Tag Archives: paleolithic diet

Diet Implications of Human Origins and Migration

African Savanna

African Savanna

Until 10,000 to 12,000 or so years ago, humans and our hominin ancestors obtained food through a combination of hunting and foraging. We hunted small or large game and birds. At some point we learned how to catch fish and shellfish. We searched for and gathered up fruits, berries, leafy plants, nuts, seeds, mussels, clams, honey, eggs, and roots.

Young woman sitting at camp fire, holding fried sausage

 

The range of edible items expanded when we harnessed the power of fire for cooking, which was at least 230,000 years ago and may have been as long as a million years ago.Tools and weapons also expanded our possibilities from the very start of the Paleolithic.

 

Prior to 10,000 years ago, we weren’t farming or raising cattle and dairy cows. Available foods depended on local climatic conditions, soil, and water availability. Climate, in turn, is heavily dependent on latitude (how far away from the equator) and altitude. East Africa at the dawn of humanity is described as savanna: grass-filled plains with scattered patches of forest, and relatively dry. Plants and animals available there would be much different than the colder but wetter Europe 200,000 years ago.

Steve Parker MD, paleo diet, paleobetic

Nubian ibex in Israel

 

Humans in Northern Europe tended to eat more animal-based food and relatively less plant matter than savanna-dwellers, perhaps just because there were fewer edible plants growing in the cold climate. Many plants would have been highly seasonal, just as they are now.

Tribes of humans walked or migrated to nearby micro-climates as one plant went out of season and another came into season. Tribes followed prey animals as they also migrated in search of seasonal food.

Due to technological limitations, we wouldn’t have been able to utilize some potential food sources that required much processing, such as cereal grains and legumes. Since we weren’t yet pastoralists (raising sheep, cattle, etc.), we would have access to milk only if we killed a nursing prey animal. Have you ever tried to milk a wild water buffalo? Not advisable. Ability to digest milk beyond infancy was marginal. Even today, two-thirds of humans lose the ability to digest milk after infancy.

The experts debate actively debate how long we’ve been consuming significant amounts of cereal grains and roots. Canadian researchers working in Africa suggest we’ve enjoyed them for over 100,000 years (see Mercader, Julio, et al. Mozambican grass seed consumption during the Middle Stone Age. Science, December 18, 2009.)

Steve Parker, M.D.

Paleolithic Diet May Help Reduce Risk of Obesity

…according to a basic science study published in the British Journal of Nutrition. The mechanism for reducing obesity risk would be increased satiety. We’ve seen that before with the paleo diet as compared to a Mediterranean-style diet. Disappointingly, the researchers didn’t see any paleo diet benefits in these healthy study participants in terms of glucose and insulin metabolism.

I haven’t read the report, don’t have it, don’t know when I’ll read it.

Abstract

There is evidence for health benefits from ‘Palaeolithic’ diets; however, there are a few data on the acute effects of rationally designed Palaeolithic-type meals. In the present study, we used Palaeolithic diet principles to construct meals comprising readily available ingredients: fish and a variety of plants, selected to be rich in fibre and phyto-nutrients. We investigated the acute effects of two Palaeolithic-type meals (PAL 1 and PAL 2) and a reference meal based on WHO guidelines (REF), on blood glucose control, gut hormone responses and appetite regulation. Using a randomised cross-over trial design, healthy subjects were given three meals on separate occasions. PAL2 and REF were matched for energy, protein, fat and carbohydrates; PAL1 contained more protein and energy. Plasma glucose, insulin, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP) and peptide YY (PYY) concentrations were measured over a period of 180 min. Satiation was assessed using electronic visual analogue scale (EVAS) scores. GLP-1 and PYY concentrations were significantly increased across 180 min for both PAL1 (P= 0·001 and P< 0·001) and PAL2 (P= 0·011 and P= 0·003) compared with the REF. Concomitant EVAS scores showed increased satiety. By contrast, GIP concentration was significantly suppressed. Positive incremental AUC over 120 min for glucose and insulin did not differ between the meals. Consumption of meals based on Palaeolithic diet principles resulted in significant increases in incretin and anorectic gut hormones and increased perceived satiety. Surprisingly, this was independent of the energy or protein content of the meal and therefore suggests potential benefits for reduced risk of obesity.

Steve Parker, M.D.

Reference: Bligh H.F., et al. British J Nutr. 2015 Feb 28;113(4):574-84. doi: 10.1017/S0007114514004012. Epub 2015 Feb 9.
Plant-rich mixed meals based on Palaeolithic diet principles have a dramatic impact on incretin, peptide YY and satiety response, but show little effect on glucose and insulin homeostasis: an acute-effects randomised study.

Short-Term Paleo Diet Improves Glucose Control in Obese Type 2 Diabetes (the Masharani Study)

UCSF is here

UCSF is here

A three-week Paleolithic-style diet improved blood sugars and lipids in obese type 2 diabetics, according to researchers at the University of California—San Francisco. This is the Lynda Frassetto study I’ve been waiting over a year for. The first named author is U. Masharani, so I’ll refer to this work in the future as the Masharani study. Sorry, Lynda.

To understand the impact of this study, you need to know about a blood test called fructosamine, which reflects blood sugar levels over the preceding 2–3 weeks. You may already be familiar with a blood test called hemoglobin A1c: it tells us about blood sugars over the preceding three months. Blood glucose binds to proteins in our blood in a process called glycation. The higher the blood glucose, the more bonding. Glucose bound to hemoglobin molecules is measured in HgbA1c. Glucose bound to plasma proteins (predominantly albumin) is measured as fructosamine. It probably has nothing to do with fructose. Fructosamine is a generic name for plasma ketoamines.

If you’re doing a diabetic diet study over over 2–3 weeks, as in the report at hand, changes in glucose control will mostly be detected in fructosamine rather than HgbA1c levels.

How Was the Research Done?

Twenty-five obese diabetics in the San Francisco Bay area were randomly assigned to either a paleo-style diet or one based on American Diabetes Association (ADA) guidelines. They followed the diets for three weeks, with various measurements taken before and after intervention.

Participants were aged 50-69; you have to guess the sex breakdown. Average body mass index was 34. Over half (63%) were White/European American; there were three each of Asian, African American, and Hispanic ethnicity. They had normal blood pressures and diabetes was well controlled, with hemoglobin A1c’s around 7% and fructosamine levels close to normal. Four subjects were on no diabetes medications; 14 were taking metformin alone, five were on metformin and a sulfonylurea, one was on long-acting insulin and a sulfonylurea. No drug dosages were changed during the study.

Both intervention diets were designed for weight maintenance, i.e., avoidance of weight loss or gain. If participants lost weight, they were instructed to eat more. All food was prepared and provided for the participants. Three meals and three snacks were provided for daily consumption.

Fourteen subjects completed the paleo diet intervention. They ate lean meats, fruits, vegetables, tree nuts, poultry, eggs, canola oil, mayonnaise, and honey. No added salt. No cereal grains, dairy, legumes, or potatoes. Calorie percentages from protein, fat, and carbohydrate were 18%, 27%, and 58%, respectively. Compared to the ADA diet, the paleo diet was significantly lower in saturated fat, calcium, and sodium (under half as much), while higher in potassium (twice as much). These dieters eased into the full paleo diet over the first week, allowing bodies to adjust to higher fiber and potassium consumption. The paleo diet had about 40 grams of fiber, over twice as much as the ADA diet.

[I wonder why they chose canola over other oils.]

Ten subjects completed the ADA diet, which included moderate salt, low-fat dairy, whole grains, rice, bread, legumes, and pasta. Calorie percentages from protein, fat, and carbohydrate were 20%, 29%, and 54%, respectively (very similar to the paleo diet). I don’t have any additional description for you. I assume it included meat, poultry, eggs, and fruit.

Diet compliance was confirmed via urine measurements of sodium, potassium, pH, and calcium.

What Did the Researchers Find?

Both groups on average lost about 2 kg (4-5 lb).

Compared to their baseline values, the paleo group saw reductions in total cholesterol, HDL cholesterol, LDL cholesterol, HgbA1c (down 0.3% absolute reduction), and fructosamine. Fructosamine fell from 294 to 260 micromole/L. [The normal non-diabetic range for fructosamine is 190-270 micromole/L.]

Compared to their baseline values, the ADA diet group saw reductions in HDL cholesterol and HgbA1c (down 0.2% absolute reduction) but no change in fructosamine, total cholesterol, and LDL cholesterol.

Comparing the groups to each other, the difference in fructosamine change was right on the cusp of statistical significance at p = 0.06.

Within each group, insulin resistance trended down, but didn’t reach statistical significance. However, when they looked at the folks who were the most insulin resistant, only the paleo dieters improved their resistance. By the way, insulin resistance was measure via euglycemic hyperinsulinemic clamp instead of the short-cut HOMA-IR method.

Blood pressures didn’t change.

The authors don’t mention hypoglycemia at all, nor alcohol consumption.

They note that some of the paleo dieters complained about the volume of food they had to eat.

Errata

I found what I think are a couple misprints. Table 1 has incorrect numbers for the amount of sodium and potassium in the ADA diet. See the text for correct values. Table 2 give fructosamine values in mg/dl; they should be micromoles/L.

Final Thoughts

This particular version of the paleo diet indeed seems to have potential to help control diabetes in obese type 2’s, perhaps even better than an ADA diet, and despite the high carb content. Obviously, it’s a very small study and I’d like to see it tested in a larger population for several months, and in type 1 diabetics. But it will be years, if ever, before we see those research results. Diabetics alive today have to decide what they’ll eat tomorrow.

I wish the researchers had explained why they chose their paleo diet macronutrient breakdown: calorie percentages from protein, fat, and carbohydrate were 18%, 27%, and 58%, respectively. Perhaps they were trying to match the ratios of the ADA diet. But from what I’ve read, the average ancestral paleo diet carbohydrate energy percentage is 30-35%, not close to 60%. My experience is that reducing carb calorie consumption to 30% or less helps even more with glucose control. Reducing carbs that low in this study would have necessitated diabetes drug adjustments and increased the risk of hypoglycemia.

The authors wonder if the high fiber content of the paleo diet drove the lowered glucose levels.

High HDL cholesterol is thought to be protective against coronary artery disease and other types of atherosclerosis. Both diet groups here saw reductions in HDL. That’s something to keep an eye on.

The ADA diet group saw a drop in HgbA1c but not fructosamine. I can’t explain how HgbA1c goes down over three weeks without a change in fructosamine level.

You have to wonder if the paleo diet results would have been more impressive if the test subjects at baseline had been sicker, with poorly controlled blood pressures and HgbA1c’s of 9% or higher. And it sounds like some of these folks would have lost weight if not forced to eat more. The paleo diet is more satiating than some.

The article was well-written and a pleasure to read, in contrast to some I’ve suffered through recently.

Steve Parker, M.D.

Reference: Masharani, U., et al. Metabolic and physiologic effects from consuming a hunter-gatherer (Paleolithic)-type diet in type 2 diabetes. European Journal of Clinical Nutrition, advance online April 1, 2015. doi: 10.1038/ejcn.2015.39

More Evidence That Modern Diets Are Bad For Our Teeth

Australian Aborigine in Swamp Darwin

Australian Aborigine in Swamp Darwin

Phys.org has an article on dental changes associated with the transition from hunter-gatherer cultures to less mobile agricultural ones. The transition occured 10,000 to 12,000 years ago at the end of the Paleolithic period. Some quotes:

“Our findings show that the hunter gatherer populations have an almost “perfect harmony” between their lower jaws and teeth,” he explains. “But this harmony begins to fade when you examine the lower jaws and teeth of the earliest farmers”.

*   *   *

The diet of the hunter-gatherer was based on “hard” foods like wild uncooked vegetables and meat, while the staple diet of the sedentary farmer is based on “soft” cooked or processed foods like cereals and legumes. With soft cooked foods there is less of a requirement for chewing which in turn lessens the size of the jaws but without a corresponding reduction in the dimensions of the teeth, there is no adequate space in the jaws and this often results in malocclusion and dental crowding.

You can read the original research report in PLOS One.

Steve Parker, M.D.

h/t Diet Doctor Eenfeldt

This bedrock metate was used by Indians (aka Native Americans) for grinding maize, acorns, and other foods

This bedrock metate was used by Indians (aka Native Americans) for grinding maize, acorns, and other foods. Rainwater fills this 4-inch deep rounded depression in granite about 10 miles from my house.

Why Do Diabetics Resist the Paleo Diet?

Dr. Ernie Garcia (MD) posted a passionate essay about his difficulty getting his patients with diabetes to follow a carbohydrate-restricted Paleolithic diet. He makes a good case for carbohydrate addiction. A few quotes:

Today I saw a lady at my office. Fairly typical middle-aged, over weight female with poorly controlled diabetes. She recently started on an insulin pump but her glucose control is no better at all. I had a suspicion why, and again started to question the details of what she eats. Of course, she eats carb after carb after carb. Whole wheat this, and low fat that. She has tried to cut the carbs in the past, and actually had pretty decent success, but quickly falls back into your carbilicious ways. Why? Why go back when a change in diet shows clear improvement in her sugars?

*   *   *

What do addicts do? They generally know what they do is bad for them, and they have periods of clarity where they do better. Eventually though, the pull of their drug of choice draws them back in. Or, they slip up and use just a little and BAM…right back to square one. They feel shame for their addiction, people look down upon them for it, and they wish so badly they could make a permanent change, but they always fall back into old habits. Now, imagine a heroin addict who is advised to control the addition by sticking with “moderation” because of course, everything is good in moderation right?

Another issue that type 2 diabetics have is that they’ve been eating copious carbohydrates for over 40 years. It’s hard to break any habit with that type of longevity. It doesn’t help that they’re immersed in a carb-centric culture.

RTWT.

Steve Parker, M.D.

 

Paleolithic Diet Improved Metabolic Syndrome in Just Two Weeks

Wish I were here

Wish I were here

A Paleolithic-type diet over two weeks improves several heart disease risk factors in folks with metabolic syndrome, according to Netherlands-based researchers.

The investigators wondered if the paleo diet, independent of weight loss, would alter characteristics of the metabolic syndrome. They seem to be the first scientists to do a study like this.

“Metabolic syndrome” may be a new term for you. It’s a collection of clinical features that are associated with increased future risk of type 2 diabetes and atherosclerotic complications such as heart attack and stroke. One in six Americans has metabolic syndrome, including almost one in four of adults. The most common definition of metabolic syndrome (and there are others) is the presence of at least three of the following characteristics:

  • high blood pressure (130/85 or higher, or using a high blood pressure medication)
  • low HDL cholesterol: under 40 mg/dl (1.03 mmol/l) in a man, under 50 mg/dl (1.28 mmol/l) in a women (or either sex taking a cholesterol-lowering drug)
  • triglycerides over 150 mg/dl (1.70 mmol/l) (or taking a triglyceride-lowering drug)
  • abdominal fat: waist circumference 40 inches (102 cm) or greater in a man, 35 inches (88 cm) or greater in a woman
  • fasting blood glucose over 100 mg/dl (5.55 mmol/l)

These five criteria were identical to the ones used in the study at hand. But the study participants were required to have only two of the five, not three, for unclear reasons. I found no consensus definition elsewhere that would define metabolic syndrome as only two of the five conditions. Study participants ate either a paleo-style diet or a reference/control diet. Those eating the reference diet didn’t quite have the metabolic syndrome since they had a mean (“average”) of 2.7 metabolic syndrome characteristics. The paleo group had 3.7 characteristics.

How Was the Study Done?

Average age of the 34 study participants was 53 and they were generally healthy. None had diabetes, cardiovascular disease, or systolic pressure over 180 mmHg. Smokers were excluded. Mean body mass index was 32 (obese). Only 9 of the 34 subjects were men. Subjects were randomized to either a Paleolithic-type diet (n=18) or a “healthy reference diet based on the guidelines of the Dutch Health Council” (n=14). Efforts were made to keep body weight stable during the two-week study. Participants were nearly all caucasian.

All meals were home-delivered free of charge by a catering service.

The Paleolithic-type diet “…was based on lean meat, fish, fruit, leafy and cruciferous vegetables, root vegetables, eggs and nuts. Dairy products, cereal grains, legumes, refined fats, extra salt and sugar were not part of it.” [I like their version of the paleo diet.] Protein supplied 24% of calories while carbohydrate was 32% and fat 41%.

You can consult the full text of the published article for details of the Dutch Health Council diet. Calories were 17% from protein, 50% from carbohydrate, and 29% from fat. Alcohol isn’t mentioned at all.

Despite randomization, the paleo diet group had more metabolic syndrome characteristics than the reference diet group. For instance, 78% of the paleo group had elevated fasting glucose compared to 44% of the reference group. And 67% of the paleo group had low HDL cholesterol compared to just 13% of the reference group. These glucose and HDL differences were statistically significant. 39% of the paleo had high triglycerides compared to 19% of the others. Furthermore, the paleos’ average body weight was 98 kg (216 lb) compared to 86 kg (189 lb) in the others. The paleo group had 3.7 characteristics of the metabolic syndrome versus 2.7 in the other cohort.

Go John trail at Cave Creek Regional Park in Scottsdale, Arizona

Go John trail at Cave Creek Regional Park in Scottsdale, Arizona

Results

Compared to the reference diet, the paleo-style diet:

  • lowered systolic pressure by 9 points and diastolic by 5
  • total cholesterol fell by 0.52 mmol/l (20 mg/dl)
  • triglycerides fell by 0.89 mmol/l (79 mg/dl)
  • HDL cholesterol (good) rose by 0.15 mmol/l (6 mg/dl)
  • body weight fell by 1.32 kg (3 lb)
  • one metabolic syndrome characteristic resolved

No significant changes were seen in intestinal permeability ( by differential sugar absorption test on urine), salivary cortisol, and inflammation (hsCRP, TNFα).

Fasting plasma insulin and HOMA-IR fell in the paleo group but not the other.[Good news for folks with diabetes or prediabetes.] Yet the authors write, “Regarding glucose intolerance we did not find significant changes in our study.”

Fasting blood glucose for the group as a whole at baseline was about 1o8 mg/dl (6.0 mmol/l). Fasting glucose fell in both groups: 16 mg/dl (0.9 mmol/l) in the paleo group, 6 mg/dl (0.35 mmol/l) in the other. This was not a statistically significant difference between the groups. These numbers are from the text of the report; looking at the tables, I calculate different and less impressive reductions. The falls in fasting glucose from baseline were statistically significant for both diets.

Nearly all the statistical analysis focused on comparing the paleo diet group to the reference diet group.

My Comments

Overall, I’m not very pleased with this study. My biggest problems are 1) the unfortunate randomization that created dissimilar experimental groups,  2) the use of two diet protocols, 3) some of the study participants didn’t even have metabolic syndrome, and 4) as is typical for paleo diet studies, not many experimental subjects were involved.

The randomization led to significant differences in the metabolic syndrome patients in the two diet groups. I’m puzzled why the authors don’t comment on this. It’s a problem with clinical studies involving low numbers of participants. Ideally, you want to apply the two different diets to groups of people that are as similar as possible. These groups weren’t that similar.

The investigators’ main goal was to study whether a paleo-style diet, independent of weight loss, alters characteristics of the metabolic syndrome. Then why introduce another variable, the Dutch Health Council diet? Is it the gold standard for treating metabolic syndrome? Has it even been used to treat metabolic syndrome? The authors don’t tell us. And why not restrict participation to subjects who meet the common international definition of metabolic syndrome (at least three of the five characteristics)? Why not just take all your subjects and switch them from their standard Netherlands diet to the paleo diet? That would increase your statistical power, and would have avoided the randomization mis-match in which some in the reference diet group didn’t even have metabolic syndrome.

Here we’ve got two different experimental groups, and we’re applying a different diet to each group. The results are going to be messy and difficult to interpret. It’s always better if you can alter just one variable.

Since the paleo and reference diet cohorts were so different at baseline, why not make it easy to simply compare the paleo diet group’s “before and after numbers”? Maybe the analysis is there and I’m just not smart enough to see it.

There weren’t enough men in the study to tell us anything about the paleo diet in men with metabolic syndrome.

The statistical analysis was difficult for me to read and understand. There’s a good chance I’ve missed or misinterpreted something.

This paleo diet reduced fasting blood sugar significantly, making me think it may help in management of diabetes and prediabetes.

I estimate that as much as a quarter of the experimental subjects didn’t even have metabolic syndrome, so the study title is a bit of a misnomer.

This paleo diet did result in resolution of one metabolic syndrome characteristic, which is a good thing. So you could say the diet improves metabolic syndrome, even resolves it in some folks if it drops their metabolic syndrome characteristics from three to two. It predominantly helps lower blood pressure and triglycerides, and reduces excess weight modestly. In white women. Compared to the healthy Dutch Health Council diet.

If I had metabolic syndrome, I’d do something about it in hopes of lowering my future risk of diabetes and atherosclerotic complications. Standard physician advice is to lose excess weight and exercise regularly. There’s no consensus on diet yet. I think carbohydrate restriction is important. If the study at hand is reproducible in a larger study population, the paleo diet is a reasonable approach. Dietitian Franziska Spritzler has a great review of nutritional management of metabolic syndrome at her blog. The Mediterranean diet supplemented with nuts helps improve metabolic syndrome. The Spanish Ketogenic Mediterranean Diet may cure metabolic syndrome.

Steve Parker, M.D.

Update: I took a fresh look at this study as if it were simply a paleo diet trial involving 18 subjects who had metabolic syndrome. If I’m interpreting Table 5 correctly, and I think I am, these are the statistically significant changes after two weeks:

  • abdominal circumference decreased by 3.1 cm
  • systolic and diastolic blood pressures dropped by 8.5 and 8, respectively
  • fasting glucose dropped by 0.4 mmol/l (7 mg/dl)
  • fasting insulin fell
  • HOMA-IR decreased (less insulin resistance)
  • total cholesterol decreased from 220 to 193 mg/dl (5.7 to 5.0 mmol/l)
  • LDL-cholesterol decreased from 135 to 124 mg/dl (3.5 to 3.2 mmol/l)
  • triglycerides decreased from 168 to 89 mg/dl (1.9 to 1.0 mmol/l)

HDL cholesterol was unchanged.

The fall in AUC (area under the curve) for insulin approached but didn’t reach statistical significance (p=0.08)

Body weight fell from 98 kg (216 lb) to 95.3 kg (210 lb) but I found no p value. HDL-cholesterol was unchanged (the higher HDL I mentioned above is only in comparison to the reference diet, in which HDL fell)

All of these changes (except the lack of change in HDL-chol) would tend to promote health in someone with metabolic syndrome, prediabetes, or overweight type 2 diabetes.

Reference: Boers, Inga, et al. Favorable effects of  consuming a Palaeolithic-type diet on characteristics of the metabolic syndrome: a randomized controlled pilot-studyLipids in Health and Disease. 2014 Oct 11;13:160. doi: 10.1186/1476-511X-13-160.

Ever Heard of Paleolithic Diet Pioneer Arnold De Vries?

paleo diet, Paleolithic diet, hunter-gatherer diet

Not Arnold Paul De Vries or Don Wiss, but a Huaorani hunter in Ecuador

Don Wiss turned me on to another “modern” paleo diet pioneer, Arnold Paul De Vries, who wrote a 1952 book called Primitive Man and His Food. I even found the book on the Internet a few months ago, perhaps in violation of copyright. I can’t find it now. You can request a digital copy of the book here.

I read his thoughts on the diets of North American Indians before my other duties interrupted me.

Steve Parker, M.D.

Reference (see Comments)

Evolutionary Aspects of Obesity, Insulin Resistance, and Cardiovascular Risk

paleo diet, Paleolithic diet, hunter-gatherer diet

Huaorani hunter in Ecuador

Spreadbury and Samis have a review-type article in Current Cardiovascular Risk Reports. Here’s the abstract:

Cardiovascular disease (CVD) is still virtually absent in those rare populations with minimal Western dietary influence. To date, exercise, altered fats, fibre, anti-oxidants or Mediterranean diet do not appear to overcome the discrepancy in CVD between hunter-gatherer and Western populations. The CVD risk factors of obesity and diabetes are driven by increased caloric intake, with carbohydrates potentially implicated. Paradoxically, non-Westernized diets vary widely in macronutrients, glycemic and insulinemic indices, yet apparently produce no obesity or CVD regardless, even with abundant food. ‘Ancestral’ grain-free whole-food diet may represent the best lifestyle intervention for obesity and CVD. Such diets are composed of the cells of living organisms, while Western grains, flour and sugar are dense, acellular powders. Bacterial inflammation of the small intestine and vagal afferents appears a crucial step in leptin-resistance and obesity. Therefore it may be important that the Western diet resembles a bacterial growth medium.

You may remember Spreadbury’s name from his theory about acellular carbohydrates causing obesity via alterations in gut microorganisms. Spreadbury is with the Gastrointestinal Diseases Research Unit, Queen’s University, Kingston, Ontario, Canada.

You can read the articles for yourself. The following are a few of the authors points I found interesting or want to remember.

Does physical activity explain differences in CVD between Westernized and non-Westernized Peoples? They say “maybe.”

Throughout the article are references to aboriginals like the Hadza, Kitavans, Ache, Shuar, Australian aborigines, and Inuits. I always take comparisons of them to modern Europeans with a grain of salt, because of potential genetic differences between the populations. Moreover, diet and activity levels are only two of myriad cultural differences.

Australian Aborigine in Swamp Darwin

Australian Aborigine in Swamp Darwin

Can dietary changes reduce the incidence of CVD? They say it’s unclear.

Regarding modern paleo diet trials, “All the studies with ad libitum eating [eat all you want] have reported a spontaneous reduction in caloric intake in the order of 15-30%.” (Three references.) “The reduced food intake appeared driven by a satiety increase that was apparently not explicable by energy density, fiber or macronutrient content.” (One reference.)

“In those eating a Westernized diet, carbohydrates are increasingly recognized as being associated with poor metabolic health.” Evidence? Only one reference cited: Zienczuk’s 2012 article on high arctic Inuits.

“…non-Westernized populations with excellent metabolic and cardiovascular health almost invariably have negligible dietary contribution from grains, as well as refined sugar.” No citations.

“For ‘western-style’ diets and most obesogenic diets tested, gut microbiota appear to play a crucial role in obesity.” That’s a bold statement. References? Only one, a mouse study.

The rest of the article is about Spreadbury’s acellular carb/obesity theory. He suggests that small intestine bacteria play a more prominent role than colonic germs. Bacterial-driven inflammation….

The authors provide an example of a grain-free whole-food diet. It’s unrestricted in fruit, leafy or root vegetables, unprocessed meats, eggs, fish, nuts (except peanuts), mushrooms, herbs and spices. Occasional foods to be eaten in moderation are legumes, rice, yogurt, milk, cheeses, sweet corn, palm oil/lard/olive oil, and salt. Avoid almost all processed foods, breads, cereals, cakes/cookies/donuts etc., refined sugars, dried or processed fruits, vegetable/seed oils, and processed meats. They advise a vitamin D supplement. I’m not sure if they came up with this diet on their own, or it’s S. Lindeberg’s outline.

A final quote:

The macronutrient independence of the health from ancestral diet suggests whole foods are more important to health than their macronutrient or other chemical components, and that good health is associated with unprocessed cellular foods. Flour, sugar and processed foods appear to be important drivers of Western metabolic dysfunction, overweight and inflammation, and may prove to have a profound impact on, or even be the initiators of cardiovascular disease.

I’m sure Spreadbury and Samis would agree we need more basic science and clinical research into these issues, involving human test subjects. Maybe I’m prejudiced, but I’m more interested in Asians, Africans, and Europeans than Shuar people.

Steve Parker, M.D.

Reference: Spreadbury, Ian and Samis, Andrew J.S. Evolutionary aspects of obesity, insulin resistance, and cardiovascular risk. Current Cardiovascular Risk Reports, April 2013, vol. 7, issue 2, pp. 136-146.

Another Paleo Diet Success Story For a Type 1 Diabetic

The Joslin Diabetes Blog has details. Lindsay Swanson was diagnosed with type 1 diabetes at age 25. Her initial interest was spurred by years of undiagnosed gastrointestinal issues. She eased into the Paleolithic diet by sequentially eliminating certain food classes, starting with grains, then soy, then legumes. As she did, she felt increasingly better. Lindsay eats few refined carbohydrates. My sense is she doesn’t require much insulin. A quote:

Much to my surprise, my blood sugars completely leveled out, so much so that I rarely need to treat a low blood sugar, and spikes are few and far between….Probably 75 percent of my diet consists of vegetables and plant based food, some with more carbohydrates depending on my activity level. I eat a lot of fat/protein regularly, examples: avocados, coconut oil (in tea and cooking), grassfed meats, bacon (and the reserved fat), oils, nuts, etc.

 

Another Review Article In Favor Of Paleolithic Eating

It’s in the Annual Review of Plant Biology. The authors promote fruit and vegetable consumption. A snippet from the 2013 article:

Our Paleolithic ancestors were hunter-gatherers, consuming diets rich in lean wild meat or fish, with relatively high consumption of fruits and green leafy vegetables. Our modern diets, in contrast, are high in saturated fats and starches, added sugars with high energy load, and “unnatural fats” such as transfats. Paleolithic diets, in contrast to those of simians and present-day hunter-gatherers, are estimated to have been approximately 75% fruit [that’s news to me; reference is from S. Lindeberg]. In modern US diets, foods unavailable to Paleolithic societies—including dairy products, cereal grains, refined cereal flour, refined sugars, refined vegetable oils, and alcohol—on average make up 70% of total energy consumption. Of this, 50% is in the form of vegetable oils and refined sugars .Americans currently consume less than 60% of the US Department of Agriculture recommendations for vegetables and less than 50% of the recommendations for fruits.

h/t Bill Lagakos

Reference: Annu. Rev. Plant Biol. 2013. 64:19–46. This article’s doi:10.1146/annurev-arplant-050312-120142