Tag Archives: paleolithic diet

Paleo Diet for Heart Patients With Diabetes and Prediabetes

Posted on October 9, 2011 | 10 comments

A Paleolithic diet lowered blood sugar levels better than a control diet in coronary heart disease patients with elevated blood sugars, according to Swedish researchers reporting in 2007.

About half of patients with coronary heart disease have abnormal glucose (blood sugar) metabolism.  Lindeberg and associates wondered if a Paleolithic diet (aka “Old Stone Age,” “caveman,” or ancestral human diet) would lead to improved blood sugar levels in heart patients, compared to healthy, Mediterranean-style, Western diet.

Methodology

Investigators at the University of Lund enrolled 38 male heart patients—average age 61—patients and randomized them to either a paleo diet or a “consensus” (Mediterranean-like) diet to be followed for 12 weeks.  Average weight was 94 kg.  Nine participants dropped out before completing the study, so results are based on 29 participants.  All subjects had either prediabetes or type 2 diabetes (the majority) but none were taking medications to lower blood sugar.  Baseline hemoglobin A1c’s were around 4.8%.  Average fasting blood sugar was 125 mg/dl (6.9 mmol/l); average sugar two hours after 75 g of oral glucose was 160 mg/dl (8.9 mmol/l).

The paleo diet was based on lean meat, fish, fruits, leafy and cruciferous vegetables, root vegetables (potatoes limited to two or fewer medium-sized per day), eggs, and nuts (no grains, rice, dairy products, salt, or refined fats and sugar). 

The Mediterranean-like diet focused on low-fat dairy, whole grains, vegetables, fruits, potatoes, fatty fish, oils and margarines rich in monounsaturated fatty acids and alpha-linolenic acid. 

Both groups were allowed up to one glass of wine daily.

No effort was made to restrict total caloric intake with a goal of weight loss.

Results

Absolute carbohydrate consumption was 43% lower in the paleo group (134 g versus 231 g), and 23% lower in terms of total calorie consumption (40% versus 52%).  Glycemic load was 47% lower in the paleo group (65 versus 122), mostly reflecting lack of cereal grains.

The paleo group ate significantly more nuts, fruit, and vegetables.  The Mediterranean group ate significantly more cereal grains, oil, margarine, and dairy products.

Glucose control improved by 26% in the paleo group compared to 7% in the consensus group.  The improvement was statisically significant only in the paleo group.  The researchers believe the improvement was independent of energy consumption, glycemic load, and dietary carb/protein/fat percentages.

High fruit consumption inthe paleo group (493 g versus 252 g daily) didn’t seem to impair glucose tolerance. 

Hemoglobin A1c’s did not change or differ significantly between the groups.

Neither group showed a change in insulin sensitivity (HOMA-IR method).

Comments

The authors’ bottom line:

In conclusion, we found marked improvement of glucose tolerance in ischemic heart disease patients with increased blood glucose or diabetes after advice to follow a Palaeolithic [sic] diet compared with a healthy Western diet.  The larger improvement of glucose tolerance in the Palaeolithic group was independent of energy intake and macronutrient composition, which suggests that avoiding Western foods is more important than counting calories, fat, carbohydrate or protein.  The study adds to the notion that healthy diets based on whole-grain cereals and low-fat dairy products are only the second best choice in the prevention and treatment of type 2 diabetes.

This was a small study; I consider it a promising pilot.  Results apply to men only, and perhaps only to Swedish men.  I have no reason to think they wouldn’t apply to women, too.  Who knows about other ethnic groups?

The Mediterranean-style concensus diet here included low-fat dairy and margarine, items I don’t associate with the traditional healthy Mediterranean diet.

This study and the one I mention below are the only two studies I’ve seen that look at the paleo diet as applied to human diabetics.  If you know of others, please mention in the Comments section. 

The higher fruit consumption of the paleo group didn’t adversely affect glucose control, which is surprising.  Fruit is supposed to raise blood sugar.  At 493 grams a day, men in the paleo group ate almost seven times the average fruit intake of Swedish men in the general population (75 g/day).  Perhaps lack of adverse effect on glucose control here reflects that these diabetics and prediabetics were mild cases early in the course of the condition (diabetes tends to worsen over time). 

Present day paleo and low-carb advocates share a degree of simpatico, mostly because of carbohydrate restriction—at least to some degree—by paleo dieters.  Both groups favor natural, relatively unprocessed foods.  Note that the average American eats 250-300 g of carbohydrates a day.  Total carb intake in the paleo group was 134 g (40% of calories) versus 231 g (55% of calories) in the Mediterranean-style diet.  Other versions of the paleo diet will yield different numbers, as will individual choices for various fruits and vegetables.  Forty percent of total energy consumption from carbs barely qualifies as low-carb. 

Study participants were mild, diet-controlled diabetics or prediabetics, not representative of the overall diabetic population, most of whom take drugs for it and have much higher hemoglobin A1c’s.

Lindeberg and associates in 2009 published results of a paleo diet versus standard diabetic diet trial in 13 diabetics.  Although a small trial (13 subjects, crossover design), it suggested advantages to the paleo diet in terms of heart disease risk factors and improved hemoglobin A1c.  Most participants were on glucose lowering drugs; none were on insulin.  Glucose levels were under fairly good control at the outset.  Compared to the standard diabetic diet, the Paleo diet yielded lower hemoglobin A1c’s (0.4% lower—absolute difference), lower trigylcerides, lower diastolic blood pressure, lower weight, lower body mass index, lower waist circumference, lower total energy (caloric) intake, and higher HDL cholesterol.  Glucose tolerance was the same for both diets.  Fasting blood sugars tended to decrease more on the Paleo diet, but did not reach statistical significance (p=0.08).

The paleo diet shows promise as a treatment or preventative for prediabetes and type 2 diabetes.  Only time will tell if it’s better than a low-carb Mediterranean diet or other low-carb diets. 

Steve Parker, M.D.

Reference: Lindeberg, S., Jönsson, T., Granfeldt, Y., Borgstrand, E., Soffman, J., Sjöström, K., & Ahrén, B. (2007). A Palaeolithic diet improves glucose tolerance more than a Mediterranean-like diet in individuals with ischaemic heart disease. Diabetologia, 50 (2007): 1795-1807.   doi 10.1007/s00125-007-0716-y

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Old Stone Age Diet Depended On Latitude

Posted on October 4, 2011 | 3 comments

There isn’t any single Stone Age diet, according to J.A.J. Gowlett, who (whom?) I assume is an archeologist with the University of Liverpool.

(I was tempted to write “there isn’t a monolithic Stone Age diet.”  Get it?  “Lith” is Greek or Latin for “stone.”)

This is probably old new for you guys who have been interested in the paleo diet for much longer than I.

Here are a few more of Gowlett’s ideas:

  • The Stone Age is is more accurately referred to as the Old Stone Age.
  • Hominids (the family of human ancestors) branched off from ape ancestors around eight to 10 million years ago.
  • Roots and tubers have been a part of our ancestral diet for perhaps as long as three million years,  which “places starchy carbohydrate consumption as part of the deep ancestry of human beings.”
  • Meat eating assumed greater importance about two million years ago.
  • Migration to colder environments necessitated more meat consumption because plant foods were more limited.
  • Our ancestors migrated from tropical to temperate latitudes about by 1.7 million years ago.
  • Early humans began using fire for cooking between 500,000 to 1.5 million years ago.
  • Neanderthals were heavily carnivorous.
  • “Ancestors of modern humans are now believed to have evolved in the tropics, probably in Africa, from about 200,000 years ago.”  Their diet was perhaps 70% plant-based.
  • “In contrast, modern humans entering Europe 40,000 years ago would have adopted a meat-based diet by necessity, and maintained this over hundreds of generations.”
  • “Modern hunters and gatherers echo the variety of past diets, ranging from largely plant based in the tropics, to being also heavily meat based in the arctic.”
  • No ancient human population depended heavily on cereals or non-human milk.  “Fruit certainly came first of all….”

Potential Implications For a Paleo Diabetic Diet (highly speculative)

Diabetics with tropical lineage may do better with a plant-based diet.  Those with northern European ancestry may do better with meat-based.

Paleo diets likely had very high fiber contents, reflecting the degree to which they were plant-based.  We’re looking at 70+ grams of fiber daily.  That much fiber would tend to reduce the effect of carbohydrate on blood sugar levels.

Fruits and roots have a high concentration of carbohydrate, with potential adverse effects on blood sugar (raising it, of course).  Diabetics eating paleo-style may need to avoid or limit certain fruits and roots: the ones with lower fiber content and higher glycemic index.  Blood sugar responses will vary from one diabetic to another.  Monitor blood sugar levels one or two hours after carb consumption to learn your idiosyncratic response.

Steve Parker, M.D.

Reference: Gowlett, J.A.J.  What actually was the Stone Age diet?  Journal of Nutritional and Environmental Medicine, 13 (2003): 143-147.

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Dan Pardi Summarizes Five Popular Paleo Diet Versions

Posted on September 29, 2011 | 3 comments

Dan Pardi has a recent blog post outlining five popular versions of the paleo diet (aka Stone Age diet, caveman diet, paleolithic diet).  (I don’t like the term “caveman diet.”)  Although it’s a short post, I haven’t read it yet.

Medical and nutrition science researchers need a concensus definition, if possible, before they begin their investigations.  I suspect they’ll end up with several definitions, as we’ve seen with the Mediterranean diet.

Steve Parker, M.D.

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Paleolithic Nutrition: Twenty-Five Years Later

Posted on September 29, 2011 | 16 comments

Melvin Konner and S. Boyd Eaton wrote a review article for Nutrition in Clinical Practice that update’s their seminal New England Journal of Medicine  paleo nutrition article of 1985.  They took a fresh look at recent  data on modern hunter-gatherer societies as well as advances in anthropology. 

NEJM likely has much wider circulation, so it’s too bad the update wasn’t published there.

I’ve written previously about the history of the modern paleo movement.  I consider S. Boyd Eaton and Melvin Konner two of the founders. 

I wanted to share a few tidbits from the new article:

  • The transition from hunting/gathering to farming (about 10,000 year ago) saw a decrease in body size and robustness, plus evidence of nutritional stress
  • Modern humans migrated away from Africa between 50,000 and 100,000 years ago
  • Levels of muscular and aerobic fitness in ancestral groups are much higher than modern societies, with a concomittant higher level of calorie consumption
  • Average life expectancies in pre-industrial hunter-gatherer (H-G) groups was only 30-35 years, but much of this low number simply reflects high infant and child death rates
  • H-G deaths overwhelmingly reflect infectious diseases
  • H-G groups had a high degree of dependence on plant foods
  • Cooking has been important to humans for at least 230,000 years, if not longer
  • Fish and shellfish are more important food sources than these authors thought 25 years ago
  • Ancestral H-G groups derived 35 to 65% of diet (calories, I guess) from animal flesh
  • Game animals have more mono- and polyunsaturated fatty acids than supermarket meat
  • H-G diets are higher in fat than they once thought: the new range is 20 to 35% of calories
  • H-G diet omega-6: omega-3 ratio was 2:1, in contrast to the modern Western ratio of 10:1
  • H-G groups eat more protein than they once thought
  • Carbohydrate consumption of H-G groups varied from about 35 to 65% of calories.  (I’ve written elsewhere about the carb content of paleo diets.)
  • Nearly all H-G carbs are from vegetables and fruits, which have more favorable glycemic responses than grains and concentrated sugars
  • Uncultivated fruits and veggies have much more fiber than commercial ones (13 versus 4 g fiber per 100 g of food)
  • H-G diets have at least 70 g of fiber daily
  • Sodium in H-G diets is very low: 800 mg/day

The Diet-Heart Hypothesis is the idea that dietary total and saturated fat, and cholesterol, cause or contribute to atherosclerosis (hardening of the arteries), leading to heart attacks and strokes.  Konner and Eaton still believe the theory is valid for fats, but not cholesterol.  The latest evidence is that even total and saturated fat are minimally or unrelated to atherosclerosis. 

They also believe total fat, due to its caloric load, is an important contributor to obesity and type 2 diabetes.  (I agree that my be true if you eat a lot of carbs with fat.)

Konner and Eaton review the very few clinical studies—a grand total of four—that apply a paleo diet to modern humans.  Results support their theory that paleo-style eating has healthful metabolic effects.

Their conception of a paleo food pyramid is a base of high-fiber vegetables and fruits, the next tier up being meat/fish/low-fat dairy (!?) (all lean), then a possible tier for whole grain (admittedly very unusual), with a small peak of oils, fats, and refined carbohydrates.

They recommend high activity levels, including resistance exercise, flexibility, and aerobics, burning over 1,000 cals/day exclusive of resting metabolism.

They also seem to favor small amounts of alcohol—not generally considered paleo—to reduce heart disease risk, admitting that “…the HG model cannot answer all questions.”

Eaton and Konner suggest the following as the “estimated ancestral diet“:

  • Carbohydrates, % daily energy                 35-40
  • Protein, % daily energy                                 25-30
  • Fat, % daily energy                                          20-35
  • Added sugar, % daily energy                            2
  • Fiber, g/day                                                        >70
  • EPA and DHA*, g/day                                    0.7-6
  • Cholesterol, mg/day                                       500+
  • Vitamin C, mg/day                                           500
  • Vitamin D, IU/day                                4,000 (sunlight)
  • Calcium, mg/day                                       1,000-1,500
  • Sodium, mg/day                                         under 1,000
  • Potassium, mg/day                                         7,000

*Eicosapentaenoic acid and docosahexaenoic acid

Konner and Eaton call for more randomized controlled studies of the paleo diet.  These studies will need to define the paleo diet carefully.  Their definition is probably as good as any, if not the best.  Of course, the listed nutrients should come from minimally processed, natural foods.  We just need Loren Cordain‘s and Staffan Lindeberg‘s  input on a concensus definition of the paleo diet, then we’re ready to rock’n’roll.

Steve Parker, M.D.

Reference:

Konner, Melvin and Eaton, S. Boyd.  Paleolithic Nutrition: Twenty-Five Years Later.  Nutrition in Clinical Practice, 25 (2010): 594-602.  doi: 10.1177/0884533610385702

Eaton, S.B. and Konner, M.  Paleolithic nutrition: a consideration of its nature and current implications.  New England Journal of Medicine, 312 (1985): 283-289.

 

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Paleo Diet and Diabetes: Improved Cardiovascular Risk Factors

Posted on September 26, 2011 | 2 comments

Sweden's Flag

Compared to a standard diabetic diet, a Paleolithic diet improves cardiovascular risk factors in type 2 diabetics, according to investigators at Lund University in Sweden.

Researchers compared the effects of a Paleo and a modern diabetic diet in 13 type 2 diabetic adults (10 men) with average hemoglobin A1c’s of 6.6% (under fairly good control, then).  Most were on diabetic pills; none were on insulin.  So this was a small, exploratory, pilot study.  Each of the diabetics followed both diets for three months.

How Did the Diets Differ?

Compared to the diabetic diet, the paleo diet was mainly lower in cereals and dairy products, higher in fruits and vegetables, meat, and eggs.  The paleo diet was lower in carbohydrates, glycemic load, and glycemic index.  Paleo vegetables were primarily leafy and cruciferous.  Cruciferous vegetables include broccoli, brussels sprouts, cauliflower, and cabbage.  Root vegetables were allowed; up to 1 medium potato daily.  The paleo diet also featured lean meats (why lean?), fish, eggs, and nuts, while forbidding refined fats, sugars, and beans.  Up to one glass of wine daily was allowed.

See the actual report for details of the diabetic diet, which seems to me to be similar to the diabetic diet recommended by most U.S. dietitians.

What Did the Researchers Find?

Compared to the diabetic diet, the paleo diet yielded lower hemoglobin A1c’s (0.4% lower—absolute difference), lower trigylcerides, lower diastolic blood pressure, lower weight, lower body mass index, lower waist circumference, lower total energy (caloric) intake, and higher HDL cholesterol (the good cholesterol).  Glucose tolerance was the same for both diets.  Fasting blood sugars tended to decrease more on the Paleo diet, but did not reach statistical significance (p=0.08, which is very close to significant).

So What?

The greater improvement in multiple cardiovascular risk factors seen here suggests that the paleo diet has potential to reduce the higher cardiovascular disease rates we see in diabetics.  This is just a pilot study.  Larger studies—more participants—are needed for confirmation.  Ultimately, we need data on hard clinical endpoints such as heart attacks, strokes, and death.

These diabetics had their blood sugars under fairly good control at baseline.  I wouldn’t be surprised if diabetics under poor control—hemoglobin A1c of 9%, for example—would see even greater improvements in risk factors as well as glucose levels while eating paleo.

There are so few women in this study as to be almost meaningless.

Results of this study may or may not apply to non-Swedes.

I see a fair amount of overlap between this version of the paleo diet and Dr. Bernstein’s Diabetes Solution diet and the Low-Carb Mediterranean Diet. 

Steve Parker, M.D.

Reference:  Jönsson, T., Granfeldt, Y., Ahrén, B., Branell, U., Pålsson, G., Hansson, A., Söderström, M., & Lindeberg, S.  Beneficial effects of a Paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study.  Cardiovascular Diabetology, 8 (2009)  doi: 10.1186/1475-2840-8-35

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A Diabetes Specialist Contemplates the Paleo Diet

Posted on September 22, 2011 | 2 comments

In 2009, David Klonoff, M.D., reviewed the existing scientific literature on treatment of diabetes with a Paleolithic diet.  The majority of his comments refer to Jönsson’s 2009 research in Cardiovascular Diabetology, which involved only 13 patients.  Dr. Klonoff, by the way, is an endocrinologist and diabetes specialist in California.

Here are a few quotes from the Dr. Klonoff:

The main ingredient lacking in a Paleolithic diet is calcium, which must be supplemented to prevent bone mineral loss.  [No references cited.]

The Jönsson study was the first to assess the potential benefit of the Paleolithic diet compared to a diabetes diet for patients with T2DM [type 2 diabetes mellitus].

The implications of identifying a safer and more effective diet than what is currently being recommended for patients with obesity or T2DM are enormous.  The paleolithic diet is certainly not a new discorvery.  What is needed now is more clinical data with greater numbers of subjects and longer study durations so that more robust conclusions can be drawn.

Potential disadvantages of a Paleolithic diet might include deficient intake of vitamin D and calcium as well as exposure to environmental toxins from high intake of fish.

The Paleolithic diet might be the best antidote to the unhealthy Western diet.

Dr. Klonoff didn’t mention whether any of his patients had tried a paleo diet.  How about now, two years later?

Steve Parker, M.D. 

Reference: Klonoff, David.  The beneficial effects of a Paleolithic diet on type 2 diabetes and other risk factors for cardiovascular disease.  Journal of Diabetes Science and Technology, 3 (2009): 1,229-1,232.

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Paleo Diet Revival Story

Posted on September 16, 2011 | 8 comments

My superficial reading of the paleo diet literature led me to think Loren Cordain, Ph.D., was the modern originator of this trend, so I was surprised to find an article on the Stone Age diet and modern degenerative diseases in a 1988 American Journal of Medicine by S. Boyd Eaton, M.D., et al.  Dr. Cordain started writing about the paleo diet around 2000, I think.

What’s So Great About the Paleolithic Lifestyle?

In case you’re not familiar with paleo diet theory, here it is.  The modern human gene pool has changed little over the last 50,000 years or so, having been developed over the previous one or two million years.  Darwins’ concept of Natural Selection suggests that organisms tend to thrive if they adhere to conditions present during their evolutionary development.  In other words, an organism is adapted over time to thrive in certain environments, but not others.

The paleo diet as a healthy way to eat appeals to me.  It’s a lifestyle, really, including lots of physical activity, avoidance of toxins, adequate sleep, etc. 

The Agricultural Revolution (starting about 10,000 years ago) and the Industrial Revolution (onset a couple centuries ago) have produced an environment and food supply vastly different from that of our Paleolithic ancestors, different from what Homo sapiens were thriving in for hundreds of thousands of years.  That discordance leads to obesity, type 2 diabetes, atherosclerosis, high blood pressure, and some cancers.  Or so goes the theory.

What’s the Paleolithic Lifestyle?  (according to Eaton’s 1988 article)

  • Average life expectancy about half of what we see these days
  • No one universal subsistence diet
  • Food: wild game (lean meat) and uncultivated vegetables and fruits (no dairy or  grain)
  • Protein provided 34% of calories (compared to about 12% in U.S. in 1988)
  • Carbohydrate provided 46% of calories (only a  tad lower than what we eat today)
  • Fat provided 21% of calories (42% today)
  • Little alcohol, but perhaps some on special occasions (honey and wild fruits can undergo natural fermentation) , compared to 7-10% of calories in U.S. today [I didn’t know it was that high]
  • No tobacco
  • More polyunsaturated than saturated fats (we ate more saturated than polyunsaturated fat, at least in 1988)
  • Minimal simple sugar availability except when honey in season
  • Food generally was less calorically dense compared to modern refined, processed foods
  • 100-150 grams of dietary fiber daily, compared to 15-20 g today
  • Two or three times as much calcium as modern Americans
  • Under a gram of sodium daily, compared to our 3 to 7 grams.
  • Much more dietary potassium than we eat
  • High levels of physical fitness, with good strength and stamina characteristic of both sexes at all ages achieved through physical activity

[These points are all debatable, and we may have better data in 2011.]

The article authors point out that recent unacculturated native populations that move to a modern Western lifestyle (and diet) then see much higher rates of obesity, diabetes, atheroslcerosis, high blood pressure, and some cancers.  “Diseases of modern civilization,” they’re called.  Cleave and Yudkin wrote about this in the 1960s and ’70s, focusing more on the refined carbohydrates in industrial societies rather than the entire lifestyle. 

Paleo diet proponents agree that grains are not a Paleolithic food.  The word “grain” isn’t in Eaton’s article.  The authors don’t outline the sources of Paleolithic carbs: tubers and roots, fruits, nuts, and vegetables, I assume.  Legumes and milk are probably out of the question, too.

The Paleolithic Prescription: A Program of Diet and Exercise and a Design for Living was published in 1988 by Harper & Row (New York).  The authors are S. Boyd Eaton, M. Shostak, and M. Konner. 

Eaton and Konner are also the authors of “Paleolithic nutrition: A consideration of its nature and current implications.”  in New England Journal of Medicine, 312 (1985): 283-289.

Mat Lalonde, Ph.D., in an interview with Jimmy Moore suggested that Cordain would credit S. Boyd Eaton, M.D., with the recent trendiness of the paleo diet.

Paul Jaminet wrote at one of my other blogs: “In 1975 a gastroenterologist named Walter L. Voegtlin published a book called The Stone Age Diet arguing for a low-carb Paleo diet.  S. Boyd Eaton was second.  Not much happened for a time, then it picked up in the late 1990s and early 2000s.  Ray Audette with Neanderthin was first to market…Oh, and I forgot Jan Kwasniewski’s Optimal Diet, which was first published in Poland around 1970.  Not exactly a Paleo diet, but close.

If you have evidence that the “modern paleo” diet goes back further than this, please leave a comment.

Steve Parker, M.D.

References:

Kuipers, R., Luxwolda, M., Janneke Dijck-Brouwer, D., Eaton, S., Crawford, M., Cordain, L., & Muskiet, F. (2010). Estimated macronutrient and fatty acid intakes from an East African Paleolithic diet British Journal of Nutrition, 1-22 DOI: 10.1017/S0007114510002679.  Note that one of the authors is Loren Cordain.  Good discussion of various Paleolithic diets.

Eaton, S., Konner, M., & Shostak, M. (1988). Stone agers in the fast lane: Chronic degenerative diseases in evolutionary perspective The American Journal of Medicine, 84 (4), 739-749 DOI: 10.1016/0002-9343(88)90113-1

Cordain, L., et al.  Plant-animal subsistance ratios and macronutrient energy estimations in worldwide hunter-gatherer diets.  American Journal of Clinical Nutrition, 71 (2000): 682-692.

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