What About Vegetarian Diets for Diabetes?

low-carb diet, spaghetti squash, paleobetic diet, diabetic diet

The spaghetti squash at top is related to pumpkins and zucchini

I was surprised to learn that well-known diabetes writer David Mendosa (Type 2 DM) has switched from a very low-carb diet to a low-carb vegetarian diet, eating no more than 50 grams/day of carbohydrate. Why?

For me the issue is that I don’t want to be responsible for harming sentient beings as much as I can avoid it while still following a healthy diet.

I can respect that. I’m sure he’s monitoring the effects of the diet on his blood sugars and weight. Probably his blood lipids, too.

It sounds like all David had to do was drop fish from his prior diet. He still eats eggs (whites only?), cheese, and full-fat yogurt, so I’d call him a lacto-ovo-vegetarian.

If you’re already convinced that the Paleolithic diet is the best one for people with diabetes, read no further.

What Is a Vegetarian Diet?

From UpToDate.com:

Vegetarian diets vary considerably depending on the degree of dietary restrictions. According to the strictest definition, a vegetarian diet consists primarily of cereals, fruits, vegetables, legumes, and nuts; animal foods, including milk, dairy products, and eggs generally are excluded. Several less restrictive vegetarian diets may include eggs and dairy products. Some vegetarian diets may be grouped as follows:

●Macrobiotic — Vegetables, fruits, legumes, and seaweeds are included in the diet, while whole grains, especially brown rice, are also emphasized. Locally-grown fruits are recommended. Animal foods limited to white meat or white-meat fish may be included in the diet once or twice a week.
●Semi-vegetarian — Meat occasionally is included in the diet. Some people who follow such a diet may not eat red meat but may eat fish and perhaps chicken.
●Lacto-ovovegetarian — Eggs, milk, and milk products (lacto = dairy; ovo = eggs) are included, but no meat is consumed.
●Lactovegetarian — Milk and milk products are included in the diet, but no eggs or meat are consumed.
●Vegan — All animal products, including eggs, milk, and milk products, are excluded from the diet. Some vegans do not use honey and may refrain from using animal products such as leather or wool. They also may avoid foods that are processed or not organically grown.

A 2012 poll in the U.S. estimated that 7% of adults eat at least one meal a week that does not include meat, fish or poultry, 4% do not eat meat, fish, or poultry, and 1–2% do not eat meat, fish, poultry, dairy products, or eggs. Roughly 5% of individuals in the UK, Germany, and Australia describe themselves as vegetarian.

Switching to the paleo diet often leads to increased vegetable and fruit consumption

A low-carb diet can still have plenty of vegetables

Are Vegetarian Diets Safe?

Vegetarians need to be careful to get enough high-quality protein, iron, vitamin B12, vitamin D, and perhaps calcium. B12 comes only from animal products, as far as I know. You can make vitamin D by exposing your skin to sufficient sunlight. Some vegetarians will need to consult a dietitian to ensure adequate nutrition. (BTW, all my comment about vegetarian diets apply to adults only—I don’t treat children, so I’m not up-to-date on their nutritional needs.)

I’ve written about vegetarian diets for diabetes before: here and here. Dr. Michael Greger couldn’t convince Dr. Harriet Hall (or me) that we should avoid eating all animal products.

The Grashow Question

Someone claiming to be Charles Grashow left a comment on one of my blogs recently:

As I’ve posted before, this [vegetarian macrobiotic diet] took Insulin Dependent T2D [patients] OFF MEDS within 21 days!

Seems much better – but then again this diet is vegan not paleo!

http://www.hoajonline.com/internalmedicine/2052-6954/2/3
Ma-Pi 2 macrobiotic diet intervention during 21 days in adults with type 2 diabetes mellitus, Ghana 2011

http://www.nutritionandmetabolism.com/content/11/1/39
The effect of the macrobiotic Ma-Pi 2 diet vs. the recommended diet in the management of type 2 diabetes: the randomized controlled MADIAB trial

http://www.hindawi.com/journals/jnme/2012/856342/
Medium- and Short-Term Interventions with Ma-Pi 2 Macrobiotic Diet in Type 2 Diabetic Adults of Bauta, Havana

SO – my question is this. Why do you not recommend this type of diet instead? Or does it not fit into your paradigm?

I responded:

Charles, that macrobiotic Ma-Pi 2 diet looks like it has significant potential. I quickly scanned your first link only. For those not familiar with the diet, here’s a description form your first link:

“Vegetarian Ma-Pi 2 macrobiotic diet, designed especially by Mario Pianesi for treating diabetic patients. Total volume of the Ma-Pi 2 diet consisted of 40-50% whole grains (rice, millet and barley), 35-40% vegetables (carrots, savoy cabbage, cabbage, chicory, onions, red radish, parsley), and 8% legumes (adzuki beans, chickpeas, lentils, black beans). As a complement we used gomasio (roasted ground sesame seeds with unrefined sea salt), fermented products (miso, tamari, umeboshi) and seaweeds (kombu, wakame, nori). Bancha tea (theine-free green tea) was the main liquid diet.”

“The assayed Ma-Pi 2 diet is lower in energy than the traditional one recommended for diabetic patients, but safe, with adequate satiating effect due to the high fiber content, adequate in protein (12% of the total energy), with an acceptable amino acid score, low in fat (15% of the total energy), and high in complex carbohydrates (73%). The diet has a high antioxidant capacity and a high content of bioactive compounds with recognized functional properties (Table 2). Foods were elaborated by culinary macrobiotic specialists from UPM, Italy, and offered at the hospital during breakfast, lunch, dinner and snacks. Unfortunately, the variety of vegetables was restricted because of limited availability.”

I wonder if that would be deficient in vitamin B12.

It looks like it would be worth a try for a type 2 diabetic under medical supervision (risk of hypoglycemia). I’d like to try a few meals with those ingredients, some of which I’ve never heard of, prepared by someone who knows what they’re doing. Unless I missed it in the link, it might be hard for the average person to replicate that study diet. If I understood correctly, the study participants stayed in a hospital for three weeks and meals were prepared for them.

I don’t have time to hit the other links right now.

-Steve

My Current Stance on Vegetarian Diets For Diabetes

I say “current stance” because I’ll change my mind based on scientific evidence as it becomes available.

I’m not convinced that any of the vegetarian diets is clearly superior to the other available “diabetic diets” in terms of quality of life, longevity, and avoidance of diabetes complications.

We have some evidence that some vegetarian diets may help control diabetic blood sugars and help reduce the need for diabetes medications, at least short-term.

If my diabetic patients want to try a vegetarian diet, I have no objections as long as these criteria are met:

  • it’s a well-designed diet that provides adequate nutrition (which may require a dietitian consultation)
  • blood sugars, hemoglobin A1c, body weight, and blood lipids are monitored periodically
  • the patient is able and willing to self-monitor blood sugars fairly frequently
  • physician oversight, especially for those taking diabetes drugs

Vegetarian diets can be very high in carbohydrate content, which potentially could wreck blood sugar control. If that happens, consider a vegetarian diet with fewer starches and sugars.

Steve Parker, M.D.

Do Sugar Substitutes Cause Overweight and T2 Diabetes?

We don’t know with certainty yet. But a recent study suggests that non-caloric artificial sweeteners do indeed cause overweight and type 2 diabetes in at least some folks. The study at hand is very small, so I wouldn’t bet the farm on it. I’m not changing any of my recommendations at this point.

exercise for weight loss and management, dumbbells

Too many diet sodas?

 

The proposed mechanism for adverse metabolic effects of sugar substitutes is that they alter the mix of germs that live in our intestines. That alteration in turn causes  the overweight and obesity. See MedPageToday for the complicated details. The first part of the article is about mice; humans are at the end.

Some quotes:

“Our results from short- and long-term human non-caloric sweetener consumer cohorts suggest that human individuals feature a personalized response to non-caloric sweeteners, possibly stemming from differences in their microbiota composition and function,” the researchers wrote.

The researchers further suggested that these individualized nutritional responses may be driven by personalized functional differences in the micro biome [intestinal germs or bacteria].

***

Diabetes researcher Robert Rizza, MD, of the Mayo Clinic in Rochester, Minn., who was not involved with the research, called the findings “fascinating.”

He noted that earlier research suggests people who eat large amounts of artificial sweeteners have higher incidences of obesity and diabetes. The new research, he said, suggests there may be a causal link.

“This was a very thorough and carefully done study, and I think the message to people who use artificial sweeteners is they need to use them in moderation,” he said. “Drinking 17 diet sodas a day is probably a bad idea, but one or two may be OK.”

I won’t argue with that last sentence! (Unless you have phenylketonuria and want to use aspartame.)

Finally, be aware that several clinical studies show no linkage between human consumption of non-caloric artificial sweeteners and overweight, obesity, and T2 diabetes.

Steve Parker, M.D.

Are Low-Carb Diets Lethal?

Adult life is a battle against gravity. Eventually we all lose.

Adult life is a battle against gravity.

Japanese researchers say low-carb diets are causing premature death. I’m skeptical.

It’s a critically important issue because many folks with diabetes restrict their carbohydrate consumption to keep their blood sugars under control. Maybe it’s crazy, but they think they’ll live longer and have fewer diabetes complications if their glucose readings are under 200 mg/dl (11.1 mmol/l) most of the time.

The potentially healthful side effects linked to low-carb eating include reduced weight, higher HDL cholesterol, and lower triglycerides and blood pressure. The aforementioned Japanese investigators wondered if the improved cardiovascular risk factors seen with low-carb diets actually translate into less heart disease and death.

How Was the Study At Hand Done?

The best way to test long-term health effects of a low-carb diet (or any diet) is to do a randomized controlled trial. You take 20,000 healthy and very similar people—not rodents—and randomize half of them to follow a specific low-carb diet while the other half all eat a standard or control diet. Teach them how to eat, make damn sure they do it, and monitor their health for five, 10, or 20 years. This has never been, and never will be, done in humans. In the old days, we could do this study on inmates of insane asylums or prisons.

What we have instead are observational studies in which people voluntarily choose what they’re eating, and we assume they keep eating that way for five or 10+ years. You also assume that folks who choose low-carb diets are very similar to other people at the outset. You depend on regular people to accurately report what and how much they’re eating. You can then estimate how much of their diet is derived from carbohydrate and other macronutrients (protein and fat), then compare health outcomes of those who were in the top 10% of carb eaters with those in the bottom 10%. (We’ve made a lot of assumptions, perhaps too many.)

Of the observational studies the authors reviewed, the majority of the study participants were from the U.S. or Sweden. So any true conclusions may not apply to you if you’re not in those countries. In looking for articles, they found no randomized controlled trials.

The observational studies estimated carb consumption at the outset, but few ever re-checked to see if participants changed their diets. That alone is a problem. I don’t know about you, but I’ve had significant changes in my diet depending on when I was in college and med school, when I was a bachelor versus married, when my income was higher or lower, and when I had young children versus teenagers. But maybe that’s just me.

The researchers looked at all-cause mortality, deaths from cardiovascular disease, and incidence of cardiovascular disease. They don’t bother to define cardiovascular disease. I assume heart attack, strokes, and peripheral vascular disease. (But aren’t aneurysms, deep vein thrombosis, and pulmonary embolism vascular diseases, too?) Wouldn’t you think they’d carefully define their end-points? I would. Since they were going to all this trouble, why not look at cancer deaths, too?

What Did the Investigators Conclude?

Very low-carbohydrate dieters had a 30% higher risk of death from any cause (aka all-cause mortality) compared to very high-carb eaters. The risk of cardiovascular disease incidence or death were not linked with low-carb diets. Nor did they find protection against cardiovascular disease.

Finally, “Given the facts that low-carbohydrate diets are likely unsafe and that calorie restriction has been demonstrated to be effective in weight loss regardless of nutritional composition, it would be prudent not to recommend low-carbohydrate diets for the time being.”

If Low-Carb Dieters Die Prematurely, What Are They Dying From?

The top four causes of death in the U.S. in 2011, in order, are:

  1. heart attacks
  2. cancer
  3. chronic lower respiratory tract disease
  4. stroke

You’ll note that two of those are cardiovascular disease (heart attacks and stroke). So if low-carb diets promote premature death, it’s from cancer, chronic lung disease, or myriad other possibilities. Seventy-five percent of Americans die from one of the top 10 causes. Causes five through 10 are:

  • accidents
  • Alzheimer disease
  • diabetes
  • flu and pneumonia
  • kidney disease
  • suicide

Problem is, no one has ever linked low-carb diets to higher risk of death from any specific disease, whether or not in the top ten. Our researchers don’t mention that. That’s one reason I’m very skeptical about their conclusion. If you’re telling me low-carb diets cause premature death, tell me the cause of death.

Another major frustration of mine with this report is that they never specify how many carbohydrates are in this lethal low-carb diet. Is it 20 grams, 100, 150? The typical American eats 250-300 grams of carb a day. If you’re going to sound the alarm against low-carb diets, you need to specify the lowest safe daily carb intake.

For most of my career—like most physicians—I’ve been wary of low-carb diets causing cardiovascular disease. That’s because they can be relatively high in total fat and saturated fat. In 2009, however, I did my own review of the scientific literature and found little evidence of fats causing cardiovascular disease.

If you’re looking for a reason to avoid carbohydrate-restricted diets, you can cite this study and its finding of premature death. I’m not convinced. I’ll turn it around on you and note this study found no evidence that low-carb diets cause cardiovascular disease. The risk of cardiovascular disease had been the traditional reason for physicians to recommend against low-carb diets.

Steve Parker, M.D.

Reference: Noto, Hiroshi et al. Low-Carbohydrate diets and all-cause mortality: A systematic review and meta-analysis of observational studies. PLoS One, 2013; 8(1): e55050

This Just In! Obesity Reduces Lifespan

I'm worried about the kid's future health

I’m worried about the kid’s future health, too

MedPageToday has the details. A quote:

In a computer modeling study, very obese men lost just over 8 years of life compared with normal-weight men, and very obese women lost as many as 6 years, Steven Grover, PhD, of McGill University, and colleagues reported online in the Lancet Diabetes and Endocrinology.

They also found that very obese men and women (defined as a body mass index [BMI] of 35 and higher) lost about 19 years of healthy life, defined as living free of chronic disease such as diabetes and cardiovascular disease.

Note that “very obese” in this context has a specific definition: body mass index 35 or higher. Calculate yours.

The number of life years lost to obesity and disease were highest for those who were very obese in young adulthood and presumably stayed obese for years. In other words, becoming very obese at age 25 is more threatening than onset 60.

I first got interested in weight loss in the 1990s when I had an office-based primary care medical practice. It was obvious that many of the medical problems I was treating were related to years of obesity. Believe me, you’re much better off preventing those problems via diet and exercise.

Click for The Lancet study abstract.

Steve Parker, M.D.

Paleo Diet Ranks Dead Last

…in U.S. News & World Report’s yearly ranking of common diets.

I have nothing to add to Tom Naughton’s excellent critique of the listicle.

FWIW, Woman’s World magazine ranked the paleo diet as America’s Best in 2013.

-Steve

Would You Believe Four in Ten U.S. Adults Will Develop Diabetes?

Like type 1 diabetics, many type 2's need insulin shots

Like type 1 diabetics, many type 2’s need insulin shots

Researchers affiliated with the U.S. Centers for Disease Control estimate that 40% of American adults will develop diabetes, mostly type 2. The CDC’s prior estimate was the one of every three Americans born in 2000 would develop diabetes. Some snippets from the article abstract:

On the basis of 2000—11 data, lifetime risk of diagnosed diabetes from age 20 years was 40·2% for men and 39·6% for women, representing increases of 20 percentage points and 13 percentage points, respectively, since 1985—89.

The number of life-years lost to diabetes when diagnosed at age 40 years decreased from 7·7 years in 1990—99 to 5·8 years in 2000—11 in men, and from 8·7 years to 6·8 years in women over the same period.

Years spent with diabetes increased by 156% in men and 70% in women.

The good news is that you can decrease your odds of type 2 diabetes via diet and exercise. The single most important issue in preventing type 2 diabetes is avoiding obesity.

Steve Parker, M.D.

 

Diabetes Drug Liraglutide Going Mainstream, for Weight Loss

Just before Christmas last year, the U.S. Food and Drug Administration approved a new weight-loss drug: Saxenda. It’s the same drug—liraglutide or Victoza—they approved for treatment of diabetes in 2010.

Click for my brief review of the drug class for diabetics.

Click for the CBS News report on Saxenda. A snippet:

One clinical trial that involved patients without diabetes found that patients taking Saxenda had an average weight loss of 4.5 percent after one year. Of the people treated with the drug, 62 percent lost at least 5 percent of their body weight. Meanwhile, only 34 percent of those given an inactive placebo had the same result.

Another clinical trial that included patients with type 2 diabetes found that patients had an average weight loss of almost 4 percent after one year. Of those given Saxenda, 49 percent lost at least 5 percent of their body weight, compared to 16 percent of those who were given a placebo treatment.

Click for the FDA’s press release.

Oh, by the way. You have to inject it daily under the skin (subcutaneous). And if you were hoping for a shortcut to weight loss, this ain’t it. You’re still supposed to follow a reduced-calorie diet and exercise regularly.

I’d try the Paleobetic Diet first if I had diabetes. Lose excess weight and control blood sugars.

Steve Parker, M.D.

PS: Full prescribing information.

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.

How Did the Agricultural and Industrial Revolutions Change Human Diets?

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With the advent of the Agricultural Revolution 10,000 years ago, mankind took a giant leap away from two million years of evolutionary adaptation. The Industrial Revolution that started in the late 18th century—about 240 years ago—was yet another watershed event. The Agricultural Revolution marks the end of the Old Stone Age and the start of the Neolithic period. The Neolithic ended four to six thousand years ago, replaced by the Bronze Age (or Iron Age in some areas).

EFFECTS OF THE AGRICULTURAL REVOLUTION

The Agricultural Revolution refers to farming the land on a large scale, and all that entails: gathering and planting seeds, nurturing the soil, breeding plants for desirable traits, storing crops, processing plants to maximize digestibility, domesticating wild animals and enhancing them by selective breeding, setting down roots in one geographic location, etc. The revolution allowed for the expansion of reliable food supplies and an explosion of human populations. Less time was needed for hunting and foraging, allowing for the development of advanced cultures.

It wasn’t all sunshine and roses, however. We have evidence that human health deteriorated as a result of the revolution. For instance, some populations declined in height and dental health.

EFFECTS OF THE INDUSTRIAL REVOLUTION

The Industrial Revolution starting in the late 18th century brought its own changes to our diet. Progressive industrialization and affluence changed the composition of our “energy foods.” For instance, peasants in poor developing countries derive about 75% of their calories from high-fiber starchy foods. With modernization, fiber-free fats and sugars become the source of 60% of calories. U.S. consumption of cereal fiber decreased by 90% between 1880 and 1976. In addition to lower fiber content, refined wheat products also had fewer vitamins and other micronutrients. Machinery allowed the production of margarine and vegetable oils. Sugar imports and snacking increased in the Western world.

Obesity suddenly became very common in the upper classes of Europe and England toward the end of the 17th century and even more so in the 18th. Weights also increased throughout populations of developed countries. For instance, if we look at U.S. men of average height between the ages of 30 to 34, average weights were 148 lb (66 kg) in 1863, but were up to 170 lb (77 kg) in 1963. Our current obesity epidemic didn’t even start until around 1970.

Let’s look at a few major U.S. diet changes from 1860 to 1975. Energy derived from protein rose from 12% to 14–15%. Energy from fat rose from 25 to 42% of calories. Energy from starches fell from 53 to 22%. Calories from sugar rose from 10 to 24%. Total carbohydrate calories fell from 63 to 46%.

It only takes a few decades to see major changes in a population’s food consumption. For instance, U.S. per capita consumption of salad and cooking oils increased from 21.2 pounds per person in 1980 to 54.3 pounds per person in 2008 (USDA data). I refer to these oils as industrial seed oils, and they include soybean, corn, and sunflower oil. We’re not entirely sure what effect these have on health. Some suspect they are related to obesity, heart disease, and other “diseases of civilization.” Per capita soybean oil consumption in the U.S. increased over a thousand-fold between 1909 and 1999, to 7.4% of total calories. It’s in many of our processed foods. Linoleic acid is a predominant omega-6 fatty acid in seed oils. Linoleic acid consumption increased by 200% in the last century. Thanks to increasing omega-6 fatty acid consumption, the omega-6/omega-3 ratio increased from 5.4:1 to 9.6:1 between 1909 and 2009. (Reference: Blasbalg TL, Hibbeln JR, Ramsden CE, Majchrzak SF, Rawlings RR. “Changes in consumption of omega-3 and omega-6 fatty acids in the United States during the 20th century.” Am J Clin Nutr. 2011 May;93(5):950-62. doi: 10.3945/ajcn.110.006643. Epub 2011 Mar 2.)

The Industrial Revolution also introduced into our diets large amounts of man-made trans-fats, which are highly detrimental to cardiovascular health. Public outcry has lead to diminishing amounts of dietary trans-fats over the last decade.

An occasional teaspoon of sugar probably won't hurt you

Added sugars: table sugar in coffee, high-fructose corn syrup in ketchup

At his Whole Health Source blog, Dr. Stephan Guyenet and Jeremy Landen produced a graph of U.S. sugar consumption from 1822 to 2005. Dr. Guyenet wrote, “It’s a remarkably straight line, increasing steadily from 6.3 pounds (2.9 kg) per person per year in 1822 to a maximum of 107.7 pounds (49 kg) per person per year in 1999. Wrap your brain around this: in 1822, we ate the amount of added sugar in one 12 ounce can of soda (360 ml) every five days, while today we eat that much sugar every seven hours.” Note that added sugars overwhelmingly supply only one nutrient: pure carbohydrate without vitamins, minerals, antioxidants, protein, fat, etc.

 

Think about the typical Western or Standard American Diet (SAD) eaten by an adult these days. It provides an average of 2673 calories a day (not accounting for wastage of calories in restaurants; 2250 cals/day is probably a more accurate figure for actual consumption). Added sugars provide 459 of those calories, or 17% of the total. Grains provide 625 calories, or 23% of the total. Most of those sugars and grains are in processed, commercial foods. So added sugars and grains provide 40% of the total calories in the SAD. That’s a huge change from the diet of our prehistoric ancestors. Remember, we need good insulin action to process these carbohydrates, which is a problem for diabetics. Anyone going from the SAD to pure paleo eating will be drastically reducing intake of added sugars and grains, our current major sources of carbohydrate. They’ll be replacing them with foods that generally require less insulin for processing. (Figures are from an April 5, 2011, infographic at Civil Eats: http://www.civileats.com.)

FUN FACTS! (from the U.S. Dept. of Agriculture)

  • A typical carbonated soda contains the equivalent of 10 tsp (50 ml) of table sugar.
  • The typical U.S. adult eats 30 tsp (150 ml) daily of added sweeteners and sugars.
  • U.S total grain product consumption was at record lows in the 1970s, at 138 pounds per person. By 2008, grain consumption was up by 45%, to 200 pounds per person.
  • Total caloric sweetener consumption (by dry weight) was 110 pounds per person in the 1950s. By 2000, it was up 39% to 150 pounds.
  • Between 1970 and 2003, consumption of added fats and oils rose by 63%, from 53 to 85 pounds. (How tasty would that be without starches and sugars? Not very.)
  • In 2008, “added fat” calories in the U.S. adult diet were 641 (24% of total calories).

Steve Parker, M.D.

What’s Your Favorite Paleo Diet Cookbook?

Would you help me out and tell me your favorite paleo diet cookbooks, and perhaps why? My patients are asking me for paleo diet recipes, and I need more sources. 

Ideally, I’d like authors who avoid or minimize use of dairy products, legumes, grains, and industrial seed oils. My favorite version of paleo is Loren Cordain’s. Let’s also minimize hard-to-find or esoteric ingredients. I don’t care whether or not the beef is pastured or if the chickens are free-range happy ones. Prep time under 30 minutes is always appreciated. I would love to have basic nutritional analysis such as digestible (net) carb grams, calories per serving, and percentage of calories from fat, protein, and carbohydrate.

I’m afraid I’m going to have to do the nutritional analyses myself, as I have with my Paleobetic Diet recipes.

Here’s one that I haven’t read yet but have great expectations that it’s good: 500 Paleo Recipes by Dana Carpenter. I’ve read several of her non-paleo low-carb cookbooks and they’re good. Her 500 Paleo Recipes book provided some basic nutritional analysis for each recipe, including carbohydrate grams, which is critical if you have diabetes.

Dr. Cordain has a new cookbook being released in March, 2015. Does his 2011 collaboration with Nell Stephenson provide nutritional analysis (unlikely)?

Some books and authors for your consideration: Mark Sisson’s Primal Blueprint Cookbook, something from the Hartwigs, Robb Wolf, Sarah Fragoso’s Everyday Paleo,  Melissa Joulwan’s Well Fed, Diane Sanfilippo, Nom Nom Paleo by Tam and Fong, and Paul Jaminet.

Steve Parker, M.D.