Tag Archives: type 2 diabetes

Fruit May Not Sabotage Control of Type 2 Diabetes

Posted on March 11, 2013 | 4 Comments

…according to an article in Nutrition Journal.  Fruit is a prominent component of the paleo diet.  It can be good for us, containing phytonutrients, fiber, etc.  But fruit has the potential to increase blood sugars, too, which may be harmful over the long run.  So whadda you do?

Researchers took newly diagnosed type 2 diabetics and split them into two groups. One group was told to eat at least two pieces of fruit daily, the other was told to eat no more than two pieces.

The researchers conclusions: 

A recommendation to reduce fruit intake as part of standard medical nutrition therapy in overweight patients with newly diagnosed type 2 diabetes resulted in eating less fruit. It had however no effect on HbA1c, weight loss or waist circumference. We recommend that the intake of fruit should not be restricted in patients with type 2 diabetes.

Read the full research report.

 

PS: I haven’t read the full report yet.

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Ideas For A Paleo Diabetic Diet

Posted on February 3, 2013 | 6 Comments
Sirloin steak, salad, cantaloupe, 3 raspberries

Sirloin steak, salad, cantaloupe, 3 raspberries

I’ve been thinking about a paleo-style diabetic diet for over a year.  Here are some miscellaneous ideas for your consideration.

A paleo diabetic diet will have the following major food groups:

  • vegetables
  • fruits
  • nuts and seeds
  • proteins (e.g., meat, fish, eggs)
  • condiments

A paleo diabetic diet could (should?) emphasize salads and low-carb colorful vegetables and only (?) low-carb or low-glycemic-index fruits.

Calories

Total calories?  Probably in the range of 1,800 to 3,000 calories daily with an average of 2,000.  Remember that 85% of type 2 diabetics are overweight or obese. Calorie restriction—regardless of macronutrient ratios (% carb, protein, fat)—tends to improve or normalize blood sugar levels.  Weight loss will likely entail some caloric restriction, whether consciously or not.

Type 1 Versus Type 2 Diabetes

Type 1 and type 2 diabetics have many pathophysiologic differences.  Could a single paleo diabetic diet serve both populations equally well?  That’s the goal.

Carbohydrates

Diabetics have trouble metabolizing carbohydrates, so a paleo diabetic diet should probably be lower-than-average in digestible carbs.  100 g/day?  30 g/day?  I’m leaning toward 60 g ± 25%, so 45–75 g.  Smaller, less active folks could eat 45 g/day; larger, more active guys eat closer to 75 g.

Is there a role for very-low-carb or ketogenic eating patterns?  For most folks, that’s less than 50 g of digestible carbohydrate daily.  Under 30 g for some.  Use that only for those needing to lose weight?  Start everybody at  very low carb levels then increase carbs as tolerated?  On the other hand, there’s a lot to be said for simplicity.  It might be best to avoid very-low-carb (ketogenic) eating entirely.  Anyone not losing the desired amount of fat weight could cut portion sizes, especially carbohydrates.

Fish

I encourage fish consumption twice a week, diabetes or no.  Cold-water fatty fish have more of the healthy omega-3 fatty acids than other fish.

Nuts

I’d encourage 1–2 ounces (28–56 g) of nuts or seeds daily.  Any more than that might crowd out other healthful nutrients.  Nuts are protective of the heart.

Proteins

Protein-rich foods can definitely raise insulin requirements and blood sugar levels, but not in an entirely predictable way, and not to the extent we see with carbohydrates.  Should insulin users dose insulin based on a protein gram sliding scale?  I’m leaning towards simply recommending the same amount of protein at each meal, perhaps 4–8 ounces (113–229 g).

Fruit and Starchy Vegetables

Could a paleo diabetic diet even be “paleo” without fruit?  The problem with classic fruits is that they spike blood sugars too high for many diabetics.  To prevent that, Dr. Richard Bernstein outlaws all classic fruits (and other starchy carbs), even limiting tomatoes and onions to small amounts.  E.g., a wedge of tomato in a salad.  He doesn’t allow carrots either, unless raw (lower glycemic index than when cooked).  A paleo diabetic diet eater may be able to get away with eating lower-carb, lower-GI (glycemic index) fruits such as cantaloupe, honeydew, strawberries and other berries.  Some paleo diabetic dieters will tolerate half an apple twice a day.

Different diabetics will have different blood sugar effects when eating starchy vegetables and higher-carb fruits.  Type 1 diabetics will tend to be more predictable than type 2s.  Both may just need to “eat to the meter”: try a serving and see what happens to blood sugar over the next hour or two.

Starchy vegetables—potatoes and carrots, for example—may well have to be limited.  Again, eat to the meter.

Gluten

This is looking to be gluten-free.  How trendy!  It’s a paleo celiac diet.

Use “natural” stevia as a sweetener?  If you read about how the product on your supermarket shelf  is made, it’s not at all natural.

Omega-6/Omega-3 Fatty Acids

A strict focus on omega-6/omega-3 fatty acid ratio will not appeal to many folks, even if it’s important from a health viewpoint.  Reserve this for advanced dieters who have mastered the basics?  Modern Western diets have an omega-6/omega-3 ratio around 10 or 15:1.  Paleolithic diets were closer to 2 or 3:1.  So we have an over-abundance of omega-6 fatty acid or deficiency of omega-3 that may be unhealthy.

Implementation

To get dieters started, I’d design a week of meals based on 2,000 to 2,200 calories.  If still hungry, eat more protein, fat, and low-carb vegetables (and fruits?).

What do you think?

Steve Parker, M.D.

Disclaimer:  All matters regarding your health require supervision by a personal physician or other appropriate health professional familiar with your current health status.  Always consult your personal physician before making any dietary or exercise changes.  

PS: See Dr. Bernstein’s “no-no” foods on page 151 of his Diabetes Solution book.

PPS: The paleo diet is also known as the Paleolithic diet, Stone Age diet, caveman diet, hunter-gatherer diet, and ancestral diet.

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Ever Heard of “Interval Walking”? You Need To Know About It!

Posted on February 2, 2013 | 1 Comment
Not ready for this? Consider interval walking then.

Not ready for this? Consider interval walking then.

Compared to a regular continuous walking program, interval walking is superior for improving physical fitness, body composition (body mass and fatness), and blood sugar control according to new research reported in Diabetes Care.  Study participants were type 2 diabetics.

Training groups were prescribed five sessions per week (60 min/session) and were controlled with an accelerometer and a heart-rate monitor. Continuous walkers performed all training at moderate intensity, whereas interval walkers alternated 3-min repetitions at low and high intensity. Before and after the 4-month intervention, the following variables were measured: VO2max, body composition, and glycemic control (fasting glucose, HbA1c, oral glucose tolerance test, and continuous glucose monitoring.

I haven’t read the full report yet, but expect that the interval walkers walked as fast as they could for three minutes (4 mph?) then slowed down to a comfortable stroll (1–2 mph?) for three minutes, alternating thusly for 60 minutes.

This should easily do-able for nearly all type 2 diabetics.  The reported results jive with other studies of more vigorous and intimidating interval training.  The only caveat is that it was a small pilot study that may or may not be reproducible.

Steve Parker, M.D.

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The Case for Carbohydrate Restriction In Diabetes

Posted on December 4, 2012 | 8 Comments

MB900402413In 1797, Dr. John Rollo (a surgeon in the British Royal Artillery) published a book entitled An Account of Two Cases of the Diabetes Mellitus. He discussed his experience treating a diabetic Army officer, Captain Meredith, with a high-fat, high-meat, low-carbohydrate diet. Mind you, this was an era devoid of effective drug therapies for diabetes.

The soldier apparently had type 2 diabetes rather than type 1.

Rollo’s diet led to loss of excess weight (original weight 232 pounds or 105 kg), elimination of symptoms such as frequent urination, and reversal of elevated blood and urine sugars.

This makes Dr. Rollo the original low-carb diabetic diet doctor. Many of the leading proponents of low-carb eating over the last two centuries—whether for diabetes or weight loss—have been physicians.

But is carbohydrate restriction a reasonable approach to diabetes, whether type 1 or type 2?

What’s the Basic Problem in Diabetes?

Diabetes and prediabetes always involve impaired carbohydrate metabolism: ingested carbs are not handled by the body in a healthy fashion, leading to high blood sugars and, eventually, poisonous complications.  In type 1 diabetes, the cause is a lack of insulin from the pancreas.  In type 2, the problem is usually a combination of insulin resistance and ineffective insulin production.

Elevated blood pressure is one component of metabolic syndrome

Elevated blood pressure is one component of metabolic syndrome

A cousin of type 2 diabetes is “metabolic syndrome.”  It’s a constellation of clinical factors 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. Diagnosis requires at least three of the following five conditions:

■  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 cholesterol-lowering drug)

■  abdominal fat:  waist circumference 40 inches (102 cm) or greater in a man, 35 inches (89 cm) or greater in a woman

■  fasting blood glucose over 100 mg/dl (5.55 mmol/l)

Metabolic syndrome and simple obesity often involve impaired carbohydrate metabolism. Over time, excessive carbohydrate consumption can turn obesity and metabolic syndrome into prediabetes, then type 2 diabetes.

Carbohydrate restriction directly addresses impaired carbohydrate metabolism naturally.

Carbohydrate Intolerance

Diabetics and prediabetics—plus many folks with metabolic syndrome—must remember that their bodies do not, and cannot, handle dietary carbohydrates in a normal, healthy fashion. In a way, carbs are toxic to them. Toxicity may lead to amputations, blindness, kidney failure, nerve damage, poor circulation, frequent infections, premature heart attacks and death, among other things.

Diabetics and prediabetics simply don’t tolerate carbs in the diet like other people. If you don’t tolerate something, you have to give it up, or at least cut way back on it. Lactose-intolerant individuals give up milk and other lactose sources. Celiac disease patients don’t tolerate gluten, so they give up wheat and other sources of gluten. One of every five high blood pressure patients can’t handle normal levels of salt in the diet; they have to cut back or their pressure’s too high. Patients with phenylketonuria don’t tolerate phenylalanine and have to restrict foods that contain it. If you’re allergic to penicillin, you have to give it up. If you don’t tolerate carbs, you have to give them up or cut way back. I’m sorry.

Carbohydrate restriction directly addresses impaired carbohydrate metabolism naturally.

But Doc, …?

1.  Why not just take more drugs to keep my blood sugars under control while eating all the carbs I want?

We have 11 classes of drugs to treat diabetes.  For most of these classes, we have little or no idea of the long-term consequences.  It’s a crap shoot.  The exceptions are insulin and metformin.  Several big-selling drugs have been taken off the market due to unforeseen side effects.  Others are sure to follow, but I can’t tell you which ones.  Adjusting insulin dose based on meal-time carb counting is popular.  Unfortunately, carb counts are not nearly as accurate as you might think; and the larger the carb amount, the larger the carb-counting and drug-dosing errors.

2.  If I reduce my carb consumption, won’t I be missing out on healthful nutrients from fruits and vegetables?

No.  Choosing low-carb fruits and vegetables will get you all the plant-based nutrients you need.  You may well end up eating more veggies and fruits than before you switched to low-carb eating.  Low-carb and paleo-style diets are unjustifiably criticized across-the-board as being meat-centric and deficient in plants.  Some are, but that’s not necessarily the case.

3.  Aren’t vegetarian and vegan diets just as good?

Maybe.  There’s some evidence that they’re better than standard diabetic diets.  My personal patients are rarely interested in vegetarian or vegan diets, so I’ve not studied them in much detail.  They tend to be rich in carbohydrates, so you may run into the drug and carb-counting issues in Question No. 1.

Steve Parker, M.D.

PS:  The American Diabetes Association recommends weight loss for all overweight diabetics. Its 2011 guidelines suggest three possible diets: “For weight loss, either low-carbohydrate [under 130 g/day], low-fat calorie-restricted, or Mediterranean diets may be effective in the short-term (up to two years).”  The average American adult eats 250–300 grams of carbohydrate daily.

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What’s Wrong With Type 2 Diabetics?

Posted on December 2, 2012 | Leave a comment

Type 2 diabetes and prediabetes are epidemics because of excessive consumption of refined sugars and starches, and lack of physical activity.  I can’t prove it; nevertheless that’s my impression after years of reading the nutrition science literature and thinking about it.

I could be wrong.  I reserve the option to change my mind based on evidence as it becomes available.  That’s one of the great things about science.  Accurately identifying the cause of diabetes could provide strong clues about optimal prevention and treatment strategies.

Genetics undoubtedly plays a major role in diabetes, but the gene pool hasn’t changed much over the last several decades as type 2 diabetes rates have soared.

The problem in type 2 diabetes and prediabetes is that the body cannot handle ingested carbohydrates in the normal fashion. In a way, dietary carbohydrates (carbs) have become toxic instead of nourishing. This is a critical point, so let’s take time to understand it.

NORMAL DIGESTION AND CARBOHYDRATE HANDLING

The major components of food are proteins, fats, and carbohydrates. We digest food either to get energy, or to use individual components of food in growth, maintenance, or repair of our own body parts.

We need some sugar (also called glucose) in our bloodstream at all times to supply us with immediate energy. “Energy” refers not only to a sense of muscular strength and vitality, but also to fuel for our brain, heart, and other automatic systems. Our brains especially need a reliable supply of bloodstream glucose.

In a normal, healthy state, our blood contains very little sugar—about a teaspoon (5 ml) of glucose. (We have about one and a third gallons (5 liters) of blood circulating. A normal blood sugar of 100 mg/dl (5.56 mmol/l) equates to about a teaspoon of glucose in the bloodstream.)

Our bodies have elaborate natural mechanisms for keeping blood sugar normal. They work continuously, a combination of adding and removing sugar from the bloodstream to keep it in a healthy range (70 to 140 mg/dl, or 3.9 to 7.8 mmol/l). These homeostatic mechanisms are out of balance in people with diabetes and prediabetes.

By the way, glucose in the bloodstream is commonly referred to as “blood sugar,” even though there are many other types of sugar other than glucose. In the U.S., blood sugar is measured in units of milligrams per deciliter (mg/dl), but other places measure in millimoles per liter (mmol/l).

When blood sugar levels start to rise in response to food, the pancreas gland—its beta cells, specifically—secrete insulin into the bloodstream to keep sugar levels from rising too high. The insulin drives the excess sugar out of the blood, into our tissues. Once inside the tissues’ cells, the glucose will be used as an immediate energy source or stored for later use. Excessive sugar is stored either as body fat or as glycogen in liver and muscle.

When we digest fats, we see very little direct effect on blood sugar levels. That’s because fat contains almost no carbohydrates. In fact, when fats are eaten with high-carb foods, they tend to slow the rise and peak in blood sugar you would see if you had eaten the carbs alone.

Ingested protein can and does raise blood sugar, usually to a mild degree. As proteins are digested, our bodies can make sugar (glucose) out of the breakdown products. The healthy pancreas releases some insulin to keep the blood sugar from going too high.

In contrast to fats and proteins, carbohydrates in food cause significant—often dramatic—rises in blood sugar. Our pancreas, in turn, secretes higher amounts of insulin to prevent excessive elevation of blood glucose. Carbohydrates are easily digested and converted into blood sugar. The exception is fiber, which is indigestible and passes through us unchanged.

During the course of a day, the pancreas of a healthy person produces an average of 40 to 60 units of insulin. Half of that insulin is secreted in response to meals, the other half is steady state or “basal” insulin. The exact amount of insulin depends quite heavily on the amount and timing of carbohydrates eaten. Dietary protein has much less influence. A pancreas in a healthy person eating a very-low-carb diet will release substantially less than 50 units of insulin a day.

To summarize thus far: dietary carbs are the major source of blood sugar for most people eating “normally.” Carbs are, in turn, the main cause for insulin release by the pancreas, to keep blood sugar levels in a safe, healthy range.

Hang on, because we’re almost done with the basic science!

You deserve a break

CARBOHYDRATE  HANDLING  IN  DIABETES  &  PREDIABETES

Type 2 diabetics and prediabetics absorb carbohydrates and break them down into glucose just fine. Problem is, they can’t clear the glucose out of the bloodstream normally. So blood sugar levels are often in the elevated, poisonous range, leading to many of the complications of diabetes.

Remember that insulin’s primary function is to drive blood glucose out of the bloodstream, into our tissues, for use as immediate energy or stored energy (as fat or glycogen).

In diabetes and prediabetes, this function of insulin is impaired.

The tissues have lost some of their sensitivity to insulin’s action. This critical concept is called insulin resistance. Insulin still has some effect on the tissues, but not as much as it should. Different diabetics have different degrees of insulin resistance, and you can’t tell by just looking.  (There are several other hormones involved in regulation of blood sugar.)

Did you know that people who work at garbage dumps, sewage treatment plants, and cattle feedlots get used to the noxious fumes after a while? They aren’t bothered by them as much as they were at first. Their noses are less sensitive to the fumes. You could call it fume resistance. In the same fashion, cells exposed to high insulin levels over time become resistant to insulin.

Insulin resistance occurs in most cases of type 2 diabetes and prediabetes. So what causes the insulin resistance? It’s debatable. In many cases it’s related to overweight, physical inactivity, and genetics. A high-carbohydrate diet may contribute. A few cases are caused by drugs. Some cases are a mystery.

To overcome the body tissue’s resistance to insulin’s effect, the pancreas beta cells pump even more insulin into the bloodstream, a condition called hyperinsulinemia. Some scientists believe high insulin levels alone cause some of the damage associated with diabetes. Whereas a healthy person without diabetes needs about 50 units of insulin a day, an obese non-diabetic needs about twice that to keep blood sugars in check. Eventually, in those who develop diabetes or prediabetes, the pancreas can’t keep up with the demand for more insulin to overcome insulin resistance. The pancreas beta cells get exhausted and start to “burn out.” That’s when blood sugars start to rise and diabetes and prediabetes are easily diagnosed. So, insulin resistance and high insulin production have been going on for years before diagnosis. By the time of diagnosis, 50% of beta cell function is lost.

Steve Parker, M.D.

EXTRA  CREDIT  FOR  INQUISITIVE  MINDS

You’ve learned that insulin’s main action is to lower blood sugar by transporting it into the cells of various tissues. But that’s not all insulin does. It also 1) impairs breakdown of glycogen into glucose, 2) stimulates glycogen formation, 3) inhibits formation of new glucose molecules by the body, 4) promotes storage of triglycerides in fat cells (i.e., lipogenesis, fat accumulation), 5) promotes formation of fatty acids (triglyceride building blocks) by the liver, 6) inhibits breakdown of stored triglycerides, and 7) supports body protein production.

In his fascinating book, Cheating Destiny: Living With Diabetes, America’s Biggest Epidemic, James Hirsch describes what happened to type 1 diabetics before insulin injections were available. Type 1 diabetics produce no insulin. Until Frederick Banting and Charles Best isolated and injected insulin in the 1920s, type 1 diabetes was a death sentence characterized not only by high blood sugars, but also extreme weight loss as muscle and fat tissue wasted away. The tissue wasting reflects insulin actions No. 4, 5, 6, and 7 above.

Banting and Best worked at the University of Toronto in Canada. Their “discovery” of insulin is one of the greatest medical achievements of all time.

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Type 2 Diabetes: Scope of the Problem

Posted on November 30, 2012 | Leave a comment

97 mg/dl. Yippee!

Type 2 diabetes is the most important public health problem in the U.S. and most of the developed world. The U.S. Centers for Disease Control and Prevention predicts that one of every three Americans born in the year 2000 will develop diabetes.

The most common form of diabetes by far is type 2, which describes at least 85% of cases. It’s less serious than type 1 diabetes. Type 1 diabetics have an immune system abnormality that destroys the pancreas’s ability to make insulin. Type 1’s will not last long without insulin injections. On the other hand, many type 2 diabetics live well without insulin shots.

The epidemic of diabetes in the U.S. and the developed world overwhelmingly involves type 2, not type 1.

“Prediabetes” is what you’d expect: a precursor that may become full-blown type 2 diabetes over time. Blood sugar levels are above average, but not yet into the diabetic range. One in four people with prediabetes develops type 2 diabetes over the course of three to five years. Researchers estimate that 35% of the adult U.S. population had prediabetes in 2008. That’s one out of every three adults, or 79 million. Only 7% of them (less than one in 10) were aware they had it.

In the U.S. as of 2010, 26 million folks have diabetes. That includes 11% of all adults.

The rise of diabetes parallels the increase in overweight and obesity, which in turn mirrors the prominence of refined sugars and starches throughout our food supply. These trends are intimately related. Public health authorities 40 years ago convinced us to cut down our fat consumption in a mistaken effort to help our hearts. We replaced fats with body-fattening carbohydrates that test the limits of our pancreas to handle them. Diabetics and prediabetics fail that test.

Dr. Richard K. Bernstein, notable diabetologist, wrote that, “Americans are fat largely because of sugar, starches, and other high-carbohydrate foods.”

We’re even starting to see type 2 diabetes in children, which was quite rare just thirty years ago. It’s undoubtedly related to overweight and obesity. Childhood obesity in the U.S. tripled from the early 1980s to 2000, ending with a 17% obesity rate.  Overweight and obesity together describe 32% of U.S. children.

Diabetes is important because it has the potential to damage many different organ systems, deteriorating quality of life. It can damage nerves (neuropathy), eyes (retinopathy), kidneys (nephropathy),  and stomach function (gastroparesis), just to name a few.

Just as important, diabetes can cut life short. Compared to those who are free of diabetes, having diabetes at age 50 more than doubles the risk of developing cardiovascular disease—heart attacks, strokes, and high blood pressure. Compared to those without diabetes, having both cardiovascular disease and diabetes approximately doubles the risk of dying. Compared to those without diabetes, women and men with diabetes at age 50 die seven or eight years earlier, on average.

Diabetic complications and survival rates will improve over the coming decades as we learn how to better treat this ancient disease.

Steve Parker, M.D.

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TV’s Biggest Loser Plan Improves Prediabetes and Diabetes in Small Study

Posted on September 17, 2012 | 1 Comment

TV’s “The Biggest Loser” weight-loss program works great for overweight diabetics and prediabetics, according to an article May 30, 2012, in MedPage Today.

This isn’t directly related to the paleo diet or lifestyle, but I thought you might be interested.

Some quotes:

For example, one man with a hemoglobin A1c (HbA1c) of 9.1, a body mass index (BMI) of 51, and who needed six insulin injections a day as well as other multiple prescriptions was off all medication by week 3, said Robert Huizenga, MD, the medical advisor for the TV show.

In addition, the mean percentage of weight loss of the 35 contestants in the study was 3.7% at week 1, 14.3% at week 5, and 31.9% at week 24…

The exercise regimen for those appearing on “The Biggest Loser” comprised about 4 hours of daily exercise: 1 hour of intense resistance training, 1 hour of intense aerobics, and 2 hours of moderate aerobics.

Caloric intake was at least 70% of the estimated resting daily energy expenditure, Huizenga said.

At the end of the program, participants are told to exercise for 90 minutes a day for the rest of their lives. Huizenga said he is often told by those listening to him that a daily 90-minute exercise regimen is impossible because everyone has such busy lives.

“I have a job and I work out from 90 to 100 minutes per day,” he said. “It’s about setting priorities. Time is not the issue; priorities are the issue.”

Of the 35 participants in this study, 12 had prediabetes and six had diabetes.  This is a small pilot study, then.  I bet the results would be reproducible on a larger scale IF all conditions of the TV program are in place.  Of course, that’s not very realistic.  A chance to win $250,000 (USD) is strong motivation for lifestyle change.

Steve Parker, M.D.

PS: Although not mentioned in the article, these must have been type 2 diabetics, not type 1.

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Aerobic Versus Strength Training?

Posted on May 2, 2012 | 2 Comments

“Resistance training, similarly to aerobic training, improves metabolic features and insulin sensitivity and reduces abdominal fat in type 2 diabetic patients,” according to a recent report in Diabetes Care.

Italian researchers randomized 40 type 2 diabetics to follow either an aerobic or strength training program for four months.  The increase in peak oxygen consumption (VO2 peak) was greater in the aerobic group, whereas the strength training group gained more strength.  Hemoglobin A1c was similarly reduced in both groups, about 0.37%.  Body fat content was reduced in both groups, and insulin sensitivity and lean limb mass were similarly increased.  Pancreas beta-cell function didn’t change.

According to this one study, neither type of training seems superior overall.  If you’re just going to do one type of exercise program, choose your goal.  Do you want more strength, or more sustainable ”windpower”?

The Pennington Biomedical Research Center found somewhat different results in their larger and more complex study published in 2010.  However, they were primarily testing for diabetes control (as judged by hemoglobin A1c improvement), rather the improvements in strength or aerobic power.  They found the combination of aerobic and strength training is needed to improve diabetic blood sugar levels.  Both types of exercise—when considered alone—did not improve diabetes control.

As for me, I do both strength and aerobic training.

By the way, I only read the abstract of the current research, not the full report.

Steve Parker, M.D.

PS: PWD = people or person with diabetes.  Do you like that term or would you prefer “diabetic”?

Reference:  Bacchi. Elizabeth, et al.  Metabolic Effects of Aerobic Training and Resistance Training in Type 2 Diabetic Subjects
A randomized controlled trial (the RAED2 study).  Diabetes Care.  Published online before print February 16, 2012, doi: 10.2337/dc11-1655

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FDA Approves Exenatide for Once Weekly Injection

Posted on April 28, 2012 | Leave a comment

Once-weekly injection of exenatide, sold in the U.S. as Bydureon, has been approved for use by the U.S. Food and Drug Administration.  It’s the first-ever once-weekly drug for type 2 diabetes.  Bydureon’s main competitors are Byetta (exenatide  injected twice daily) and Victoza  (liraglutide).  Byetta and Bydureon are made by the same company, Amylin Pharmaceuticals.  Bydureon is a slow-release formulation of exenatide.

Victoza is the one that celebrity chef Paula Deen endorsed about a month ago, around the same time she revealed she’s had type 2 diabetes for three years.  Victoza’s injected once daily.

The New York Times has a January 27, 2012, article on Bydureon, focusing on business and investing.  The new drug is expected to retail for $4,200 (USD) a year.

Click for complete prescribing information.

Click for a press release approved by Amylin.

David Mendosa is excited about Bydureon.

These drugs are in a class called GLP-1 receptor agonists, which mimic the effect of glucagonlike peptide-1, a hormone that increases insulin secretion by the pancreas when blood sugar levels are high.  They are prescribed as adjuncts to diet and exercise in adults with type 2 diabetes.

Steve Parker, M.D.

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Classic Australian Aborigine Study on Return to Ancestral Diet and Lifestyle

Posted on March 10, 2012 | 17 Comments

Did you know kangaroo is edible?

The scientific article I review today is often cited by those who favor a Paleolithic diet for diabetics.  Cordain and Stefanson have written about it, for example.

Background

Urbanized Australian Aboriginal communities have a high prevalence of type 2 diabetes.   Kerin O’Dea writes:

The change from an urban to a traditional lifestyle involves several factors that directly affect insulin sensitivity: increased physical activity, reduced energy intake and weight loss, and changes in the overall dietary composition.  All of these factors improve insulin sensitivity and should, therefore, be of benefit to the insulin-resistant diabetic.

Methods

Ten urban type 2 diabetic and four nondiabetic full-blood Aborigines agreed to revert to their traditional lifestyle as hunter-gatherers in an isolated region of Australia for seven weeks.  Average age was 53.  Half of them were moderate to heavy alcohol drinkers.  Average diabetic weight was 82 kg (180 lb); nondiabetics averaged 77 kg (169 lb).  There were equal numbers of men and omen.  None of the diabetics was on insulin, and only one was on an oral diabetic drug (a sulfonylurea). 

Ayers Rock, Uluru National Park, Australia

The study was carried out at Pantijan, the traditional land of these Aborigines.  It’s a day-and-a-half drive in a four-wheel vehicle from Derby.  At least it was in 1984.

For seven weeks, the participants ate only what they hunted or collected.  Diet composition was dependent on whether they were travelling to the homeland (1.5 weeks), at the coastal location (2 weeks), or inland on the river (3.5 weeks). Protein sources were mainly beef, kangaroo, fish, birds, crocodiles, and turtles.  Carboydrate content ranged from under 5% to 33%.  Protein content varied from 50 to 80%.  Fat was 13 to 40%.  So, very high protein and low-carb.  Carb sources were yams, honey, and figs.  Yams were the predominant carb source.  They also eat yabbies (shrimp or crayfish (“crawdads” in Oklahoma)).  Average energy intake was a very low 1,200 calories a day. 

The author implies this was the traditional Aboriginal diet.

What did they eat back home in the city? 

The main dietary components were flour, sugar, rice, carbonated drinks, alcoholic drinks (beer and port), powdered milk, cheap fatty meat, potatoes, onions, and variable contributions of other fresh fruit and vegetables. 

O’Dea estimates a macronutrient breakdown of 50% carb, 40% fat, and 10% protein (similar to the Standard American Diet, then).

What Did O’Dea Find Out?

Everyone lost weight, a group average of 8 kg (18 lb) over the seven weeks.

Fasting blood sugars fell in the diabetics from 11.6 mmol/l to 6.6 mmol/l (209 to 119 mg/dl).  After-meal blood sugars also fell dramatically.

Fasting insulin levels fell from 23 to 12 mU/l.

Fasting triglycerides fell drastically. 

HDL cholesterol fell significantly, whereas LDL cholesterol tended to rise.

So What?

How often do you see a scientific article with just one author?  Rarely, these days.

The investigator wrote that, “Under the conditions of the study it is difficult to separate out effects of dietary composition, low energy intake, and weight loss.”

O’Dea estimates that experimental activity levels were probably higher than in the urban setting, but not dramatically more so.  (He was with the participants throughout the experiment.)

The main carbohydrate sources in this ancestral diet were yams, honey, and figs.  Modern Australian honey is probably similar to the honey of 100,000 years ago.  But what about yams and figs? 

These folks had to have been eating twice as many calories, at least, back in their urban environment.  O’Dea didn’t comment on how well the participants tolerated calorie restriction.  Did they complain?  Did they eat to satiety?  They had no access to food other than what they could hunt and gather.  Was food in short supply?  It’s not documented.  You’d think O’Dea would mention these issues if they were a problem. 

This particular ancestral diet was extremely high in protein: 50–80% of calories.  (Eaton and Konner suggest that an average ancestral diet provides only 25–30% of total calories from protein.  A typical modern high-protein diet derives about 30% of calories from protein, compared with 15–18% in the standard American diet.)  Protein helps combat hunger.  But halving caloric intake for seven weeks is extreme.  Don’t believe me?  Just try it.  This degree of caloric restriction by itself would tend to lower blood sugar levels and body weight in most humans, regardless of macronutrient ratios and ethnicity.

I know nothing about Australian Aborigines as an ethnic and genetic group.  Is their diabetes similar to European diabetes?  Pima Indian diabetes?   

O’Dea never called the study diet Paleolithic, because it wasn’t. It was a modern hunter-gatherer diet eaten by rural, isolated Australian Aboriginal communities.

This calorie-restricted, very-high-protein, natural diet was very effective for weight loss and blood sugar control in this tiny, seven-week study on a specific ethnic population.  I bet the caloric restriction was the most effective component of the lifestyle change.  Restriction of refined sugars and starches also helped. 

This ancestral diet was beneficial for a few Australian Aborigines.  Are the lessons widely applicable?  Not yet.  As they say, “further studies are needed.”  You can’t just cite this study to say that paleo diets are healthy for diabetics.

It does jibe with plenty of other research that shows severe calorie restriction leads to weight loss and lower blood sugar levels.

Steve Parker, M.D.

Reference: O’Dea, Kerin.  Marked improvement in carbohydrate and lipid metabolism in diabetic Australian Aborigines after temporary reversion to traditional lifestyle.  Diabetes, 33 (1984): 596-603.

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