Tag Archives: paleolithic diet

Paleo Diet for Heart Patients With Diabetes and Prediabetes

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 found 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?

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 (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.

ResearchBlogging.orgPresent 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 (9), 1795-1807 DOI: 10.1007/s00125-007-0716-y

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Filed under Carbohydrate, coronary heart disease, Dairy Products, Fruits, Glycemic Index and Load, Grains, Mediterranean Diet, nuts

Paleo Diet and Diabetes: Improved Cardiovascular Risk Factors

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 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?

ResearchBlogging.orgCompared 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.  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.  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).

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.  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.

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. (2009). Beneficial effects of a Paleolithic diet on cardiovascular risk factors in type 2 diabetes: a randomized cross-over pilot study Cardiovascular Diabetology, 8 (1) DOI: 10.1186/1475-2840-8-35

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Filed under coronary heart disease, Glycemic Index and Load, Mediterranean Diet

What About the Paleo Diet?

Paleo diets have been increasingly popular over the last few years.  The idea is that, for optimal health, we should be eating the things that we are evolutionarily adapted to eat.  Those foods pre-date the onset of large-scale agriculture 10-12,000 years ago.  So grains and modern fruits and vegetables play little or no role in someone who has “gone paleo.”

My recollection from college courses years ago is that average lifespan in paleolithic times was perhaps 25-30 years, or less.  If you’re going to die at 25, it may not matter if you eat a lot of  wooly mammath, berries, insects, cholesterol, saturated fats, Doritos, Ding Dongs, or Cheetos.  The diseases of civilization we worry about today—coronary heart disease, high blood pressure, cancer, dementia, type 2 diabetes, etc.—don’t usually appear until after age 30.  Paleolithic Man worried more about starvation.

Jenny Ruhl, at her Diabetes Update blog, recently put much more critical thought than I into the concept of paleo diets.  Recommended reading.    

Steve Parker, M.D. 

Extra credit

For purposes of discussion, let’s assume that human evolution actually occurred over millions, or at least hundreds of thousands, of years.  In other words, assume that God didn’t make Adam and Eve in human form in one day.

The theory of evolution proposes that genes that allow an animal to live and reproduce more vigorously in a particular environment will be passed on to the animal’s offspringNature will select those genes to spread through the animal population over time, assuming the environment doesn’t change.  The offspring with those genes will be able to compete with other animals more successfully for food, shelter, and mates.  Factors that promote the persistence and inheritance of specific genes are called “selection pressure.”

Here’s an example of selection pressure.  Remember when you were in grade school on the playground, some people could naturally run faster than others?  Were you one of the fast ones?  If you’ve never seen it for yourself, take my word for it: Some people are naturally gifted with athletic genes.

Let’s say you and I are outside collecting berries and nuts in paleolithic times.  A saber-toothed tiger spots us and charges, hungry for a meal.  You don’t have to outrun the tiger: you just have to outrun me.  I’m slower than you, and get eaten.   I can no longer pass on my slow-running genes to the next generation.  You live another day and pass on your fast-running genes to your children. 

Viola!  Natural selection, via selection pressure, has promoted your genes over mine.

[The tiger also passes on her genes since she was fast and smart enough to catch me, preventing starvation of her and her offspring.] 

[I’m 99% sure I wrote the preceeding few paragraphs originally about a year ago.  My notes, however, hint that they may have been written by Dr. J., a regular contributor at CalorieLab.  Dr. J., let me know if I’ve plagiarized you and I’ll give you full credit and delete my writing.]

The paleo diet rationale seems to be based on an evolutionary argument: Certain foods were available to us during 99% of our evolution, so our bodies are adapted to work optimally with them.  For example, humans/humanoids/higher primates who were not suited to the available food did not survive and reproduce, so their genes were not passed on to us.

For most of human existence, maximum lifespan was probably 25-30 years, on average. If that’s as long as you’re going to live, it may not matter much what you eat. Eat paleo, vegetarian, McDonald’s, Atkins, or Mediterranean. Most diet-related conditions except overweight and under-nutrition are not going to be an issue before age 30. 

[The modern paleos argue that infant and childhood mortality were extremely high in paleolithic times.  If you survived childhood, you could easily live to be 50+.]

But now we live to be 80, long enough for diet-related diseases to appear. We have cancer, heart attacks, and strokes that paleo man never saw because he died of trauma or infection or starvation. We even see the expression of genes that were not subjected to survival or selection pressure: Alzheimers disease, Huntingtons chorea, some breast cancers, etc.  People with genes for these diseases reproduce before the genes do their damage.

In other words, we carry genes that don’t matter if you die at age 30. If you live longer, they express themselves, and I believe we can modify their expression through diet and lifestyle. And not necessarily the paleo diet.

I’m still thinking it through.

For the other side of the argument, visit Mark’s Daily Apple, At Darwin’s Table, or read Dr. Loren Cordain’s The Paleo Diet.

-Steve

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