Joslin blogger(s).  I’m sure they’d agree we need more clinical studies of it, involving both type 1 and 2 diabetics.  I appreciate the “heads up” regarding potential vitamin B deficiencies.  My sense is that the Joslin folks are willing to reassess their position based on scientific studies.

I bet some of our paleo-friendly registered dietitians have addressed the potential adverse health issues of the paleo diet.  Try Amy KubalFranziska Spritzler (more low-carb than paleo) or Aglaée Jacob.  I assume the leading paleo diet book authors have done it also.

If you’re worried about adverse blood lipid changes on the paleo diet, get them tested before you start, then after two months of dieting.

Steve Parker, M.D.

PS: The paleo diet is also referred to as the Stone Age diet, caveman diet, Paleolithic diet, hunter-gatherer diet, and ancestral diet.

Matthew Yglesias Says “Paleo Diet Is Nonsense Science”

Here’s his brief article at Slate.  Mr. Yglesias was apparently influenced by Marlene Zuk.

Well, now that that’s settled, I can shut down this blog and start another hobby.

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.